Merge pull request #902 from quantified-uncertainty/develop

Develop -> Master July 28 2022

.github/CODEOWNERS

@@ -9,8 +9,8 @@
 # This also holds true for GitHub teams.
 
 # Rescript 
-*.res @OAGr @quinn-dougherty
-*.resi @OAGr @quinn-dougherty
+*.res @OAGr
+*.resi @OAGr
 
 # Typescript 
 *.tsx @Hazelfire @OAGr

.github/workflows/ci.yml

@@ -19,6 +19,8 @@ jobs:
       should_skip_lang: ${{ steps.skip_lang_check.outputs.should_skip }}
       should_skip_components: ${{ steps.skip_components_check.outputs.should_skip }}
       should_skip_website: ${{ steps.skip_website_check.outputs.should_skip }}
+      should_skip_vscodeext: ${{ steps.skip_vscodeext_check.outputs.should_skip }}
+      should_skip_cli: ${{ steps.skip_cli_check.outputs.should_skip }}
     steps:
       - id: skip_lang_check
         name: Check if the changes are about squiggle-lang src files
@@ -35,6 +37,16 @@ jobs:
         uses: fkirc/skip-duplicate-actions@v3.4.1
         with:
           paths: '["packages/website/**"]'
+      - id: skip_vscodeext_check
+        name: Check if the changes are about vscode extension src files
+        uses: fkirc/skip-duplicate-actions@v3.4.1
+        with:
+          paths: '["packages/vscode-ext/**"]'
+      - id: skip_cli_check
+        name: Check if the changes are about cli src files
+        uses: fkirc/skip-duplicate-actions@v3.4.1
+        with:
+          paths: '["packages/cli/**"]'
 
   lang-lint:
     name: Language lint
@@ -158,3 +170,52 @@ jobs:
         run: cd ../components && yarn build
       - name: Build website assets
         run: yarn build
+
+  vscode-ext-lint:
+    name: VS Code extension lint
+    runs-on: ubuntu-latest
+    needs: pre_check
+    if: ${{ needs.pre_check.outputs.should_skip_vscodeext != 'true' }}
+    defaults:
+      run:
+        shell: bash
+        working-directory: packages/vscode-ext
+    steps:
+      - uses: actions/checkout@v2
+      - name: Install dependencies from monorepo level
+        run: cd ../../ && yarn
+      - name: Lint the VSCode Extension source code
+        run: yarn lint
+
+  vscode-ext-build:
+    name: VS Code extension build
+    runs-on: ubuntu-latest
+    needs: pre_check
+    if: ${{ (needs.pre_check.outputs.should_skip_components != 'true') || (needs.pre_check.outputs.should_skip_lang != 'true') }} || (needs.pre_check.outputs.should_skip_vscodeext != 'true') }}
+    defaults:
+      run:
+        shell: bash
+        working-directory: packages/vscode-ext
+    steps:
+      - uses: actions/checkout@v2
+      - name: Install dependencies from monorepo level
+        run: cd ../../ && yarn
+      - name: Build
+        run: yarn compile
+
+  cli-lint:
+    name: CLI lint
+    runs-on: ubuntu-latest
+    needs: pre_check
+    if: ${{ needs.pre_check.outputs.should_skip_cli != 'true' }}
+    defaults:
+      run:
+        shell: bash
+        working-directory: packages/cli
+    steps:
+      - uses: actions/checkout@v2
+      - name: Check javascript, typescript, and markdown lint
+        uses: creyD/prettier_action@v4.2
+        with:
+          dry: true
+          prettier_options: --check packages/cli

.prettierignore

@@ -12,3 +12,4 @@ packages/squiggle-lang/coverage/
 packages/squiggle-lang/.cache/
 packages/website/build/
 packages/squiggle-lang/src/rescript/Reducer/Reducer_Peggy/Reducer_Peggy_GeneratedParser.js
+packages/vscode-ext/media/vendor/

README.md

@@ -17,6 +17,7 @@ _An estimation language_.
 - [Known bugs](https://www.squiggle-language.com/docs/Discussions/Bugs)
 - [Original lesswrong sequence](https://www.lesswrong.com/s/rDe8QE5NvXcZYzgZ3)
 - [Author your squiggle models as Observable notebooks](https://observablehq.com/@hazelfire/squiggle)
+- [Use squiggle in VS Code](https://marketplace.visualstudio.com/items?itemName=QURI.vscode-squiggle)
 
 ## Our deployments
 
@@ -39,6 +40,8 @@ the packages can be found in `packages`.
   of the calculation.
 - `packages/website` is the main descriptive website for squiggle,
   it is hosted at `squiggle-language.com`.
+- `packages/vscode-ext` is the VS Code extension for writing estimation functions.
+- `packages/cli` is an experimental way of using imports in squiggle, which is also on [npm](https://www.npmjs.com/package/squiggle-cli-experimental).
 
 # Develop
 

package.json

@@ -7,7 +7,7 @@
     "lint:all": "prettier --check . && cd packages/squiggle-lang && yarn lint:rescript"
   },
   "devDependencies": {
-    "prettier": "^2.6.2"
+    "prettier": "^2.7.1"
   },
   "workspaces": [
     "packages/*"

packages/cli/.gitignore

@@ -0,0 +1,4 @@
+## Artifacts
+*.swp
+/node_modules/
+yarn-error.log

packages/cli/README.md

@@ -0,0 +1,22 @@
+## Squiggle CLI
+
+This package can be used to incorporate a very simple `import` system into Squiggle.
+
+To use, write special files with a `.squiggleU` file type. In these files, you can write lines like,
+
+```
+@import(models/gdp_over_time.squiggle, gdpOverTime)
+gdpOverTime(2.5)
+```
+
+The imports will be replaced with the contents of the file in `models/gdp_over_time.squiggle` upon compilation. The `.squiggleU` file will be converted into a `.squiggle` file with the `import` statement having this replacement.
+
+## Running
+
+### `npx squiggle-cli-experimental compile`
+
+Runs compilation in the current directory and all of its subdirectories.
+
+### `npx squiggle-cli-experimental watch`
+
+Watches `.squiggleU` files in the current directory (and subdirectories) and rebuilds them when they are saved. Note that this will _not_ rebuild files when their dependencies are changed, just when they are changed directly.

packages/cli/index.js

@@ -0,0 +1,96 @@
+#!/usr/bin/env node
+
+import fs from "fs";
+import path from "path";
+import indentString from "indent-string";
+import chokidar from "chokidar";
+import chalk from "chalk";
+import { Command } from "commander";
+import glob from "glob";
+
+const processFile = (fileName, seen = []) => {
+  const normalizedFileName = path.resolve(fileName);
+  if (seen.includes(normalizedFileName)) {
+    throw new Error(`Recursive dependency for file ${fileName}`);
+  }
+
+  const fileContents = fs.readFileSync(fileName, "utf-8");
+  if (!fileName.endsWith(".squiggleU")) {
+    return fileContents;
+  }
+
+  const regex = /\@import\(\s*([^)]+?)\s*\)/g;
+  const matches = Array.from(fileContents.matchAll(regex)).map((r) =>
+    r[1].split(/\s*,\s*/)
+  );
+  const newContent = fileContents.replaceAll(regex, "");
+  const appendings = [];
+
+  matches.forEach((r) => {
+    const importFileName = r[0];
+    const rename = r[1];
+    const item = fs.statSync(importFileName);
+    if (item.isFile()) {
+      const data = processFile(importFileName, [...seen, normalizedFileName]);
+      if (data) {
+        const importString = `${rename} = {\n${indentString(data, 2)}\n}\n`;
+        appendings.push(importString);
+      }
+    } else {
+      console.log(
+        chalk.red(`Import Error`) +
+          `: ` +
+          chalk.cyan(importFileName) +
+          ` not found in file ` +
+          chalk.cyan(fileName) +
+          `. Make sure the @import file names all exist in this repo.`
+      );
+    }
+  });
+  const imports = appendings.join("\n");
+
+  const newerContent = imports.concat(newContent);
+  return newerContent;
+};
+
+const run = (fileName) => {
+  const content = processFile(fileName);
+  const parsedPath = path.parse(path.resolve(fileName));
+  const newFilename = `${parsedPath.dir}/${parsedPath.name}.squiggle`;
+  fs.writeFileSync(newFilename, content);
+  console.log(chalk.cyan(`Updated ${fileName} -> ${newFilename}`));
+};
+
+const compile = () => {
+  glob("**/*.squiggleU", (_err, files) => {
+    files.forEach(run);
+  });
+};
+
+const watch = () => {
+  chokidar
+    .watch("**.squiggleU")
+    .on("ready", () => console.log(chalk.green("Ready!")))
+    .on("change", (event, _) => {
+      run(event);
+    });
+};
+
+const program = new Command();
+
+program
+  .name("squiggle-utils")
+  .description("CLI to transform squiggle files with @imports")
+  .version("0.0.1");
+
+program
+  .command("watch")
+  .description("watch files and compile on the fly")
+  .action(watch);
+
+program
+  .command("compile")
+  .description("compile all .squiggleU files into .squiggle files")
+  .action(compile);
+
+program.parse();

packages/cli/package.json

@@ -0,0 +1,21 @@
+{
+  "name": "squiggle-cli-experimental",
+  "version": "0.0.3",
+  "main": "index.js",
+  "homepage": "https://squiggle-language.com",
+  "author": "Quantified Uncertainty Research Institute",
+  "bin": "index.js",
+  "type": "module",
+  "scripts": {
+    "start": "node ."
+  },
+  "license": "MIT",
+  "dependencies": {
+    "chalk": "^5.0.1",
+    "chokidar": "^3.5.3",
+    "commander": "^9.4.0",
+    "fs": "^0.0.1-security",
+    "glob": "^8.0.3",
+    "indent-string": "^5.0.0"
+  }
+}

packages/components/README.md

@@ -20,11 +20,47 @@ Add to `App.js`:
 ```jsx
 import { SquiggleEditor } from "@quri/squiggle-components";
 <SquiggleEditor
-  initialSquiggleString="x = beta($alpha, 10); x + $shift"
+  defaultCode="x = beta($alpha, 10); x + $shift"
   jsImports={{ alpha: 3, shift: 20 }}
 />;
 ```
 
+# Usage in a Nextjs project
+
+For now, `squiggle-components` requires the `window` property, so using the package in nextjs requires dynamic loading:
+
+```
+
+import React from "react";
+import { SquiggleChart } from "@quri/squiggle-components";
+
+import dynamic from "next/dynamic";
+
+const SquiggleChart = dynamic(
+  () => import("@quri/squiggle-components").then((mod) => mod.SquiggleChart),
+  {
+    loading: () => <p>Loading...</p>,
+    ssr: false,
+  }
+);
+
+export function DynamicSquiggleChart({ squiggleString }) {
+  if (squiggleString == "") {
+    return null;
+  } else {
+    return (
+        <SquiggleChart
+          defaultCode={squiggleString}
+          width={445}
+          height={200}
+          showSummary={true}
+        />
+    );
+  }
+}
+
+```
+
 # Build storybook for development
 
 We assume that you had run `yarn` at monorepo level, installing dependencies.

packages/components/package.json

@@ -1,65 +1,75 @@
 {
   "name": "@quri/squiggle-components",
-  "version": "0.2.20",
+  "version": "0.2.24",
   "license": "MIT",
   "dependencies": {
-    "@headlessui/react": "^1.6.4",
+    "@floating-ui/react-dom": "^0.7.2",
+    "@floating-ui/react-dom-interactions": "^0.6.6",
+    "@headlessui/react": "^1.6.6",
     "@heroicons/react": "^1.0.6",
-    "@hookform/resolvers": "^2.9.1",
+    "@hookform/resolvers": "^2.9.6",
     "@quri/squiggle-lang": "^0.2.8",
     "@react-hook/size": "^2.1.2",
-    "clsx": "^1.1.1",
+    "clsx": "^1.2.1",
+    "framer-motion": "^6.5.1",
     "lodash": "^4.17.21",
     "react": "^18.1.0",
     "react-ace": "^10.1.0",
-    "react-dom": "^18.1.0",
-    "react-hook-form": "^7.32.0",
+    "react-hook-form": "^7.33.1",
     "react-use": "^17.4.0",
-    "react-vega": "^7.5.1",
+    "react-vega": "^7.6.0",
     "vega": "^5.22.1",
-    "vega-embed": "^6.20.6",
-    "vega-lite": "^5.2.0",
+    "vega-embed": "^6.21.0",
+    "vega-lite": "^5.3.0",
+    "vscode-uri": "^3.0.3",
     "yup": "^0.32.11"
   },
   "devDependencies": {
-    "@babel/plugin-proposal-private-property-in-object": "^7.17.12",
-    "@storybook/addon-actions": "^6.5.8",
-    "@storybook/addon-essentials": "^6.5.8",
-    "@storybook/addon-links": "^6.5.8",
-    "@storybook/builder-webpack5": "^6.5.8",
-    "@storybook/manager-webpack5": "^6.5.8",
-    "@storybook/node-logger": "^6.5.6",
+    "@babel/plugin-proposal-private-property-in-object": "^7.18.6",
+    "@storybook/addon-actions": "^6.5.9",
+    "@storybook/addon-essentials": "^6.5.9",
+    "@storybook/addon-links": "^6.5.9",
+    "@storybook/builder-webpack5": "^6.5.9",
+    "@storybook/manager-webpack5": "^6.5.9",
+    "@storybook/node-logger": "^6.5.9",
     "@storybook/preset-create-react-app": "^4.1.2",
-    "@storybook/react": "^6.5.8",
+    "@storybook/react": "^6.5.9",
     "@testing-library/jest-dom": "^5.16.4",
     "@testing-library/react": "^13.3.0",
-    "@testing-library/user-event": "^14.2.0",
+    "@testing-library/user-event": "^14.3.0",
     "@types/jest": "^27.5.0",
     "@types/lodash": "^4.14.182",
-    "@types/node": "^17.0.42",
+    "@types/node": "^18.6.1",
     "@types/react": "^18.0.9",
-    "@types/react-dom": "^18.0.5",
     "@types/styled-components": "^5.1.24",
     "@types/webpack": "^5.28.0",
     "cross-env": "^7.0.3",
-    "mini-css-extract-plugin": "^2.6.0",
-    "postcss-cli": "^9.1.0",
+    "mini-css-extract-plugin": "^2.6.1",
+    "postcss-cli": "^10.0.0",
     "postcss-import": "^14.1.0",
-    "postcss-loader": "^7.0.0",
+    "postcss-loader": "^7.0.1",
+    "react": "^18.1.0",
     "react-scripts": "^5.0.1",
     "style-loader": "^3.3.1",
-    "tailwindcss": "^3.1.2",
+    "tailwindcss": "^3.1.6",
     "ts-loader": "^9.3.0",
     "tsconfig-paths-webpack-plugin": "^3.5.2",
-    "typescript": "^4.7.3",
+    "typescript": "^4.7.4",
     "web-vitals": "^2.1.4",
-    "webpack": "^5.73.0",
+    "webpack": "^5.74.0",
     "webpack-cli": "^4.10.0",
-    "webpack-dev-server": "^4.9.2"
+    "webpack-dev-server": "^4.9.3"
+  },
+  "peerDependencies": {
+    "react": "^16.8.0 || ^17 || ^18",
+    "react-dom": "^16.8.0 || ^17 || ^18"
   },
   "scripts": {
     "start": "cross-env REACT_APP_FAST_REFRESH=false && start-storybook -p 6006 -s public",
-    "build": "tsc -b && postcss ./src/styles/main.css -o ./dist/main.css && build-storybook -s public",
+    "build:cjs": "tsc -b",
+    "build:css": "postcss ./src/styles/main.css -o ./dist/main.css",
+    "build:storybook": "build-storybook -s public",
+    "build": "yarn run build:cjs && yarn run build:css && yarn run build:storybook",
     "bundle": "webpack",
     "all": "yarn bundle && yarn build",
     "lint": "prettier --check .",

packages/components/src/components/CodeEditor.tsx

@@ -1,5 +1,5 @@
 import _ from "lodash";
-import React, { FC } from "react";
+import React, { FC, useMemo, useRef } from "react";
 import AceEditor from "react-ace";
 
 import "ace-builds/src-noconflict/mode-golang";
@@ -8,6 +8,7 @@ import "ace-builds/src-noconflict/theme-github";
 interface CodeEditorProps {
   value: string;
   onChange: (value: string) => void;
+  onSubmit?: () => void;
   oneLine?: boolean;
   width?: number;
   height: number;
@@ -17,18 +18,24 @@ interface CodeEditorProps {
 export const CodeEditor: FC<CodeEditorProps> = ({
   value,
   onChange,
+  onSubmit,
   oneLine = false,
   showGutter = false,
   height,
 }) => {
-  let lineCount = value.split("\n").length;
-  let id = _.uniqueId();
+  const lineCount = value.split("\n").length;
+  const id = useMemo(() => _.uniqueId(), []);
+
+  // this is necessary because AceEditor binds commands on mount, see https://github.com/securingsincity/react-ace/issues/684
+  const onSubmitRef = useRef<typeof onSubmit | null>(null);
+  onSubmitRef.current = onSubmit;
+
   return (
     <AceEditor
       value={value}
       mode="golang"
       theme="github"
-      width={"100%"}
+      width="100%"
       fontSize={14}
       height={String(height) + "px"}
       minLines={oneLine ? lineCount : undefined}
@@ -45,6 +52,13 @@ export const CodeEditor: FC<CodeEditorProps> = ({
         enableBasicAutocompletion: false,
         enableLiveAutocompletion: false,
       }}
+      commands={[
+        {
+          name: "submit",
+          bindKey: { mac: "Cmd-Enter", win: "Ctrl-Enter" },
+          exec: () => onSubmitRef.current?.(),
+        },
+      ]}
     />
   );
 };

packages/components/src/components/DistributionChart.tsx

@@ -5,39 +5,38 @@ import {
   distributionError,
   distributionErrorToString,
 } from "@quri/squiggle-lang";
-import { Vega, VisualizationSpec } from "react-vega";
-import * as chartSpecification from "../vega-specs/spec-distributions.json";
+import { Vega } from "react-vega";
 import { ErrorAlert } from "./Alert";
 import { useSize } from "react-use";
-import clsx from "clsx";
 
 import {
-  linearXScale,
-  logXScale,
-  linearYScale,
-  expYScale,
-} from "./DistributionVegaScales";
+  buildVegaSpec,
+  DistributionChartSpecOptions,
+} from "../lib/distributionSpecBuilder";
 import { NumberShower } from "./NumberShower";
+import { hasMassBelowZero } from "../lib/distributionUtils";
 
-type DistributionChartProps = {
+export type DistributionPlottingSettings = {
+  /** Whether to show a summary of means, stdev, percentiles etc */
+  showSummary: boolean;
+  actions?: boolean;
+} & DistributionChartSpecOptions;
+
+export type DistributionChartProps = {
   distribution: Distribution;
   width?: number;
   height: number;
-  /** Whether to show a summary of means, stdev, percentiles etc */
-  showSummary: boolean;
-  /** Whether to show the user graph controls (scale etc) */
-  showControls?: boolean;
-};
+} & DistributionPlottingSettings;
 
-export const DistributionChart: React.FC<DistributionChartProps> = ({
-  distribution,
-  height,
-  showSummary,
-  width,
-  showControls = false,
-}) => {
-  const [isLogX, setLogX] = React.useState(false);
-  const [isExpY, setExpY] = React.useState(false);
+export const DistributionChart: React.FC<DistributionChartProps> = (props) => {
+  const {
+    distribution,
+    height,
+    showSummary,
+    width,
+    logX,
+    actions = false,
+  } = props;
   const shape = distribution.pointSet();
   const [sized] = useSize((size) => {
     if (shape.tag === "Error") {
@@ -48,10 +47,7 @@ export const DistributionChart: React.FC<DistributionChartProps> = ({
       );
     }
 
-    const massBelow0 =
-      shape.value.continuous.some((x) => x.x <= 0) ||
-      shape.value.discrete.some((x) => x.x <= 0);
-    const spec = buildVegaSpec(isLogX, isExpY);
+    const spec = buildVegaSpec(props);
 
     let widthProp = width ? width : size.width;
     if (widthProp < 20) {
@@ -63,79 +59,28 @@ export const DistributionChart: React.FC<DistributionChartProps> = ({
 
     return (
       <div style={{ width: widthProp }}>
-        <Vega
-          spec={spec}
-          data={{ con: shape.value.continuous, dis: shape.value.discrete }}
-          width={widthProp - 10}
-          height={height}
-          actions={false}
-        />
+        {logX && hasMassBelowZero(shape.value) ? (
+          <ErrorAlert heading="Log Domain Error">
+            Cannot graph distribution with negative values on logarithmic scale.
+          </ErrorAlert>
+        ) : (
+          <Vega
+            spec={spec}
+            data={{ con: shape.value.continuous, dis: shape.value.discrete }}
+            width={widthProp - 10}
+            height={height}
+            actions={actions}
+          />
+        )}
         <div className="flex justify-center">
           {showSummary && <SummaryTable distribution={distribution} />}
         </div>
-        {showControls && (
-          <div>
-            <CheckBox
-              label="Log X scale"
-              value={isLogX}
-              onChange={setLogX}
-              // Check whether we should disable the checkbox
-              {...(massBelow0
-                ? {
-                    disabled: true,
-                    tooltip:
-                      "Your distribution has mass lower than or equal to 0. Log only works on strictly positive values.",
-                  }
-                : {})}
-            />
-            <CheckBox label="Exp Y scale" value={isExpY} onChange={setExpY} />
-          </div>
-        )}
       </div>
     );
   });
   return sized;
 };
 
-function buildVegaSpec(isLogX: boolean, isExpY: boolean): VisualizationSpec {
-  return {
-    ...chartSpecification,
-    scales: [
-      isLogX ? logXScale : linearXScale,
-      isExpY ? expYScale : linearYScale,
-    ],
-  } as VisualizationSpec;
-}
-
-interface CheckBoxProps {
-  label: string;
-  onChange: (x: boolean) => void;
-  value: boolean;
-  disabled?: boolean;
-  tooltip?: string;
-}
-
-export const CheckBox: React.FC<CheckBoxProps> = ({
-  label,
-  onChange,
-  value,
-  disabled = false,
-  tooltip,
-}) => {
-  return (
-    <span title={tooltip}>
-      <input
-        type="checkbox"
-        value={value + ""}
-        onChange={() => onChange(!value)}
-        disabled={disabled}
-        className="form-checkbox"
-      />
-      <label className={clsx(disabled && "text-slate-400")}> {label}</label>
-    </span>
-  );
-};
-
 const TableHeadCell: React.FC<{ children: React.ReactNode }> = ({
   children,
 }) => (

packages/components/src/components/FunctionChart.tsx

@@ -1,7 +1,13 @@
 import * as React from "react";
-import { lambdaValue, environment, runForeign } from "@quri/squiggle-lang";
+import {
+  lambdaValue,
+  environment,
+  runForeign,
+  errorValueToString,
+} from "@quri/squiggle-lang";
 import { FunctionChart1Dist } from "./FunctionChart1Dist";
 import { FunctionChart1Number } from "./FunctionChart1Number";
+import { DistributionPlottingSettings } from "./DistributionChart";
 import { ErrorAlert, MessageAlert } from "./Alert";
 
 export type FunctionChartSettings = {
@@ -13,6 +19,7 @@ export type FunctionChartSettings = {
 interface FunctionChartProps {
   fn: lambdaValue;
   chartSettings: FunctionChartSettings;
+  distributionPlotSettings: DistributionPlottingSettings;
   environment: environment;
   height: number;
 }
@@ -21,6 +28,7 @@ export const FunctionChart: React.FC<FunctionChartProps> = ({
   fn,
   chartSettings,
   environment,
+  distributionPlotSettings,
   height,
 }) => {
   if (fn.parameters.length > 1) {
@@ -42,10 +50,16 @@ export const FunctionChart: React.FC<FunctionChartProps> = ({
     }
   };
   const validResult = getValidResult();
-  const resultType =
-    validResult.tag === "Ok" ? validResult.value.tag : ("Error" as const);
 
-  switch (resultType) {
+  if (validResult.tag === "Error") {
+    return (
+      <ErrorAlert heading="Error">
+        {errorValueToString(validResult.value)}
+      </ErrorAlert>
+    );
+  }
+
+  switch (validResult.value.tag) {
     case "distribution":
       return (
         <FunctionChart1Dist
@@ -53,6 +67,7 @@ export const FunctionChart: React.FC<FunctionChartProps> = ({
           chartSettings={chartSettings}
           environment={environment}
           height={height}
+          distributionPlotSettings={distributionPlotSettings}
         />
       );
     case "number":
@@ -64,15 +79,11 @@ export const FunctionChart: React.FC<FunctionChartProps> = ({
           height={height}
         />
       );
-    case "Error":
-      return (
-        <ErrorAlert heading="Error">The function failed to be run</ErrorAlert>
-      );
     default:
       return (
         <MessageAlert heading="Function Display Not Supported">
           There is no function visualization for this type of output:{" "}
-          <span className="font-bold">{resultType}</span>
+          <span className="font-bold">{validResult.value.tag}</span>
         </MessageAlert>
       );
   }

packages/components/src/components/FunctionChart1Dist.tsx

@@ -13,7 +13,10 @@ import {
 } from "@quri/squiggle-lang";
 import { createClassFromSpec } from "react-vega";
 import * as percentilesSpec from "../vega-specs/spec-percentiles.json";
-import { DistributionChart } from "./DistributionChart";
+import {
+  DistributionChart,
+  DistributionPlottingSettings,
+} from "./DistributionChart";
 import { NumberShower } from "./NumberShower";
 import { ErrorAlert } from "./Alert";
 
@@ -44,6 +47,7 @@ export type FunctionChartSettings = {
 interface FunctionChart1DistProps {
   fn: lambdaValue;
   chartSettings: FunctionChartSettings;
+  distributionPlotSettings: DistributionPlottingSettings;
   environment: environment;
   height: number;
 }
@@ -84,7 +88,7 @@ let getPercentiles = ({ chartSettings, fn, environment }) => {
   let chartPointsData: point[] = chartPointsToRender.map((x) => {
     let result = runForeign(fn, [x], environment);
     if (result.tag === "Ok") {
-      if (result.value.tag == "distribution") {
+      if (result.value.tag === "distribution") {
         return { x, value: { tag: "Ok", value: result.value.value } };
       } else {
         return {
@@ -150,6 +154,7 @@ export const FunctionChart1Dist: React.FC<FunctionChart1DistProps> = ({
   fn,
   chartSettings,
   environment,
+  distributionPlotSettings,
   height,
 }) => {
   let [mouseOverlay, setMouseOverlay] = React.useState(0);
@@ -160,12 +165,14 @@ export const FunctionChart1Dist: React.FC<FunctionChart1DistProps> = ({
     setMouseOverlay(NaN);
   }
   const signalListeners = { mousemove: handleHover, mouseout: handleOut };
+
+  //TODO: This custom error handling is a bit hacky and should be improved.
   let mouseItem: result<squiggleExpression, errorValue> = !!mouseOverlay
     ? runForeign(fn, [mouseOverlay], environment)
     : {
         tag: "Error",
         value: {
-          tag: "REExpectedType",
+          tag: "RETodo",
           value: "Hover x-coordinate returned NaN. Expected a number.",
         },
       };
@@ -175,7 +182,7 @@ export const FunctionChart1Dist: React.FC<FunctionChart1DistProps> = ({
         distribution={mouseItem.value.value}
         width={400}
         height={50}
-        showSummary={false}
+        {...distributionPlotSettings}
       />
     ) : null;
 

packages/components/src/components/SquiggleChart.tsx

@@ -1,7 +1,5 @@
 import * as React from "react";
 import {
-  run,
-  errorValueToString,
   squiggleExpression,
   bindings,
   environment,
@@ -9,265 +7,27 @@ import {
   defaultImports,
   defaultBindings,
   defaultEnvironment,
-  declaration,
 } from "@quri/squiggle-lang";
-import { NumberShower } from "./NumberShower";
-import { DistributionChart } from "./DistributionChart";
-import { ErrorAlert } from "./Alert";
-import { FunctionChart, FunctionChartSettings } from "./FunctionChart";
-
-function getRange<a>(x: declaration<a>) {
-  let first = x.args[0];
-  switch (first.tag) {
-    case "Float": {
-      return { floats: { min: first.value.min, max: first.value.max } };
-    }
-    case "Date": {
-      return { time: { min: first.value.min, max: first.value.max } };
-    }
-  }
-}
-
-function getChartSettings<a>(x: declaration<a>): FunctionChartSettings {
-  let range = getRange(x);
-  let min = range.floats ? range.floats.min : 0;
-  let max = range.floats ? range.floats.max : 10;
-  return {
-    start: min,
-    stop: max,
-    count: 20,
-  };
-}
-
-interface VariableBoxProps {
-  heading: string;
-  children: React.ReactNode;
-  showTypes: boolean;
-}
-
-export const VariableBox: React.FC<VariableBoxProps> = ({
-  heading = "Error",
-  children,
-  showTypes = false,
-}) => {
-  if (showTypes) {
-    return (
-      <div className="bg-white border border-grey-200 m-2">
-        <div className="border-b border-grey-200 p-3">
-          <header className="font-mono">{heading}</header>
-        </div>
-        <div className="p-3">{children}</div>
-      </div>
-    );
-  } else {
-    return <div>{children}</div>;
-  }
-};
-
-export interface SquiggleItemProps {
-  /** The input string for squiggle */
-  expression: squiggleExpression;
-  width?: number;
-  height: number;
-  /** Whether to show a summary of statistics for distributions */
-  showSummary: boolean;
-  /** Whether to show type information */
-  showTypes: boolean;
-  /** Whether to show users graph controls (scale etc) */
-  showControls: boolean;
-  /** Settings for displaying functions */
-  chartSettings: FunctionChartSettings;
-  /** Environment for further function executions */
-  environment: environment;
-}
-
-const SquiggleItem: React.FC<SquiggleItemProps> = ({
-  expression,
-  width,
-  height,
-  showSummary,
-  showTypes = false,
-  showControls = false,
-  chartSettings,
-  environment,
-}) => {
-  switch (expression.tag) {
-    case "number":
-      return (
-        <VariableBox heading="Number" showTypes={showTypes}>
-          <div className="font-semibold text-slate-600">
-            <NumberShower precision={3} number={expression.value} />
-          </div>
-        </VariableBox>
-      );
-    case "distribution": {
-      let distType = expression.value.type();
-      return (
-        <VariableBox
-          heading={`Distribution (${distType})`}
-          showTypes={showTypes}
-        >
-          {distType === "Symbolic" && showTypes ? (
-            <div>{expression.value.toString()}</div>
-          ) : null}
-          <DistributionChart
-            distribution={expression.value}
-            height={height}
-            width={width}
-            showSummary={showSummary}
-            showControls={showControls}
-          />
-        </VariableBox>
-      );
-    }
-    case "string":
-      return (
-        <VariableBox heading="String" showTypes={showTypes}>
-          <span className="text-slate-400">"</span>
-          <span className="text-slate-600 font-semibold">
-            {expression.value}
-          </span>
-          <span className="text-slate-400">"</span>
-        </VariableBox>
-      );
-    case "boolean":
-      return (
-        <VariableBox heading="Boolean" showTypes={showTypes}>
-          {expression.value.toString()}
-        </VariableBox>
-      );
-    case "symbol":
-      return (
-        <VariableBox heading="Symbol" showTypes={showTypes}>
-          <span className="text-slate-500 mr-2">Undefined Symbol:</span>
-          <span className="text-slate-600">{expression.value}</span>
-        </VariableBox>
-      );
-    case "call":
-      return (
-        <VariableBox heading="Call" showTypes={showTypes}>
-          {expression.value}
-        </VariableBox>
-      );
-    case "array":
-      return (
-        <VariableBox heading="Array" showTypes={showTypes}>
-          {expression.value.map((r, i) => (
-            <div key={i} className="flex pt-1">
-              <div className="flex-none bg-slate-100 rounded-sm px-1">
-                <header className="text-slate-400 font-mono">{i}</header>
-              </div>
-              <div className="px-2 mb-2 grow">
-                <SquiggleItem
-                  key={i}
-                  expression={r}
-                  width={width !== undefined ? width - 20 : width}
-                  height={50}
-                  showTypes={showTypes}
-                  showControls={showControls}
-                  chartSettings={chartSettings}
-                  environment={environment}
-                  showSummary={showSummary}
-                />
-              </div>
-            </div>
-          ))}
-        </VariableBox>
-      );
-    case "record":
-      return (
-        <VariableBox heading="Record" showTypes={showTypes}>
-          <div className="space-y-3">
-            {Object.entries(expression.value).map(([key, r]) => (
-              <div key={key} className="flex space-x-2">
-                <div className="flex-none">
-                  <header className="text-slate-500 font-mono">{key}:</header>
-                </div>
-                <div className="px-2 grow bg-gray-50 border border-gray-100 rounded-sm">
-                  <SquiggleItem
-                    expression={r}
-                    width={width !== undefined ? width - 20 : width}
-                    height={height / 3}
-                    showTypes={showTypes}
-                    showSummary={showSummary}
-                    showControls={showControls}
-                    chartSettings={chartSettings}
-                    environment={environment}
-                  />
-                </div>
-              </div>
-            ))}
-          </div>
-        </VariableBox>
-      );
-    case "arraystring":
-      return (
-        <VariableBox heading="Array String" showTypes={showTypes}>
-          {expression.value.map((r) => `"${r}"`).join(", ")}
-        </VariableBox>
-      );
-    case "date":
-      return (
-        <VariableBox heading="Date" showTypes={showTypes}>
-          {expression.value.toDateString()}
-        </VariableBox>
-      );
-    case "timeDuration": {
-      return (
-        <VariableBox heading="Time Duration" showTypes={showTypes}>
-          <NumberShower precision={3} number={expression.value} />
-        </VariableBox>
-      );
-    }
-    case "lambda":
-      return (
-        <VariableBox heading="Function" showTypes={showTypes}>
-          <div className="text-amber-700 bg-amber-100 rounded-md font-mono p-1 pl-2 mb-3 mt-1 text-sm">{`function(${expression.value.parameters.join(
-            ","
-          )})`}</div>
-          <FunctionChart
-            fn={expression.value}
-            chartSettings={chartSettings}
-            height={height}
-            environment={{
-              sampleCount: environment.sampleCount / 10,
-              xyPointLength: environment.xyPointLength / 10,
-            }}
-          />
-        </VariableBox>
-      );
-    case "lambdaDeclaration": {
-      return (
-        <VariableBox heading="Function Declaration" showTypes={showTypes}>
-          <FunctionChart
-            fn={expression.value.fn}
-            chartSettings={getChartSettings(expression.value)}
-            height={height}
-            environment={{
-              sampleCount: environment.sampleCount / 10,
-              xyPointLength: environment.xyPointLength / 10,
-            }}
-          />
-        </VariableBox>
-      );
-    }
-    default: {
-      return <>Should be unreachable</>;
-    }
-  }
-};
+import { useSquiggle } from "../lib/hooks";
+import { SquiggleViewer } from "./SquiggleViewer";
 
 export interface SquiggleChartProps {
   /** The input string for squiggle */
-  squiggleString?: string;
+  code?: string;
+  /** Allows to re-run the code if code hasn't changed */
+  executionId?: number;
   /** If the output requires monte carlo sampling, the amount of samples */
   sampleCount?: number;
   /** The amount of points returned to draw the distribution */
   environment?: environment;
-  /** If the result is a function, where the function starts, ends and the amount of stops */
-  chartSettings?: FunctionChartSettings;
-  /** When the environment changes */
-  onChange?(expr: squiggleExpression): void;
+  /** If the result is a function, where the function domain starts */
+  diagramStart?: number;
+  /** If the result is a function, where the function domain ends */
+  diagramStop?: number;
+  /** If the result is a function, the amount of stops sampled */
+  diagramCount?: number;
+  /** When the squiggle code gets reevaluated */
+  onChange?(expr: squiggleExpression | undefined): void;
   /** CSS width of the element */
   width?: number;
   height?: number;
@@ -275,51 +35,90 @@ export interface SquiggleChartProps {
   bindings?: bindings;
   /** JS imported parameters */
   jsImports?: jsImports;
-  /** Whether to show a summary of the distirbution */
+  /** Whether to show a summary of the distribution */
   showSummary?: boolean;
-  /** Whether to show type information about returns, default false */
-  showTypes?: boolean;
-  /** Whether to show graph controls (scale etc)*/
-  showControls?: boolean;
+  /** Set the x scale to be logarithmic by deault */
+  logX?: boolean;
+  /** Set the y scale to be exponential by deault */
+  expY?: boolean;
+  /** How to format numbers on the x axis */
+  tickFormat?: string;
+  /** Title of the graphed distribution */
+  title?: string;
+  /** Color of the graphed distribution */
+  color?: string;
+  /** Specify the lower bound of the x scale */
+  minX?: number;
+  /** Specify the upper bound of the x scale */
+  maxX?: number;
+  /** Whether to show vega actions to the user, so they can copy the chart spec */
+  distributionChartActions?: boolean;
+  enableLocalSettings?: boolean;
 }
 
-const defaultChartSettings = { start: 0, stop: 10, count: 20 };
+const defaultOnChange = () => {};
+
+export const SquiggleChart: React.FC<SquiggleChartProps> = React.memo(
+  ({
+    code = "",
+    executionId = 0,
+    environment,
+    onChange = defaultOnChange, // defaultOnChange must be constant, don't move its definition here
+    height = 200,
+    bindings = defaultBindings,
+    jsImports = defaultImports,
+    showSummary = false,
+    width,
+    logX = false,
+    expY = false,
+    diagramStart = 0,
+    diagramStop = 10,
+    diagramCount = 100,
+    tickFormat,
+    minX,
+    maxX,
+    color,
+    title,
+    distributionChartActions,
+    enableLocalSettings = false,
+  }) => {
+    const result = useSquiggle({
+      code,
+      bindings,
+      environment,
+      jsImports,
+      onChange,
+      executionId,
+    });
+
+    const distributionPlotSettings = {
+      showSummary,
+      logX,
+      expY,
+      format: tickFormat,
+      minX,
+      maxX,
+      color,
+      title,
+      actions: distributionChartActions,
+    };
+
+    const chartSettings = {
+      start: diagramStart,
+      stop: diagramStop,
+      count: diagramCount,
+    };
 
-export const SquiggleChart: React.FC<SquiggleChartProps> = ({
-  squiggleString = "",
-  environment,
-  onChange = () => {},
-  height = 200,
-  bindings = defaultBindings,
-  jsImports = defaultImports,
-  showSummary = false,
-  width,
-  showTypes = false,
-  showControls = false,
-  chartSettings = defaultChartSettings,
-}) => {
-  let expressionResult = run(squiggleString, bindings, environment, jsImports);
-  if (expressionResult.tag !== "Ok") {
     return (
-      <ErrorAlert heading={"Parse Error"}>
-        {errorValueToString(expressionResult.value)}
-      </ErrorAlert>
+      <SquiggleViewer
+        result={result}
+        width={width}
+        height={height}
+        distributionPlotSettings={distributionPlotSettings}
+        chartSettings={chartSettings}
+        environment={environment ?? defaultEnvironment}
+        enableLocalSettings={enableLocalSettings}
+      />
     );
   }
-
-  let e = environment ?? defaultEnvironment;
-  let expression = expressionResult.value;
-  onChange(expression);
-  return (
-    <SquiggleItem
-      expression={expression}
-      width={width}
-      height={height}
-      showSummary={showSummary}
-      showTypes={showTypes}
-      showControls={showControls}
-      chartSettings={chartSettings}
-      environment={e}
-    />
-  );
-};
+);

packages/components/src/components/SquiggleContainer.tsx

@@ -13,6 +13,7 @@ const SquiggleContext = React.createContext<SquiggleContextShape>({
 
 export const SquiggleContainer: React.FC<Props> = ({ children }) => {
   const context = useContext(SquiggleContext);
+
   if (context.containerized) {
     return <>{children}</>;
   } else {

packages/components/src/components/SquiggleEditor.tsx

@@ -1,212 +1,92 @@
-import * as React from "react";
-import * as ReactDOM from "react-dom";
-import { SquiggleChart } from "./SquiggleChart";
+import React from "react";
 import { CodeEditor } from "./CodeEditor";
-import type {
-  squiggleExpression,
-  environment,
-  bindings,
-  jsImports,
-} from "@quri/squiggle-lang";
-import {
-  runPartial,
-  errorValueToString,
-  defaultImports,
-  defaultBindings,
-} from "@quri/squiggle-lang";
-import { ErrorAlert } from "./Alert";
+import { environment, bindings, jsImports } from "@quri/squiggle-lang";
+import { defaultImports, defaultBindings } from "@quri/squiggle-lang";
 import { SquiggleContainer } from "./SquiggleContainer";
+import { SquiggleChart, SquiggleChartProps } from "./SquiggleChart";
+import { useSquigglePartial, useMaybeControlledValue } from "../lib/hooks";
+import { SquiggleErrorAlert } from "./SquiggleErrorAlert";
 
-export interface SquiggleEditorProps {
-  /** The input string for squiggle */
-  initialSquiggleString?: string;
-  /** If the output requires monte carlo sampling, the amount of samples */
-  environment?: environment;
-  /** If the result is a function, where the function starts */
-  diagramStart?: number;
-  /** If the result is a function, where the function ends */
-  diagramStop?: number;
-  /** If the result is a function, how many points along the function it samples */
-  diagramCount?: number;
-  /** when the environment changes. Used again for notebook magic*/
-  onChange?(expr: squiggleExpression): void;
-  /** The width of the element */
-  width?: number;
-  /** Previous variable declarations */
-  bindings?: bindings;
-  /** JS Imports */
-  jsImports?: jsImports;
-  /** Whether to show detail about types of the returns, default false */
-  showTypes?: boolean;
-  /** Whether to give users access to graph controls */
-  showControls?: boolean;
-  /** Whether to show a summary table */
-  showSummary?: boolean;
-}
+const WrappedCodeEditor: React.FC<{
+  code: string;
+  setCode: (code: string) => void;
+}> = ({ code, setCode }) => (
+  <div className="border border-grey-200 p-2 m-4">
+    <CodeEditor
+      value={code}
+      onChange={setCode}
+      oneLine={true}
+      showGutter={false}
+      height={20}
+    />
+  </div>
+);
 
-export let SquiggleEditor: React.FC<SquiggleEditorProps> = ({
-  initialSquiggleString = "",
-  width,
-  environment,
-  diagramStart = 0,
-  diagramStop = 10,
-  diagramCount = 20,
-  onChange,
-  bindings = defaultBindings,
-  jsImports = defaultImports,
-  showTypes = false,
-  showControls = false,
-  showSummary = false,
-}: SquiggleEditorProps) => {
-  const [expression, setExpression] = React.useState(initialSquiggleString);
-  const chartSettings = {
-    start: diagramStart,
-    stop: diagramStop,
-    count: diagramCount,
-  };
+export type SquiggleEditorProps = SquiggleChartProps & {
+  defaultCode?: string;
+  onCodeChange?: (code: string) => void;
+};
+
+export const SquiggleEditor: React.FC<SquiggleEditorProps> = (props) => {
+  const [code, setCode] = useMaybeControlledValue({
+    value: props.code,
+    defaultValue: props.defaultCode ?? "",
+    onChange: props.onCodeChange,
+  });
+
+  let chartProps = { ...props, code };
   return (
     <SquiggleContainer>
-      <div>
-        <div className="border border-grey-200 p-2 m-4">
-          <CodeEditor
-            value={expression}
-            onChange={setExpression}
-            oneLine={true}
-            showGutter={false}
-            height={20}
-          />
-        </div>
-        <SquiggleChart
-          width={width}
-          environment={environment}
-          squiggleString={expression}
-          chartSettings={chartSettings}
-          onChange={onChange}
-          bindings={bindings}
-          jsImports={jsImports}
-          showTypes={showTypes}
-          showControls={showControls}
-          showSummary={showSummary}
-        />
-      </div>
+      <WrappedCodeEditor code={code} setCode={setCode} />
+      <SquiggleChart {...chartProps} />
     </SquiggleContainer>
   );
 };
 
-export function renderSquiggleEditorToDom(props: SquiggleEditorProps) {
-  let parent = document.createElement("div");
-  ReactDOM.render(
-    <SquiggleEditor
-      {...props}
-      onChange={(expr) => {
-        // Typescript complains on two levels here.
-        //  - Div elements don't have a value property
-        //  - Even if it did (like it was an input element), it would have to
-        //    be a string
-        //
-        //  Which are reasonable in most web contexts.
-        //
-        //  However we're using observable, neither of those things have to be
-        //  true there. div elements can contain the value property, and can have
-        //  the value be any datatype they wish.
-        //
-        //  This is here to get the 'viewof' part of:
-        //  viewof env = cell('normal(0,1)')
-        //  to work
-        // @ts-ignore
-        parent.value = expr;
-
-        parent.dispatchEvent(new CustomEvent("input"));
-        if (props.onChange) props.onChange(expr);
-      }}
-    />,
-    parent
-  );
-  return parent;
-}
-
 export interface SquigglePartialProps {
-  /** The input string for squiggle */
-  initialSquiggleString?: string;
-  /** If the output requires monte carlo sampling, the amount of samples */
-  environment?: environment;
-  /** If the result is a function, where the function starts */
-  diagramStart?: number;
-  /** If the result is a function, where the function ends */
-  diagramStop?: number;
-  /** If the result is a function, how many points along the function it samples */
-  diagramCount?: number;
+  /** The text inside the input (controlled) */
+  code?: string;
+  /** The default text inside the input (unControlled) */
+  defaultCode?: string;
   /** when the environment changes. Used again for notebook magic*/
-  onChange?(expr: bindings): void;
+  onChange?(expr: bindings | undefined): void;
+  /** When the code changes */
+  onCodeChange?(code: string): void;
   /** Previously declared variables */
   bindings?: bindings;
+  /** If the output requires monte carlo sampling, the amount of samples */
+  environment?: environment;
   /** Variables imported from js */
   jsImports?: jsImports;
-  /** Whether to give users access to graph controls */
-  showControls?: boolean;
 }
 
-export let SquigglePartial: React.FC<SquigglePartialProps> = ({
-  initialSquiggleString = "",
+export const SquigglePartial: React.FC<SquigglePartialProps> = ({
+  code: controlledCode,
+  defaultCode = "",
   onChange,
+  onCodeChange,
   bindings = defaultBindings,
   environment,
   jsImports = defaultImports,
 }: SquigglePartialProps) => {
-  const [expression, setExpression] = React.useState(initialSquiggleString);
-  const [error, setError] = React.useState<string | null>(null);
+  const [code, setCode] = useMaybeControlledValue<string>({
+    value: controlledCode,
+    defaultValue: defaultCode,
+    onChange: onCodeChange,
+  });
 
-  const runSquiggleAndUpdateBindings = () => {
-    const squiggleResult = runPartial(
-      expression,
-      bindings,
-      environment,
-      jsImports
-    );
-    if (squiggleResult.tag === "Ok") {
-      if (onChange) onChange(squiggleResult.value);
-      setError(null);
-    } else {
-      setError(errorValueToString(squiggleResult.value));
-    }
-  };
-
-  React.useEffect(runSquiggleAndUpdateBindings, [expression]);
+  const result = useSquigglePartial({
+    code,
+    bindings,
+    environment,
+    jsImports,
+    onChange,
+  });
 
   return (
     <SquiggleContainer>
-      <div>
-        <div className="border border-grey-200 p-2 m-4">
-          <CodeEditor
-            value={expression}
-            onChange={setExpression}
-            oneLine={true}
-            showGutter={false}
-            height={20}
-          />
-        </div>
-        {error !== null ? (
-          <ErrorAlert heading="Error">{error}</ErrorAlert>
-        ) : null}
-      </div>
+      <WrappedCodeEditor code={code} setCode={setCode} />
+      {result.tag !== "Ok" ? <SquiggleErrorAlert error={result.value} /> : null}
     </SquiggleContainer>
   );
 };
-
-export function renderSquigglePartialToDom(props: SquigglePartialProps) {
-  let parent = document.createElement("div");
-  ReactDOM.render(
-    <SquigglePartial
-      {...props}
-      onChange={(bindings) => {
-        // @ts-ignore
-        parent.value = bindings;
-
-        parent.dispatchEvent(new CustomEvent("input"));
-        if (props.onChange) props.onChange(bindings);
-      }}
-    />,
-    parent
-  );
-  return parent;
-}

packages/components/src/components/SquiggleEditorWithImportedBindings.tsx

@@ -0,0 +1,52 @@
+import React from "react";
+import { SquiggleEditor } from "./SquiggleEditor";
+import type { SquiggleEditorProps } from "./SquiggleEditor";
+import { runPartial, defaultBindings } from "@quri/squiggle-lang";
+import type {
+  result,
+  errorValue,
+  bindings as bindingsType,
+} from "@quri/squiggle-lang";
+
+function resultDefault(x: result<bindingsType, errorValue>): bindingsType {
+  switch (x.tag) {
+    case "Ok":
+      return x.value;
+    case "Error":
+      return defaultBindings;
+  }
+}
+
+export type SquiggleEditorWithImportedBindingsProps = SquiggleEditorProps & {
+  bindingsImportUrl: string;
+};
+
+export const SquiggleEditorWithImportedBindings: React.FC<
+  SquiggleEditorWithImportedBindingsProps
+> = (props) => {
+  const { bindingsImportUrl, ...editorProps } = props;
+  const [bindingsResult, setBindingsResult] = React.useState({
+    tag: "Ok",
+    value: defaultBindings,
+  } as result<bindingsType, errorValue>);
+  React.useEffect(() => {
+    async function retrieveBindings(fileName: string) {
+      let contents = await fetch(fileName).then((response) => {
+        return response.text();
+      });
+      setBindingsResult(
+        runPartial(
+          contents,
+          editorProps.bindings,
+          editorProps.environment,
+          editorProps.jsImports
+        )
+      );
+    }
+    retrieveBindings(bindingsImportUrl);
+  }, [bindingsImportUrl]);
+  const deliveredBindings = resultDefault(bindingsResult);
+  return (
+    <SquiggleEditor {...{ ...editorProps, bindings: deliveredBindings }} />
+  );
+};

packages/components/src/components/SquiggleErrorAlert.tsx

@@ -0,0 +1,11 @@
+import { errorValue, errorValueToString } from "@quri/squiggle-lang";
+import React from "react";
+import { ErrorAlert } from "./Alert";
+
+type Props = {
+  error: errorValue;
+};
+
+export const SquiggleErrorAlert: React.FC<Props> = ({ error }) => {
+  return <ErrorAlert heading="Error">{errorValueToString(error)}</ErrorAlert>;
+};

packages/components/src/components/SquigglePlayground.tsx

@@ -1,40 +1,62 @@
-import React, { FC, Fragment, useState } from "react";
-import ReactDOM from "react-dom";
-import { Path, useForm, UseFormRegister, useWatch } from "react-hook-form";
+import React, {
+  FC,
+  useState,
+  useEffect,
+  useMemo,
+  useRef,
+  useCallback,
+} from "react";
+import { useForm, UseFormRegister, useWatch } from "react-hook-form";
 import * as yup from "yup";
+import { useMaybeControlledValue, useRunnerState } from "../lib/hooks";
 import { yupResolver } from "@hookform/resolvers/yup";
-import { Tab } from "@headlessui/react";
 import {
   ChartSquareBarIcon,
+  CheckCircleIcon,
+  ClipboardCopyIcon,
   CodeIcon,
   CogIcon,
   CurrencyDollarIcon,
+  EyeIcon,
+  PauseIcon,
+  PlayIcon,
+  RefreshIcon,
 } from "@heroicons/react/solid";
 import clsx from "clsx";
 
 import { defaultBindings, environment } from "@quri/squiggle-lang";
 
-import { SquiggleChart } from "./SquiggleChart";
+import { SquiggleChart, SquiggleChartProps } from "./SquiggleChart";
 import { CodeEditor } from "./CodeEditor";
 import { JsonEditor } from "./JsonEditor";
 import { ErrorAlert, SuccessAlert } from "./Alert";
 import { SquiggleContainer } from "./SquiggleContainer";
+import { Toggle } from "./ui/Toggle";
+import { StyledTab } from "./ui/StyledTab";
+import { InputItem } from "./ui/InputItem";
+import { Text } from "./ui/Text";
+import { ViewSettings, viewSettingsSchema } from "./ViewSettings";
+import { HeadedSection } from "./ui/HeadedSection";
+import {
+  defaultColor,
+  defaultTickFormat,
+} from "../lib/distributionSpecBuilder";
+import { Button } from "./ui/Button";
 
-interface PlaygroundProps {
+type PlaygroundProps = SquiggleChartProps & {
   /** The initial squiggle string to put in the playground */
-  initialSquiggleString?: string;
-  /** How many pixels high is the playground */
-  height?: number;
-  /** Whether to show the types of outputs in the playground */
-  showTypes?: boolean;
-  /** Whether to show the log scale controls in the playground */
-  showControls?: boolean;
-  /** Whether to show the summary table in the playground */
-  showSummary?: boolean;
-}
+  defaultCode?: string;
+  onCodeChange?(expr: string): void;
+  /* When settings change */
+  onSettingsChange?(settings: any): void;
+  /** Should we show the editor? */
+  showEditor?: boolean;
+  /** Useful for playground on squiggle website, where we update the anchor link based on current code and settings */
+  showShareButton?: boolean;
+};
 
 const schema = yup
-  .object()
+  .object({})
   .shape({
     sampleCount: yup
       .number()
@@ -52,297 +74,68 @@ const schema = yup
       .default(1000)
       .min(10)
       .max(10000),
-    chartHeight: yup.number().required().positive().integer().default(350),
-    leftSizePercent: yup
-      .number()
-      .required()
-      .positive()
-      .integer()
-      .min(10)
-      .max(100)
-      .default(50),
-    showTypes: yup.boolean(),
-    showControls: yup.boolean(),
-    showSummary: yup.boolean(),
-    showSettingsPage: yup.boolean().default(false),
-    diagramStart: yup
-      .number()
-      .required()
-      .positive()
-      .integer()
-      .default(0)
-      .min(0),
-    diagramStop: yup
-      .number()
-      .required()
-      .positive()
-      .integer()
-      .default(10)
-      .min(0),
-    diagramCount: yup
-      .number()
-      .required()
-      .positive()
-      .integer()
-      .default(20)
-      .min(2),
   })
-  .required();
+  .concat(viewSettingsSchema);
 
-type StyledTabProps = {
-  name: string;
-  icon: (props: React.ComponentProps<"svg">) => JSX.Element;
-};
+type FormFields = yup.InferType<typeof schema>;
 
-const StyledTab: React.FC<StyledTabProps> = ({ name, icon: Icon }) => {
-  return (
-    <Tab key={name} as={Fragment}>
-      {({ selected }) => (
-        <button className="group flex rounded-md focus:outline-none focus-visible:ring-offset-gray-100">
-          <span
-            className={clsx(
-              "p-1 pl-2.5 pr-3.5 rounded-md flex items-center text-sm font-medium",
-              selected && "bg-white shadow-sm ring-1 ring-black ring-opacity-5"
-            )}
-          >
-            <Icon
-              className={clsx(
-                "-ml-0.5 mr-2 h-4 w-4",
-                selected
-                  ? "text-slate-500"
-                  : "text-gray-400 group-hover:text-gray-900"
-              )}
-            />
-            <span
-              className={clsx(
-                selected
-                  ? "text-gray-900"
-                  : "text-gray-600 group-hover:text-gray-900"
-              )}
-            >
-              {name}
-            </span>
-          </span>
-        </button>
-      )}
-    </Tab>
-  );
-};
-
-const HeadedSection: FC<{ title: string; children: React.ReactNode }> = ({
-  title,
-  children,
+const SamplingSettings: React.FC<{ register: UseFormRegister<FormFields> }> = ({
+  register,
 }) => (
-  <div>
-    <header className="text-lg leading-6 font-medium text-gray-900">
-      {title}
-    </header>
-    <div className="mt-4">{children}</div>
+  <div className="space-y-6 p-3 max-w-xl">
+    <div>
+      <InputItem
+        name="sampleCount"
+        type="number"
+        label="Sample Count"
+        register={register}
+      />
+      <div className="mt-2">
+        <Text>
+          How many samples to use for Monte Carlo simulations. This can
+          occasionally be overridden by specific Squiggle programs.
+        </Text>
+      </div>
+    </div>
+    <div>
+      <InputItem
+        name="xyPointLength"
+        type="number"
+        register={register}
+        label="Coordinate Count (For PointSet Shapes)"
+      />
+      <div className="mt-2">
+        <Text>
+          When distributions are converted into PointSet shapes, we need to know
+          how many coordinates to use.
+        </Text>
+      </div>
+    </div>
   </div>
 );
 
-const Text: FC<{ children: React.ReactNode }> = ({ children }) => (
-  <p className="text-sm text-gray-500">{children}</p>
-);
-
-function InputItem<T>({
-  name,
-  label,
-  type,
-  register,
-}: {
-  name: Path<T>;
-  label: string;
-  type: "number";
-  register: UseFormRegister<T>;
-}) {
-  return (
-    <label className="block">
-      <div className="text-sm font-medium text-gray-600 mb-1">{label}</div>
-      <input
-        type={type}
-        {...register(name)}
-        className="form-input max-w-lg block w-full shadow-sm focus:ring-indigo-500 focus:border-indigo-500 sm:max-w-xs sm:text-sm border-gray-300 rounded-md"
-      />
-    </label>
+const InputVariablesSettings: React.FC<{
+  initialImports: any; // TODO - any json type
+  setImports: (imports: any) => void;
+}> = ({ initialImports, setImports }) => {
+  const [importString, setImportString] = useState(() =>
+    JSON.stringify(initialImports)
   );
-}
-
-function Checkbox<T>({
-  name,
-  label,
-  register,
-}: {
-  name: Path<T>;
-  label: string;
-  register: UseFormRegister<T>;
-}) {
-  return (
-    <label className="flex items-center">
-      <input
-        type="checkbox"
-        {...register(name)}
-        className="form-checkbox focus:ring-indigo-500 h-4 w-4 text-indigo-600 border-gray-300 rounded"
-      />
-      {/* Clicking on the div makes the checkbox lose focus while mouse button is pressed, leading to annoying blinking; I couldn't figure out how to fix this. */}
-      <div className="ml-3 text-sm font-medium text-gray-700">{label}</div>
-    </label>
-  );
-}
-
-const SquigglePlayground: FC<PlaygroundProps> = ({
-  initialSquiggleString = "",
-  height = 500,
-  showTypes = false,
-  showControls = false,
-  showSummary = false,
-}) => {
-  const [squiggleString, setSquiggleString] = useState(initialSquiggleString);
-  const [importString, setImportString] = useState("{}");
-  const [imports, setImports] = useState({});
   const [importsAreValid, setImportsAreValid] = useState(true);
-  const { register, control } = useForm({
-    resolver: yupResolver(schema),
-    defaultValues: {
-      sampleCount: 1000,
-      xyPointLength: 1000,
-      chartHeight: 150,
-      showTypes: showTypes,
-      showControls: showControls,
-      showSummary: showSummary,
-      leftSizePercent: 50,
-      showSettingsPage: false,
-      diagramStart: 0,
-      diagramStop: 10,
-      diagramCount: 20,
-    },
-  });
-  const vars = useWatch({
-    control,
-  });
-  const chartSettings = {
-    start: Number(vars.diagramStart),
-    stop: Number(vars.diagramStop),
-    count: Number(vars.diagramCount),
-  };
-  const env: environment = {
-    sampleCount: Number(vars.sampleCount),
-    xyPointLength: Number(vars.xyPointLength),
-  };
-  const getChangeJson = (r: string) => {
-    setImportString(r);
+
+  const onChange = (value: string) => {
+    setImportString(value);
+    let imports = {} as any;
     try {
-      setImports(JSON.parse(r));
+      imports = JSON.parse(value);
       setImportsAreValid(true);
     } catch (e) {
       setImportsAreValid(false);
     }
+    setImports(imports);
   };
 
-  const samplingSettings = (
-    <div className="space-y-6 p-3 max-w-xl">
-      <div>
-        <InputItem
-          name="sampleCount"
-          type="number"
-          label="Sample Count"
-          register={register}
-        />
-        <div className="mt-2">
-          <Text>
-            How many samples to use for Monte Carlo simulations. This can
-            occasionally be overridden by specific Squiggle programs.
-          </Text>
-        </div>
-      </div>
-      <div>
-        <InputItem
-          name="xyPointLength"
-          type="number"
-          register={register}
-          label="Coordinate Count (For PointSet Shapes)"
-        />
-        <div className="mt-2">
-          <Text>
-            When distributions are converted into PointSet shapes, we need to
-            know how many coordinates to use.
-          </Text>
-        </div>
-      </div>
-    </div>
-  );
-
-  const viewSettings = (
-    <div className="space-y-6 p-3 divide-y divide-gray-200 max-w-xl">
-      <HeadedSection title="General Display Settings">
-        <div className="space-y-4">
-          <InputItem
-            name="chartHeight"
-            type="number"
-            register={register}
-            label="Chart Height (in pixels)"
-          />
-          <Checkbox
-            name="showTypes"
-            register={register}
-            label="Show information about displayed types"
-          />
-        </div>
-      </HeadedSection>
-
-      <div className="pt-8">
-        <HeadedSection title="Distribution Display Settings">
-          <div className="space-y-2">
-            <Checkbox
-              register={register}
-              name="showControls"
-              label="Show toggles to adjust scale of x and y axes"
-            />
-            <Checkbox
-              register={register}
-              name="showSummary"
-              label="Show summary statistics"
-            />
-          </div>
-        </HeadedSection>
-      </div>
-
-      <div className="pt-8">
-        <HeadedSection title="Function Display Settings">
-          <div className="space-y-6">
-            <Text>
-              When displaying functions of single variables that return numbers
-              or distributions, we need to use defaults for the x-axis. We need
-              to select a minimum and maximum value of x to sample, and a number
-              n of the number of points to sample.
-            </Text>
-            <div className="space-y-4">
-              <InputItem
-                type="number"
-                name="diagramStart"
-                register={register}
-                label="Min X Value"
-              />
-              <InputItem
-                type="number"
-                name="diagramStop"
-                register={register}
-                label="Max X Value"
-              />
-              <InputItem
-                type="number"
-                name="diagramCount"
-                register={register}
-                label="Points between X min and X max to sample"
-              />
-            </div>
-          </div>
-        </HeadedSection>
-      </div>
-    </div>
-  );
-
-  const inputVariableSettings = (
+  return (
     <div className="p-3 max-w-3xl">
       <HeadedSection title="Import Variables from JSON">
         <div className="space-y-6">
@@ -354,7 +147,7 @@ const SquigglePlayground: FC<PlaygroundProps> = ({
           <div className="border border-slate-200 mt-6 mb-2">
             <JsonEditor
               value={importString}
-              onChange={getChangeJson}
+              onChange={onChange}
               oneLine={false}
               showGutter={true}
               height={150}
@@ -373,62 +166,253 @@ const SquigglePlayground: FC<PlaygroundProps> = ({
       </HeadedSection>
     </div>
   );
+};
+
+const RunControls: React.FC<{
+  autorunMode: boolean;
+  isRunning: boolean;
+  isStale: boolean;
+  onAutorunModeChange: (value: boolean) => void;
+  run: () => void;
+}> = ({ autorunMode, isRunning, isStale, onAutorunModeChange, run }) => {
+  const CurrentPlayIcon = isRunning ? RefreshIcon : PlayIcon;
 
   return (
-    <SquiggleContainer>
-      <Tab.Group>
-        <div className="pb-4">
-          <Tab.List className="flex w-fit p-0.5 rounded-md bg-slate-100 hover:bg-slate-200">
-            <StyledTab name="Code" icon={CodeIcon} />
-            <StyledTab name="Sampling Settings" icon={CogIcon} />
-            <StyledTab name="View Settings" icon={ChartSquareBarIcon} />
-            <StyledTab name="Input Variables" icon={CurrencyDollarIcon} />
-          </Tab.List>
-        </div>
-        <div className="flex" style={{ height }}>
-          <div className="w-1/2">
-            <Tab.Panels>
-              <Tab.Panel>
-                <div className="border border-slate-200">
-                  <CodeEditor
-                    value={squiggleString}
-                    onChange={setSquiggleString}
-                    oneLine={false}
-                    showGutter={true}
-                    height={height - 1}
-                  />
-                </div>
-              </Tab.Panel>
-              <Tab.Panel>{samplingSettings}</Tab.Panel>
-              <Tab.Panel>{viewSettings}</Tab.Panel>
-              <Tab.Panel>{inputVariableSettings}</Tab.Panel>
-            </Tab.Panels>
-          </div>
-
-          <div className="w-1/2 p-2 pl-4">
-            <div style={{ maxHeight: height }}>
-              <SquiggleChart
-                squiggleString={squiggleString}
-                environment={env}
-                chartSettings={chartSettings}
-                height={vars.chartHeight}
-                showTypes={vars.showTypes}
-                showControls={vars.showControls}
-                bindings={defaultBindings}
-                jsImports={imports}
-                showSummary={vars.showSummary}
-              />
-            </div>
-          </div>
-        </div>
-      </Tab.Group>
-    </SquiggleContainer>
+    <div className="flex space-x-1 items-center">
+      {autorunMode ? null : (
+        <button onClick={run}>
+          <CurrentPlayIcon
+            className={clsx(
+              "w-8 h-8",
+              isRunning && "animate-spin",
+              isStale ? "text-indigo-500" : "text-gray-400"
+            )}
+          />
+        </button>
+      )}
+      <Toggle
+        texts={["Autorun", "Paused"]}
+        icons={[CheckCircleIcon, PauseIcon]}
+        status={autorunMode}
+        onChange={onAutorunModeChange}
+        spinIcon={autorunMode && isRunning}
+      />
+    </div>
   );
 };
 
-export default SquigglePlayground;
-export function renderSquigglePlaygroundToDom(props: PlaygroundProps) {
-  const parent = document.createElement("div");
-  ReactDOM.render(<SquigglePlayground {...props} />, parent);
-  return parent;
-}
+const ShareButton: React.FC = () => {
+  const [isCopied, setIsCopied] = useState(false);
+  const copy = () => {
+    navigator.clipboard.writeText((window.top || window).location.href);
+    setIsCopied(true);
+    setTimeout(() => setIsCopied(false), 1000);
+  };
+  return (
+    <div className="w-36">
+      <Button onClick={copy} wide>
+        {isCopied ? (
+          "Copied to clipboard!"
+        ) : (
+          <div className="flex items-center space-x-1">
+            <ClipboardCopyIcon className="w-4 h-4" />
+            <span>Copy share link</span>
+          </div>
+        )}
+      </Button>
+    </div>
+  );
+};
+
+type PlaygroundContextShape = {
+  getLeftPanelElement: () => HTMLDivElement | undefined;
+};
+export const PlaygroundContext = React.createContext<PlaygroundContextShape>({
+  getLeftPanelElement: () => undefined,
+});
+
+export const SquigglePlayground: FC<PlaygroundProps> = ({
+  defaultCode = "",
+  height = 500,
+  showSummary = false,
+  logX = false,
+  expY = false,
+  title,
+  minX,
+  maxX,
+  color = defaultColor,
+  tickFormat = defaultTickFormat,
+  distributionChartActions,
+  code: controlledCode,
+  onCodeChange,
+  onSettingsChange,
+  showEditor = true,
+  showShareButton = false,
+}) => {
+  const [code, setCode] = useMaybeControlledValue({
+    value: controlledCode,
+    defaultValue: defaultCode,
+    onChange: onCodeChange,
+  });
+
+  const [imports, setImports] = useState({});
+
+  const { register, control } = useForm({
+    resolver: yupResolver(schema),
+    defaultValues: {
+      sampleCount: 1000,
+      xyPointLength: 1000,
+      chartHeight: 150,
+      logX,
+      expY,
+      title,
+      minX,
+      maxX,
+      color,
+      tickFormat,
+      distributionChartActions,
+      showSummary,
+      showEditor,
+      diagramStart: 0,
+      diagramStop: 10,
+      diagramCount: 20,
+    },
+  });
+  const vars = useWatch({
+    control,
+  });
+
+  useEffect(() => {
+    onSettingsChange?.(vars);
+  }, [vars, onSettingsChange]);
+
+  const env: environment = useMemo(
+    () => ({
+      sampleCount: Number(vars.sampleCount),
+      xyPointLength: Number(vars.xyPointLength),
+    }),
+    [vars.sampleCount, vars.xyPointLength]
+  );
+
+  const {
+    run,
+    autorunMode,
+    setAutorunMode,
+    isRunning,
+    renderedCode,
+    executionId,
+  } = useRunnerState(code);
+
+  const squiggleChart =
+    renderedCode === "" ? null : (
+      <div className="relative">
+        {isRunning ? (
+          <div className="absolute inset-0 bg-white opacity-0 animate-semi-appear" />
+        ) : null}
+        <SquiggleChart
+          code={renderedCode}
+          executionId={executionId}
+          environment={env}
+          {...vars}
+          bindings={defaultBindings}
+          jsImports={imports}
+          enableLocalSettings={true}
+        />
+      </div>
+    );
+
+  const firstTab = vars.showEditor ? (
+    <div className="border border-slate-200">
+      <CodeEditor
+        value={code}
+        onChange={setCode}
+        onSubmit={run}
+        oneLine={false}
+        showGutter={true}
+        height={height - 1}
+      />
+    </div>
+  ) : (
+    squiggleChart
+  );
+
+  const tabs = (
+    <StyledTab.Panels>
+      <StyledTab.Panel>{firstTab}</StyledTab.Panel>
+      <StyledTab.Panel>
+        <SamplingSettings register={register} />
+      </StyledTab.Panel>
+      <StyledTab.Panel>
+        <ViewSettings
+          register={
+            // This is dangerous, but doesn't cause any problems.
+            // I tried to make `ViewSettings` generic (to allow it to accept any extension of a settings schema), but it didn't work.
+            register as unknown as UseFormRegister<
+              yup.InferType<typeof viewSettingsSchema>
+            >
+          }
+        />
+      </StyledTab.Panel>
+      <StyledTab.Panel>
+        <InputVariablesSettings
+          initialImports={imports}
+          setImports={setImports}
+        />
+      </StyledTab.Panel>
+    </StyledTab.Panels>
+  );
+
+  const leftPanelRef = useRef<HTMLDivElement | null>(null);
+
+  const withEditor = (
+    <div className="flex mt-2">
+      <div
+        className="w-1/2 relative"
+        style={{ minHeight: height }}
+        ref={leftPanelRef}
+      >
+        {tabs}
+      </div>
+      <div className="w-1/2 p-2 pl-4">{squiggleChart}</div>
+    </div>
+  );
+
+  const withoutEditor = <div className="mt-3">{tabs}</div>;
+
+  const getLeftPanelElement = useCallback(() => {
+    return leftPanelRef.current ?? undefined;
+  }, []);
+
+  return (
+    <SquiggleContainer>
+      <PlaygroundContext.Provider value={{ getLeftPanelElement }}>
+        <StyledTab.Group>
+          <div className="pb-4">
+            <div className="flex justify-between items-center">
+              <StyledTab.List>
+                <StyledTab
+                  name={vars.showEditor ? "Code" : "Display"}
+                  icon={vars.showEditor ? CodeIcon : EyeIcon}
+                />
+                <StyledTab name="Sampling Settings" icon={CogIcon} />
+                <StyledTab name="View Settings" icon={ChartSquareBarIcon} />
+                <StyledTab name="Input Variables" icon={CurrencyDollarIcon} />
+              </StyledTab.List>
+              <div className="flex space-x-2 items-center">
+                <RunControls
+                  autorunMode={autorunMode}
+                  isStale={renderedCode !== code}
+                  run={run}
+                  isRunning={isRunning}
+                  onAutorunModeChange={setAutorunMode}
+                />
+                {showShareButton && <ShareButton />}
+              </div>
+            </div>
+            {vars.showEditor ? withEditor : withoutEditor}
+          </div>
+        </StyledTab.Group>
+      </PlaygroundContext.Provider>
+    </SquiggleContainer>
+  );
+};

packages/components/src/components/SquiggleViewer/ExpressionViewer.tsx

@@ -0,0 +1,291 @@
+import React from "react";
+import { squiggleExpression, declaration } from "@quri/squiggle-lang";
+import { NumberShower } from "../NumberShower";
+import { DistributionChart } from "../DistributionChart";
+import { FunctionChart, FunctionChartSettings } from "../FunctionChart";
+import clsx from "clsx";
+import { VariableBox } from "./VariableBox";
+import { ItemSettingsMenu } from "./ItemSettingsMenu";
+import { hasMassBelowZero } from "../../lib/distributionUtils";
+import { MergedItemSettings } from "./utils";
+
+function getRange<a>(x: declaration<a>) {
+  const first = x.args[0];
+  switch (first.tag) {
+    case "Float": {
+      return { floats: { min: first.value.min, max: first.value.max } };
+    }
+    case "Date": {
+      return { time: { min: first.value.min, max: first.value.max } };
+    }
+  }
+}
+
+function getChartSettings<a>(x: declaration<a>): FunctionChartSettings {
+  const range = getRange(x);
+  const min = range.floats ? range.floats.min : 0;
+  const max = range.floats ? range.floats.max : 10;
+  return {
+    start: min,
+    stop: max,
+    count: 20,
+  };
+}
+
+const VariableList: React.FC<{
+  path: string[];
+  heading: string;
+  children: (settings: MergedItemSettings) => React.ReactNode;
+}> = ({ path, heading, children }) => (
+  <VariableBox path={path} heading={heading}>
+    {(settings) => (
+      <div className={clsx("space-y-3", path.length ? "pt-1 mt-1" : null)}>
+        {children(settings)}
+      </div>
+    )}
+  </VariableBox>
+);
+
+export interface Props {
+  /** The output of squiggle's run */
+  expression: squiggleExpression;
+  /** Path to the current item, e.g. `['foo', 'bar', '3']` for `foo.bar[3]`; can be empty on the top-level item. */
+  path: string[];
+  width?: number;
+}
+
+export const ExpressionViewer: React.FC<Props> = ({
+  path,
+  expression,
+  width,
+}) => {
+  switch (expression.tag) {
+    case "number":
+      return (
+        <VariableBox path={path} heading="Number">
+          {() => (
+            <div className="font-semibold text-slate-600">
+              <NumberShower precision={3} number={expression.value} />
+            </div>
+          )}
+        </VariableBox>
+      );
+    case "distribution": {
+      const distType = expression.value.type();
+      return (
+        <VariableBox
+          path={path}
+          heading={`Distribution (${distType})\n${
+            distType === "Symbolic" ? expression.value.toString() : ""
+          }`}
+          renderSettingsMenu={({ onChange }) => {
+            const shape = expression.value.pointSet();
+            return (
+              <ItemSettingsMenu
+                path={path}
+                onChange={onChange}
+                disableLogX={
+                  shape.tag === "Ok" && hasMassBelowZero(shape.value)
+                }
+                withFunctionSettings={false}
+              />
+            );
+          }}
+        >
+          {(settings) => {
+            return (
+              <DistributionChart
+                distribution={expression.value}
+                {...settings.distributionPlotSettings}
+                height={settings.height}
+                width={width}
+              />
+            );
+          }}
+        </VariableBox>
+      );
+    }
+    case "string":
+      return (
+        <VariableBox path={path} heading="String">
+          {() => (
+            <>
+              <span className="text-slate-400">"</span>
+              <span className="text-slate-600 font-semibold font-mono">
+                {expression.value}
+              </span>
+              <span className="text-slate-400">"</span>
+            </>
+          )}
+        </VariableBox>
+      );
+    case "boolean":
+      return (
+        <VariableBox path={path} heading="Boolean">
+          {() => expression.value.toString()}
+        </VariableBox>
+      );
+    case "symbol":
+      return (
+        <VariableBox path={path} heading="Symbol">
+          {() => (
+            <>
+              <span className="text-slate-500 mr-2">Undefined Symbol:</span>
+              <span className="text-slate-600">{expression.value}</span>
+            </>
+          )}
+        </VariableBox>
+      );
+    case "call":
+      return (
+        <VariableBox path={path} heading="Call">
+          {() => expression.value}
+        </VariableBox>
+      );
+    case "arraystring":
+      return (
+        <VariableBox path={path} heading="Array String">
+          {() => expression.value.map((r) => `"${r}"`).join(", ")}
+        </VariableBox>
+      );
+    case "date":
+      return (
+        <VariableBox path={path} heading="Date">
+          {() => expression.value.toDateString()}
+        </VariableBox>
+      );
+    case "void":
+      return (
+        <VariableBox path={path} heading="Void">
+          {() => "Void"}
+        </VariableBox>
+      );
+    case "timeDuration": {
+      return (
+        <VariableBox path={path} heading="Time Duration">
+          {() => <NumberShower precision={3} number={expression.value} />}
+        </VariableBox>
+      );
+    }
+    case "lambda":
+      return (
+        <VariableBox
+          path={path}
+          heading="Function"
+          renderSettingsMenu={({ onChange }) => {
+            return (
+              <ItemSettingsMenu
+                path={path}
+                onChange={onChange}
+                withFunctionSettings={true}
+              />
+            );
+          }}
+        >
+          {(settings) => (
+            <>
+              <div className="text-amber-700 bg-amber-100 rounded-md font-mono p-1 pl-2 mb-3 mt-1 text-sm">{`function(${expression.value.parameters.join(
+                ","
+              )})`}</div>
+              <FunctionChart
+                fn={expression.value}
+                chartSettings={settings.chartSettings}
+                distributionPlotSettings={settings.distributionPlotSettings}
+                height={settings.height}
+                environment={{
+                  sampleCount: settings.environment.sampleCount / 10,
+                  xyPointLength: settings.environment.xyPointLength / 10,
+                }}
+              />
+            </>
+          )}
+        </VariableBox>
+      );
+    case "lambdaDeclaration": {
+      return (
+        <VariableBox
+          path={path}
+          heading="Function Declaration"
+          renderSettingsMenu={({ onChange }) => {
+            return (
+              <ItemSettingsMenu
+                onChange={onChange}
+                path={path}
+                withFunctionSettings={true}
+              />
+            );
+          }}
+        >
+          {(settings) => (
+            <FunctionChart
+              fn={expression.value.fn}
+              chartSettings={getChartSettings(expression.value)}
+              distributionPlotSettings={settings.distributionPlotSettings}
+              height={settings.height}
+              environment={{
+                sampleCount: settings.environment.sampleCount / 10,
+                xyPointLength: settings.environment.xyPointLength / 10,
+              }}
+            />
+          )}
+        </VariableBox>
+      );
+    }
+    case "module": {
+      return (
+        <VariableList path={path} heading="Module">
+          {(settings) =>
+            Object.entries(expression.value)
+              .filter(([key, r]) => !key.match(/^(Math|System)\./))
+              .map(([key, r]) => (
+                <ExpressionViewer
+                  key={key}
+                  path={[...path, key]}
+                  expression={r}
+                  width={width !== undefined ? width - 20 : width}
+                />
+              ))
+          }
+        </VariableList>
+      );
+    }
+    case "record":
+      return (
+        <VariableList path={path} heading="Record">
+          {(settings) =>
+            Object.entries(expression.value).map(([key, r]) => (
+              <ExpressionViewer
+                key={key}
+                path={[...path, key]}
+                expression={r}
+                width={width !== undefined ? width - 20 : width}
+              />
+            ))
+          }
+        </VariableList>
+      );
+    case "array":
+      return (
+        <VariableList path={path} heading="Array">
+          {(settings) =>
+            expression.value.map((r, i) => (
+              <ExpressionViewer
+                key={i}
+                path={[...path, String(i)]}
+                expression={r}
+                width={width !== undefined ? width - 20 : width}
+              />
+            ))
+          }
+        </VariableList>
+      );
+    default: {
+      return (
+        <div>
+          <span>No display for type: </span>{" "}
+          <span className="font-semibold text-slate-600">{expression.tag}</span>
+        </div>
+      );
+    }
+  }
+};

packages/components/src/components/SquiggleViewer/ItemSettingsMenu.tsx

@@ -0,0 +1,168 @@
+import { CogIcon } from "@heroicons/react/solid";
+import React, { useContext, useRef, useState, useEffect } from "react";
+import { useForm } from "react-hook-form";
+import { yupResolver } from "@hookform/resolvers/yup";
+import { Modal } from "../ui/Modal";
+import { ViewSettings, viewSettingsSchema } from "../ViewSettings";
+import { Path, pathAsString } from "./utils";
+import { ViewerContext } from "./ViewerContext";
+import {
+  defaultColor,
+  defaultTickFormat,
+} from "../../lib/distributionSpecBuilder";
+import { PlaygroundContext } from "../SquigglePlayground";
+
+type Props = {
+  path: Path;
+  onChange: () => void;
+  disableLogX?: boolean;
+  withFunctionSettings: boolean;
+};
+
+const ItemSettingsModal: React.FC<
+  Props & { close: () => void; resetScroll: () => void }
+> = ({
+  path,
+  onChange,
+  disableLogX,
+  withFunctionSettings,
+  close,
+  resetScroll,
+}) => {
+  const { setSettings, getSettings, getMergedSettings } =
+    useContext(ViewerContext);
+
+  const mergedSettings = getMergedSettings(path);
+
+  const { register, watch } = useForm({
+    resolver: yupResolver(viewSettingsSchema),
+    defaultValues: {
+      // this is a mess and should be fixed
+      showEditor: true, // doesn't matter
+      chartHeight: mergedSettings.height,
+      showSummary: mergedSettings.distributionPlotSettings.showSummary,
+      logX: mergedSettings.distributionPlotSettings.logX,
+      expY: mergedSettings.distributionPlotSettings.expY,
+      tickFormat:
+        mergedSettings.distributionPlotSettings.format || defaultTickFormat,
+      title: mergedSettings.distributionPlotSettings.title,
+      color: mergedSettings.distributionPlotSettings.color || defaultColor,
+      minX: mergedSettings.distributionPlotSettings.minX,
+      maxX: mergedSettings.distributionPlotSettings.maxX,
+      distributionChartActions: mergedSettings.distributionPlotSettings.actions,
+      diagramStart: mergedSettings.chartSettings.start,
+      diagramStop: mergedSettings.chartSettings.stop,
+      diagramCount: mergedSettings.chartSettings.count,
+    },
+  });
+  useEffect(() => {
+    const subscription = watch((vars) => {
+      const settings = getSettings(path); // get the latest version
+      setSettings(path, {
+        ...settings,
+        distributionPlotSettings: {
+          showSummary: vars.showSummary,
+          logX: vars.logX,
+          expY: vars.expY,
+          format: vars.tickFormat,
+          title: vars.title,
+          color: vars.color,
+          minX: vars.minX,
+          maxX: vars.maxX,
+          actions: vars.distributionChartActions,
+        },
+        chartSettings: {
+          start: vars.diagramStart,
+          stop: vars.diagramStop,
+          count: vars.diagramCount,
+        },
+      });
+      onChange();
+    });
+    return () => subscription.unsubscribe();
+  }, [getSettings, setSettings, onChange, path, watch]);
+
+  const { getLeftPanelElement } = useContext(PlaygroundContext);
+
+  return (
+    <Modal container={getLeftPanelElement()} close={close}>
+      <Modal.Header>
+        Chart settings
+        {path.length ? (
+          <>
+            {" for "}
+            <span
+              title="Scroll to item"
+              className="cursor-pointer"
+              onClick={resetScroll}
+            >
+              {pathAsString(path)}
+            </span>{" "}
+          </>
+        ) : (
+          ""
+        )}
+      </Modal.Header>
+      <Modal.Body>
+        <ViewSettings
+          register={register}
+          withShowEditorSetting={false}
+          withFunctionSettings={withFunctionSettings}
+          disableLogXSetting={disableLogX}
+        />
+      </Modal.Body>
+    </Modal>
+  );
+};
+
+export const ItemSettingsMenu: React.FC<Props> = (props) => {
+  const [isOpen, setIsOpen] = useState(false);
+  const { enableLocalSettings, setSettings, getSettings } =
+    useContext(ViewerContext);
+
+  const ref = useRef<HTMLDivElement | null>(null);
+
+  if (!enableLocalSettings) {
+    return null;
+  }
+  const settings = getSettings(props.path);
+
+  const resetScroll = () => {
+    if (!ref.current) return;
+    window.scroll({
+      top: ref.current.getBoundingClientRect().y + window.scrollY,
+      behavior: "smooth",
+    });
+  };
+
+  return (
+    <div className="flex gap-2" ref={ref}>
+      <CogIcon
+        className="h-5 w-5 cursor-pointer text-slate-400 hover:text-slate-500"
+        onClick={() => setIsOpen(!isOpen)}
+      />
+      {settings.distributionPlotSettings || settings.chartSettings ? (
+        <button
+          onClick={() => {
+            setSettings(props.path, {
+              ...settings,
+              distributionPlotSettings: undefined,
+              chartSettings: undefined,
+            });
+            props.onChange();
+          }}
+          className="text-xs px-1 py-0.5 rounded bg-slate-300"
+        >
+          Reset settings
+        </button>
+      ) : null}
+      {isOpen ? (
+        <ItemSettingsModal
+          {...props}
+          close={() => setIsOpen(false)}
+          resetScroll={resetScroll}
+        />
+      ) : null}
+    </div>
+  );
+};

packages/components/src/components/SquiggleViewer/VariableBox.tsx

@@ -0,0 +1,79 @@
+import React, { useContext, useReducer } from "react";
+import { Tooltip } from "../ui/Tooltip";
+import { LocalItemSettings, MergedItemSettings } from "./utils";
+import { ViewerContext } from "./ViewerContext";
+
+type SettingsMenuParams = {
+  onChange: () => void; // used to notify VariableBox that settings have changed, so that VariableBox could re-render itself
+};
+
+type VariableBoxProps = {
+  path: string[];
+  heading: string;
+  renderSettingsMenu?: (params: SettingsMenuParams) => React.ReactNode;
+  children: (settings: MergedItemSettings) => React.ReactNode;
+};
+
+export const VariableBox: React.FC<VariableBoxProps> = ({
+  path,
+  heading = "Error",
+  renderSettingsMenu,
+  children,
+}) => {
+  const { setSettings, getSettings, getMergedSettings } =
+    useContext(ViewerContext);
+
+  // Since ViewerContext doesn't keep the actual settings, VariableBox won't rerender when setSettings is called.
+  // So we use `forceUpdate` to force rerendering.
+  const [_, forceUpdate] = useReducer((x) => x + 1, 0);
+
+  const settings = getSettings(path);
+
+  const setSettingsAndUpdate = (newSettings: LocalItemSettings) => {
+    setSettings(path, newSettings);
+    forceUpdate();
+  };
+
+  const toggleCollapsed = () => {
+    setSettingsAndUpdate({ ...settings, collapsed: !settings.collapsed });
+  };
+
+  const isTopLevel = path.length === 0;
+  const name = isTopLevel ? "Result" : path[path.length - 1];
+
+  return (
+    <div>
+      <header className="inline-flex space-x-1">
+        <Tooltip text={heading}>
+          <span
+            className="text-slate-500 font-mono text-sm cursor-pointer"
+            onClick={toggleCollapsed}
+          >
+            {name}:
+          </span>
+        </Tooltip>
+        {settings.collapsed ? (
+          <span
+            className="rounded p-0.5 bg-slate-200 text-slate-500 font-mono text-xs cursor-pointer"
+            onClick={toggleCollapsed}
+          >
+            ...
+          </span>
+        ) : renderSettingsMenu ? (
+          renderSettingsMenu({ onChange: forceUpdate })
+        ) : null}
+      </header>
+      {settings.collapsed ? null : (
+        <div className="flex w-full">
+          {path.length ? (
+            <div
+              className="border-l-2 border-slate-200 hover:border-indigo-600 w-4 cursor-pointer"
+              onClick={toggleCollapsed}
+            ></div>
+          ) : null}
+          <div className="grow">{children(getMergedSettings(path))}</div>
+        </div>
+      )}
+    </div>
+  );
+};

packages/components/src/components/SquiggleViewer/ViewerContext.ts

@@ -0,0 +1,35 @@
+import { defaultEnvironment } from "@quri/squiggle-lang";
+import React from "react";
+import { LocalItemSettings, MergedItemSettings, Path } from "./utils";
+
+type ViewerContextShape = {
+  // Note that we don't store settings themselves in the context (that would cause rerenders of the entire tree on each settings update).
+  // Instead, we keep settings in local state and notify the global context via setSettings to pass them down the component tree again if it got rebuilt from scratch.
+  // See ./SquiggleViewer.tsx and ./VariableBox.tsx for other implementation details on this.
+  getSettings(path: Path): LocalItemSettings;
+  getMergedSettings(path: Path): MergedItemSettings;
+  setSettings(path: Path, value: LocalItemSettings): void;
+  enableLocalSettings: boolean; // show local settings icon in the UI
+};
+
+export const ViewerContext = React.createContext<ViewerContextShape>({
+  getSettings: () => ({ collapsed: false }),
+  getMergedSettings: () => ({
+    collapsed: false,
+    // copy-pasted from SquiggleChart
+    chartSettings: {
+      start: 0,
+      stop: 10,
+      count: 100,
+    },
+    distributionPlotSettings: {
+      showSummary: false,
+      logX: false,
+      expY: false,
+    },
+    environment: defaultEnvironment,
+    height: 150,
+  }),
+  setSettings() {},
+  enableLocalSettings: false,
+});

packages/components/src/components/SquiggleViewer/index.tsx

@@ -0,0 +1,100 @@
+import React, { useCallback, useRef } from "react";
+import { environment } from "@quri/squiggle-lang";
+import { DistributionPlottingSettings } from "../DistributionChart";
+import { FunctionChartSettings } from "../FunctionChart";
+import { ExpressionViewer } from "./ExpressionViewer";
+import { ViewerContext } from "./ViewerContext";
+import {
+  LocalItemSettings,
+  MergedItemSettings,
+  Path,
+  pathAsString,
+} from "./utils";
+import { useSquiggle } from "../../lib/hooks";
+import { SquiggleErrorAlert } from "../SquiggleErrorAlert";
+
+type Props = {
+  /** The output of squiggle's run */
+  result: ReturnType<typeof useSquiggle>;
+  width?: number;
+  height: number;
+  distributionPlotSettings: DistributionPlottingSettings;
+  /** Settings for displaying functions */
+  chartSettings: FunctionChartSettings;
+  /** Environment for further function executions */
+  environment: environment;
+  enableLocalSettings?: boolean;
+};
+
+type Settings = {
+  [k: string]: LocalItemSettings;
+};
+
+const defaultSettings: LocalItemSettings = { collapsed: false };
+
+export const SquiggleViewer: React.FC<Props> = ({
+  result,
+  width,
+  height,
+  distributionPlotSettings,
+  chartSettings,
+  environment,
+  enableLocalSettings = false,
+}) => {
+  // can't store settings in the state because we don't want to rerender the entire tree on every change
+  const settingsRef = useRef<Settings>({});
+
+  const getSettings = useCallback(
+    (path: Path) => {
+      return settingsRef.current[pathAsString(path)] || defaultSettings;
+    },
+    [settingsRef]
+  );
+
+  const setSettings = useCallback(
+    (path: Path, value: LocalItemSettings) => {
+      settingsRef.current[pathAsString(path)] = value;
+    },
+    [settingsRef]
+  );
+
+  const getMergedSettings = useCallback(
+    (path: Path) => {
+      const localSettings = getSettings(path);
+      const result: MergedItemSettings = {
+        distributionPlotSettings: {
+          ...distributionPlotSettings,
+          ...(localSettings.distributionPlotSettings || {}),
+        },
+        chartSettings: {
+          ...chartSettings,
+          ...(localSettings.chartSettings || {}),
+        },
+        environment: {
+          ...environment,
+          ...(localSettings.environment || {}),
+        },
+        height: localSettings.height || height,
+      };
+      return result;
+    },
+    [distributionPlotSettings, chartSettings, environment, height, getSettings]
+  );
+
+  return (
+    <ViewerContext.Provider
+      value={{
+        getSettings,
+        setSettings,
+        getMergedSettings,
+        enableLocalSettings,
+      }}
+    >
+      {result.tag === "Ok" ? (
+        <ExpressionViewer path={[]} expression={result.value} width={width} />
+      ) : (
+        <SquiggleErrorAlert error={result.value} />
+      )}
+    </ViewerContext.Provider>
+  );
+};

packages/components/src/components/SquiggleViewer/utils.ts

@@ -0,0 +1,22 @@
+import { DistributionPlottingSettings } from "../DistributionChart";
+import { FunctionChartSettings } from "../FunctionChart";
+import { environment } from "@quri/squiggle-lang";
+
+export type LocalItemSettings = {
+  collapsed: boolean;
+  distributionPlotSettings?: Partial<DistributionPlottingSettings>;
+  chartSettings?: Partial<FunctionChartSettings>;
+  height?: number;
+  environment?: Partial<environment>;
+};
+
+export type MergedItemSettings = {
+  distributionPlotSettings: DistributionPlottingSettings;
+  chartSettings: FunctionChartSettings;
+  height: number;
+  environment: environment;
+};
+
+export type Path = string[];
+
+export const pathAsString = (path: Path) => path.join(".");

packages/components/src/components/ViewSettings.tsx

@@ -0,0 +1,163 @@
+import React from "react";
+import * as yup from "yup";
+import { UseFormRegister } from "react-hook-form";
+import { InputItem } from "./ui/InputItem";
+import { Checkbox } from "./ui/Checkbox";
+import { HeadedSection } from "./ui/HeadedSection";
+import { Text } from "./ui/Text";
+import {
+  defaultColor,
+  defaultTickFormat,
+} from "../lib/distributionSpecBuilder";
+
+export const viewSettingsSchema = yup.object({}).shape({
+  chartHeight: yup.number().required().positive().integer().default(350),
+  showSummary: yup.boolean().required(),
+  showEditor: yup.boolean().required(),
+  logX: yup.boolean().required(),
+  expY: yup.boolean().required(),
+  tickFormat: yup.string().default(defaultTickFormat),
+  title: yup.string(),
+  color: yup.string().default(defaultColor).required(),
+  minX: yup.number(),
+  maxX: yup.number(),
+  distributionChartActions: yup.boolean(),
+  diagramStart: yup.number().required().positive().integer().default(0).min(0),
+  diagramStop: yup.number().required().positive().integer().default(10).min(0),
+  diagramCount: yup.number().required().positive().integer().default(20).min(2),
+});
+
+type FormFields = yup.InferType<typeof viewSettingsSchema>;
+
+// This component is used in two places: for global settings in SquigglePlayground, and for item-specific settings in modal dialogs.
+export const ViewSettings: React.FC<{
+  withShowEditorSetting?: boolean;
+  withFunctionSettings?: boolean;
+  disableLogXSetting?: boolean;
+  register: UseFormRegister<FormFields>;
+}> = ({
+  withShowEditorSetting = true,
+  withFunctionSettings = true,
+  disableLogXSetting,
+  register,
+}) => {
+  return (
+    <div className="space-y-6 p-3 divide-y divide-gray-200 max-w-xl">
+      <HeadedSection title="General Display Settings">
+        <div className="space-y-4">
+          {withShowEditorSetting ? (
+            <Checkbox
+              name="showEditor"
+              register={register}
+              label="Show code editor on left"
+            />
+          ) : null}
+          <InputItem
+            name="chartHeight"
+            type="number"
+            register={register}
+            label="Chart Height (in pixels)"
+          />
+        </div>
+      </HeadedSection>
+
+      <div className="pt-8">
+        <HeadedSection title="Distribution Display Settings">
+          <div className="space-y-2">
+            <Checkbox
+              register={register}
+              name="logX"
+              label="Show x scale logarithmically"
+              disabled={disableLogXSetting}
+              tooltip={
+                disableLogXSetting
+                  ? "Your distribution has mass lower than or equal to 0. Log only works on strictly positive values."
+                  : undefined
+              }
+            />
+            <Checkbox
+              register={register}
+              name="expY"
+              label="Show y scale exponentially"
+            />
+            <Checkbox
+              register={register}
+              name="distributionChartActions"
+              label="Show vega chart controls"
+            />
+            <Checkbox
+              register={register}
+              name="showSummary"
+              label="Show summary statistics"
+            />
+            <InputItem
+              name="minX"
+              type="number"
+              register={register}
+              label="Min X Value"
+            />
+            <InputItem
+              name="maxX"
+              type="number"
+              register={register}
+              label="Max X Value"
+            />
+            <InputItem
+              name="title"
+              type="text"
+              register={register}
+              label="Title"
+            />
+            <InputItem
+              name="tickFormat"
+              type="text"
+              register={register}
+              label="Tick Format"
+            />
+            <InputItem
+              name="color"
+              type="color"
+              register={register}
+              label="Color"
+            />
+          </div>
+        </HeadedSection>
+      </div>
+
+      {withFunctionSettings ? (
+        <div className="pt-8">
+          <HeadedSection title="Function Display Settings">
+            <div className="space-y-6">
+              <Text>
+                When displaying functions of single variables that return
+                numbers or distributions, we need to use defaults for the
+                x-axis. We need to select a minimum and maximum value of x to
+                sample, and a number n of the number of points to sample.
+              </Text>
+              <div className="space-y-4">
+                <InputItem
+                  type="number"
+                  name="diagramStart"
+                  register={register}
+                  label="Min X Value"
+                />
+                <InputItem
+                  type="number"
+                  name="diagramStop"
+                  register={register}
+                  label="Max X Value"
+                />
+                <InputItem
+                  type="number"
+                  name="diagramCount"
+                  register={register}
+                  label="Points between X min and X max to sample"
+                />
+              </div>
+            </div>
+          </HeadedSection>
+        </div>
+      ) : null}
+    </div>
+  );
+};

packages/components/src/components/ui/Button.tsx

@@ -0,0 +1,22 @@
+import clsx from "clsx";
+import React from "react";
+
+type Props = {
+  onClick: () => void;
+  children: React.ReactNode;
+  wide?: boolean; // stretch the button horizontally
+};
+
+export const Button: React.FC<Props> = ({ onClick, wide, children }) => {
+  return (
+    <button
+      className={clsx(
+        "rounded-md py-1.5 px-2 bg-slate-500 text-white text-xs font-semibold flex items-center justify-center space-x-1",
+        wide && "w-full"
+      )}
+      onClick={onClick}
+    >
+      {children}
+    </button>
+  );
+};

packages/components/src/components/ui/Checkbox.tsx

@@ -0,0 +1,37 @@
+import clsx from "clsx";
+import React from "react";
+import { Path, UseFormRegister } from "react-hook-form";
+
+export function Checkbox<T>({
+  name,
+  label,
+  register,
+  disabled,
+  tooltip,
+}: {
+  name: Path<T>;
+  label: string;
+  register: UseFormRegister<T>;
+  disabled?: boolean;
+  tooltip?: string;
+}) {
+  return (
+    <label className="flex items-center" title={tooltip}>
+      <input
+        type="checkbox"
+        disabled={disabled}
+        {...register(name)}
+        className="form-checkbox focus:ring-indigo-500 h-4 w-4 text-indigo-600 border-gray-300 rounded"
+      />
+      {/* Clicking on the div makes the checkbox lose focus while mouse button is pressed, leading to annoying blinking; I couldn't figure out how to fix this. */}
+      <div
+        className={clsx(
+          "ml-3 text-sm font-medium",
+          disabled ? "text-gray-400" : "text-gray-700"
+        )}
+      >
+        {label}
+      </div>
+    </label>
+  );
+}

packages/components/src/components/ui/HeadedSection.tsx

@@ -0,0 +1,13 @@
+import React from "react";
+
+export const HeadedSection: React.FC<{
+  title: string;
+  children: React.ReactNode;
+}> = ({ title, children }) => (
+  <div>
+    <header className="text-lg leading-6 font-medium text-gray-900">
+      {title}
+    </header>
+    <div className="mt-4">{children}</div>
+  </div>
+);

packages/components/src/components/ui/InputItem.tsx

@@ -0,0 +1,25 @@
+import React from "react";
+import { Path, UseFormRegister } from "react-hook-form";
+
+export function InputItem<T>({
+  name,
+  label,
+  type,
+  register,
+}: {
+  name: Path<T>;
+  label: string;
+  type: "number" | "text" | "color";
+  register: UseFormRegister<T>;
+}) {
+  return (
+    <label className="block">
+      <div className="text-sm font-medium text-gray-600 mb-1">{label}</div>
+      <input
+        type={type}
+        {...register(name, { valueAsNumber: type === "number" })}
+        className="form-input max-w-lg block w-full shadow-sm focus:ring-indigo-500 focus:border-indigo-500 sm:max-w-xs sm:text-sm border-gray-300 rounded-md"
+      />
+    </label>
+  );
+}

packages/components/src/components/ui/Modal.tsx

@@ -0,0 +1,184 @@
+import { motion } from "framer-motion";
+import React, { useContext } from "react";
+import * as ReactDOM from "react-dom";
+import { XIcon } from "@heroicons/react/solid";
+import clsx from "clsx";
+import { useWindowScroll, useWindowSize } from "react-use";
+
+type ModalContextShape = {
+  close: () => void;
+};
+const ModalContext = React.createContext<ModalContextShape>({
+  close: () => undefined,
+});
+
+const Overlay: React.FC = () => {
+  const { close } = useContext(ModalContext);
+  return (
+    <motion.div
+      className="absolute inset-0 -z-10 bg-black"
+      initial={{ opacity: 0 }}
+      animate={{ opacity: 0.1 }}
+      onClick={close}
+    />
+  );
+};
+
+const ModalHeader: React.FC<{
+  children: React.ReactNode;
+}> = ({ children }) => {
+  const { close } = useContext(ModalContext);
+  return (
+    <header className="px-5 py-3 border-b border-gray-200 font-bold flex items-center justify-between">
+      <div>{children}</div>
+      <button
+        className="px-1 bg-transparent cursor-pointer text-gray-700 hover:text-accent-500"
+        type="button"
+        onClick={close}
+      >
+        <XIcon className="h-5 w-5 cursor-pointer text-slate-400 hover:text-slate-500" />
+      </button>
+    </header>
+  );
+};
+
+// TODO - get rid of forwardRef, support `focus` and `{...hotkeys}` via smart props
+const ModalBody = React.forwardRef<
+  HTMLDivElement,
+  JSX.IntrinsicElements["div"]
+>(function ModalBody(props, ref) {
+  return <div ref={ref} className="px-5 py-3 overflow-auto" {...props} />;
+});
+
+const ModalFooter: React.FC<{ children: React.ReactNode }> = ({ children }) => (
+  <div className="px-5 py-3 border-t border-gray-200">{children}</div>
+);
+
+const ModalWindow: React.FC<{
+  children: React.ReactNode;
+  container?: HTMLElement;
+}> = ({ children, container }) => {
+  // This component works in two possible modes:
+  // 1. container mode - the modal is rendered inside a container element
+  // 2. centered mode - the modal is rendered in the middle of the screen
+  // The mode is determined by the presence of the `container` prop and by whether the available space is large enough to fit the modal.
+
+  // Necessary for container mode - need to reposition the modal on scroll and resize events.
+  useWindowSize();
+  useWindowScroll();
+
+  let position:
+    | {
+        left: number;
+        top: number;
+        maxWidth: number;
+        maxHeight: number;
+        transform: string;
+      }
+    | undefined;
+
+  // If available space in `visibleRect` is smaller than these, fallback to positioning in the middle of the screen.
+  const minWidth = 384;
+  const minHeight = 300;
+  const offset = 8;
+  const naturalWidth = 576; // maximum possible width; modal tries to take this much space, but can be smaller
+
+  if (container) {
+    const { clientWidth: screenWidth, clientHeight: screenHeight } =
+      document.documentElement;
+    const rect = container?.getBoundingClientRect();
+
+    const visibleRect = {
+      left: Math.max(rect.left, 0),
+      right: Math.min(rect.right, screenWidth),
+      top: Math.max(rect.top, 0),
+      bottom: Math.min(rect.bottom, screenHeight),
+    };
+    const maxWidth = visibleRect.right - visibleRect.left - 2 * offset;
+    const maxHeight = visibleRect.bottom - visibleRect.top - 2 * offset;
+
+    const center = {
+      left: visibleRect.left + (visibleRect.right - visibleRect.left) / 2,
+      top: visibleRect.top + (visibleRect.bottom - visibleRect.top) / 2,
+    };
+    position = {
+      left: center.left,
+      top: center.top,
+      transform: "translate(-50%, -50%)",
+      maxWidth,
+      maxHeight,
+    };
+    if (maxWidth < minWidth || maxHeight < minHeight) {
+      position = undefined; // modal is hard to fit in the container, fallback to positioning it in the middle of the screen
+    }
+  }
+  return (
+    <div
+      className={clsx(
+        "bg-white rounded-md shadow-toast flex flex-col overflow-auto border",
+        position ? "fixed" : null
+      )}
+      style={{
+        width: naturalWidth,
+        ...(position ?? {
+          maxHeight: "calc(100% - 20px)",
+          maxWidth: "calc(100% - 20px)",
+          width: naturalWidth,
+        }),
+      }}
+    >
+      {children}
+    </div>
+  );
+};
+
+type ModalType = React.FC<{
+  children: React.ReactNode;
+  container?: HTMLElement; // if specified, modal will be positioned over the visible part of the container, if it's not too small
+  close: () => void;
+}> & {
+  Body: typeof ModalBody;
+  Footer: typeof ModalFooter;
+  Header: typeof ModalHeader;
+};
+
+export const Modal: ModalType = ({ children, container, close }) => {
+  const [el] = React.useState(() => document.createElement("div"));
+
+  React.useEffect(() => {
+    document.body.appendChild(el);
+    return () => {
+      document.body.removeChild(el);
+    };
+  }, [el]);
+
+  React.useEffect(() => {
+    const handleEscape = (e: KeyboardEvent) => {
+      if (e.key === "Escape") {
+        close();
+      }
+    };
+    document.addEventListener("keydown", handleEscape);
+
+    return () => {
+      document.removeEventListener("keydown", handleEscape);
+    };
+  }, [close]);
+
+  const modal = (
+    <ModalContext.Provider value={{ close }}>
+      <div className="squiggle">
+        <div className="fixed inset-0 z-40 flex justify-center items-center">
+          <Overlay />
+          <ModalWindow container={container}>{children}</ModalWindow>
+        </div>
+      </div>
+    </ModalContext.Provider>
+  );
+
+  return ReactDOM.createPortal(modal, container || el);
+};
+
+Modal.Body = ModalBody;
+Modal.Footer = ModalFooter;
+Modal.Header = ModalHeader;

packages/components/src/components/ui/StyledTab.tsx

@@ -0,0 +1,60 @@
+import React, { Fragment } from "react";
+import { Tab } from "@headlessui/react";
+import clsx from "clsx";
+
+type StyledTabProps = {
+  name: string;
+  icon: (props: React.ComponentProps<"svg">) => JSX.Element;
+};
+
+type StyledTabType = React.FC<StyledTabProps> & {
+  List: React.FC<{ children: React.ReactNode }>;
+  Group: typeof Tab.Group;
+  Panels: typeof Tab.Panels;
+  Panel: typeof Tab.Panel;
+};
+
+export const StyledTab: StyledTabType = ({ name, icon: Icon }) => {
+  return (
+    <Tab as={Fragment}>
+      {({ selected }) => (
+        <button className="group flex rounded-md focus:outline-none focus-visible:ring-offset-gray-100">
+          <span
+            className={clsx(
+              "p-1 pl-2.5 pr-3.5 rounded-md flex items-center text-sm font-medium",
+              selected && "bg-white shadow-sm ring-1 ring-black ring-opacity-5"
+            )}
+          >
+            <Icon
+              className={clsx(
+                "-ml-0.5 mr-2 h-4 w-4",
+                selected
+                  ? "text-slate-500"
+                  : "text-gray-400 group-hover:text-gray-900"
+              )}
+            />
+            <span
+              className={clsx(
+                selected
+                  ? "text-gray-900"
+                  : "text-gray-600 group-hover:text-gray-900"
+              )}
+            >
+              {name}
+            </span>
+          </span>
+        </button>
+      )}
+    </Tab>
+  );
+};
+
+StyledTab.List = ({ children }) => (
+  <Tab.List className="flex w-fit p-0.5 rounded-md bg-slate-100 hover:bg-slate-200">
+    {children}
+  </Tab.List>
+);
+
+StyledTab.Group = Tab.Group;
+StyledTab.Panels = Tab.Panels;
+StyledTab.Panel = Tab.Panel;

packages/components/src/components/ui/Text.tsx

@@ -0,0 +1,5 @@
+import React from "react";
+
+export const Text: React.FC<{ children: React.ReactNode }> = ({ children }) => (
+  <p className="text-sm text-gray-500">{children}</p>
+);

packages/components/src/components/ui/Toggle.tsx

@@ -0,0 +1,47 @@
+import { RefreshIcon } from "@heroicons/react/solid";
+import clsx from "clsx";
+import React from "react";
+
+type IconType = (props: React.ComponentProps<"svg">) => JSX.Element;
+
+type Props = {
+  status: boolean;
+  onChange: (status: boolean) => void;
+  texts: [string, string];
+  icons: [IconType, IconType];
+  spinIcon?: boolean;
+};
+
+export const Toggle: React.FC<Props> = ({
+  status,
+  onChange,
+  texts: [onText, offText],
+  icons: [OnIcon, OffIcon],
+  spinIcon,
+}) => {
+  const CurrentIcon = status ? OnIcon : OffIcon;
+  return (
+    <button
+      className={clsx(
+        "rounded-md py-0.5 bg-slate-500 text-white text-xs font-semibold flex items-center space-x-1",
+        status ? "bg-slate-500" : "bg-gray-400",
+        status ? "pl-1 pr-3" : "pl-3 pr-1",
+        !status && "flex-row-reverse space-x-reverse"
+      )}
+      onClick={() => onChange(!status)}
+    >
+      <div className="relative w-6 h-6" key={String(spinIcon)}>
+        <CurrentIcon
+          className={clsx(
+            "w-6 h-6 absolute opacity-100",
+            spinIcon && "animate-hide"
+          )}
+        />
+        {spinIcon && (
+          <RefreshIcon className="w-6 h-6 absolute opacity-0 animate-appear-and-spin" />
+        )}
+      </div>
+      <span>{status ? onText : offText}</span>
+    </button>
+  );
+};

packages/components/src/components/ui/Tooltip.tsx

@@ -0,0 +1,64 @@
+import React, { cloneElement, useState } from "react";
+import { AnimatePresence, motion } from "framer-motion";
+import {
+  flip,
+  shift,
+  useDismiss,
+  useFloating,
+  useHover,
+  useInteractions,
+  useRole,
+} from "@floating-ui/react-dom-interactions";
+
+interface Props {
+  text: string;
+  children: JSX.Element;
+}
+
+export const Tooltip: React.FC<Props> = ({ text, children }) => {
+  const [isOpen, setIsOpen] = useState(false);
+
+  const { x, y, reference, floating, strategy, context } = useFloating({
+    placement: "top",
+    open: isOpen,
+    onOpenChange: setIsOpen,
+    middleware: [shift(), flip()],
+  });
+
+  const { getReferenceProps, getFloatingProps } = useInteractions([
+    useHover(context),
+    useRole(context, { role: "tooltip" }),
+    useDismiss(context),
+  ]);
+
+  return (
+    <>
+      {cloneElement(
+        children,
+        getReferenceProps({ ref: reference, ...children.props })
+      )}
+      <AnimatePresence>
+        {isOpen && (
+          <motion.div
+            initial={{ opacity: 0 }}
+            animate={{ opacity: 1 }}
+            exit={{ opacity: 0 }}
+            transition={{ duration: 0.15 }}
+            {...getFloatingProps({
+              ref: floating,
+              className:
+                "text-xs p-2 border border-gray-300 rounded bg-white z-10",
+              style: {
+                position: strategy,
+                top: y ?? 0,
+                left: x ?? 0,
+              },
+            })}
+          >
+            <div className="font-mono whitespace-pre">{text}</div>
+          </motion.div>
+        )}
+      </AnimatePresence>
+    </>
+  );
+};

packages/components/src/index.ts

@@ -1,14 +1,7 @@
 export { SquiggleChart } from "./components/SquiggleChart";
-export {
-  SquiggleEditor,
-  SquigglePartial,
-  renderSquiggleEditorToDom,
-  renderSquigglePartialToDom,
-} from "./components/SquiggleEditor";
-export {
-  default as SquigglePlayground,
-  renderSquigglePlaygroundToDom,
-} from "./components/SquigglePlayground";
+export { SquiggleEditor, SquigglePartial } from "./components/SquiggleEditor";
+export { SquigglePlayground } from "./components/SquigglePlayground";
 export { SquiggleContainer } from "./components/SquiggleContainer";
+export { SquiggleEditorWithImportedBindings } from "./components/SquiggleEditorWithImportedBindings";
 
 export { mergeBindings } from "@quri/squiggle-lang";

packages/components/src/lib/distributionSpecBuilder.ts

@@ -0,0 +1,259 @@
+import { VisualizationSpec } from "react-vega";
+import type { LogScale, LinearScale, PowScale } from "vega";
+
+export type DistributionChartSpecOptions = {
+  /** Set the x scale to be logarithmic by deault */
+  logX: boolean;
+  /** Set the y scale to be exponential by deault */
+  expY: boolean;
+  /** The minimum x coordinate shown on the chart */
+  minX?: number;
+  /** The maximum x coordinate shown on the chart */
+  maxX?: number;
+  /** The color of the chart */
+  color?: string;
+  /** The title of the chart */
+  title?: string;
+  /** The formatting of the ticks */
+  format?: string;
+};
+
+export let linearXScale: LinearScale = {
+  name: "xscale",
+  clamp: true,
+  type: "linear",
+  range: "width",
+  zero: false,
+  nice: false,
+  domain: {
+    fields: [
+      {
+        data: "con",
+        field: "x",
+      },
+      {
+        data: "dis",
+        field: "x",
+      },
+    ],
+  },
+};
+export let linearYScale: LinearScale = {
+  name: "yscale",
+  type: "linear",
+  range: "height",
+  zero: true,
+  domain: {
+    fields: [
+      {
+        data: "con",
+        field: "y",
+      },
+      {
+        data: "dis",
+        field: "y",
+      },
+    ],
+  },
+};
+
+export let logXScale: LogScale = {
+  name: "xscale",
+  type: "log",
+  range: "width",
+  zero: false,
+  base: 10,
+  nice: false,
+  clamp: true,
+  domain: {
+    fields: [
+      {
+        data: "con",
+        field: "x",
+      },
+      {
+        data: "dis",
+        field: "x",
+      },
+    ],
+  },
+};
+
+export let expYScale: PowScale = {
+  name: "yscale",
+  type: "pow",
+  exponent: 0.1,
+  range: "height",
+  zero: true,
+  nice: false,
+  domain: {
+    fields: [
+      {
+        data: "con",
+        field: "y",
+      },
+      {
+        data: "dis",
+        field: "y",
+      },
+    ],
+  },
+};
+
+export const defaultTickFormat = ".9~s";
+export const defaultColor = "#739ECC";
+
+export function buildVegaSpec(
+  specOptions: DistributionChartSpecOptions
+): VisualizationSpec {
+  let {
+    format = defaultTickFormat,
+    color = defaultColor,
+    title,
+    minX,
+    maxX,
+    logX,
+    expY,
+  } = specOptions;
+
+  let xScale = logX ? logXScale : linearXScale;
+  if (minX !== undefined && Number.isFinite(minX)) {
+    xScale = { ...xScale, domainMin: minX };
+  }
+
+  if (maxX !== undefined && Number.isFinite(maxX)) {
+    xScale = { ...xScale, domainMax: maxX };
+  }
+
+  let spec: VisualizationSpec = {
+    $schema: "https://vega.github.io/schema/vega/v5.json",
+    description: "A basic area chart example",
+    width: 500,
+    height: 100,
+    padding: 5,
+    data: [
+      {
+        name: "con",
+      },
+      {
+        name: "dis",
+      },
+    ],
+    signals: [],
+    scales: [xScale, expY ? expYScale : linearYScale],
+    axes: [
+      {
+        orient: "bottom",
+        scale: "xscale",
+        labelColor: "#727d93",
+        tickColor: "#fff",
+        tickOpacity: 0.0,
+        domainColor: "#fff",
+        domainOpacity: 0.0,
+        format: format,
+        tickCount: 10,
+      },
+    ],
+    marks: [
+      {
+        type: "area",
+        from: {
+          data: "con",
+        },
+        encode: {
+          update: {
+            interpolate: { value: "linear" },
+            x: {
+              scale: "xscale",
+              field: "x",
+            },
+            y: {
+              scale: "yscale",
+              field: "y",
+            },
+            y2: {
+              scale: "yscale",
+              value: 0,
+            },
+            fill: {
+              value: color,
+            },
+            fillOpacity: {
+              value: 1,
+            },
+          },
+        },
+      },
+      {
+        type: "rect",
+        from: {
+          data: "dis",
+        },
+        encode: {
+          enter: {
+            width: {
+              value: 1,
+            },
+          },
+          update: {
+            x: {
+              scale: "xscale",
+              field: "x",
+            },
+            y: {
+              scale: "yscale",
+              field: "y",
+            },
+            y2: {
+              scale: "yscale",
+              value: 0,
+            },
+            fill: {
+              value: "#2f65a7",
+            },
+          },
+        },
+      },
+      {
+        type: "symbol",
+        from: {
+          data: "dis",
+        },
+        encode: {
+          enter: {
+            shape: {
+              value: "circle",
+            },
+            size: [{ value: 100 }],
+            tooltip: {
+              signal: "{ probability: datum.y, value: datum.x }",
+            },
+          },
+          update: {
+            x: {
+              scale: "xscale",
+              field: "x",
+            },
+            y: {
+              scale: "yscale",
+              field: "y",
+            },
+            fill: {
+              value: "#1e4577",
+            },
+          },
+        },
+      },
+    ],
+  };
+  if (title) {
+    spec = {
+      ...spec,
+      title: {
+        text: title,
+      },
+    };
+  }
+
+  return spec;
+}

packages/components/src/lib/distributionUtils.ts

@@ -0,0 +1,5 @@
+import { shape } from "@quri/squiggle-lang";
+
+export const hasMassBelowZero = (shape: shape) =>
+  shape.continuous.some((x) => x.x <= 0) ||
+  shape.discrete.some((x) => x.x <= 0);

packages/components/src/lib/hooks/index.ts

@@ -0,0 +1,3 @@
+export { useMaybeControlledValue } from "./useMaybeControlledValue";
+export { useSquiggle, useSquigglePartial } from "./useSquiggle";
+export { useRunnerState } from "./useRunnerState";

packages/components/src/lib/hooks/useMaybeControlledValue.ts

@@ -0,0 +1,22 @@
+import { useState } from "react";
+
+type ControlledValueArgs<T> = {
+  value?: T;
+  defaultValue: T;
+  onChange?: (x: T) => void;
+};
+
+export function useMaybeControlledValue<T>(
+  args: ControlledValueArgs<T>
+): [T, (x: T) => void] {
+  let [uncontrolledValue, setUncontrolledValue] = useState(args.defaultValue);
+  let value = args.value ?? uncontrolledValue;
+  let onChange = (newValue: T) => {
+    if (args.value === undefined) {
+      // uncontrolled mode
+      setUncontrolledValue(newValue);
+    }
+    args.onChange?.(newValue);
+  };
+  return [value, onChange];
+}

packages/components/src/lib/hooks/useRunnerState.ts

@@ -0,0 +1,100 @@
+import { useLayoutEffect, useReducer } from "react";
+
+type State = {
+  autorunMode: boolean;
+  renderedCode: string;
+  // "prepared" is for rendering a spinner; "run" for executing squiggle code; then it gets back to "none" on the next render
+  runningState: "none" | "prepared" | "run";
+  executionId: number;
+};
+
+const buildInitialState = (code: string): State => ({
+  autorunMode: true,
+  renderedCode: "",
+  runningState: "none",
+  executionId: 1,
+});
+
+type Action =
+  | {
+      type: "SET_AUTORUN_MODE";
+      value: boolean;
+      code: string;
+    }
+  | {
+      type: "PREPARE_RUN";
+    }
+  | {
+      type: "RUN";
+      code: string;
+    }
+  | {
+      type: "STOP_RUN";
+    };
+
+const reducer = (state: State, action: Action): State => {
+  switch (action.type) {
+    case "SET_AUTORUN_MODE":
+      return {
+        ...state,
+        autorunMode: action.value,
+      };
+    case "PREPARE_RUN":
+      return {
+        ...state,
+        runningState: "prepared",
+      };
+    case "RUN":
+      return {
+        ...state,
+        runningState: "run",
+        renderedCode: action.code,
+        executionId: state.executionId + 1,
+      };
+    case "STOP_RUN":
+      return {
+        ...state,
+        runningState: "none",
+      };
+  }
+};
+
+export const useRunnerState = (code: string) => {
+  const [state, dispatch] = useReducer(reducer, buildInitialState(code));
+
+  useLayoutEffect(() => {
+    if (state.runningState === "prepared") {
+      // this is necessary for async playground loading - otherwise it executes the code synchronously on the initial load
+      // (it's surprising that this is necessary, but empirically it _is_ necessary, both with `useEffect` and `useLayoutEffect`)
+      setTimeout(() => {
+        dispatch({ type: "RUN", code });
+      }, 0);
+    } else if (state.runningState === "run") {
+      dispatch({ type: "STOP_RUN" });
+    }
+  }, [state.runningState, code]);
+
+  const run = () => {
+    // The rest will be handled by dispatches above on following renders, but we need to update the spinner first.
+    dispatch({ type: "PREPARE_RUN" });
+  };
+
+  if (
+    state.autorunMode &&
+    state.renderedCode !== code &&
+    state.runningState === "none"
+  ) {
+    run();
+  }
+
+  return {
+    run,
+    autorunMode: state.autorunMode,
+    renderedCode: state.renderedCode,
+    isRunning: state.runningState !== "none",
+    executionId: state.executionId,
+    setAutorunMode: (newValue: boolean) => {
+      dispatch({ type: "SET_AUTORUN_MODE", value: newValue, code });
+    },
+  };
+};

packages/components/src/lib/hooks/useSquiggle.ts

@@ -0,0 +1,53 @@
+import {
+  bindings,
+  environment,
+  jsImports,
+  run,
+  runPartial,
+} from "@quri/squiggle-lang";
+import { useEffect, useMemo } from "react";
+
+type SquiggleArgs<T extends ReturnType<typeof run | typeof runPartial>> = {
+  code: string;
+  executionId?: number;
+  bindings?: bindings;
+  jsImports?: jsImports;
+  environment?: environment;
+  onChange?: (expr: Extract<T, { tag: "Ok" }>["value"] | undefined) => void;
+};
+
+const useSquiggleAny = <T extends ReturnType<typeof run | typeof runPartial>>(
+  args: SquiggleArgs<T>,
+  f: (...args: Parameters<typeof run>) => T
+) => {
+  const result: T = useMemo<T>(
+    () => f(args.code, args.bindings, args.environment, args.jsImports),
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+    [
+      f,
+      args.code,
+      args.bindings,
+      args.environment,
+      args.jsImports,
+      args.executionId,
+    ]
+  );
+
+  const { onChange } = args;
+
+  useEffect(() => {
+    onChange?.(result.tag === "Ok" ? result.value : undefined);
+  }, [result, onChange]);
+
+  return result;
+};
+
+export const useSquigglePartial = (
+  args: SquiggleArgs<ReturnType<typeof runPartial>>
+) => {
+  return useSquiggleAny(args, runPartial);
+};
+
+export const useSquiggle = (args: SquiggleArgs<ReturnType<typeof run>>) => {
+  return useSquiggleAny(args, run);
+};

packages/components/src/stories/SquiggleChart.stories.mdx

@@ -3,7 +3,7 @@ import { Canvas, Meta, Story, Props } from "@storybook/addon-docs";
 
 <Meta title="Squiggle/SquiggleChart" component={SquiggleChart} />
 
-export const Template = SquiggleChart;
+export const Template = (props) => <SquiggleChart {...props} />;
 /* 
   We have to hardcode a width here, because otherwise some interaction with
   Storybook creates an infinite loop with the internal width
@@ -29,7 +29,7 @@ could be continuous, discrete or mixed.
   <Story
     name="Continuous Symbolic"
     args={{
-      squiggleString: "normal(5,2)",
+      code: "normal(5,2)",
       width,
     }}
   >
@@ -43,7 +43,7 @@ could be continuous, discrete or mixed.
   <Story
     name="Continuous Pointset"
     args={{
-      squiggleString: "toPointSet(normal(5,2))",
+      code: "PointSet.fromDist(normal(5,2))",
       width,
     }}
   >
@@ -57,7 +57,7 @@ could be continuous, discrete or mixed.
   <Story
     name="Continuous SampleSet"
     args={{
-      squiggleString: "toSampleSet(normal(5,2), 1000)",
+      code: "SampleSet.fromDist(normal(5,2))",
       width,
     }}
   >
@@ -71,7 +71,7 @@ could be continuous, discrete or mixed.
   <Story
     name="Discrete"
     args={{
-      squiggleString: "mx(0, 1, 3, 5, 8, 10, [0.1, 0.8, 0.5, 0.3, 0.2, 0.1])",
+      code: "mx(0, 1, 3, 5, 8, 10, [0.1, 0.8, 0.5, 0.3, 0.2, 0.1])",
       width,
     }}
   >
@@ -85,8 +85,7 @@ could be continuous, discrete or mixed.
   <Story
     name="Mixed"
     args={{
-      squiggleString:
-        "mx(0, 1, 3, 5, 8, normal(8, 1), [0.1, 0.3, 0.4, 0.35, 0.2, 0.8])",
+      code: "mx(0, 1, 3, 5, 8, normal(8, 1), [0.1, 0.3, 0.4, 0.35, 0.2, 0.8])",
       width,
     }}
   >
@@ -103,7 +102,7 @@ to allow large and small numbers being printed cleanly.
   <Story
     name="Constant"
     args={{
-      squiggleString: "500000000",
+      code: "500000000",
       width,
     }}
   >
@@ -117,7 +116,7 @@ to allow large and small numbers being printed cleanly.
   <Story
     name="Array"
     args={{
-      squiggleString: "[normal(5,2), normal(10,1), normal(40,2), 400000]",
+      code: "[normal(5,2), normal(10,1), normal(40,2), 400000]",
       width,
     }}
   >
@@ -131,7 +130,7 @@ to allow large and small numbers being printed cleanly.
   <Story
     name="Error"
     args={{
-      squiggleString: "f(x) = normal(",
+      code: "f(x) = normal(",
       width,
     }}
   >
@@ -145,7 +144,7 @@ to allow large and small numbers being printed cleanly.
   <Story
     name="Boolean"
     args={{
-      squiggleString: "3 == 3",
+      code: "3 == 3",
       width,
     }}
   >
@@ -159,7 +158,7 @@ to allow large and small numbers being printed cleanly.
   <Story
     name="Function to Distribution"
     args={{
-      squiggleString: "foo(t) = normal(t,2)*normal(5,3); foo",
+      code: "foo(t) = normal(t,2)*normal(5,3); foo",
       width,
     }}
   >
@@ -173,7 +172,7 @@ to allow large and small numbers being printed cleanly.
   <Story
     name="Function to Number"
     args={{
-      squiggleString: "foo(t) = t^2; foo",
+      code: "foo(t) = t^2; foo",
       width,
     }}
   >
@@ -187,7 +186,7 @@ to allow large and small numbers being printed cleanly.
   <Story
     name="Record"
     args={{
-      squiggleString: "{foo: 35 to 50, bar: [1,2,3]}",
+      code: "{foo: 35 to 50, bar: [1,2,3]}",
       width,
     }}
   >
@@ -201,7 +200,7 @@ to allow large and small numbers being printed cleanly.
   <Story
     name="String"
     args={{
-      squiggleString: '"Lucky day!"',
+      code: '"Lucky day!"',
       width,
     }}
   >

packages/components/src/stories/SquiggleEditor.stories.mdx

@@ -14,7 +14,20 @@ the distribution.
   <Story
     name="Normal"
     args={{
-      initialSquiggleString: "normal(5,2)",
+      defaultCode: "normal(5,2)",
+    }}
+  >
+    {Template.bind({})}
+  </Story>
+</Canvas>
+
+It's also possible to create a controlled version of the same component
+
+<Canvas>
+  <Story
+    name="Controlled"
+    args={{
+      code: "normal(5,2)",
     }}
   >
     {Template.bind({})}
@@ -27,7 +40,7 @@ You can also name variables like so:
   <Story
     name="Variables"
     args={{
-      initialSquiggleString: "x = 2\nnormal(x,2)",
+      defaultCode: "x = 2\nnormal(x,2)",
     }}
   >
     {Template.bind({})}

packages/components/src/stories/SquigglePartial.stories.mdx

@@ -15,7 +15,7 @@ instead returns bindings that can be used by further Squiggle Editors.
   <Story
     name="Standalone"
     args={{
-      initialSquiggleString: "x = normal(5,2)",
+      defaultCode: "x = normal(5,2)",
     }}
   >
     {Template.bind({})}
@@ -36,12 +36,12 @@ instead returns bindings that can be used by further Squiggle Editors.
         <>
           <SquigglePartial
             {...props}
-            initialSquiggleString={props.initialPartialString}
+            defaultCode={props.initialPartialString}
             onChange={setBindings}
           />
           <SquiggleEditor
             {...props}
-            initialSquiggleString={props.initialEditorString}
+            defaultCode={props.initialEditorString}
             bindings={bindings}
           />
         </>

packages/components/src/stories/SquigglePlayground.stories.mdx

@@ -1,4 +1,4 @@
-import SquigglePlayground from "../components/SquigglePlayground";
+import { SquigglePlayground } from "../components/SquigglePlayground";
 import { Canvas, Meta, Story, Props } from "@storybook/addon-docs";
 
 <Meta title="Squiggle/SquigglePlayground" component={SquigglePlayground} />
@@ -14,10 +14,23 @@ including sampling settings, in squiggle.
   <Story
     name="Normal"
     args={{
-      initialSquiggleString: "normal(5,2)",
+      defaultCode: "normal(5,2)",
       height: 800,
     }}
   >
     {Template.bind({})}
   </Story>
 </Canvas>
+
+<Canvas>
+  <Story
+    name="With share button"
+    args={{
+      defaultCode: "normal(5,2)",
+      height: 800,
+      showShareButton: true,
+    }}
+  >
+    {Template.bind({})}
+  </Story>
+</Canvas>

packages/components/src/styles/base.css

@@ -1,5 +1,5 @@
 .squiggle {
-/*
+  /*
 This file contains:
 1) Base Tailwind preflight styles
 2) Base https://github.com/tailwindlabs/tailwindcss-forms styles
@@ -7,365 +7,390 @@ This file contains:
 (Both are wrapped in .squiggle)
 */
 
-/*
+  /*
 1. Use a consistent sensible line-height in all browsers.
 2. Prevent adjustments of font size after orientation changes in iOS.
 3. Use a more readable tab size.
 4. Use the user's configured `sans` font-family by default.
 */
 
-/* html { */
+  /* html { */
   line-height: 1.5; /* 1 */
   -webkit-text-size-adjust: 100%; /* 2 */
   -moz-tab-size: 4; /* 3 */
   tab-size: 4; /* 3 */
-  font-family: theme('fontFamily.sans', ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji"); /* 4 */
-/* } */
+  font-family: theme(
+    "fontFamily.sans",
+    ui-sans-serif,
+    system-ui,
+    -apple-system,
+    BlinkMacSystemFont,
+    "Segoe UI",
+    Roboto,
+    "Helvetica Neue",
+    Arial,
+    "Noto Sans",
+    sans-serif,
+    "Apple Color Emoji",
+    "Segoe UI Emoji",
+    "Segoe UI Symbol",
+    "Noto Color Emoji"
+  ); /* 4 */
+  /* } */
 
-/*
+  /*
 1. Remove the margin in all browsers.
 2. Inherit line-height from `html` so users can set them as a class directly on the `html` element.
 */
 
-/* body { */
+  /* body { */
   margin: 0; /* 1 */
   line-height: inherit; /* 2 */
-/* } */
+  /* } */
 
-
-/*
+  /*
 1. Prevent padding and border from affecting element width. (https://github.com/mozdevs/cssremedy/issues/4)
 2. Allow adding a border to an element by just adding a border-width. (https://github.com/tailwindcss/tailwindcss/pull/116)
 */
 
-*,
-::before,
-::after {
-  box-sizing: border-box; /* 1 */
-  border-width: 0; /* 2 */
-  border-style: solid; /* 2 */
-  border-color: theme('borderColor.DEFAULT', currentColor); /* 2 */
-}
+  *,
+  ::before,
+  ::after {
+    box-sizing: border-box; /* 1 */
+    border-width: 0; /* 2 */
+    border-style: solid; /* 2 */
+    border-color: theme("borderColor.DEFAULT", currentColor); /* 2 */
+  }
 
-::before,
-::after {
-  --tw-content: '';
-}
+  ::before,
+  ::after {
+    --tw-content: "";
+  }
 
-/*
+  /*
 1. Add the correct height in Firefox.
 2. Correct the inheritance of border color in Firefox. (https://bugzilla.mozilla.org/show_bug.cgi?id=190655)
 3. Ensure horizontal rules are visible by default.
 */
 
-hr {
-  height: 0; /* 1 */
-  color: inherit; /* 2 */
-  border-top-width: 1px; /* 3 */
-}
+  hr {
+    height: 0; /* 1 */
+    color: inherit; /* 2 */
+    border-top-width: 1px; /* 3 */
+  }
 
-/*
+  /*
 Add the correct text decoration in Chrome, Edge, and Safari.
 */
 
-abbr:where([title]) {
-  text-decoration: underline dotted;
-}
+  abbr:where([title]) {
+    text-decoration: underline dotted;
+  }
 
-/*
+  /*
 Remove the default font size and weight for headings.
 */
 
-h1,
-h2,
-h3,
-h4,
-h5,
-h6 {
-  font-size: inherit;
-  font-weight: inherit;
-}
+  h1,
+  h2,
+  h3,
+  h4,
+  h5,
+  h6 {
+    font-size: inherit;
+    font-weight: inherit;
+  }
 
-/*
+  /*
 Reset links to optimize for opt-in styling instead of opt-out.
 */
 
-a {
-  color: inherit;
-  text-decoration: inherit;
-}
+  a {
+    color: inherit;
+    text-decoration: inherit;
+  }
 
-/*
+  /*
 Add the correct font weight in Edge and Safari.
 */
 
-b,
-strong {
-  font-weight: bolder;
-}
+  b,
+  strong {
+    font-weight: bolder;
+  }
 
-/*
+  /*
 1. Use the user's configured `mono` font family by default.
 2. Correct the odd `em` font sizing in all browsers.
 */
 
-code,
-kbd,
-samp,
-pre {
-  font-family: theme('fontFamily.mono', ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace); /* 1 */
-  font-size: 1em; /* 2 */
-}
+  code,
+  kbd,
+  samp,
+  pre {
+    font-family: theme(
+      "fontFamily.mono",
+      ui-monospace,
+      SFMono-Regular,
+      Menlo,
+      Monaco,
+      Consolas,
+      "Liberation Mono",
+      "Courier New",
+      monospace
+    ); /* 1 */
+    font-size: 1em; /* 2 */
+  }
 
-/*
+  /*
 Add the correct font size in all browsers.
 */
 
-small {
-  font-size: 80%;
-}
+  small {
+    font-size: 80%;
+  }
 
-/*
+  /*
 Prevent `sub` and `sup` elements from affecting the line height in all browsers.
 */
 
-sub,
-sup {
-  font-size: 75%;
-  line-height: 0;
-  position: relative;
-  vertical-align: baseline;
-}
+  sub,
+  sup {
+    font-size: 75%;
+    line-height: 0;
+    position: relative;
+    vertical-align: baseline;
+  }
 
-sub {
-  bottom: -0.25em;
-}
+  sub {
+    bottom: -0.25em;
+  }
 
-sup {
-  top: -0.5em;
-}
+  sup {
+    top: -0.5em;
+  }
 
-/*
+  /*
 1. Remove text indentation from table contents in Chrome and Safari. (https://bugs.chromium.org/p/chromium/issues/detail?id=999088, https://bugs.webkit.org/show_bug.cgi?id=201297)
 2. Correct table border color inheritance in all Chrome and Safari. (https://bugs.chromium.org/p/chromium/issues/detail?id=935729, https://bugs.webkit.org/show_bug.cgi?id=195016)
 3. Remove gaps between table borders by default.
 */
 
-table {
-  text-indent: 0; /* 1 */
-  border-color: inherit; /* 2 */
-  border-collapse: collapse; /* 3 */
-}
+  table {
+    text-indent: 0; /* 1 */
+    border-color: inherit; /* 2 */
+    border-collapse: collapse; /* 3 */
+  }
 
-/*
+  /*
 1. Change the font styles in all browsers.
 2. Remove the margin in Firefox and Safari.
 3. Remove default padding in all browsers.
 */
 
-button,
-input,
-optgroup,
-select,
-textarea {
-  font-family: inherit; /* 1 */
-  font-size: 100%; /* 1 */
-  font-weight: inherit; /* 1 */
-  line-height: inherit; /* 1 */
-  color: inherit; /* 1 */
-  margin: 0; /* 2 */
-  padding: 0; /* 3 */
-}
+  button,
+  input,
+  optgroup,
+  select,
+  textarea {
+    font-family: inherit; /* 1 */
+    font-size: 100%; /* 1 */
+    font-weight: inherit; /* 1 */
+    line-height: inherit; /* 1 */
+    color: inherit; /* 1 */
+    margin: 0; /* 2 */
+    padding: 0; /* 3 */
+  }
 
-/*
+  /*
 Remove the inheritance of text transform in Edge and Firefox.
 */
 
-button,
-select {
-  text-transform: none;
-}
+  button,
+  select {
+    text-transform: none;
+  }
 
-/*
+  /*
 1. Correct the inability to style clickable types in iOS and Safari.
 2. Remove default button styles.
 */
 
-button,
-[type='button'],
-[type='reset'],
-[type='submit'] {
-  -webkit-appearance: button; /* 1 */
-  background-color: transparent; /* 2 */
-  background-image: none; /* 2 */
-}
+  button,
+  [type="button"],
+  [type="reset"],
+  [type="submit"] {
+    -webkit-appearance: button; /* 1 */
+    background-color: transparent; /* 2 */
+    background-image: none; /* 2 */
+  }
 
-/*
+  /*
 Use the modern Firefox focus style for all focusable elements.
 */
 
-:-moz-focusring {
-  outline: auto;
-}
+  :-moz-focusring {
+    outline: auto;
+  }
 
-/*
+  /*
 Remove the additional `:invalid` styles in Firefox. (https://github.com/mozilla/gecko-dev/blob/2f9eacd9d3d995c937b4251a5557d95d494c9be1/layout/style/res/forms.css#L728-L737)
 */
 
-:-moz-ui-invalid {
-  box-shadow: none;
-}
+  :-moz-ui-invalid {
+    box-shadow: none;
+  }
 
-/*
+  /*
 Add the correct vertical alignment in Chrome and Firefox.
 */
 
-progress {
-  vertical-align: baseline;
-}
+  progress {
+    vertical-align: baseline;
+  }
 
-/*
+  /*
 Correct the cursor style of increment and decrement buttons in Safari.
 */
 
-::-webkit-inner-spin-button,
-::-webkit-outer-spin-button {
-  height: auto;
-}
+  ::-webkit-inner-spin-button,
+  ::-webkit-outer-spin-button {
+    height: auto;
+  }
 
-/*
+  /*
 1. Correct the odd appearance in Chrome and Safari.
 2. Correct the outline style in Safari.
 */
 
-[type='search'] {
-  -webkit-appearance: textfield; /* 1 */
-  outline-offset: -2px; /* 2 */
-}
+  [type="search"] {
+    -webkit-appearance: textfield; /* 1 */
+    outline-offset: -2px; /* 2 */
+  }
 
-/*
+  /*
 Remove the inner padding in Chrome and Safari on macOS.
 */
 
-::-webkit-search-decoration {
-  -webkit-appearance: none;
-}
+  ::-webkit-search-decoration {
+    -webkit-appearance: none;
+  }
 
-/*
+  /*
 1. Correct the inability to style clickable types in iOS and Safari.
 2. Change font properties to `inherit` in Safari.
 */
 
-::-webkit-file-upload-button {
-  -webkit-appearance: button; /* 1 */
-  font: inherit; /* 2 */
-}
+  ::-webkit-file-upload-button {
+    -webkit-appearance: button; /* 1 */
+    font: inherit; /* 2 */
+  }
 
-/*
+  /*
 Add the correct display in Chrome and Safari.
 */
 
-summary {
-  display: list-item;
-}
+  summary {
+    display: list-item;
+  }
 
-/*
+  /*
 Removes the default spacing and border for appropriate elements.
 */
 
-blockquote,
-dl,
-dd,
-h1,
-h2,
-h3,
-h4,
-h5,
-h6,
-hr,
-figure,
-p,
-pre {
-  margin: 0;
-}
+  blockquote,
+  dl,
+  dd,
+  h1,
+  h2,
+  h3,
+  h4,
+  h5,
+  h6,
+  hr,
+  figure,
+  p,
+  pre {
+    margin: 0;
+  }
 
-fieldset {
-  margin: 0;
-  padding: 0;
-}
+  fieldset {
+    margin: 0;
+    padding: 0;
+  }
 
-legend {
-  padding: 0;
-}
+  legend {
+    padding: 0;
+  }
 
-ol,
-ul,
-menu {
-  list-style: none;
-  margin: 0;
-  padding: 0;
-}
+  ol,
+  ul,
+  menu {
+    list-style: none;
+    margin: 0;
+    padding: 0;
+  }
 
-/*
+  /*
 Prevent resizing textareas horizontally by default.
 */
 
-textarea {
-  resize: vertical;
-}
+  textarea {
+    resize: vertical;
+  }
 
-/*
+  /*
 1. Reset the default placeholder opacity in Firefox. (https://github.com/tailwindlabs/tailwindcss/issues/3300)
 2. Set the default placeholder color to the user's configured gray 400 color.
 */
 
-input::placeholder,
-textarea::placeholder {
-  opacity: 1; /* 1 */
-  color: theme('colors.gray.400', #9ca3af); /* 2 */
-}
+  input::placeholder,
+  textarea::placeholder {
+    opacity: 1; /* 1 */
+    color: theme("colors.gray.400", #9ca3af); /* 2 */
+  }
 
-/*
+  /*
 Set the default cursor for buttons.
 */
 
-button,
-[role="button"] {
-  cursor: pointer;
-}
+  button,
+  [role="button"] {
+    cursor: pointer;
+  }
 
-/*
+  /*
 Make sure disabled buttons don't get the pointer cursor.
 */
-:disabled {
-  cursor: default;
-}
+  :disabled {
+    cursor: default;
+  }
 
-/*
+  /*
 1. Make replaced elements `display: block` by default. (https://github.com/mozdevs/cssremedy/issues/14)
 2. Add `vertical-align: middle` to align replaced elements more sensibly by default. (https://github.com/jensimmons/cssremedy/issues/14#issuecomment-634934210)
    This can trigger a poorly considered lint error in some tools but is included by design.
 */
 
-img,
-svg,
-video,
-canvas,
-audio,
-iframe,
-embed,
-object {
-  display: block; /* 1 */
-  vertical-align: middle; /* 2 */
-}
+  img,
+  svg,
+  video,
+  canvas,
+  audio,
+  iframe,
+  embed,
+  object {
+    display: block; /* 1 */
+    vertical-align: middle; /* 2 */
+  }
 
-/*
+  /*
 Constrain images and videos to the parent width and preserve their intrinsic aspect ratio. (https://github.com/mozdevs/cssremedy/issues/14)
 */
 
-img,
-video {
-  max-width: 100%;
-  height: auto;
-}
+  img,
+  video {
+    max-width: 100%;
+    height: auto;
+  }
 }

packages/components/src/styles/forms.css

@@ -1,102 +1,130 @@
 /* Fork of https://github.com/tailwindlabs/tailwindcss-forms styles, see the comment in main.css for details. */
 .squiggle {
-.form-input,.form-textarea,.form-select,.form-multiselect {
-appearance: none;
-background-color: #fff;
-border-color: #6b7280;
-border-width: 1px;
-border-radius: 0px;
-padding-top: 0.5rem;
-padding-right: 0.75rem;
-padding-bottom: 0.5rem;
-padding-left: 0.75rem;
-font-size: 1rem;
-line-height: 1.5rem;
---tw-shadow: 0 0 #0000;
-}
-.form-input:focus, .form-textarea:focus, .form-select:focus, .form-multiselect:focus {
-outline: 2px solid transparent;
-outline-offset: 2px;
---tw-ring-inset: var(--tw-empty,/*!*/ /*!*/);
---tw-ring-offset-width: 0px;
---tw-ring-offset-color: #fff;
---tw-ring-color: #2563eb;
---tw-ring-offset-shadow: var(--tw-ring-inset) 0 0 0 var(--tw-ring-offset-width) var(--tw-ring-offset-color);
---tw-ring-shadow: var(--tw-ring-inset) 0 0 0 calc(1px + var(--tw-ring-offset-width)) var(--tw-ring-color);
-box-shadow: var(--tw-ring-offset-shadow), var(--tw-ring-shadow), var(--tw-shadow);
-border-color: #2563eb;
-}
-.form-input::placeholder,.form-textarea::placeholder {
-color: #6b7280;
-opacity: 1;
-}
-.form-input::-webkit-datetime-edit-fields-wrapper {
-padding: 0;
-}
-.form-input::-webkit-date-and-time-value {
-min-height: 1.5em;
-}
-.form-input::-webkit-datetime-edit,.form-input::-webkit-datetime-edit-year-field,.form-input::-webkit-datetime-edit-month-field,.form-input::-webkit-datetime-edit-day-field,.form-input::-webkit-datetime-edit-hour-field,.form-input::-webkit-datetime-edit-minute-field,.form-input::-webkit-datetime-edit-second-field,.form-input::-webkit-datetime-edit-millisecond-field,.form-input::-webkit-datetime-edit-meridiem-field {
-padding-top: 0;
-padding-bottom: 0;
-}
-.form-checkbox,.form-radio {
-appearance: none;
-padding: 0;
--webkit-print-color-adjust: exact;
-        print-color-adjust: exact;
-display: inline-block;
-vertical-align: middle;
-background-origin: border-box;
--webkit-user-select: none;
-        user-select: none;
-flex-shrink: 0;
-height: 1rem;
-width: 1rem;
-color: #2563eb;
-background-color: #fff;
-border-color: #6b7280;
-border-width: 1px;
---tw-shadow: 0 0 #0000;
-}
-.form-checkbox {
-border-radius: 0px;
-}
-.form-checkbox:focus,.form-radio:focus {
-outline: 2px solid transparent;
-outline-offset: 2px;
---tw-ring-inset: var(--tw-empty,/*!*/ /*!*/);
---tw-ring-offset-width: 2px;
---tw-ring-offset-color: #fff;
---tw-ring-color: #2563eb;
---tw-ring-offset-shadow: var(--tw-ring-inset) 0 0 0 var(--tw-ring-offset-width) var(--tw-ring-offset-color);
---tw-ring-shadow: var(--tw-ring-inset) 0 0 0 calc(2px + var(--tw-ring-offset-width)) var(--tw-ring-color);
-box-shadow: var(--tw-ring-offset-shadow), var(--tw-ring-shadow), var(--tw-shadow);
-}
-.form-checkbox:checked,.form-radio:checked {
-border-color: transparent;
-background-color: currentColor;
-background-size: 100% 100%;
-background-position: center;
-background-repeat: no-repeat;
-}
-.form-checkbox:checked {
-background-image: url("data:image/svg+xml,%3csvg viewBox='0 0 16 16' fill='white' xmlns='http://www.w3.org/2000/svg'%3e%3cpath d='M12.207 4.793a1 1 0 010 1.414l-5 5a1 1 0 01-1.414 0l-2-2a1 1 0 011.414-1.414L6.5 9.086l4.293-4.293a1 1 0 011.414 0z'/%3e%3c/svg%3e");
-}
-.form-checkbox:checked:hover,.form-checkbox:checked:focus,.form-radio:checked:hover,.form-radio:checked:focus {
-border-color: transparent;
-background-color: currentColor;
-}
-.form-checkbox:indeterminate {
-background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 16 16'%3e%3cpath stroke='white' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M4 8h8'/%3e%3c/svg%3e");
-border-color: transparent;
-background-color: currentColor;
-background-size: 100% 100%;
-background-position: center;
-background-repeat: no-repeat;
-}
-.form-checkbox:indeterminate:hover,.form-checkbox:indeterminate:focus {
-border-color: transparent;
-background-color: currentColor;
-}
+  .form-input,
+  .form-textarea,
+  .form-select,
+  .form-multiselect {
+    appearance: none;
+    background-color: #fff;
+    border-color: #6b7280;
+    border-width: 1px;
+    border-radius: 0px;
+    padding-top: 0.5rem;
+    padding-right: 0.75rem;
+    padding-bottom: 0.5rem;
+    padding-left: 0.75rem;
+    font-size: 1rem;
+    line-height: 1.5rem;
+    --tw-shadow: 0 0 #0000;
+  }
+  .form-input:focus,
+  .form-textarea:focus,
+  .form-select:focus,
+  .form-multiselect:focus {
+    outline: 2px solid transparent;
+    outline-offset: 2px;
+    --tw-ring-inset: var(--tw-empty, /*!*/ /*!*/);
+    --tw-ring-offset-width: 0px;
+    --tw-ring-offset-color: #fff;
+    --tw-ring-color: #2563eb;
+    --tw-ring-offset-shadow: var(--tw-ring-inset) 0 0 0
+      var(--tw-ring-offset-width) var(--tw-ring-offset-color);
+    --tw-ring-shadow: var(--tw-ring-inset) 0 0 0
+      calc(1px + var(--tw-ring-offset-width)) var(--tw-ring-color);
+    box-shadow: var(--tw-ring-offset-shadow), var(--tw-ring-shadow),
+      var(--tw-shadow);
+    border-color: #2563eb;
+  }
+  .form-input::placeholder,
+  .form-textarea::placeholder {
+    color: #6b7280;
+    opacity: 1;
+  }
+  .form-input::-webkit-datetime-edit-fields-wrapper {
+    padding: 0;
+  }
+  .form-input::-webkit-date-and-time-value {
+    min-height: 1.5em;
+  }
+  .form-input::-webkit-datetime-edit,
+  .form-input::-webkit-datetime-edit-year-field,
+  .form-input::-webkit-datetime-edit-month-field,
+  .form-input::-webkit-datetime-edit-day-field,
+  .form-input::-webkit-datetime-edit-hour-field,
+  .form-input::-webkit-datetime-edit-minute-field,
+  .form-input::-webkit-datetime-edit-second-field,
+  .form-input::-webkit-datetime-edit-millisecond-field,
+  .form-input::-webkit-datetime-edit-meridiem-field {
+    padding-top: 0;
+    padding-bottom: 0;
+  }
+  .form-checkbox,
+  .form-radio {
+    appearance: none;
+    padding: 0;
+    -webkit-print-color-adjust: exact;
+    print-color-adjust: exact;
+    display: inline-block;
+    vertical-align: middle;
+    background-origin: border-box;
+    -webkit-user-select: none;
+    user-select: none;
+    flex-shrink: 0;
+    height: 1rem;
+    width: 1rem;
+    color: #2563eb;
+    background-color: #fff;
+    border-color: #6b7280;
+    border-width: 1px;
+    --tw-shadow: 0 0 #0000;
+  }
+  .form-checkbox {
+    border-radius: 0px;
+  }
+  .form-checkbox:focus,
+  .form-radio:focus {
+    outline: 2px solid transparent;
+    outline-offset: 2px;
+    --tw-ring-inset: var(--tw-empty, /*!*/ /*!*/);
+    --tw-ring-offset-width: 2px;
+    --tw-ring-offset-color: #fff;
+    --tw-ring-color: #2563eb;
+    --tw-ring-offset-shadow: var(--tw-ring-inset) 0 0 0
+      var(--tw-ring-offset-width) var(--tw-ring-offset-color);
+    --tw-ring-shadow: var(--tw-ring-inset) 0 0 0
+      calc(2px + var(--tw-ring-offset-width)) var(--tw-ring-color);
+    box-shadow: var(--tw-ring-offset-shadow), var(--tw-ring-shadow),
+      var(--tw-shadow);
+  }
+  .form-checkbox:checked,
+  .form-radio:checked {
+    border-color: transparent;
+    background-color: currentColor;
+    background-size: 100% 100%;
+    background-position: center;
+    background-repeat: no-repeat;
+  }
+  .form-checkbox:checked {
+    background-image: url("data:image/svg+xml,%3csvg viewBox='0 0 16 16' fill='white' xmlns='http://www.w3.org/2000/svg'%3e%3cpath d='M12.207 4.793a1 1 0 010 1.414l-5 5a1 1 0 01-1.414 0l-2-2a1 1 0 011.414-1.414L6.5 9.086l4.293-4.293a1 1 0 011.414 0z'/%3e%3c/svg%3e");
+  }
+  .form-checkbox:checked:hover,
+  .form-checkbox:checked:focus,
+  .form-radio:checked:hover,
+  .form-radio:checked:focus {
+    border-color: transparent;
+    background-color: currentColor;
+  }
+  .form-checkbox:indeterminate {
+    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 16 16'%3e%3cpath stroke='white' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M4 8h8'/%3e%3c/svg%3e");
+    border-color: transparent;
+    background-color: currentColor;
+    background-size: 100% 100%;
+    background-position: center;
+    background-repeat: no-repeat;
+  }
+  .form-checkbox:indeterminate:hover,
+  .form-checkbox:indeterminate:focus {
+    border-color: transparent;
+    background-color: currentColor;
+  }
 }

packages/components/tailwind.config.js

@@ -5,6 +5,27 @@ module.exports = {
   },
   important: ".squiggle",
   theme: {
-    extend: {},
+    extend: {
+      animation: {
+        "appear-and-spin":
+          "spin 1s linear infinite, squiggle-appear 0.2s forwards",
+        "semi-appear": "squiggle-semi-appear 0.2s forwards",
+        hide: "squiggle-hide 0.2s forwards",
+      },
+      keyframes: {
+        "squiggle-appear": {
+          from: { opacity: 0 },
+          to: { opacity: 1 },
+        },
+        "squiggle-semi-appear": {
+          from: { opacity: 0 },
+          to: { opacity: 0.5 },
+        },
+        "squiggle-hide": {
+          from: { opacity: 1 },
+          to: { opacity: 0 },
+        },
+      },
+    },
   },
 };

packages/components/webpack.config.js

@@ -1,11 +1,10 @@
 const path = require("path");
-const MiniCssExtractPlugin = require("mini-css-extract-plugin");
 
 module.exports = {
   mode: "production",
   devtool: "source-map",
   profile: true,
-  entry: ["./src/index.ts", "./src/styles/main.css"],
+  entry: "./src/index.ts",
   module: {
     rules: [
       {
@@ -14,13 +13,8 @@ module.exports = {
         options: { projectReferences: true },
         exclude: /node_modules/,
       },
-      {
-        test: /\.css$/i,
-        use: [MiniCssExtractPlugin.loader, "css-loader", "postcss-loader"],
-      },
     ],
   },
-  plugins: [new MiniCssExtractPlugin()],
   resolve: {
     extensions: [".js", ".tsx", ".ts"],
     alias: {
@@ -42,4 +36,18 @@ module.exports = {
     compress: true,
     port: 9000,
   },
+  externals: {
+    react: {
+      commonjs: "react",
+      commonjs2: "react",
+      amd: "react",
+      root: "React",
+    },
+    "react-dom": {
+      commonjs: "react-dom",
+      commonjs2: "react-dom",
+      amd: "react-dom",
+      root: "ReactDOM",
+    },
+  },
 };

packages/squiggle-lang/.gitignore

@@ -22,3 +22,4 @@ _coverage
 coverage
 .nyc_output/
 src/rescript/Reducer/Reducer_Peggy/Reducer_Peggy_GeneratedParser.js
+src/rescript/Reducer/Reducer_Peggy/helpers.js

packages/squiggle-lang/__tests__/Distributions/AlgebraicShapeCombination_test.res

@@ -14,4 +14,16 @@ describe("Combining Continuous and Discrete Distributions", () => {
     ), // Multiply distribution by -1
     true,
   )
+  makeTest(
+    "keep order of xs when first number is discrete and adding",
+    AlgebraicShapeCombination.isOrdered(
+      AlgebraicShapeCombination.combineShapesContinuousDiscrete(
+        #Add,
+        {xs: [0., 1.], ys: [1., 1.]},
+        {xs: [1.], ys: [1.]},
+        ~discretePosition=First,
+      ),
+    ), // 1 + distribution
+    true,
+  )
 })

packages/squiggle-lang/__tests__/Distributions/DistributionOperation_test.res

@@ -1,7 +1,7 @@
 open Jest
 open Expect
 
-let env: DistributionOperation.env = {
+let env: GenericDist.env = {
   sampleCount: 100,
   xyPointLength: 100,
 }
@@ -34,7 +34,7 @@ describe("sparkline", () => {
     expected: DistributionOperation.outputType,
   ) => {
     test(name, () => {
-      let result = DistributionOperation.run(~env, FromDist(ToString(ToSparkline(20)), dist))
+      let result = DistributionOperation.run(~env, FromDist(#ToString(ToSparkline(20)), dist))
       expect(result)->toEqual(expected)
     })
   }
@@ -81,8 +81,8 @@ describe("sparkline", () => {
 describe("toPointSet", () => {
   test("on symbolic normal distribution", () => {
     let result =
-      run(FromDist(ToDist(ToPointSet), normalDist5))
-      ->outputMap(FromDist(ToFloat(#Mean)))
+      run(FromDist(#ToDist(ToPointSet), normalDist5))
+      ->outputMap(FromDist(#ToFloat(#Mean)))
       ->toFloat
       ->toExt
     expect(result)->toBeSoCloseTo(5.0, ~digits=0)
@@ -90,10 +90,10 @@ describe("toPointSet", () => {
 
   test("on sample set", () => {
     let result =
-      run(FromDist(ToDist(ToPointSet), normalDist5))
-      ->outputMap(FromDist(ToDist(ToSampleSet(1000))))
-      ->outputMap(FromDist(ToDist(ToPointSet)))
-      ->outputMap(FromDist(ToFloat(#Mean)))
+      run(FromDist(#ToDist(ToPointSet), normalDist5))
+      ->outputMap(FromDist(#ToDist(ToSampleSet(1000))))
+      ->outputMap(FromDist(#ToDist(ToPointSet)))
+      ->outputMap(FromDist(#ToFloat(#Mean)))
       ->toFloat
       ->toExt
     expect(result)->toBeSoCloseTo(5.0, ~digits=-1)

packages/squiggle-lang/__tests__/Distributions/GenericDist_Fixtures.res

@@ -19,7 +19,6 @@ exception MixtureFailed
 let float1 = 1.0
 let float2 = 2.0
 let float3 = 3.0
-let {mkDelta} = module(TestHelpers)
-let point1 = mkDelta(float1)
-let point2 = mkDelta(float2)
-let point3 = mkDelta(float3)
+let point1 = TestHelpers.mkDelta(float1)
+let point2 = TestHelpers.mkDelta(float2)
+let point3 = TestHelpers.mkDelta(float3)

packages/squiggle-lang/__tests__/Distributions/Mixture_test.res

@@ -11,7 +11,7 @@ describe("mixture", () => {
       let (mean1, mean2) = tup
       let meanValue = {
         run(Mixture([(mkNormal(mean1, 9e-1), 0.5), (mkNormal(mean2, 9e-1), 0.5)]))->outputMap(
-          FromDist(ToFloat(#Mean)),
+          FromDist(#ToFloat(#Mean)),
         )
       }
       meanValue->unpackFloat->expect->toBeSoCloseTo((mean1 +. mean2) /. 2.0, ~digits=-1)
@@ -28,7 +28,7 @@ describe("mixture", () => {
       let meanValue = {
         run(
           Mixture([(mkBeta(alpha, beta), betaWeight), (mkExponential(rate), exponentialWeight)]),
-        )->outputMap(FromDist(ToFloat(#Mean)))
+        )->outputMap(FromDist(#ToFloat(#Mean)))
       }
       let betaMean = 1.0 /. (1.0 +. beta /. alpha)
       let exponentialMean = 1.0 /. rate
@@ -52,7 +52,7 @@ describe("mixture", () => {
             (mkUniform(low, high), uniformWeight),
             (mkLognormal(mu, sigma), lognormalWeight),
           ]),
-        )->outputMap(FromDist(ToFloat(#Mean)))
+        )->outputMap(FromDist(#ToFloat(#Mean)))
       }
       let uniformMean = (low +. high) /. 2.0
       let lognormalMean = mu +. sigma ** 2.0 /. 2.0

packages/squiggle-lang/__tests__/Distributions/Scoring/KlDivergence_test.res

@@ -3,6 +3,7 @@ open Expect
 open TestHelpers
 open GenericDist_Fixtures
 
+let klDivergence = DistributionOperation.Constructors.LogScore.distEstimateDistAnswer(~env)
 // integral from low to high of 1 / (high - low) log(normal(mean, stdev)(x) / (1 / (high - low))) dx
 let klNormalUniform = (mean, stdev, low, high): float =>
   -.Js.Math.log((high -. low) /. Js.Math.sqrt(2.0 *. MagicNumbers.Math.pi *. stdev ** 2.0)) +.
@@ -11,8 +12,6 @@ let klNormalUniform = (mean, stdev, low, high): float =>
   (mean ** 2.0 -. (high +. low) *. mean +. (low ** 2.0 +. high *. low +. high ** 2.0) /. 3.0)
 
 describe("klDivergence: continuous -> continuous -> float", () => {
-  let klDivergence = DistributionOperation.Constructors.klDivergence(~env)
-
   let testUniform = (lowAnswer, highAnswer, lowPrediction, highPrediction) => {
     test("of two uniforms is equal to the analytic expression", () => {
       let answer =
@@ -58,7 +57,7 @@ describe("klDivergence: continuous -> continuous -> float", () => {
     let kl = E.R.liftJoin2(klDivergence, prediction, answer)
 
     switch kl {
-    | Ok(kl') => kl'->expect->toBeSoCloseTo(analyticalKl, ~digits=3)
+    | Ok(kl') => kl'->expect->toBeSoCloseTo(analyticalKl, ~digits=2)
     | Error(err) => {
         Js.Console.log(DistributionTypes.Error.toString(err))
         raise(KlFailed)
@@ -82,7 +81,6 @@ describe("klDivergence: continuous -> continuous -> float", () => {
 })
 
 describe("klDivergence: discrete -> discrete -> float", () => {
-  let klDivergence = DistributionOperation.Constructors.klDivergence(~env)
   let mixture = a => DistributionTypes.DistributionOperation.Mixture(a)
   let a' = [(point1, 1e0), (point2, 1e0)]->mixture->run
   let b' = [(point1, 1e0), (point2, 1e0), (point3, 1e0)]->mixture->run
@@ -117,7 +115,6 @@ describe("klDivergence: discrete -> discrete -> float", () => {
 })
 
 describe("klDivergence: mixed -> mixed -> float", () => {
-  let klDivergence = DistributionOperation.Constructors.klDivergence(~env)
   let mixture' = a => DistributionTypes.DistributionOperation.Mixture(a)
   let mixture = a => {
     let dist' = a->mixture'->run
@@ -189,15 +186,15 @@ describe("combineAlongSupportOfSecondArgument0", () => {
       uniformMakeR(lowPrediction, highPrediction)->E.R2.errMap(s => DistributionTypes.ArgumentError(
         s,
       ))
-    let answerWrapped = E.R.fmap(a => run(FromDist(ToDist(ToPointSet), a)), answer)
-    let predictionWrapped = E.R.fmap(a => run(FromDist(ToDist(ToPointSet), a)), prediction)
+    let answerWrapped = E.R.fmap(a => run(FromDist(#ToDist(ToPointSet), a)), answer)
+    let predictionWrapped = E.R.fmap(a => run(FromDist(#ToDist(ToPointSet), a)), prediction)
 
     let interpolator = XYShape.XtoY.continuousInterpolator(#Stepwise, #UseZero)
-    let integrand = PointSetDist_Scoring.KLDivergence.integrand
+    let integrand = PointSetDist_Scoring.WithDistAnswer.integrand
 
     let result = switch (answerWrapped, predictionWrapped) {
     | (Ok(Dist(PointSet(Continuous(a)))), Ok(Dist(PointSet(Continuous(b))))) =>
-      Some(combineAlongSupportOfSecondArgument(integrand, interpolator, a.xyShape, b.xyShape))
+      Some(combineAlongSupportOfSecondArgument(interpolator, integrand, a.xyShape, b.xyShape))
     | _ => None
     }
     result

packages/squiggle-lang/__tests__/Distributions/Scoring/WithScalarAnswer_test.res

@@ -0,0 +1,68 @@
+open Jest
+open Expect
+open TestHelpers
+open GenericDist_Fixtures
+exception ScoreFailed
+
+describe("WithScalarAnswer: discrete -> scalar -> score", () => {
+  let mixture = a => DistributionTypes.DistributionOperation.Mixture(a)
+  let pointA = mkDelta(3.0)
+  let pointB = mkDelta(2.0)
+  let pointC = mkDelta(1.0)
+  let pointD = mkDelta(0.0)
+
+  test("score: agrees with analytical answer when finite", () => {
+    let prediction' = [(pointA, 0.25), (pointB, 0.25), (pointC, 0.25), (pointD, 0.25)]->mixture->run
+    let prediction = switch prediction' {
+    | Dist(PointSet(p)) => p
+    | _ => raise(MixtureFailed)
+    }
+
+    let answer = 2.0 // So this is: assigning 100% probability to 2.0
+    let result = PointSetDist_Scoring.WithScalarAnswer.score(~estimate=prediction, ~answer)
+    switch result {
+    | Ok(x) => x->expect->toEqual(-.Js.Math.log(0.25 /. 1.0))
+    | _ => raise(ScoreFailed)
+    }
+  })
+
+  test("score: agrees with analytical answer when finite", () => {
+    let prediction' = [(pointA, 0.75), (pointB, 0.25)]->mixture->run
+    let prediction = switch prediction' {
+    | Dist(PointSet(p)) => p
+    | _ => raise(MixtureFailed)
+    }
+    let answer = 3.0 // So this is: assigning 100% probability to 2.0
+    let result = PointSetDist_Scoring.WithScalarAnswer.score(~estimate=prediction, ~answer)
+    switch result {
+    | Ok(x) => x->expect->toEqual(-.Js.Math.log(0.75 /. 1.0))
+    | _ => raise(ScoreFailed)
+    }
+  })
+
+  test("scoreWithPrior: agrees with analytical answer when finite", () => {
+    let prior' = [(pointA, 0.5), (pointB, 0.5)]->mixture->run
+    let prediction' = [(pointA, 0.75), (pointB, 0.25)]->mixture->run
+
+    let prediction = switch prediction' {
+    | Dist(PointSet(p)) => p
+    | _ => raise(MixtureFailed)
+    }
+
+    let prior = switch prior' {
+    | Dist(PointSet(p)) => p
+    | _ => raise(MixtureFailed)
+    }
+
+    let answer = 3.0 // So this is: assigning 100% probability to 2.0
+    let result = PointSetDist_Scoring.WithScalarAnswer.scoreWithPrior(
+      ~estimate=prediction,
+      ~answer,
+      ~prior,
+    )
+    switch result {
+    | Ok(x) => x->expect->toEqual(-.Js.Math.log(0.75 /. 1.0) -. -.Js.Math.log(0.5 /. 1.0))
+    | _ => raise(ScoreFailed)
+    }
+  })
+})

packages/squiggle-lang/__tests__/Distributions/Symbolic_test.res

@@ -8,34 +8,34 @@ let mkNormal = (mean, stdev) => DistributionTypes.Symbolic(#Normal({mean: mean,
 describe("(Symbolic) normalize", () => {
   testAll("has no impact on normal distributions", list{-1e8, -1e-2, 0.0, 1e-4, 1e16}, mean => {
     let normalValue = mkNormal(mean, 2.0)
-    let normalizedValue = run(FromDist(ToDist(Normalize), normalValue))
+    let normalizedValue = run(FromDist(#ToDist(Normalize), normalValue))
     normalizedValue->unpackDist->expect->toEqual(normalValue)
   })
 })
 
 describe("(Symbolic) mean", () => {
   testAll("of normal distributions", list{-1e8, -16.0, -1e-2, 0.0, 1e-4, 32.0, 1e16}, mean => {
-    run(FromDist(ToFloat(#Mean), mkNormal(mean, 4.0)))->unpackFloat->expect->toBeCloseTo(mean)
+    run(FromDist(#ToFloat(#Mean), mkNormal(mean, 4.0)))->unpackFloat->expect->toBeCloseTo(mean)
   })
 
   Skip.test("of normal(0, -1) (it NaNs out)", () => {
-    run(FromDist(ToFloat(#Mean), mkNormal(1e1, -1e0)))->unpackFloat->expect->ExpectJs.toBeFalsy
+    run(FromDist(#ToFloat(#Mean), mkNormal(1e1, -1e0)))->unpackFloat->expect->ExpectJs.toBeFalsy
   })
 
   test("of normal(0, 1e-8) (it doesn't freak out at tiny stdev)", () => {
-    run(FromDist(ToFloat(#Mean), mkNormal(0.0, 1e-8)))->unpackFloat->expect->toBeCloseTo(0.0)
+    run(FromDist(#ToFloat(#Mean), mkNormal(0.0, 1e-8)))->unpackFloat->expect->toBeCloseTo(0.0)
   })
 
   testAll("of exponential distributions", list{1e-7, 2.0, 10.0, 100.0}, rate => {
     let meanValue = run(
-      FromDist(ToFloat(#Mean), DistributionTypes.Symbolic(#Exponential({rate: rate}))),
+      FromDist(#ToFloat(#Mean), DistributionTypes.Symbolic(#Exponential({rate: rate}))),
     )
     meanValue->unpackFloat->expect->toBeCloseTo(1.0 /. rate) // https://en.wikipedia.org/wiki/Exponential_distribution#Mean,_variance,_moments,_and_median
   })
 
   test("of a cauchy distribution", () => {
     let meanValue = run(
-      FromDist(ToFloat(#Mean), DistributionTypes.Symbolic(#Cauchy({local: 1.0, scale: 1.0}))),
+      FromDist(#ToFloat(#Mean), DistributionTypes.Symbolic(#Cauchy({local: 1.0, scale: 1.0}))),
     )
     meanValue->unpackFloat->expect->toBeSoCloseTo(1.0098094001641797, ~digits=5)
     //-> toBe(GenDistError(Other("Cauchy distributions may have no mean value.")))
@@ -48,7 +48,7 @@ describe("(Symbolic) mean", () => {
       let (low, medium, high) = tup
       let meanValue = run(
         FromDist(
-          ToFloat(#Mean),
+          #ToFloat(#Mean),
           DistributionTypes.Symbolic(#Triangular({low: low, medium: medium, high: high})),
         ),
       )
@@ -63,7 +63,7 @@ describe("(Symbolic) mean", () => {
     tup => {
       let (alpha, beta) = tup
       let meanValue = run(
-        FromDist(ToFloat(#Mean), DistributionTypes.Symbolic(#Beta({alpha: alpha, beta: beta}))),
+        FromDist(#ToFloat(#Mean), DistributionTypes.Symbolic(#Beta({alpha: alpha, beta: beta}))),
       )
       meanValue->unpackFloat->expect->toBeCloseTo(1.0 /. (1.0 +. beta /. alpha)) // https://en.wikipedia.org/wiki/Beta_distribution#Mean
     },
@@ -72,18 +72,35 @@ describe("(Symbolic) mean", () => {
   // TODO: When we have our theory of validators we won't want this to be NaN but to be an error.
   test("of beta(0, 0)", () => {
     let meanValue = run(
-      FromDist(ToFloat(#Mean), DistributionTypes.Symbolic(#Beta({alpha: 0.0, beta: 0.0}))),
+      FromDist(#ToFloat(#Mean), DistributionTypes.Symbolic(#Beta({alpha: 0.0, beta: 0.0}))),
     )
     meanValue->unpackFloat->expect->ExpectJs.toBeFalsy
   })
 
+  testAll(
+    "of beta distributions from mean and standard dev",
+    list{(0.39, 0.1), (0.08, 0.1), (0.8, 0.3)},
+    tup => {
+      let (mean, stdev) = tup
+      let betaDistribution = SymbolicDist.Beta.fromMeanAndStdev(mean, stdev)
+      let meanValue =
+        betaDistribution->E.R2.fmap(d =>
+          run(FromDist(#ToFloat(#Mean), d->DistributionTypes.Symbolic))
+        )
+      switch meanValue {
+      | Ok(value) => value->unpackFloat->expect->toBeCloseTo(mean)
+      | Error(err) => err->expect->toBe("shouldn't happen")
+      }
+    },
+  )
+
   testAll(
     "of lognormal distributions",
     list{(2.0, 4.0), (1e-7, 1e-2), (-1e6, 10.0), (1e3, -1e2), (-1e8, -1e4), (1e2, 1e-5)},
     tup => {
       let (mu, sigma) = tup
       let meanValue = run(
-        FromDist(ToFloat(#Mean), DistributionTypes.Symbolic(#Lognormal({mu: mu, sigma: sigma}))),
+        FromDist(#ToFloat(#Mean), DistributionTypes.Symbolic(#Lognormal({mu: mu, sigma: sigma}))),
       )
       meanValue->unpackFloat->expect->toBeCloseTo(Js.Math.exp(mu +. sigma ** 2.0 /. 2.0)) // https://brilliant.org/wiki/log-normal-distribution/
     },
@@ -95,14 +112,14 @@ describe("(Symbolic) mean", () => {
     tup => {
       let (low, high) = tup
       let meanValue = run(
-        FromDist(ToFloat(#Mean), DistributionTypes.Symbolic(#Uniform({low: low, high: high}))),
+        FromDist(#ToFloat(#Mean), DistributionTypes.Symbolic(#Uniform({low: low, high: high}))),
       )
       meanValue->unpackFloat->expect->toBeCloseTo((low +. high) /. 2.0) // https://en.wikipedia.org/wiki/Continuous_uniform_distribution#Moments
     },
   )
 
   test("of a float", () => {
-    let meanValue = run(FromDist(ToFloat(#Mean), DistributionTypes.Symbolic(#Float(7.7))))
+    let meanValue = run(FromDist(#ToFloat(#Mean), DistributionTypes.Symbolic(#Float(7.7))))
     meanValue->unpackFloat->expect->toBeCloseTo(7.7)
   })
 })

packages/squiggle-lang/__tests__/Reducer/Reducer_Category/Reducer_Category_Module_TypeChecker_test.res

@@ -0,0 +1,4 @@
+open Jest
+open Expect
+
+test("todo", () => expect("1")->toBe("1"))

packages/squiggle-lang/__tests__/Reducer/Reducer_Dispatch/Reducer_Dispatch_BuiltInMacros_test.res

@@ -19,23 +19,23 @@ describe("bindStatement", () => {
   testMacro(
     [],
     eBindStatement(eBindings([]), exampleStatementY),
-    "Ok((:$_setBindings_$ {} :y 1) context: {})",
+    "Ok((:$_setBindings_$ @{} :y 1) context: @{})",
   )
   // Then it answers the bindings for the next statement when reduced
-  testMacroEval([], eBindStatement(eBindings([]), exampleStatementY), "Ok({y: 1})")
+  testMacroEval([], eBindStatement(eBindings([]), exampleStatementY), "Ok(@{y: 1})")
   // Now let's feed a binding to see what happens
   testMacro(
     [],
-    eBindStatement(eBindings([("x", EvNumber(2.))]), exampleStatementX),
-    "Ok((:$_setBindings_$ {x: 2} :y 2) context: {x: 2})",
+    eBindStatement(eBindings([("x", IEvNumber(2.))]), exampleStatementX),
+    "Ok((:$_setBindings_$ @{x: 2} :y 2) context: @{x: 2})",
   )
   // An expression does not return a binding, thus error
   testMacro([], eBindStatement(eBindings([]), exampleExpression), "Assignment expected")
   // When bindings from previous statement are missing the context is injected. This must be the first statement of a block
   testMacro(
-    [("z", EvNumber(99.))],
+    [("z", IEvNumber(99.))],
     eBindStatementDefault(exampleStatementY),
-    "Ok((:$_setBindings_$ {z: 99} :y 1) context: {z: 99})",
+    "Ok((:$_setBindings_$ @{z: 99} :y 1) context: @{z: 99})",
   )
 })
 
@@ -43,26 +43,26 @@ describe("bindExpression", () => {
   // x is simply bound in the expression
   testMacro(
     [],
-    eBindExpression(eBindings([("x", EvNumber(2.))]), eSymbol("x")),
-    "Ok(2 context: {x: 2})",
+    eBindExpression(eBindings([("x", IEvNumber(2.))]), eSymbol("x")),
+    "Ok(2 context: @{x: 2})",
   )
   // When an let statement is the end expression then bindings are returned
   testMacro(
     [],
-    eBindExpression(eBindings([("x", EvNumber(2.))]), exampleStatementY),
-    "Ok((:$_exportBindings_$ (:$_setBindings_$ {x: 2} :y 1)) context: {x: 2})",
+    eBindExpression(eBindings([("x", IEvNumber(2.))]), exampleStatementY),
+    "Ok((:$_exportBindings_$ (:$_setBindings_$ @{x: 2} :y 1)) context: @{x: 2})",
   )
   // Now let's reduce that expression
   testMacroEval(
     [],
-    eBindExpression(eBindings([("x", EvNumber(2.))]), exampleStatementY),
-    "Ok({x: 2,y: 1})",
+    eBindExpression(eBindings([("x", IEvNumber(2.))]), exampleStatementY),
+    "Ok(@{x: 2,y: 1})",
   )
   // When bindings are missing the context is injected. This must be the first and last statement of a block
   testMacroEval(
-    [("z", EvNumber(99.))],
+    [("z", IEvNumber(99.))],
     eBindExpressionDefault(exampleStatementY),
-    "Ok({y: 1,z: 99})",
+    "Ok(@{y: 1,z: 99})",
   )
 })
 
@@ -72,7 +72,7 @@ describe("block", () => {
   testMacroEval([], eBlock(list{exampleExpression}), "Ok(1)")
   // Block with a single statement
   testMacro([], eBlock(list{exampleStatementY}), "Ok((:$$_bindExpression_$$ (:$_let_$ :y 1)))")
-  testMacroEval([], eBlock(list{exampleStatementY}), "Ok({y: 1})")
+  testMacroEval([], eBlock(list{exampleStatementY}), "Ok(@{y: 1})")
   // Block with a statement and an expression
   testMacro(
     [],
@@ -86,7 +86,7 @@ describe("block", () => {
     eBlock(list{exampleStatementY, exampleStatementZ}),
     "Ok((:$$_bindExpression_$$ (:$$_bindStatement_$$ (:$_let_$ :y 1)) (:$_let_$ :z :y)))",
   )
-  testMacroEval([], eBlock(list{exampleStatementY, exampleStatementZ}), "Ok({y: 1,z: 1})")
+  testMacroEval([], eBlock(list{exampleStatementY, exampleStatementZ}), "Ok(@{y: 1,z: 1})")
   // Block inside a block
   testMacro([], eBlock(list{eBlock(list{exampleExpression})}), "Ok((:$$_bindExpression_$$ {1}))")
   testMacroEval([], eBlock(list{eBlock(list{exampleExpression})}), "Ok(1)")
@@ -99,7 +99,7 @@ describe("block", () => {
   testMacroEval(
     [],
     eBlock(list{eLetStatement("z", eBlock(list{eBlock(list{exampleExpressionY})}))}),
-    "Ok({z: :y})",
+    "Ok(@{z: :y})",
   )
   // Empty block
   testMacro([], eBlock(list{}), "Ok(:undefined block)") //TODO: should be an error
@@ -115,7 +115,7 @@ describe("block", () => {
     "Ok((:$$_bindExpression_$$ {(:$_let_$ :y (:add :x 1)); :y}))",
   )
   testMacroEval(
-    [("x", EvNumber(1.))],
+    [("x", IEvNumber(1.))],
     eBlock(list{
       eBlock(list{
         eLetStatement("y", eFunction("add", list{eSymbol("x"), eNumber(1.)})),
@@ -135,12 +135,12 @@ describe("lambda", () => {
   testMacro([], callLambdaExpression, "Ok(((:$$_lambda_$$ [y] :y) 1))")
   testMacroEval([], callLambdaExpression, "Ok(1)")
   // Parameters shadow the outer scope
-  testMacroEval([("y", EvNumber(666.))], callLambdaExpression, "Ok(1)")
+  testMacroEval([("y", IEvNumber(666.))], callLambdaExpression, "Ok(1)")
   // When not shadowed by the parameters, the outer scope variables are available
   let lambdaExpression = eFunction(
     "$$_lambda_$$",
     list{eArrayString(["z"]), eFunction("add", list{eSymbol("y"), eSymbol("z")})},
   )
   let callLambdaExpression = eList(list{lambdaExpression, eNumber(1.)})
-  testMacroEval([("y", EvNumber(666.))], callLambdaExpression, "Ok(667)")
+  testMacroEval([("y", IEvNumber(666.))], callLambdaExpression, "Ok(667)")
 })

packages/squiggle-lang/__tests__/Reducer/Reducer_Dispatch/Reducer_Dispatch_BuiltIn_test.res

@@ -1,4 +1,4 @@
-module ExpressionValue = ReducerInterface.ExpressionValue
+module ExpressionValue = ReducerInterface.ExternalExpressionValue
 
 open Jest
 open Expect
@@ -17,10 +17,6 @@ describe("builtin", () => {
   testEval("1-1", "Ok(0)")
   testEval("2>1", "Ok(true)")
   testEval("concat('a','b')", "Ok('ab')")
-  testEval(
-    "addOne(t)=t+1; toList(mapSamples(fromSamples([1,2,3,4,5,6]), addOne))",
-    "Ok([2,3,4,5,6,7])",
-  )
 })
 
 describe("builtin exception", () => {

packages/squiggle-lang/__tests__/Reducer/Reducer_Helpers.res

@@ -1,19 +1,22 @@
-module ExpressionT = Reducer_Expression_T
-module ExpressionValue = ReducerInterface.ExpressionValue
+// Reducer_Helpers
 module ErrorValue = Reducer_ErrorValue
-module Bindings = Reducer_Category_Bindings
+module ExternalExpressionValue = ReducerInterface.ExternalExpressionValue
+module InternalExpressionValue = ReducerInterface.InternalExpressionValue
+module Bindings = Reducer_Bindings
 
-let removeDefaults = (ev: ExpressionT.expressionValue): ExpressionT.expressionValue =>
-  switch ev {
-  | EvRecord(extbindings) => {
-      let bindings: Bindings.t = Bindings.fromRecord(extbindings)
-      let keys = Js.Dict.keys(Reducer.defaultExternalBindings)
-      Belt.Map.String.keep(bindings, (key, _value) => {
-        let removeThis = Js.Array2.includes(keys, key)
-        !removeThis
-      })->Bindings.toExpressionValue
-    }
+let removeDefaultsInternal = (iev: InternalExpressionValue.t) => {
+  switch iev {
+  | InternalExpressionValue.IEvBindings(nameSpace) =>
+    Bindings.removeOther(
+      nameSpace,
+      ReducerInterface.StdLib.internalStdLib,
+    )->InternalExpressionValue.IEvBindings
   | value => value
   }
+}
 
-let rRemoveDefaults = r => Belt.Result.map(r, ev => removeDefaults(ev))
+let removeDefaultsExternal = (ev: ExternalExpressionValue.t): ExternalExpressionValue.t =>
+  ev->InternalExpressionValue.toInternal->removeDefaultsInternal->InternalExpressionValue.toExternal
+
+let rRemoveDefaultsInternal = r => Belt.Result.map(r, removeDefaultsInternal)
+let rRemoveDefaultsExternal = r => Belt.Result.map(r, removeDefaultsExternal)

packages/squiggle-lang/__tests__/Reducer/Reducer_MathJs/Reducer_MathJsEval_test.res

@@ -1,4 +1,3 @@
-open ReducerInterface.ExpressionValue
 module MathJs = Reducer_MathJs
 module ErrorValue = Reducer.ErrorValue
 
@@ -6,14 +5,14 @@ open Jest
 open ExpectJs
 
 describe("eval", () => {
-  test("Number", () => expect(MathJs.Eval.eval("1"))->toEqual(Ok(EvNumber(1.))))
-  test("Number expr", () => expect(MathJs.Eval.eval("1-1"))->toEqual(Ok(EvNumber(0.))))
-  test("String", () => expect(MathJs.Eval.eval("'hello'"))->toEqual(Ok(EvString("hello"))))
+  test("Number", () => expect(MathJs.Eval.eval("1"))->toEqual(Ok(IEvNumber(1.))))
+  test("Number expr", () => expect(MathJs.Eval.eval("1-1"))->toEqual(Ok(IEvNumber(0.))))
+  test("String", () => expect(MathJs.Eval.eval("'hello'"))->toEqual(Ok(IEvString("hello"))))
   test("String expr", () =>
-    expect(MathJs.Eval.eval("concat('hello ','world')"))->toEqual(Ok(EvString("hello world")))
+    expect(MathJs.Eval.eval("concat('hello ','world')"))->toEqual(Ok(IEvString("hello world")))
   )
-  test("Boolean", () => expect(MathJs.Eval.eval("true"))->toEqual(Ok(EvBool(true))))
-  test("Boolean expr", () => expect(MathJs.Eval.eval("2>1"))->toEqual(Ok(EvBool(true))))
+  test("Boolean", () => expect(MathJs.Eval.eval("true"))->toEqual(Ok(IEvBool(true))))
+  test("Boolean expr", () => expect(MathJs.Eval.eval("2>1"))->toEqual(Ok(IEvBool(true))))
 })
 
 describe("errors", () => {

packages/squiggle-lang/__tests__/Reducer/Reducer_Peggy/Reducer_Peggy_Parse_test.res

@@ -236,7 +236,8 @@ describe("Peggy parse", () => {
     testParse("1m+2cm", "{(::add (::fromUnit_m 1) (::fromUnit_cm 2))}")
   })
   describe("Module", () => {
-    testParse("Math.pi", "{(::$_atIndex_$ @Math 'pi')}")
+    testParse("x", "{:x}")
+    testParse("Math.pi", "{:Math.pi}")
   })
 })
 

packages/squiggle-lang/__tests__/Reducer/Reducer_Peggy/Reducer_Peggy_Parse_type_test.res

@@ -20,7 +20,7 @@ describe("Peggy parse type", () => {
       "{(::$_typeOf_$ :f (::$_typeFunction_$ (::$_constructArray_$ (#number #number #number))))}",
     )
   })
-  describe("high priority modifier", () => {
+  describe("high priority contract", () => {
     testParse(
       "answer: number<-min<-max(100)|string",
       "{(::$_typeOf_$ :answer (::$_typeOr_$ (::$_constructArray_$ ((::$_typeModifier_max_$ (::$_typeModifier_min_$ #number) 100) #string))))}",
@@ -30,7 +30,7 @@ describe("Peggy parse type", () => {
       "{(::$_typeOf_$ :answer (::$_typeModifier_memberOf_$ #number (::$_constructArray_$ (1 3 5))))}",
     )
   })
-  describe("low priority modifier", () => {
+  describe("low priority contract", () => {
     testParse(
       "answer: number | string $ opaque",
       "{(::$_typeOf_$ :answer (::$_typeModifier_opaque_$ (::$_typeOr_$ (::$_constructArray_$ (#number #string)))))}",
@@ -63,14 +63,14 @@ describe("Peggy parse type", () => {
       "{(::$_typeOf_$ :weekend (::$_typeOr_$ (::$_constructArray_$ ((::$_typeConstructor_$ #Saturday (::$_constructArray_$ ())) (::$_typeConstructor_$ #Sunday (::$_constructArray_$ ()))))))}",
     )
   })
-  describe("type paranthesis", () => {
-    //$ is introduced to avoid paranthesis
+  describe("type parenthesis", () => {
+    //$ is introduced to avoid parenthesis
     testParse(
       "answer: (number|string)<-opaque",
       "{(::$_typeOf_$ :answer (::$_typeModifier_opaque_$ (::$_typeOr_$ (::$_constructArray_$ (#number #string)))))}",
     )
   })
-  describe("squiggle expressions in type modifiers", () => {
+  describe("squiggle expressions in type contracts", () => {
     testParse(
       "odds1 = [1,3,5]; odds2 = [7, 9]; type odds = number<-memberOf(concat(odds1, odds2))",
       "{:odds1 = {(::$_constructArray_$ (1 3 5))}; :odds2 = {(::$_constructArray_$ (7 9))}; (::$_typeAlias_$ #odds (::$_typeModifier_memberOf_$ #number (::concat :odds1 :odds2)))}",

packages/squiggle-lang/__tests__/Reducer/Reducer_Peggy/Reducer_Peggy_TestHelpers.res

@@ -1,9 +1,10 @@
 module Expression = Reducer_Expression
 module ExpressionT = Reducer_Expression_T
-module ExpressionValue = ReducerInterface_ExpressionValue
+module ExpressionValue = ReducerInterface.InternalExpressionValue
 module Parse = Reducer_Peggy_Parse
 module Result = Belt.Result
 module ToExpression = Reducer_Peggy_ToExpression
+module Bindings = Reducer_Bindings
 
 open Jest
 open Expect
@@ -29,7 +30,7 @@ let expectToExpressionToBe = (expr, answer, ~v="_", ()) => {
           ExpressionValue.defaultEnvironment,
         )
       )
-      ->Reducer_Helpers.rRemoveDefaults
+      ->Reducer_Helpers.rRemoveDefaultsInternal
       ->ExpressionValue.toStringResultOkless
     (a1, a2)->expect->toEqual((answer, v))
   }

packages/squiggle-lang/__tests__/Reducer/Reducer_Peggy/Reducer_Peggy_ToExpression_test.res

@@ -1,9 +1,12 @@
+module Bindings = Reducer_Bindings
+module InternalExpressionValue = ReducerInterface_InternalExpressionValue
+
 open Jest
 open Reducer_Peggy_TestHelpers
 
 describe("Peggy to Expression", () => {
   describe("literals operators parenthesis", () => {
-    // Note that there is always an outer block. Otherwise, external bindings are ignrored at the first statement
+    // Note that there is always an outer block. Otherwise, external bindings are ignored at the first statement
     testToExpression("1", "{1}", ~v="1", ())
     testToExpression("'hello'", "{'hello'}", ~v="'hello'", ())
     testToExpression("true", "{true}", ~v="true", ())
@@ -22,11 +25,11 @@ describe("Peggy to Expression", () => {
 
   describe("multi-line", () => {
     testToExpression("x=1; 2", "{(:$_let_$ :x {1}); 2}", ~v="2", ())
-    testToExpression("x=1; y=2", "{(:$_let_$ :x {1}); (:$_let_$ :y {2})}", ~v="{x: 1,y: 2}", ())
+    testToExpression("x=1; y=2", "{(:$_let_$ :x {1}); (:$_let_$ :y {2})}", ~v="@{x: 1,y: 2}", ())
   })
 
   describe("variables", () => {
-    testToExpression("x = 1", "{(:$_let_$ :x {1})}", ~v="{x: 1}", ())
+    testToExpression("x = 1", "{(:$_let_$ :x {1})}", ~v="@{x: 1}", ())
     testToExpression("x", "{:x}", ~v=":x", ()) //TODO: value should return error
     testToExpression("x = 1; x", "{(:$_let_$ :x {1}); :x}", ~v="1", ())
   })
@@ -35,7 +38,7 @@ describe("Peggy to Expression", () => {
     testToExpression(
       "identity(x) = x",
       "{(:$_let_$ :identity (:$$_lambda_$$ [x] {:x}))}",
-      ~v="{identity: lambda(x=>internal code)}",
+      ~v="@{identity: lambda(x=>internal code)}",
       (),
     ) // Function definitions become lambda assignments
     testToExpression("identity(x)", "{(:identity :x)}", ()) // Note value returns error properly
@@ -155,7 +158,7 @@ describe("Peggy to Expression", () => {
     testToExpression(
       "y=99; x={y=1; y}",
       "{(:$_let_$ :y {99}); (:$_let_$ :x {(:$_let_$ :y {1}); :y})}",
-      ~v="{x: 1,y: 99}",
+      ~v="@{x: 1,y: 99}",
       (),
     )
   })
@@ -165,24 +168,32 @@ describe("Peggy to Expression", () => {
     testToExpression(
       "f={|x| x}",
       "{(:$_let_$ :f {(:$$_lambda_$$ [x] {:x})})}",
-      ~v="{f: lambda(x=>internal code)}",
+      ~v="@{f: lambda(x=>internal code)}",
       (),
     )
     testToExpression(
       "f(x)=x",
       "{(:$_let_$ :f (:$$_lambda_$$ [x] {:x}))}",
-      ~v="{f: lambda(x=>internal code)}",
+      ~v="@{f: lambda(x=>internal code)}",
       (),
     ) // Function definitions are lambda assignments
     testToExpression(
       "f(x)=x ? 1 : 0",
       "{(:$_let_$ :f (:$$_lambda_$$ [x] {(:$$_ternary_$$ :x 1 0)}))}",
-      ~v="{f: lambda(x=>internal code)}",
+      ~v="@{f: lambda(x=>internal code)}",
       (),
     )
   })
 
   describe("module", () => {
-    testToExpression("Math.pi", "{(:$_atIndex_$ :Math 'pi')}", ~v="3.141592653589793", ())
+    // testToExpression("Math.pi", "{:Math.pi}", ~v="3.141592653589793", ())
+    // Only.test("stdlibrary", () => {
+    //   ReducerInterface_StdLib.internalStdLib
+    //   ->IEvBindings
+    //   ->InternalExpressionValue.toString
+    //   ->expect
+    //   ->toBe("")
+    // })
+    testToExpression("Math.pi", "{:Math.pi}", ~v="3.141592653589793", ())
   })
 })

packages/squiggle-lang/__tests__/Reducer/Reducer_Peggy/Reducer_Peggy_ToExpression_type_test.res

@@ -6,7 +6,7 @@ describe("Peggy Types to Expression", () => {
     testToExpression(
       "p: number",
       "{(:$_typeOf_$ :p #number)}",
-      ~v="{_typeReferences_: {p: #number}}",
+      ~v="@{_typeReferences_: {p: #number}}",
       (),
     )
   })
@@ -14,7 +14,7 @@ describe("Peggy Types to Expression", () => {
     testToExpression(
       "type index=number",
       "{(:$_typeAlias_$ #index #number)}",
-      ~v="{_typeAliases_: {index: #number}}",
+      ~v="@{_typeAliases_: {index: #number}}",
       (),
     )
   })
@@ -22,7 +22,7 @@ describe("Peggy Types to Expression", () => {
     testToExpression(
       "answer: number|string|distribution",
       "{(:$_typeOf_$ :answer (:$_typeOr_$ (:$_constructArray_$ (#number #string #distribution))))}",
-      ~v="{_typeReferences_: {answer: {typeTag: 'typeOr',typeOr: [#number,#string,#distribution]}}}",
+      ~v="@{_typeReferences_: {answer: {typeOr: [#number,#string,#distribution],typeTag: 'typeOr'}}}",
       (),
     )
   })
@@ -30,67 +30,67 @@ describe("Peggy Types to Expression", () => {
     testToExpression(
       "f: number=>number=>number",
       "{(:$_typeOf_$ :f (:$_typeFunction_$ (:$_constructArray_$ (#number #number #number))))}",
-      ~v="{_typeReferences_: {f: {typeTag: 'typeFunction',inputs: [#number,#number],output: #number}}}",
+      ~v="@{_typeReferences_: {f: {inputs: [#number,#number],output: #number,typeTag: 'typeFunction'}}}",
       (),
     )
     testToExpression(
       "f: number=>number",
       "{(:$_typeOf_$ :f (:$_typeFunction_$ (:$_constructArray_$ (#number #number))))}",
-      ~v="{_typeReferences_: {f: {typeTag: 'typeFunction',inputs: [#number],output: #number}}}",
+      ~v="@{_typeReferences_: {f: {inputs: [#number],output: #number,typeTag: 'typeFunction'}}}",
       (),
     )
   })
-  describe("high priority modifier", () => {
+  describe("high priority contract", () => {
     testToExpression(
       "answer: number<-min(1)<-max(100)|string",
       "{(:$_typeOf_$ :answer (:$_typeOr_$ (:$_constructArray_$ ((:$_typeModifier_max_$ (:$_typeModifier_min_$ #number 1) 100) #string))))}",
-      ~v="{_typeReferences_: {answer: {typeTag: 'typeOr',typeOr: [{typeTag: 'typeIdentifier',typeIdentifier: #number,min: 1,max: 100},#string]}}}",
+      ~v="@{_typeReferences_: {answer: {typeOr: [{max: 100,min: 1,typeIdentifier: #number,typeTag: 'typeIdentifier'},#string],typeTag: 'typeOr'}}}",
       (),
     )
     testToExpression(
       "answer: number<-memberOf([1,3,5])",
       "{(:$_typeOf_$ :answer (:$_typeModifier_memberOf_$ #number (:$_constructArray_$ (1 3 5))))}",
-      ~v="{_typeReferences_: {answer: {typeTag: 'typeIdentifier',typeIdentifier: #number,memberOf: [1,3,5]}}}",
+      ~v="@{_typeReferences_: {answer: {memberOf: [1,3,5],typeIdentifier: #number,typeTag: 'typeIdentifier'}}}",
       (),
     )
     testToExpression(
       "answer: number<-min(1)",
       "{(:$_typeOf_$ :answer (:$_typeModifier_min_$ #number 1))}",
-      ~v="{_typeReferences_: {answer: {typeTag: 'typeIdentifier',typeIdentifier: #number,min: 1}}}",
+      ~v="@{_typeReferences_: {answer: {min: 1,typeIdentifier: #number,typeTag: 'typeIdentifier'}}}",
       (),
     )
     testToExpression(
       "answer: number<-max(10)",
       "{(:$_typeOf_$ :answer (:$_typeModifier_max_$ #number 10))}",
-      ~v="{_typeReferences_: {answer: {typeTag: 'typeIdentifier',typeIdentifier: #number,max: 10}}}",
+      ~v="@{_typeReferences_: {answer: {max: 10,typeIdentifier: #number,typeTag: 'typeIdentifier'}}}",
       (),
     )
     testToExpression(
       "answer: number<-min(1)<-max(10)",
       "{(:$_typeOf_$ :answer (:$_typeModifier_max_$ (:$_typeModifier_min_$ #number 1) 10))}",
-      ~v="{_typeReferences_: {answer: {typeTag: 'typeIdentifier',typeIdentifier: #number,min: 1,max: 10}}}",
+      ~v="@{_typeReferences_: {answer: {max: 10,min: 1,typeIdentifier: #number,typeTag: 'typeIdentifier'}}}",
       (),
     )
     testToExpression(
       "answer: number<-max(10)<-min(1)",
       "{(:$_typeOf_$ :answer (:$_typeModifier_min_$ (:$_typeModifier_max_$ #number 10) 1))}",
-      ~v="{_typeReferences_: {answer: {typeTag: 'typeIdentifier',typeIdentifier: #number,max: 10,min: 1}}}",
+      ~v="@{_typeReferences_: {answer: {max: 10,min: 1,typeIdentifier: #number,typeTag: 'typeIdentifier'}}}",
       (),
     )
   })
-  describe("low priority modifier", () => {
+  describe("low priority contract", () => {
     testToExpression(
       "answer: number | string $ opaque",
       "{(:$_typeOf_$ :answer (:$_typeModifier_opaque_$ (:$_typeOr_$ (:$_constructArray_$ (#number #string)))))}",
-      ~v="{_typeReferences_: {answer: {typeTag: 'typeOr',typeOr: [#number,#string],opaque: true}}}",
+      ~v="@{_typeReferences_: {answer: {opaque: true,typeOr: [#number,#string],typeTag: 'typeOr'}}}",
       (),
     )
   })
-  describe("squiggle expressions in type modifiers", () => {
+  describe("squiggle expressions in type contracts", () => {
     testToExpression(
       "odds1 = [1,3,5]; odds2 = [7, 9]; type odds = number<-memberOf(concat(odds1, odds2))",
       "{(:$_let_$ :odds1 {(:$_constructArray_$ (1 3 5))}); (:$_let_$ :odds2 {(:$_constructArray_$ (7 9))}); (:$_typeAlias_$ #odds (:$_typeModifier_memberOf_$ #number (:concat :odds1 :odds2)))}",
-      ~v="{_typeAliases_: {odds: {typeTag: 'typeIdentifier',typeIdentifier: #number,memberOf: [1,3,5,7,9]}},odds1: [1,3,5],odds2: [7,9]}",
+      ~v="@{_typeAliases_: {odds: {memberOf: [1,3,5,7,9],typeIdentifier: #number,typeTag: 'typeIdentifier'}},odds1: [1,3,5],odds2: [7,9]}",
       (),
     )
   })

packages/squiggle-lang/__tests__/Reducer/Reducer_Peggy/Reducer_Peggy_ToExpression_void_test.res

@@ -0,0 +1,20 @@
+open Jest
+open Reducer_Peggy_TestHelpers
+
+describe("Peggy void", () => {
+  //literal
+  testToExpression("()", "{()}", ~v="()", ())
+  testToExpression(
+    "fn()=1",
+    "{(:$_let_$ :fn (:$$_lambda_$$ [_] {1}))}",
+    ~v="@{fn: lambda(_=>internal code)}",
+    (),
+  )
+  testToExpression("fn()=1; fn()", "{(:$_let_$ :fn (:$$_lambda_$$ [_] {1})); (:fn ())}", ~v="1", ())
+  testToExpression(
+    "fn(a)=(); call fn(1)",
+    "{(:$_let_$ :fn (:$$_lambda_$$ [a] {()})); (:$_let_$ :_ {(:fn 1)})}",
+    ~v="@{_: (),fn: lambda(a=>internal code)}",
+    (),
+  )
+})

packages/squiggle-lang/__tests__/Reducer/Reducer_TestHelpers.res

@@ -1,7 +1,6 @@
 module ExpressionT = Reducer_Expression_T
-module ExpressionValue = ReducerInterface.ExpressionValue
+module ExternalExpressionValue = ReducerInterface.ExternalExpressionValue
 module ErrorValue = Reducer_ErrorValue
-module Bindings = Reducer_Category_Bindings
 
 open Jest
 open Expect
@@ -9,7 +8,7 @@ open Expect
 let unwrapRecord = rValue =>
   rValue->Belt.Result.flatMap(value =>
     switch value {
-    | ExpressionValue.EvRecord(aRecord) => Ok(aRecord)
+    | ExternalExpressionValue.EvRecord(aRecord) => Ok(aRecord)
     | _ => ErrorValue.RETodo("TODO: External bindings must be returned")->Error
     }
   )
@@ -19,18 +18,18 @@ let expectParseToBe = (expr: string, answer: string) =>
 
 let expectEvalToBe = (expr: string, answer: string) =>
   Reducer.evaluate(expr)
-  ->Reducer_Helpers.rRemoveDefaults
-  ->ExpressionValue.toStringResult
+  ->Reducer_Helpers.rRemoveDefaultsExternal
+  ->ExternalExpressionValue.toStringResult
   ->expect
   ->toBe(answer)
 
 let expectEvalError = (expr: string) =>
-  Reducer.evaluate(expr)->ExpressionValue.toStringResult->expect->toMatch("Error\(")
+  Reducer.evaluate(expr)->ExternalExpressionValue.toStringResult->expect->toMatch("Error\(")
 
 let expectEvalBindingsToBe = (expr: string, bindings: Reducer.externalBindings, answer: string) =>
   Reducer.evaluateUsingOptions(expr, ~externalBindings=Some(bindings), ~environment=None)
-  ->Reducer_Helpers.rRemoveDefaults
-  ->ExpressionValue.toStringResult
+  ->Reducer_Helpers.rRemoveDefaultsExternal
+  ->ExternalExpressionValue.toStringResult
   ->expect
   ->toBe(answer)
 

packages/squiggle-lang/__tests__/Reducer/Reducer_TestMacroHelpers.res

@@ -1,25 +1,27 @@
 open Jest
 open Expect
 
-module Bindings = Reducer_Expression_Bindings
+module BindingsReplacer = Reducer_Expression_BindingsReplacer
 module Expression = Reducer_Expression
-module ExpressionValue = ReducerInterface_ExpressionValue
+// module ExpressionValue = ReducerInterface.ExpressionValue
+module InternalExpressionValue = ReducerInterface.InternalExpressionValue
 module ExpressionWithContext = Reducer_ExpressionWithContext
 module Macro = Reducer_Expression_Macro
 module T = Reducer_Expression_T
+module Bindings = Reducer_Bindings
 
 let testMacro_ = (
   tester,
-  bindArray: array<(string, ExpressionValue.expressionValue)>,
+  bindArray: array<(string, InternalExpressionValue.t)>,
   expr: T.expression,
   expectedCode: string,
 ) => {
-  let bindings = Belt.Map.String.fromArray(bindArray)
+  let bindings = Bindings.fromArray(bindArray)
   tester(expr->T.toString, () =>
     expr
     ->Macro.expandMacroCall(
       bindings,
-      ExpressionValue.defaultEnvironment,
+      InternalExpressionValue.defaultEnvironment,
       Expression.reduceExpression,
     )
     ->ExpressionWithContext.toStringResult
@@ -30,39 +32,43 @@ let testMacro_ = (
 
 let testMacroEval_ = (
   tester,
-  bindArray: array<(string, ExpressionValue.expressionValue)>,
+  bindArray: array<(string, InternalExpressionValue.t)>,
   expr: T.expression,
   expectedValue: string,
 ) => {
-  let bindings = Belt.Map.String.fromArray(bindArray)
+  let bindings = Bindings.fromArray(bindArray)
   tester(expr->T.toString, () =>
     expr
-    ->Macro.doMacroCall(bindings, ExpressionValue.defaultEnvironment, Expression.reduceExpression)
-    ->ExpressionValue.toStringResult
+    ->Macro.doMacroCall(
+      bindings,
+      InternalExpressionValue.defaultEnvironment,
+      Expression.reduceExpression,
+    )
+    ->InternalExpressionValue.toStringResult
     ->expect
     ->toEqual(expectedValue)
   )
 }
 
 let testMacro = (
-  bindArray: array<(string, ExpressionValue.expressionValue)>,
+  bindArray: array<(string, InternalExpressionValue.t)>,
   expr: T.expression,
   expectedExpr: string,
 ) => testMacro_(test, bindArray, expr, expectedExpr)
 let testMacroEval = (
-  bindArray: array<(string, ExpressionValue.expressionValue)>,
+  bindArray: array<(string, InternalExpressionValue.t)>,
   expr: T.expression,
   expectedValue: string,
 ) => testMacroEval_(test, bindArray, expr, expectedValue)
 
 module MySkip = {
   let testMacro = (
-    bindArray: array<(string, ExpressionValue.expressionValue)>,
+    bindArray: array<(string, InternalExpressionValue.t)>,
     expr: T.expression,
     expectedExpr: string,
   ) => testMacro_(Skip.test, bindArray, expr, expectedExpr)
   let testMacroEval = (
-    bindArray: array<(string, ExpressionValue.expressionValue)>,
+    bindArray: array<(string, InternalExpressionValue.t)>,
     expr: T.expression,
     expectedValue: string,
   ) => testMacroEval_(Skip.test, bindArray, expr, expectedValue)
@@ -70,12 +76,12 @@ module MySkip = {
 
 module MyOnly = {
   let testMacro = (
-    bindArray: array<(string, ExpressionValue.expressionValue)>,
+    bindArray: array<(string, InternalExpressionValue.t)>,
     expr: T.expression,
     expectedExpr: string,
   ) => testMacro_(Only.test, bindArray, expr, expectedExpr)
   let testMacroEval = (
-    bindArray: array<(string, ExpressionValue.expressionValue)>,
+    bindArray: array<(string, InternalExpressionValue.t)>,
     expr: T.expression,
     expectedValue: string,
   ) => testMacroEval_(Only.test, bindArray, expr, expectedValue)

packages/squiggle-lang/__tests__/Reducer/Reducer_Type/Reducer_Type_Compile_test.res

@@ -0,0 +1,52 @@
+module Expression = Reducer_Expression
+module InternalExpressionValue = ReducerInterface_InternalExpressionValue
+module Bindings = Reducer_Bindings
+module T = Reducer_Type_T
+module TypeCompile = Reducer_Type_Compile
+
+open Jest
+open Expect
+
+let myIevEval = (aTypeSourceCode: string) =>
+  TypeCompile.ievFromTypeExpression(aTypeSourceCode, Expression.reduceExpression)
+let myIevEvalToString = (aTypeSourceCode: string) =>
+  myIevEval(aTypeSourceCode)->InternalExpressionValue.toStringResult
+
+let myIevExpectEqual = (aTypeSourceCode, answer) =>
+  expect(myIevEvalToString(aTypeSourceCode))->toEqual(answer)
+
+let myIevTest = (test, aTypeSourceCode, answer) =>
+  test(aTypeSourceCode, () => myIevExpectEqual(aTypeSourceCode, answer))
+
+let myTypeEval = (aTypeSourceCode: string) =>
+  TypeCompile.fromTypeExpression(aTypeSourceCode, Expression.reduceExpression)
+let myTypeEvalToString = (aTypeSourceCode: string) => myTypeEval(aTypeSourceCode)->T.toStringResult
+
+let myTypeExpectEqual = (aTypeSourceCode, answer) =>
+  expect(myTypeEvalToString(aTypeSourceCode))->toEqual(answer)
+
+let myTypeTest = (test, aTypeSourceCode, answer) =>
+  test(aTypeSourceCode, () => myTypeExpectEqual(aTypeSourceCode, answer))
+
+//   | ItTypeIdentifier(string)
+myTypeTest(test, "number", "number")
+myTypeTest(test, "(number)", "number")
+//   | ItModifiedType({modifiedType: iType})
+myIevTest(test, "number<-min(0)", "Ok({min: 0,typeIdentifier: #number,typeTag: 'typeIdentifier'})")
+myTypeTest(test, "number<-min(0)", "number<-min(0)")
+//   | ItTypeOr({typeOr: array<iType>})
+myTypeTest(test, "number | string", "(number | string)")
+//   | ItTypeFunction({inputs: array<iType>, output: iType})
+myTypeTest(test, "number => number => number", "(number => number => number)")
+//   | ItTypeArray({element: iType})
+myIevTest(test, "[number]", "Ok({element: #number,typeTag: 'typeArray'})")
+myTypeTest(test, "[number]", "[number]")
+//   | ItTypeTuple({elements: array<iType>})
+myTypeTest(test, "[number, string]", "[number, string]")
+//   | ItTypeRecord({properties: Belt.Map.String.t<iType>})
+myIevTest(
+  test,
+  "{age: number, name: string}",
+  "Ok({properties: {age: #number,name: #string},typeTag: 'typeRecord'})",
+)
+myTypeTest(test, "{age: number, name: string}", "{age: number, name: string}")

packages/squiggle-lang/__tests__/Reducer/Reducer_Type/Reducer_Type_TypeChecker_arguments_test.res

@@ -0,0 +1,41 @@
+module Expression = Reducer_Expression
+module ExpressionT = Reducer_Expression_T
+module ErrorValue = Reducer_ErrorValue
+module InternalExpressionValue = ReducerInterface_InternalExpressionValue
+module Bindings = Reducer_Bindings
+module T = Reducer_Type_T
+module TypeChecker = Reducer_Type_TypeChecker
+
+open Jest
+open Expect
+
+let checkArgumentsSourceCode = (aTypeSourceCode: string, sourceCode: string): result<
+  'v,
+  ErrorValue.t,
+> => {
+  let reducerFn = Expression.reduceExpression
+  let rResult =
+    Reducer.parse(sourceCode)->Belt.Result.flatMap(expr =>
+      reducerFn(expr, Bindings.emptyBindings, InternalExpressionValue.defaultEnvironment)
+    )
+  rResult->Belt.Result.flatMap(result =>
+    switch result {
+    | IEvArray(args) => TypeChecker.checkArguments(aTypeSourceCode, args, reducerFn)
+    | _ => Js.Exn.raiseError("Arguments has to be an array")
+    }
+  )
+}
+
+let myCheckArguments = (aTypeSourceCode: string, sourceCode: string): string =>
+  switch checkArgumentsSourceCode(aTypeSourceCode, sourceCode) {
+  | Ok(_) => "Ok"
+  | Error(error) => ErrorValue.errorToString(error)
+  }
+
+let myCheckArgumentsExpectEqual = (aTypeSourceCode, sourceCode, answer) =>
+  expect(myCheckArguments(aTypeSourceCode, sourceCode))->toEqual(answer)
+
+let myCheckArgumentsTest = (test, aTypeSourceCode, sourceCode, answer) =>
+  test(aTypeSourceCode, () => myCheckArgumentsExpectEqual(aTypeSourceCode, sourceCode, answer))
+
+myCheckArgumentsTest(test, "number=>number=>number", "[1,2]", "Ok")

packages/squiggle-lang/__tests__/Reducer/Reducer_Type/Reducer_Type_TypeChecker_test.res

@@ -0,0 +1,70 @@
+module Expression = Reducer_Expression
+module ExpressionT = Reducer_Expression_T
+module ErrorValue = Reducer_ErrorValue
+module InternalExpressionValue = ReducerInterface_InternalExpressionValue
+module Bindings = Reducer_Bindings
+module T = Reducer_Type_T
+module TypeChecker = Reducer_Type_TypeChecker
+
+open Jest
+open Expect
+
+// In development, you are expected to use TypeChecker.isTypeOf(aTypeSourceCode, result, reducerFn).
+// isTypeOfSourceCode is written to use strings instead of expression values.
+
+let isTypeOfSourceCode = (aTypeSourceCode: string, sourceCode: string): result<
+  'v,
+  ErrorValue.t,
+> => {
+  let reducerFn = Expression.reduceExpression
+  let rResult =
+    Reducer.parse(sourceCode)->Belt.Result.flatMap(expr =>
+      reducerFn(expr, Bindings.emptyBindings, InternalExpressionValue.defaultEnvironment)
+    )
+  rResult->Belt.Result.flatMap(result => TypeChecker.isTypeOf(aTypeSourceCode, result, reducerFn))
+}
+
+let myTypeCheck = (aTypeSourceCode: string, sourceCode: string): string =>
+  switch isTypeOfSourceCode(aTypeSourceCode, sourceCode) {
+  | Ok(_) => "Ok"
+  | Error(error) => ErrorValue.errorToString(error)
+  }
+
+let myTypeCheckExpectEqual = (aTypeSourceCode, sourceCode, answer) =>
+  expect(myTypeCheck(aTypeSourceCode, sourceCode))->toEqual(answer)
+
+let myTypeCheckTest = (test, aTypeSourceCode, sourceCode, answer) =>
+  test(aTypeSourceCode, () => myTypeCheckExpectEqual(aTypeSourceCode, sourceCode, answer))
+
+myTypeCheckTest(test, "number", "1", "Ok")
+myTypeCheckTest(test, "number", "'2'", "Expected type: number but got: '2'")
+myTypeCheckTest(test, "string", "3", "Expected type: string but got: 3")
+myTypeCheckTest(test, "string", "'a'", "Ok")
+myTypeCheckTest(test, "[number]", "[1,2,3]", "Ok")
+myTypeCheckTest(test, "[number]", "['a','a','a']", "Expected type: number but got: 'a'")
+myTypeCheckTest(test, "[number]", "[1,'a',3]", "Expected type: number but got: 'a'")
+myTypeCheckTest(test, "[number, string]", "[1,'a']", "Ok")
+myTypeCheckTest(test, "[number, string]", "[1, 2]", "Expected type: string but got: 2")
+myTypeCheckTest(
+  test,
+  "[number, string, string]",
+  "[1,'a']",
+  "Expected type: [number, string, string] but got: [1,'a']",
+)
+myTypeCheckTest(
+  test,
+  "[number, string]",
+  "[1,'a', 3]",
+  "Expected type: [number, string] but got: [1,'a',3]",
+)
+myTypeCheckTest(test, "{age: number, name: string}", "{age: 1, name: 'a'}", "Ok")
+myTypeCheckTest(
+  test,
+  "{age: number, name: string}",
+  "{age: 1, name: 'a', job: 'IT'}",
+  "Expected type: {age: number, name: string} but got: {age: 1,job: 'IT',name: 'a'}",
+)
+myTypeCheckTest(test, "number | string", "1", "Ok")
+myTypeCheckTest(test, "date | string", "1", "Expected type: (date | string) but got: 1")
+myTypeCheckTest(test, "number<-min(10)", "10", "Ok")
+myTypeCheckTest(test, "number<-min(10)", "0", "Expected type: number<-min(10) but got: 0")

packages/squiggle-lang/__tests__/Reducer/Reducer_externalBindings_test.res

@@ -1,11 +1,14 @@
-// TODO: Reimplement with usual parse
 open Jest
 open Reducer_TestHelpers
 
 describe("Eval with Bindings", () => {
-  testEvalBindingsToBe("x", list{("x", ExpressionValue.EvNumber(1.))}, "Ok(1)")
-  testEvalBindingsToBe("x+1", list{("x", ExpressionValue.EvNumber(1.))}, "Ok(2)")
+  testEvalBindingsToBe("x", list{("x", ExternalExpressionValue.EvNumber(1.))}, "Ok(1)")
+  testEvalBindingsToBe("x+1", list{("x", ExternalExpressionValue.EvNumber(1.))}, "Ok(2)")
   testParseToBe("y = x+1; y", "Ok({(:$_let_$ :y {(:add :x 1)}); :y})")
-  testEvalBindingsToBe("y = x+1; y", list{("x", ExpressionValue.EvNumber(1.))}, "Ok(2)")
-  testEvalBindingsToBe("y = x+1", list{("x", ExpressionValue.EvNumber(1.))}, "Ok({x: 1,y: 2})")
+  testEvalBindingsToBe("y = x+1; y", list{("x", ExternalExpressionValue.EvNumber(1.))}, "Ok(2)")
+  testEvalBindingsToBe(
+    "y = x+1",
+    list{("x", ExternalExpressionValue.EvNumber(1.))},
+    "Ok(@{x: 1,y: 2})",
+  )
 })

packages/squiggle-lang/__tests__/Reducer/Reducer_functionTricks_test.res

@@ -39,15 +39,15 @@ describe("symbol not defined", () => {
 })
 
 describe("call and bindings", () => {
-  testEvalToBe("f(x)=x+1", "Ok({f: lambda(x=>internal code)})")
+  testEvalToBe("f(x)=x+1", "Ok(@{f: lambda(x=>internal code)})")
   testEvalToBe("f(x)=x+1; f(1)", "Ok(2)")
-  testEvalToBe("f=1;y=2", "Ok({f: 1,y: 2})")
-  testEvalToBe("f(x)=x+1; y=f(1)", "Ok({f: lambda(x=>internal code),y: 2})")
+  testEvalToBe("f=1;y=2", "Ok(@{f: 1,y: 2})")
+  testEvalToBe("f(x)=x+1; y=f(1)", "Ok(@{f: lambda(x=>internal code),y: 2})")
   testEvalToBe("f(x)=x+1; y=f(1); f(1)", "Ok(2)")
-  testEvalToBe("f(x)=x+1; y=f(1); z=f(1)", "Ok({f: lambda(x=>internal code),y: 2,z: 2})")
+  testEvalToBe("f(x)=x+1; y=f(1); z=f(1)", "Ok(@{f: lambda(x=>internal code),y: 2,z: 2})")
   testEvalToBe(
     "f(x)=x+1; g(x)=f(x)+1",
-    "Ok({f: lambda(x=>internal code),g: lambda(x=>internal code)})",
+    "Ok(@{f: lambda(x=>internal code),g: lambda(x=>internal code)})",
   )
   testParseToBe(
     "f=99; g(x)=f; g(2)",
@@ -57,7 +57,7 @@ describe("call and bindings", () => {
   testEvalToBe("f(x)=x; g(x)=f(x); g(2)", "Ok(2)")
   testEvalToBe(
     "f(x)=x+1; g(x)=f(x)+1; y=g(2)",
-    "Ok({f: lambda(x=>internal code),g: lambda(x=>internal code),y: 4})",
+    "Ok(@{f: lambda(x=>internal code),g: lambda(x=>internal code),y: 4})",
   )
   testEvalToBe("f(x)=x+1; g(x)=f(x)+1; g(2)", "Ok(4)")
 })
@@ -65,7 +65,7 @@ describe("call and bindings", () => {
 describe("function tricks", () => {
   testEvalError("f(x)=f(y)=2; f(2)") //Error because chain assignment is not allowed
   testEvalToBe("y=2;g(x)=y+1;g(2)", "Ok(3)")
-  testEvalToBe("y=2;g(x)=inspect(y)+1", "Ok({g: lambda(x=>internal code),y: 2})")
+  testEvalToBe("y=2;g(x)=inspect(y)+1", "Ok(@{g: lambda(x=>internal code),y: 2})")
   MySkip.testEvalToBe("f(x) = x(x); f(f)", "????") // TODO: Infinite loop. Any solution? Catching proper exception or timeout?
   MySkip.testEvalToBe("f(x, x)=x+x; f(1,2)", "????") // TODO: Duplicate parameters
   testEvalToBe("myadd(x,y)=x+y; z=myadd; z", "Ok(lambda(x,y=>internal code))")
@@ -75,7 +75,7 @@ describe("function tricks", () => {
 describe("lambda in structures", () => {
   testEvalToBe(
     "myadd(x,y)=x+y; z=[myadd]",
-    "Ok({myadd: lambda(x,y=>internal code),z: [lambda(x,y=>internal code)]})",
+    "Ok(@{myadd: lambda(x,y=>internal code),z: [lambda(x,y=>internal code)]})",
   )
   testEvalToBe("myadd(x,y)=x+y; z=[myadd]; z[0]", "Ok(lambda(x,y=>internal code))")
   testEvalToBe("myadd(x,y)=x+y; z=[myadd]; z[0](3,2)", "Ok(5)")

packages/squiggle-lang/__tests__/Reducer/Reducer_mapReduce_test.res

@@ -1,15 +1,6 @@
 open Jest
 open Reducer_TestHelpers
 
-describe("map reduce", () => {
-  testEvalToBe("double(x)=2*x; arr=[1,2,3]; map(arr, double)", "Ok([2,4,6])")
-  testEvalToBe("myadd(acc,x)=acc+x; arr=[1,2,3]; reduce(arr, 0, myadd)", "Ok(6)")
-  testEvalToBe("change(acc,x)=acc*x+x; arr=[1,2,3]; reduce(arr, 0, change)", "Ok(15)")
-  testEvalToBe("change(acc,x)=acc*x+x; arr=[1,2,3]; reduceReverse(arr, 0, change)", "Ok(9)")
-  testEvalToBe("arr=[1,2,3]; reverse(arr)", "Ok([3,2,1])")
-  testEvalToBe("check(x)=(x==2);arr=[1,2,3]; filter(arr,check)", "Ok([2])")
-})
-
 Skip.describe("map reduce (sam)", () => {
   testEvalToBe("addone(x)=x+1; map(2, addone)", "Error???")
   testEvalToBe("addone(x)=x+1; map(2, {x: addone})", "Error???")

packages/squiggle-lang/__tests__/Reducer/Reducer_ternaryOperator_test.res

@@ -10,5 +10,5 @@ describe("Evaluate ternary operator", () => {
   testEvalToBe("false ? 'YES' : 'NO'", "Ok('NO')")
   testEvalToBe("2 > 1 ? 'YES' : 'NO'", "Ok('YES')")
   testEvalToBe("2 <= 1 ? 'YES' : 'NO'", "Ok('NO')")
-  testEvalToBe("1+1 ? 'YES' : 'NO'", "Error(Expected type: Boolean)")
+  testEvalToBe("1+1 ? 'YES' : 'NO'", "Error(Expected type: Boolean but got: )")
 })

packages/squiggle-lang/__tests__/Reducer/Reducer_test.res

@@ -39,7 +39,7 @@ describe("eval", () => {
     testEvalToBe("x=1; y=x+1; y+1", "Ok(3)")
     testEvalError("1; x=1")
     testEvalError("1; 1")
-    testEvalToBe("x=1; x=1", "Ok({x: 1})")
+    testEvalToBe("x=1; x=1", "Ok(@{x: 1})")
   })
 })
 

packages/squiggle-lang/__tests__/ReducerInterface/ReducerInterface_Distribution_test.res

@@ -41,12 +41,6 @@ describe("eval on distribution functions", () => {
   describe("normalize", () => {
     testEval("normalize(normal(5,2))", "Ok(Normal(5,2))")
   })
-  describe("toPointSet", () => {
-    testEval("toPointSet(normal(5,2))", "Ok(Point Set Distribution)")
-  })
-  describe("toSampleSet", () => {
-    testEval("toSampleSet(normal(5,2), 100)", "Ok(Sample Set Distribution)")
-  })
   describe("add", () => {
     testEval("add(normal(5,2), normal(10,2))", "Ok(Normal(15,2.8284271247461903))")
     testEval("add(normal(5,2), lognormal(10,2))", "Ok(Sample Set Distribution)")

packages/squiggle-lang/__tests__/ReducerInterface/ReducerInterface_ExpressionValue_test.res

@@ -1,4 +1,4 @@
-open ReducerInterface.ExpressionValue
+open ReducerInterface.ExternalExpressionValue
 open Jest
 open Expect
 

packages/squiggle-lang/__tests__/SquiggleLibrary/SquiggleLibrary_FunctionRegistryLibrary_test.res

@@ -0,0 +1,98 @@
+open Jest
+open Expect
+open Reducer_TestHelpers
+
+let expectEvalToBeOk = (expr: string) =>
+  Reducer.evaluate(expr)->Reducer_Helpers.rRemoveDefaultsExternal->E.R.isOk->expect->toBe(true)
+
+let registry = FunctionRegistry_Library.registry
+let examples = E.A.to_list(FunctionRegistry_Core.Registry.allExamples(registry))
+
+describe("FunctionRegistry Library", () => {
+  describe("Regular tests", () => {
+    testEvalToBe("List.make(3, 'HI')", "Ok(['HI','HI','HI'])")
+    testEvalToBe("make(3, 'HI')", "Error(Function not found: make(Number,String))")
+    testEvalToBe("List.upTo(1,3)", "Ok([1,2,3])")
+    testEvalToBe("List.first([3,5,8])", "Ok(3)")
+    testEvalToBe("List.last([3,5,8])", "Ok(8)")
+    testEvalToBe("List.reverse([3,5,8])", "Ok([8,5,3])")
+    testEvalToBe("double(x)=2*x; arr=[1,2,3]; List.map(arr, double)", "Ok([2,4,6])")
+    testEvalToBe("double(x)=2*x; arr=[1,2,3]; map(arr, double)", "Ok([2,4,6])")
+    testEvalToBe("myadd(acc,x)=acc+x; arr=[1,2,3]; List.reduce(arr, 0, myadd)", "Ok(6)")
+    testEvalToBe("change(acc,x)=acc*x+x; arr=[1,2,3]; List.reduce(arr, 0, change)", "Ok(15)")
+    testEvalToBe("change(acc,x)=acc*x+x; arr=[1,2,3]; List.reduceReverse(arr, 0, change)", "Ok(9)")
+    testEvalToBe("check(x)=(x==2);arr=[1,2,3]; List.filter(arr,check)", "Ok([2])")
+    testEvalToBe("arr=[1,2,3]; List.reverse(arr)", "Ok([3,2,1])")
+    testEvalToBe("Dist.normal(5,2)", "Ok(Normal(5,2))")
+    testEvalToBe("normal(5,2)", "Ok(Normal(5,2))")
+    testEvalToBe("normal({mean:5,stdev:2})", "Ok(Normal(5,2))")
+    testEvalToBe("-2 to 4", "Ok(Normal(1,1.8238704957353074))")
+    testEvalToBe("pointMass(5)", "Ok(PointMass(5))")
+    testEvalToBe("Number.floor(5.5)", "Ok(5)")
+    testEvalToBe("Number.ceil(5.5)", "Ok(6)")
+    testEvalToBe("floor(5.5)", "Ok(5)")
+    testEvalToBe("ceil(5.5)", "Ok(6)")
+    testEvalToBe("Number.abs(5.5)", "Ok(5.5)")
+    testEvalToBe("abs(5.5)", "Ok(5.5)")
+    testEvalToBe("Number.exp(10)", "Ok(22026.465794806718)")
+    testEvalToBe("Number.log10(10)", "Ok(1)")
+    testEvalToBe("Number.log2(10)", "Ok(3.321928094887362)")
+    testEvalToBe("Number.sum([2,5,3])", "Ok(10)")
+    testEvalToBe("sum([2,5,3])", "Ok(10)")
+    testEvalToBe("Number.product([2,5,3])", "Ok(30)")
+    testEvalToBe("Number.min([2,5,3])", "Ok(2)")
+    testEvalToBe("Number.max([2,5,3])", "Ok(5)")
+    testEvalToBe("Number.mean([0,5,10])", "Ok(5)")
+    testEvalToBe("Number.geomean([1,5,18])", "Ok(4.481404746557164)")
+    testEvalToBe("Number.stdev([0,5,10,15])", "Ok(5.5901699437494745)")
+    testEvalToBe("Number.variance([0,5,10,15])", "Ok(31.25)")
+    testEvalToBe("Number.sort([10,0,15,5])", "Ok([0,5,10,15])")
+    testEvalToBe("Number.cumsum([1,5,3])", "Ok([1,6,9])")
+    testEvalToBe("Number.cumprod([1,5,3])", "Ok([1,5,15])")
+    testEvalToBe("Number.diff([1,5,3])", "Ok([4,-2])")
+    testEvalToBe(
+      "Dist.logScore({estimate: normal(5,2), answer: normal(5.2,1), prior: normal(5.5,3)})",
+      "Ok(-0.33591375663884876)",
+    )
+    testEvalToBe(
+      "Dist.logScore({estimate: normal(5,2), answer: normal(5.2,1)})",
+      "Ok(0.32244107041564646)",
+    )
+    testEvalToBe("Dist.logScore({estimate: normal(5,2), answer: 4.5})", "Ok(1.6433360626394853)")
+    testEvalToBe("Dist.klDivergence(normal(5,2), normal(5,1.5))", "Ok(0.06874342818671068)")
+    testEvalToBe("SampleSet.fromList([3,5,2,3,5,2,3,5,2,3,3,5])", "Ok(Sample Set Distribution)")
+    testEvalToBe("SampleSet.fromList([3,5,2,3,5,2,3,5,2,3,3,5])", "Ok(Sample Set Distribution)")
+    testEvalToBe("SampleSet.fromFn({|| sample(normal(5,2))})", "Ok(Sample Set Distribution)")
+    testEvalToBe(
+      "addOne(t)=t+1; SampleSet.toList(SampleSet.map(SampleSet.fromList([1,2,3,4,5,6]), addOne))",
+      "Ok([2,3,4,5,6,7])",
+    )
+    testEvalToBe(
+      "SampleSet.toList(SampleSet.mapN([SampleSet.fromList([1,2,3,4,5,6]), SampleSet.fromList([6, 5, 4, 3, 2, 1])], {|x| x[0] > x[1] ? x[0] : x[1]}))",
+      "Ok([6,5,4,4,5,6])",
+    )
+  })
+
+  describe("Fn auto-testing", () => {
+    testAll("tests of validity", examples, r => {
+      expectEvalToBeOk(r)
+    })
+
+    testAll(
+      "tests of type",
+      E.A.to_list(
+        FunctionRegistry_Core.Registry.allExamplesWithFns(registry)->E.A2.filter(((fn, _)) =>
+          E.O.isSome(fn.output)
+        ),
+      ),
+      ((fn, example)) => {
+        let responseType =
+          example
+          ->Reducer.evaluate
+          ->E.R2.fmap(ReducerInterface_InternalExpressionValue.externalValueToValueType)
+        let expectedOutputType = fn.output |> E.O.toExn("")
+        expect(responseType)->toEqual(Ok(expectedOutputType))
+      },
+    )
+  })
+})

packages/squiggle-lang/__tests__/TS/Jstat_test.ts

@@ -5,7 +5,7 @@ import { testRun } from "./TestHelpers";
 describe("cumulative density function of a normal distribution", () => {
   test("at 3 stdevs to the right of the mean is near 1", () => {
     fc.assert(
-      fc.property(fc.float(), fc.float({ min: 1e-7 }), (mean, stdev) => {
+      fc.property(fc.integer(), fc.integer({ min: 1 }), (mean, stdev) => {
         let threeStdevsAboveMean = mean + 3 * stdev;
         let squiggleString = `cdf(normal(${mean}, ${stdev}), ${threeStdevsAboveMean})`;
         let squiggleResult = testRun(squiggleString);
@@ -16,7 +16,7 @@ describe("cumulative density function of a normal distribution", () => {
 
   test("at 3 stdevs to the left of the mean is near 0", () => {
     fc.assert(
-      fc.property(fc.float(), fc.float({ min: 1e-7 }), (mean, stdev) => {
+      fc.property(fc.integer(), fc.integer({ min: 1 }), (mean, stdev) => {
         let threeStdevsBelowMean = mean - 3 * stdev;
         let squiggleString = `cdf(normal(${mean}, ${stdev}), ${threeStdevsBelowMean})`;
         let squiggleResult = testRun(squiggleString);

packages/squiggle-lang/__tests__/TS/SampleSet_test.ts

@@ -4,13 +4,16 @@ import * as fc from "fast-check";
 
 // Beware: float64Array makes it appear in an infinite loop.
 let arrayGen = () =>
-  fc.float32Array({
-    minLength: 10,
-    maxLength: 10000,
-    noDefaultInfinity: true,
-    noNaN: true,
-  });
-
+  fc
+    .float32Array({
+      minLength: 10,
+      maxLength: 10000,
+      noDefaultInfinity: true,
+      noNaN: true,
+    })
+    .filter(
+      (xs_) => Math.min(...Array.from(xs_)) != Math.max(...Array.from(xs_))
+    );
 describe("cumulative density function", () => {
   let n = 10000;
 
@@ -119,11 +122,7 @@ describe("cumulative density function", () => {
           { sampleCount: n, xyPointLength: 100 }
         );
         let cdfValue = dist.cdf(x).value;
-        if (x < Math.min(...xs)) {
-          expect(cdfValue).toEqual(0);
-        } else {
-          expect(cdfValue).toBeGreaterThan(0);
-        }
+        expect(cdfValue).toBeGreaterThanOrEqual(0);
       })
     );
   });

packages/squiggle-lang/__tests__/TS/Scalars_test.ts

@@ -5,15 +5,11 @@ import * as fc from "fast-check";
 describe("Scalar manipulation is well-modeled by javascript math", () => {
   test("in the case of natural logarithms", () => {
     fc.assert(
-      fc.property(fc.float(), (x) => {
+      fc.property(fc.integer(), (x) => {
         let squiggleString = `log(${x})`;
         let squiggleResult = testRun(squiggleString);
         if (x == 0) {
           expect(squiggleResult.value).toEqual(-Infinity);
-        } else if (x < 0) {
-          expect(squiggleResult.value).toEqual(
-            "somemessage (confused why a test case hasn't pointed out to me that this message is bogus)"
-          );
         } else {
           expect(squiggleResult.value).toEqual(Math.log(x));
         }
@@ -23,7 +19,7 @@ describe("Scalar manipulation is well-modeled by javascript math", () => {
 
   test("in the case of addition (with assignment)", () => {
     fc.assert(
-      fc.property(fc.float(), fc.float(), fc.float(), (x, y, z) => {
+      fc.property(fc.integer(), fc.integer(), fc.integer(), (x, y, z) => {
         let squiggleString = `x = ${x}; y = ${y}; z = ${z}; x + y + z`;
         let squiggleResult = testRun(squiggleString);
         expect(squiggleResult.value).toBeCloseTo(x + y + z);

packages/squiggle-lang/__tests__/TS/Symbolic_test.ts

@@ -1,11 +1,10 @@
-import { errorValueToString } from "../../src/js/index";
 import { testRun } from "./TestHelpers";
 import * as fc from "fast-check";
 
 describe("Symbolic mean", () => {
   test("mean(triangular(x,y,z))", () => {
     fc.assert(
-      fc.property(fc.float(), fc.float(), fc.float(), (x, y, z) => {
+      fc.property(fc.integer(), fc.integer(), fc.integer(), (x, y, z) => {
         if (!(x < y && y < z)) {
           try {
             let squiggleResult = testRun(`mean(triangular(${x},${y},${z}))`);

packages/squiggle-lang/__tests__/TestHelpers.res

@@ -29,7 +29,7 @@ let {toFloat, toDist, toString, toError, fmap} = module(DistributionOperation.Ou
 
 let fnImage = (theFn, inps) => Js.Array.map(theFn, inps)
 
-let env: DistributionOperation.env = {
+let env: GenericDist.env = {
   sampleCount: MagicNumbers.Environment.defaultSampleCount,
   xyPointLength: MagicNumbers.Environment.defaultXYPointLength,
 }

packages/squiggle-lang/bsconfig.json

@@ -31,6 +31,7 @@
       "basic": false
     }
   },
+  "external-stdlib": "@rescript/std",
   "refmt": 3,
   "warnings": {
     "number": "+A-42-48-9-30-4"

packages/squiggle-lang/lint.sh

@@ -19,7 +19,7 @@ do
   fi
 done
 
-files=`ls src/rescript/**/**/*.resi src/rescript/**/*.resi`  # src/rescript/*/resi
+files=`ls src/rescript/**/*.resi`  # src/rescript/*/resi
 for file in $files
 do
   current=`cat $file`

packages/squiggle-lang/package.json

@@ -1,12 +1,14 @@
 {
   "name": "@quri/squiggle-lang",
-  "version": "0.2.9",
+  "version": "0.2.11",
   "homepage": "https://squiggle-language.com",
   "license": "MIT",
   "scripts": {
     "peggy": "peggy --cache",
+    "rescript": "rescript",
     "build": "yarn build:peggy && yarn build:rescript && yarn build:typescript",
-    "build:peggy": "find . -type f -name *.peggy -exec yarn peggy {} \\;",
+    "build:peggy:helpers": "tsc --module commonjs --outDir src/rescript/Reducer/Reducer_Peggy/ src/rescript/Reducer/Reducer_Peggy/helpers.ts",
+    "build:peggy": "yarn build:peggy:helpers && find . -type f -name *.peggy -exec yarn peggy {} \\;",
     "build:rescript": "rescript build -with-deps",
     "build:typescript": "tsc",
     "bundle": "webpack",
@@ -18,6 +20,7 @@
     "test:ts": "jest __tests__/TS/",
     "test:rescript": "jest --modulePathIgnorePatterns=__tests__/TS/*",
     "test:watch": "jest --watchAll",
+    "test:fnRegistry": "jest __tests__/SquiggleLibrary/SquiggleLibrary_FunctionRegistryLibrary_test.bs.js",
     "coverage:rescript": "rm -f *.coverage && yarn clean && BISECT_ENABLE=yes yarn build && yarn test:rescript && bisect-ppx-report html",
     "coverage:ts": "yarn clean && yarn build && nyc --reporter=lcov yarn test:ts",
     "coverage:rescript:ci": "yarn clean && BISECT_ENABLE=yes yarn build:rescript && yarn test:rescript && bisect-ppx-report send-to Codecov",
@@ -29,6 +32,7 @@
     "format:prettier": "prettier --write .",
     "format": "yarn format:rescript && yarn format:prettier",
     "prepack": "yarn build && yarn test && yarn bundle",
+    "all:rescript": "yarn build:rescript && yarn test:rescript && yarn format:rescript",
     "all": "yarn build && yarn bundle && yarn test"
   },
   "keywords": [
@@ -36,11 +40,12 @@
   ],
   "author": "Quantified Uncertainty Research Institute",
   "dependencies": {
+    "@rescript/std": "^9.1.4",
     "@stdlib/stats": "^0.0.13",
     "jstat": "^1.9.5",
-    "mathjs": "^10.6.0",
-    "pdfast": "^0.2.0",
-    "rescript": "^9.1.4"
+    "lodash": "^4.17.21",
+    "mathjs": "^11.0.1",
+    "pdfast": "^0.2.0"
   },
   "devDependencies": {
     "@glennsl/rescript-jest": "^0.9.0",
@@ -50,20 +55,21 @@
     "bisect_ppx": "^2.7.1",
     "chalk": "^5.0.1",
     "codecov": "^3.8.3",
-    "fast-check": "^2.25.0",
-    "gentype": "^4.4.0",
+    "fast-check": "^3.1.0",
+    "gentype": "^4.5.0",
     "jest": "^27.5.1",
-    "lodash": "^4.17.21",
     "moduleserve": "^0.9.1",
     "nyc": "^15.1.0",
     "peggy": "^2.0.1",
+    "prettier": "^2.7.1",
     "reanalyze": "^2.23.0",
+    "rescript": "^9.1.4",
     "rescript-fast-check": "^1.1.1",
     "ts-jest": "^27.1.4",
     "ts-loader": "^9.3.0",
-    "ts-node": "^10.8.1",
-    "typescript": "^4.7.3",
-    "webpack": "^5.73.0",
+    "ts-node": "^10.9.1",
+    "typescript": "^4.7.4",
+    "webpack": "^5.74.0",
     "webpack-cli": "^4.10.0"
   },
   "source": "./src/js/index.ts",

packages/squiggle-lang/src/js/index.ts

@@ -37,6 +37,8 @@ import { Distribution, shape } from "./distribution";
 export { Distribution, resultMap, defaultEnvironment };
 export type { result, shape, environment, lambdaValue, squiggleExpression };
 
+export { parse } from "./parse";
+
 export let defaultSamplingInputs: environment = {
   sampleCount: 10000,
   xyPointLength: 10000,
@@ -118,85 +120,86 @@ function createTsExport(
   x: expressionValue,
   environment: environment
 ): squiggleExpression {
-  switch (x.tag) {
-    case "EvArray":
-      // genType doesn't convert anything more than 2 layers down into {tag: x, value: x}
-      // format, leaving it as the raw values. This converts the raw values
-      // directly into typescript values.
-      //
-      // The casting here is because genType is about the types of the returned
-      // values, claiming they are fully recursive when that's not actually the
-      // case
-      return tag(
-        "array",
-        x.value.map((arrayItem): squiggleExpression => {
-          switch (arrayItem.tag) {
-            case "EvRecord":
-              return tag(
-                "record",
-                _.mapValues(arrayItem.value, (recordValue: unknown) =>
-                  convertRawToTypescript(
-                    recordValue as rescriptExport,
-                    environment
-                  )
+  switch (x) {
+    case "EvVoid":
+      return tag("void", "");
+    default: {
+      switch (x.tag) {
+        case "EvArray":
+          // genType doesn't convert anything more than 2 layers down into {tag: x, value: x}
+          // format, leaving it as the raw values. This converts the raw values
+          // directly into typescript values.
+          //
+          // The casting here is because genType is about the types of the returned
+          // values, claiming they are fully recursive when that's not actually the
+          // case
+          return tag(
+            "array",
+            x.value.map(
+              (arrayItem): squiggleExpression =>
+                convertRawToTypescript(
+                  arrayItem as unknown as rescriptExport,
+                  environment
                 )
-              );
-            case "EvArray":
-              let y = arrayItem.value as unknown as rescriptExport[];
-              return tag(
-                "array",
-                y.map((childArrayItem) =>
-                  convertRawToTypescript(childArrayItem, environment)
-                )
-              );
-            default:
-              return createTsExport(arrayItem, environment);
-          }
-        })
-      );
-    case "EvArrayString":
-      return tag("arraystring", x.value);
-    case "EvBool":
-      return tag("boolean", x.value);
-    case "EvCall":
-      return tag("call", x.value);
-    case "EvLambda":
-      return tag("lambda", x.value);
-    case "EvDistribution":
-      return tag("distribution", new Distribution(x.value, environment));
-    case "EvNumber":
-      return tag("number", x.value);
-    case "EvRecord":
-      // genType doesn't support records, so we have to do the raw conversion ourself
-      let result: tagged<"record", { [key: string]: squiggleExpression }> = tag(
-        "record",
-        _.mapValues(x.value, (x: unknown) =>
-          convertRawToTypescript(x as rescriptExport, environment)
-        )
-      );
-      return result;
-    case "EvString":
-      return tag("string", x.value);
-    case "EvSymbol":
-      return tag("symbol", x.value);
-    case "EvDate":
-      return tag("date", x.value);
-    case "EvTimeDuration":
-      return tag("timeDuration", x.value);
-    case "EvDeclaration":
-      return tag("lambdaDeclaration", x.value);
-    case "EvTypeIdentifier":
-      return tag("typeIdentifier", x.value);
-    case "EvModule":
-      let moduleResult: tagged<
-        "module",
-        { [key: string]: squiggleExpression }
-      > = tag(
-        "module",
-        _.mapValues(x.value, (x: unknown) =>
-          convertRawToTypescript(x as rescriptExport, environment)
-        )
-      );
-      return moduleResult;
+            )
+          );
+        case "EvArrayString":
+          return tag("arraystring", x.value);
+        case "EvBool":
+          return tag("boolean", x.value);
+        case "EvCall":
+          return tag("call", x.value);
+        case "EvLambda":
+          return tag("lambda", x.value);
+        case "EvDistribution":
+          return tag("distribution", new Distribution(x.value, environment));
+        case "EvNumber":
+          return tag("number", x.value);
+        case "EvRecord":
+          // genType doesn't support records, so we have to do the raw conversion ourself
+          let result: tagged<"record", { [key: string]: squiggleExpression }> =
+            tag(
+              "record",
+              _.mapValues(x.value, (x: unknown) =>
+                convertRawToTypescript(x as rescriptExport, environment)
+              )
+            );
+          return result;
+        case "EvString":
+          return tag("string", x.value);
+        case "EvSymbol":
+          return tag("symbol", x.value);
+        case "EvDate":
+          return tag("date", x.value);
+        case "EvTimeDuration":
+          return tag("timeDuration", x.value);
+        case "EvDeclaration":
+          return tag("lambdaDeclaration", x.value);
+        case "EvTypeIdentifier":
+          return tag("typeIdentifier", x.value);
+        case "EvType":
+          let typeResult: tagged<
+            "type",
+            { [key: string]: squiggleExpression }
+          > = tag(
+            "type",
+            _.mapValues(x.value, (x: unknown) =>
+              convertRawToTypescript(x as rescriptExport, environment)
+            )
+          );
+          return typeResult;
+        case "EvModule":
+          let moduleResult: tagged<
+            "module",
+            { [key: string]: squiggleExpression }
+          > = tag(
+            "module",
+            _.mapValues(x.value, (x: unknown) =>
+              convertRawToTypescript(x as rescriptExport, environment)
+            )
+          );
+          return moduleResult;
+      }
+    }
   }
 }

packages/squiggle-lang/src/js/parse.ts

@@ -0,0 +1,23 @@
+import {
+  errorValue,
+  parse as parseRescript,
+} from "../rescript/TypescriptInterface.gen";
+import { result } from "./types";
+import { AnyPeggyNode } from "../rescript/Reducer/Reducer_Peggy/helpers";
+
+export function parse(
+  squiggleString: string
+): result<AnyPeggyNode, Extract<errorValue, { tag: "RESyntaxError" }>> {
+  const maybeExpression = parseRescript(squiggleString);
+  if (maybeExpression.tag === "Ok") {
+    return { tag: "Ok", value: maybeExpression.value as AnyPeggyNode };
+  } else {
+    if (
+      typeof maybeExpression.value !== "object" ||
+      maybeExpression.value.tag !== "RESyntaxError"
+    ) {
+      throw new Error("Expected syntax error");
+    }
+    return { tag: "Error", value: maybeExpression.value };
+  }
+}

packages/squiggle-lang/src/js/rescript_interop.ts

@@ -129,8 +129,10 @@ export type squiggleExpression =
   | tagged<"timeDuration", number>
   | tagged<"lambdaDeclaration", lambdaDeclaration>
   | tagged<"record", { [key: string]: squiggleExpression }>
+  | tagged<"type", { [key: string]: squiggleExpression }>
   | tagged<"typeIdentifier", string>
-  | tagged<"module", { [key: string]: squiggleExpression }>;
+  | tagged<"module", { [key: string]: squiggleExpression }>
+  | tagged<"void", string>;
 
 export { lambdaValue };
 

packages/squiggle-lang/src/rescript/Distributions/DistributionOperation.res

@@ -4,12 +4,9 @@ type error = DistributionTypes.error
 
 // TODO: It could be great to use a cache for some calculations (basically, do memoization). Also, better analytics/tracking could go a long way.
 
-type env = {
-  sampleCount: int,
-  xyPointLength: int,
-}
+type env = GenericDist.env
 
-let defaultEnv = {
+let defaultEnv: env = {
   sampleCount: MagicNumbers.Environment.defaultSampleCount,
   xyPointLength: MagicNumbers.Environment.defaultXYPointLength,
 }
@@ -93,7 +90,7 @@ module OutputLocal = {
     }
 }
 
-let rec run = (~env, functionCallInfo: functionCallInfo): outputType => {
+let rec run = (~env: env, functionCallInfo: functionCallInfo): outputType => {
   let {sampleCount, xyPointLength} = env
 
   let reCall = (~env=env, ~functionCallInfo=functionCallInfo, ()) => {
@@ -101,14 +98,14 @@ let rec run = (~env, functionCallInfo: functionCallInfo): outputType => {
   }
 
   let toPointSetFn = r => {
-    switch reCall(~functionCallInfo=FromDist(ToDist(ToPointSet), r), ()) {
+    switch reCall(~functionCallInfo=FromDist(#ToDist(ToPointSet), r), ()) {
     | Dist(PointSet(p)) => Ok(p)
     | e => Error(OutputLocal.toErrorOrUnreachable(e))
     }
   }
 
   let toSampleSetFn = r => {
-    switch reCall(~functionCallInfo=FromDist(ToDist(ToSampleSet(sampleCount)), r), ()) {
+    switch reCall(~functionCallInfo=FromDist(#ToDist(ToSampleSet(sampleCount)), r), ()) {
     | Dist(SampleSet(p)) => Ok(p)
     | e => Error(OutputLocal.toErrorOrUnreachable(e))
     }
@@ -116,13 +113,13 @@ let rec run = (~env, functionCallInfo: functionCallInfo): outputType => {
 
   let scaleMultiply = (r, weight) =>
     reCall(
-      ~functionCallInfo=FromDist(ToDistCombination(Pointwise, #Multiply, #Float(weight)), r),
+      ~functionCallInfo=FromDist(#ToDistCombination(Pointwise, #Multiply, #Float(weight)), r),
       (),
     )->OutputLocal.toDistR
 
   let pointwiseAdd = (r1, r2) =>
     reCall(
-      ~functionCallInfo=FromDist(ToDistCombination(Pointwise, #Add, #Dist(r2)), r1),
+      ~functionCallInfo=FromDist(#ToDistCombination(Pointwise, #Add, #Dist(r2)), r1),
       (),
     )->OutputLocal.toDistR
 
@@ -131,49 +128,40 @@ let rec run = (~env, functionCallInfo: functionCallInfo): outputType => {
     dist: genericDist,
   ): outputType => {
     let response = switch subFnName {
-    | ToFloat(distToFloatOperation) =>
+    | #ToFloat(distToFloatOperation) =>
       GenericDist.toFloatOperation(dist, ~toPointSetFn, ~distToFloatOperation)
       ->E.R2.fmap(r => Float(r))
       ->OutputLocal.fromResult
-    | ToString(ToString) => dist->GenericDist.toString->String
-    | ToString(ToSparkline(bucketCount)) =>
+    | #ToString(ToString) => dist->GenericDist.toString->String
+    | #ToString(ToSparkline(bucketCount)) =>
       GenericDist.toSparkline(dist, ~sampleCount, ~bucketCount, ())
       ->E.R2.fmap(r => String(r))
       ->OutputLocal.fromResult
-    | ToDist(Inspect) => {
+    | #ToDist(Inspect) => {
         Js.log2("Console log requested: ", dist)
         Dist(dist)
       }
-    | ToDist(Normalize) => dist->GenericDist.normalize->Dist
-    | ToScore(KLDivergence(t2)) =>
-      GenericDist.Score.klDivergence(dist, t2, ~toPointSetFn)
-      ->E.R2.fmap(r => Float(r))
+    | #ToDist(Normalize) => dist->GenericDist.normalize->Dist
+    | #ToScore(LogScore(answer, prior)) =>
+      GenericDist.Score.logScore(~estimate=dist, ~answer, ~prior, ~env)
+      ->E.R2.fmap(s => Float(s))
       ->OutputLocal.fromResult
-    | ToScore(LogScore(answer, prior)) =>
-      GenericDist.Score.logScoreWithPointResolution(
-        ~prediction=dist,
-        ~answer,
-        ~prior,
-        ~toPointSetFn,
-      )
-      ->E.R2.fmap(r => Float(r))
-      ->OutputLocal.fromResult
-    | ToBool(IsNormalized) => dist->GenericDist.isNormalized->Bool
-    | ToDist(Truncate(leftCutoff, rightCutoff)) =>
+    | #ToBool(IsNormalized) => dist->GenericDist.isNormalized->Bool
+    | #ToDist(Truncate(leftCutoff, rightCutoff)) =>
       GenericDist.truncate(~toPointSetFn, ~leftCutoff, ~rightCutoff, dist, ())
       ->E.R2.fmap(r => Dist(r))
       ->OutputLocal.fromResult
-    | ToDist(ToSampleSet(n)) =>
+    | #ToDist(ToSampleSet(n)) =>
       dist
       ->GenericDist.toSampleSetDist(n)
       ->E.R2.fmap(r => Dist(SampleSet(r)))
       ->OutputLocal.fromResult
-    | ToDist(ToPointSet) =>
+    | #ToDist(ToPointSet) =>
       dist
       ->GenericDist.toPointSet(~xyPointLength, ~sampleCount, ())
       ->E.R2.fmap(r => Dist(PointSet(r)))
       ->OutputLocal.fromResult
-    | ToDist(Scale(#LogarithmWithThreshold(eps), f)) =>
+    | #ToDist(Scale(#LogarithmWithThreshold(eps), f)) =>
       dist
       ->GenericDist.pointwiseCombinationFloat(
         ~toPointSetFn,
@@ -182,18 +170,23 @@ let rec run = (~env, functionCallInfo: functionCallInfo): outputType => {
       )
       ->E.R2.fmap(r => Dist(r))
       ->OutputLocal.fromResult
-    | ToDist(Scale(#Logarithm, f)) =>
+    | #ToDist(Scale(#Multiply, f)) =>
+      dist
+      ->GenericDist.pointwiseCombinationFloat(~toPointSetFn, ~algebraicCombination=#Multiply, ~f)
+      ->E.R2.fmap(r => Dist(r))
+      ->OutputLocal.fromResult
+    | #ToDist(Scale(#Logarithm, f)) =>
       dist
       ->GenericDist.pointwiseCombinationFloat(~toPointSetFn, ~algebraicCombination=#Logarithm, ~f)
       ->E.R2.fmap(r => Dist(r))
       ->OutputLocal.fromResult
-    | ToDist(Scale(#Power, f)) =>
+    | #ToDist(Scale(#Power, f)) =>
       dist
       ->GenericDist.pointwiseCombinationFloat(~toPointSetFn, ~algebraicCombination=#Power, ~f)
       ->E.R2.fmap(r => Dist(r))
       ->OutputLocal.fromResult
-    | ToDistCombination(Algebraic(_), _, #Float(_)) => GenDistError(NotYetImplemented)
-    | ToDistCombination(Algebraic(strategy), arithmeticOperation, #Dist(t2)) =>
+    | #ToDistCombination(Algebraic(_), _, #Float(_)) => GenDistError(NotYetImplemented)
+    | #ToDistCombination(Algebraic(strategy), arithmeticOperation, #Dist(t2)) =>
       dist
       ->GenericDist.algebraicCombination(
         ~strategy,
@@ -204,12 +197,12 @@ let rec run = (~env, functionCallInfo: functionCallInfo): outputType => {
       )
       ->E.R2.fmap(r => Dist(r))
       ->OutputLocal.fromResult
-    | ToDistCombination(Pointwise, algebraicCombination, #Dist(t2)) =>
+    | #ToDistCombination(Pointwise, algebraicCombination, #Dist(t2)) =>
       dist
       ->GenericDist.pointwiseCombination(~toPointSetFn, ~algebraicCombination, ~t2)
       ->E.R2.fmap(r => Dist(r))
       ->OutputLocal.fromResult
-    | ToDistCombination(Pointwise, algebraicCombination, #Float(f)) =>
+    | #ToDistCombination(Pointwise, algebraicCombination, #Float(f)) =>
       dist
       ->GenericDist.pointwiseCombinationFloat(~toPointSetFn, ~algebraicCombination, ~f)
       ->E.R2.fmap(r => Dist(r))
@@ -220,8 +213,7 @@ let rec run = (~env, functionCallInfo: functionCallInfo): outputType => {
 
   switch functionCallInfo {
   | FromDist(subFnName, dist) => fromDistFn(subFnName, dist)
-  | FromFloat(subFnName, float) =>
-    reCall(~functionCallInfo=FromDist(subFnName, GenericDist.fromFloat(float)), ())
+  | FromFloat(subFnName, x) => reCall(~functionCallInfo=FromFloat(subFnName, x), ())
   | Mixture(dists) =>
     dists
     ->GenericDist.mixture(~scaleMultiplyFn=scaleMultiply, ~pointwiseAddFn=pointwiseAdd)
@@ -273,13 +265,16 @@ module Constructors = {
   let pdf = (~env, dist, f) => C.pdf(dist, f)->run(~env)->toFloatR
   let normalize = (~env, dist) => C.normalize(dist)->run(~env)->toDistR
   let isNormalized = (~env, dist) => C.isNormalized(dist)->run(~env)->toBoolR
-  let klDivergence = (~env, dist1, dist2) => C.klDivergence(dist1, dist2)->run(~env)->toFloatR
-  let logScoreWithPointResolution = (
-    ~env,
-    ~prediction: DistributionTypes.genericDist,
-    ~answer: float,
-    ~prior: option<DistributionTypes.genericDist>,
-  ) => C.logScoreWithPointResolution(~prediction, ~answer, ~prior)->run(~env)->toFloatR
+  module LogScore = {
+    let distEstimateDistAnswer = (~env, estimate, answer) =>
+      C.LogScore.distEstimateDistAnswer(estimate, answer)->run(~env)->toFloatR
+    let distEstimateDistAnswerWithPrior = (~env, estimate, answer, prior) =>
+      C.LogScore.distEstimateDistAnswerWithPrior(estimate, answer, prior)->run(~env)->toFloatR
+    let distEstimateScalarAnswer = (~env, estimate, answer) =>
+      C.LogScore.distEstimateScalarAnswer(estimate, answer)->run(~env)->toFloatR
+    let distEstimateScalarAnswerWithPrior = (~env, estimate, answer, prior) =>
+      C.LogScore.distEstimateScalarAnswerWithPrior(estimate, answer, prior)->run(~env)->toFloatR
+  }
   let toPointSet = (~env, dist) => C.toPointSet(dist)->run(~env)->toDistR
   let toSampleSet = (~env, dist, n) => C.toSampleSet(dist, n)->run(~env)->toDistR
   let fromSamples = (~env, xs) => C.fromSamples(xs)->run(~env)->toDistR
@@ -298,6 +293,7 @@ module Constructors = {
   let algebraicLogarithm = (~env, dist1, dist2) =>
     C.algebraicLogarithm(dist1, dist2)->run(~env)->toDistR
   let algebraicPower = (~env, dist1, dist2) => C.algebraicPower(dist1, dist2)->run(~env)->toDistR
+  let scaleMultiply = (~env, dist, n) => C.scaleMultiply(dist, n)->run(~env)->toDistR
   let scalePower = (~env, dist, n) => C.scalePower(dist, n)->run(~env)->toDistR
   let scaleLogarithm = (~env, dist, n) => C.scaleLogarithm(dist, n)->run(~env)->toDistR
   let pointwiseAdd = (~env, dist1, dist2) => C.pointwiseAdd(dist1, dist2)->run(~env)->toDistR

packages/squiggle-lang/src/rescript/Distributions/DistributionOperation.resi

@@ -1,11 +1,5 @@
 @genType
-type env = {
-  sampleCount: int,
-  xyPointLength: int,
-}
-
-@genType
-let defaultEnv: env
+let defaultEnv: GenericDist.env
 
 open DistributionTypes
 
@@ -19,15 +13,18 @@ type outputType =
   | GenDistError(error)
 
 @genType
-let run: (~env: env, DistributionTypes.DistributionOperation.genericFunctionCallInfo) => outputType
+let run: (
+  ~env: GenericDist.env,
+  DistributionTypes.DistributionOperation.genericFunctionCallInfo,
+) => outputType
 let runFromDist: (
-  ~env: env,
+  ~env: GenericDist.env,
   ~functionCallInfo: DistributionTypes.DistributionOperation.fromDist,
   genericDist,
 ) => outputType
 let runFromFloat: (
-  ~env: env,
-  ~functionCallInfo: DistributionTypes.DistributionOperation.fromDist,
+  ~env: GenericDist.env,
+  ~functionCallInfo: DistributionTypes.DistributionOperation.fromFloat,
   float,
 ) => outputType
 
@@ -42,77 +39,147 @@ module Output: {
   let toBool: t => option<bool>
   let toBoolR: t => result<bool, error>
   let toError: t => option<error>
-  let fmap: (~env: env, t, DistributionTypes.DistributionOperation.singleParamaterFunction) => t
+  let fmap: (
+    ~env: GenericDist.env,
+    t,
+    DistributionTypes.DistributionOperation.singleParamaterFunction,
+  ) => t
 }
 
 module Constructors: {
   @genType
-  let mean: (~env: env, genericDist) => result<float, error>
+  let mean: (~env: GenericDist.env, genericDist) => result<float, error>
   @genType
-  let stdev: (~env: env, genericDist) => result<float, error>
+  let stdev: (~env: GenericDist.env, genericDist) => result<float, error>
   @genType
-  let variance: (~env: env, genericDist) => result<float, error>
+  let variance: (~env: GenericDist.env, genericDist) => result<float, error>
   @genType
-  let sample: (~env: env, genericDist) => result<float, error>
+  let sample: (~env: GenericDist.env, genericDist) => result<float, error>
   @genType
-  let cdf: (~env: env, genericDist, float) => result<float, error>
+  let cdf: (~env: GenericDist.env, genericDist, float) => result<float, error>
   @genType
-  let inv: (~env: env, genericDist, float) => result<float, error>
+  let inv: (~env: GenericDist.env, genericDist, float) => result<float, error>
   @genType
-  let pdf: (~env: env, genericDist, float) => result<float, error>
+  let pdf: (~env: GenericDist.env, genericDist, float) => result<float, error>
   @genType
-  let normalize: (~env: env, genericDist) => result<genericDist, error>
+  let normalize: (~env: GenericDist.env, genericDist) => result<genericDist, error>
   @genType
-  let isNormalized: (~env: env, genericDist) => result<bool, error>
+  let isNormalized: (~env: GenericDist.env, genericDist) => result<bool, error>
+  module LogScore: {
+    @genType
+    let distEstimateDistAnswer: (
+      ~env: GenericDist.env,
+      genericDist,
+      genericDist,
+    ) => result<float, error>
+    @genType
+    let distEstimateDistAnswerWithPrior: (
+      ~env: GenericDist.env,
+      genericDist,
+      genericDist,
+      genericDist,
+    ) => result<float, error>
+    @genType
+    let distEstimateScalarAnswer: (
+      ~env: GenericDist.env,
+      genericDist,
+      float,
+    ) => result<float, error>
+    @genType
+    let distEstimateScalarAnswerWithPrior: (
+      ~env: GenericDist.env,
+      genericDist,
+      float,
+      genericDist,
+    ) => result<float, error>
+  }
   @genType
-  let klDivergence: (~env: env, genericDist, genericDist) => result<float, error>
+  let toPointSet: (~env: GenericDist.env, genericDist) => result<genericDist, error>
   @genType
-  let logScoreWithPointResolution: (
-    ~env: env,
-    ~prediction: genericDist,
-    ~answer: float,
-    ~prior: option<genericDist>,
-  ) => result<float, error>
+  let toSampleSet: (~env: GenericDist.env, genericDist, int) => result<genericDist, error>
   @genType
-  let toPointSet: (~env: env, genericDist) => result<genericDist, error>
+  let fromSamples: (~env: GenericDist.env, SampleSetDist.t) => result<genericDist, error>
   @genType
-  let toSampleSet: (~env: env, genericDist, int) => result<genericDist, error>
+  let truncate: (
+    ~env: GenericDist.env,
+    genericDist,
+    option<float>,
+    option<float>,
+  ) => result<genericDist, error>
   @genType
-  let fromSamples: (~env: env, SampleSetDist.t) => result<genericDist, error>
+  let inspect: (~env: GenericDist.env, genericDist) => result<genericDist, error>
   @genType
-  let truncate: (~env: env, genericDist, option<float>, option<float>) => result<genericDist, error>
+  let toString: (~env: GenericDist.env, genericDist) => result<string, error>
   @genType
-  let inspect: (~env: env, genericDist) => result<genericDist, error>
+  let toSparkline: (~env: GenericDist.env, genericDist, int) => result<string, error>
   @genType
-  let toString: (~env: env, genericDist) => result<string, error>
+  let algebraicAdd: (~env: GenericDist.env, genericDist, genericDist) => result<genericDist, error>
   @genType
-  let toSparkline: (~env: env, genericDist, int) => result<string, error>
+  let algebraicMultiply: (
+    ~env: GenericDist.env,
+    genericDist,
+    genericDist,
+  ) => result<genericDist, error>
   @genType
-  let algebraicAdd: (~env: env, genericDist, genericDist) => result<genericDist, error>
+  let algebraicDivide: (
+    ~env: GenericDist.env,
+    genericDist,
+    genericDist,
+  ) => result<genericDist, error>
   @genType
-  let algebraicMultiply: (~env: env, genericDist, genericDist) => result<genericDist, error>
+  let algebraicSubtract: (
+    ~env: GenericDist.env,
+    genericDist,
+    genericDist,
+  ) => result<genericDist, error>
   @genType
-  let algebraicDivide: (~env: env, genericDist, genericDist) => result<genericDist, error>
+  let algebraicLogarithm: (
+    ~env: GenericDist.env,
+    genericDist,
+    genericDist,
+  ) => result<genericDist, error>
   @genType
-  let algebraicSubtract: (~env: env, genericDist, genericDist) => result<genericDist, error>
+  let algebraicPower: (
+    ~env: GenericDist.env,
+    genericDist,
+    genericDist,
+  ) => result<genericDist, error>
   @genType
-  let algebraicLogarithm: (~env: env, genericDist, genericDist) => result<genericDist, error>
+  let scaleLogarithm: (~env: GenericDist.env, genericDist, float) => result<genericDist, error>
   @genType
-  let algebraicPower: (~env: env, genericDist, genericDist) => result<genericDist, error>
+  let scaleMultiply: (~env: GenericDist.env, genericDist, float) => result<genericDist, error>
   @genType
-  let scaleLogarithm: (~env: env, genericDist, float) => result<genericDist, error>
+  let scalePower: (~env: GenericDist.env, genericDist, float) => result<genericDist, error>
   @genType
-  let scalePower: (~env: env, genericDist, float) => result<genericDist, error>
+  let pointwiseAdd: (~env: GenericDist.env, genericDist, genericDist) => result<genericDist, error>
   @genType
-  let pointwiseAdd: (~env: env, genericDist, genericDist) => result<genericDist, error>
+  let pointwiseMultiply: (
+    ~env: GenericDist.env,
+    genericDist,
+    genericDist,
+  ) => result<genericDist, error>
   @genType
-  let pointwiseMultiply: (~env: env, genericDist, genericDist) => result<genericDist, error>
+  let pointwiseDivide: (
+    ~env: GenericDist.env,
+    genericDist,
+    genericDist,
+  ) => result<genericDist, error>
   @genType
-  let pointwiseDivide: (~env: env, genericDist, genericDist) => result<genericDist, error>
+  let pointwiseSubtract: (
+    ~env: GenericDist.env,
+    genericDist,
+    genericDist,
+  ) => result<genericDist, error>
   @genType
-  let pointwiseSubtract: (~env: env, genericDist, genericDist) => result<genericDist, error>
+  let pointwiseLogarithm: (
+    ~env: GenericDist.env,
+    genericDist,
+    genericDist,
+  ) => result<genericDist, error>
   @genType
-  let pointwiseLogarithm: (~env: env, genericDist, genericDist) => result<genericDist, error>
-  @genType
-  let pointwisePower: (~env: env, genericDist, genericDist) => result<genericDist, error>
+  let pointwisePower: (
+    ~env: GenericDist.env,
+    genericDist,
+    genericDist,
+  ) => result<genericDist, error>
 }

packages/squiggle-lang/src/rescript/Distributions/DistributionTypes.res

@@ -76,6 +76,7 @@ module DistributionOperation = {
   ]
 
   type toScaleFn = [
+    | #Multiply
     | #Power
     | #Logarithm
     | #LogarithmWithThreshold(float)
@@ -97,60 +98,86 @@ module DistributionOperation = {
     | ToString
     | ToSparkline(int)
 
-  type toScore = KLDivergence(genericDist) | LogScore(float, option<genericDist>)
+  type genericDistOrScalar = Score_Dist(genericDist) | Score_Scalar(float)
 
-  type fromDist =
-    | ToFloat(toFloat)
-    | ToDist(toDist)
-    | ToScore(toScore)
-    | ToDistCombination(direction, Operation.Algebraic.t, [#Dist(genericDist) | #Float(float)])
-    | ToString(toString)
-    | ToBool(toBool)
+  type toScore = LogScore(genericDistOrScalar, option<genericDist>)
+
+  type fromFloat = [
+    | #ToFloat(toFloat)
+    | #ToDist(toDist)
+    | #ToDistCombination(direction, Operation.Algebraic.t, [#Dist(genericDist) | #Float(float)])
+    | #ToString(toString)
+    | #ToBool(toBool)
+  ]
+
+  type fromDist = [
+    | fromFloat
+    | #ToScore(toScore)
+  ]
 
   type singleParamaterFunction =
     | FromDist(fromDist)
-    | FromFloat(fromDist)
+    | FromFloat(fromFloat)
 
   type genericFunctionCallInfo =
     | FromDist(fromDist, genericDist)
-    | FromFloat(fromDist, float)
+    | FromFloat(fromFloat, float)
     | FromSamples(array<float>)
     | Mixture(array<(genericDist, float)>)
 
-  let distCallToString = (distFunction: fromDist): string =>
-    switch distFunction {
-    | ToFloat(#Cdf(r)) => `cdf(${E.Float.toFixed(r)})`
-    | ToFloat(#Inv(r)) => `inv(${E.Float.toFixed(r)})`
-    | ToFloat(#Mean) => `mean`
-    | ToFloat(#Min) => `min`
-    | ToFloat(#Max) => `max`
-    | ToFloat(#Stdev) => `stdev`
-    | ToFloat(#Variance) => `variance`
-    | ToFloat(#Mode) => `mode`
-    | ToFloat(#Pdf(r)) => `pdf(${E.Float.toFixed(r)})`
-    | ToFloat(#Sample) => `sample`
-    | ToFloat(#IntegralSum) => `integralSum`
-    | ToScore(KLDivergence(_)) => `klDivergence`
-    | ToScore(LogScore(x, _)) => `logScore against ${E.Float.toFixed(x)}`
-    | ToDist(Normalize) => `normalize`
-    | ToDist(ToPointSet) => `toPointSet`
-    | ToDist(ToSampleSet(r)) => `toSampleSet(${E.I.toString(r)})`
-    | ToDist(Truncate(_, _)) => `truncate`
-    | ToDist(Inspect) => `inspect`
-    | ToDist(Scale(#Power, r)) => `scalePower(${E.Float.toFixed(r)})`
-    | ToDist(Scale(#Logarithm, r)) => `scaleLog(${E.Float.toFixed(r)})`
-    | ToDist(Scale(#LogarithmWithThreshold(eps), r)) =>
+  let floatCallToString = (floatFunction: fromFloat): string =>
+    switch floatFunction {
+    | #ToFloat(#Cdf(r)) => `cdf(${E.Float.toFixed(r)})`
+    | #ToFloat(#Inv(r)) => `inv(${E.Float.toFixed(r)})`
+    | #ToFloat(#Mean) => `mean`
+    | #ToFloat(#Min) => `min`
+    | #ToFloat(#Max) => `max`
+    | #ToFloat(#Stdev) => `stdev`
+    | #ToFloat(#Variance) => `variance`
+    | #ToFloat(#Mode) => `mode`
+    | #ToFloat(#Pdf(r)) => `pdf(${E.Float.toFixed(r)})`
+    | #ToFloat(#Sample) => `sample`
+    | #ToFloat(#IntegralSum) => `integralSum`
+    | #ToDist(Normalize) => `normalize`
+    | #ToDist(ToPointSet) => `toPointSet`
+    | #ToDist(ToSampleSet(r)) => `toSampleSet(${E.I.toString(r)})`
+    | #ToDist(Truncate(_, _)) => `truncate`
+    | #ToDist(Inspect) => `inspect`
+    | #ToDist(Scale(#Power, r)) => `scalePower(${E.Float.toFixed(r)})`
+    | #ToDist(Scale(#Multiply, r)) => `scaleMultiply(${E.Float.toFixed(r)})`
+    | #ToDist(Scale(#Logarithm, r)) => `scaleLog(${E.Float.toFixed(r)})`
+    | #ToDist(Scale(#LogarithmWithThreshold(eps), r)) =>
       `scaleLogWithThreshold(${E.Float.toFixed(r)}, epsilon=${E.Float.toFixed(eps)})`
-    | ToString(ToString) => `toString`
-    | ToString(ToSparkline(n)) => `sparkline(${E.I.toString(n)})`
-    | ToBool(IsNormalized) => `isNormalized`
-    | ToDistCombination(Algebraic(_), _, _) => `algebraic`
-    | ToDistCombination(Pointwise, _, _) => `pointwise`
+    | #ToString(ToString) => `toString`
+    | #ToString(ToSparkline(n)) => `sparkline(${E.I.toString(n)})`
+    | #ToBool(IsNormalized) => `isNormalized`
+    | #ToDistCombination(Algebraic(_), _, _) => `algebraic`
+    | #ToDistCombination(Pointwise, _, _) => `pointwise`
+    }
+
+  let distCallToString = (
+    distFunction: [
+      | #ToFloat(toFloat)
+      | #ToDist(toDist)
+      | #ToDistCombination(direction, Operation.Algebraic.t, [#Dist(genericDist) | #Float(float)])
+      | #ToString(toString)
+      | #ToBool(toBool)
+      | #ToScore(toScore)
+    ],
+  ): string =>
+    switch distFunction {
+    | #ToScore(_) => `logScore`
+    | #ToFloat(x) => floatCallToString(#ToFloat(x))
+    | #ToDist(x) => floatCallToString(#ToDist(x))
+    | #ToString(x) => floatCallToString(#ToString(x))
+    | #ToBool(x) => floatCallToString(#ToBool(x))
+    | #ToDistCombination(x, y, z) => floatCallToString(#ToDistCombination(x, y, z))
     }
 
   let toString = (d: genericFunctionCallInfo): string =>
     switch d {
-    | FromDist(f, _) | FromFloat(f, _) => distCallToString(f)
+    | FromDist(f, _) => distCallToString(f)
+    | FromFloat(f, _) => floatCallToString(f)
     | Mixture(_) => `mixture`
     | FromSamples(_) => `fromSamples`
     }
@@ -160,79 +187,93 @@ module Constructors = {
 
   module UsingDists = {
     @genType
-    let mean = (dist): t => FromDist(ToFloat(#Mean), dist)
-    let stdev = (dist): t => FromDist(ToFloat(#Stdev), dist)
-    let variance = (dist): t => FromDist(ToFloat(#Variance), dist)
-    let sample = (dist): t => FromDist(ToFloat(#Sample), dist)
-    let cdf = (dist, x): t => FromDist(ToFloat(#Cdf(x)), dist)
-    let inv = (dist, x): t => FromDist(ToFloat(#Inv(x)), dist)
-    let pdf = (dist, x): t => FromDist(ToFloat(#Pdf(x)), dist)
-    let normalize = (dist): t => FromDist(ToDist(Normalize), dist)
-    let isNormalized = (dist): t => FromDist(ToBool(IsNormalized), dist)
-    let toPointSet = (dist): t => FromDist(ToDist(ToPointSet), dist)
-    let toSampleSet = (dist, r): t => FromDist(ToDist(ToSampleSet(r)), dist)
+    let mean = (dist): t => FromDist(#ToFloat(#Mean), dist)
+    let stdev = (dist): t => FromDist(#ToFloat(#Stdev), dist)
+    let variance = (dist): t => FromDist(#ToFloat(#Variance), dist)
+    let sample = (dist): t => FromDist(#ToFloat(#Sample), dist)
+    let cdf = (dist, x): t => FromDist(#ToFloat(#Cdf(x)), dist)
+    let inv = (dist, x): t => FromDist(#ToFloat(#Inv(x)), dist)
+    let pdf = (dist, x): t => FromDist(#ToFloat(#Pdf(x)), dist)
+    let normalize = (dist): t => FromDist(#ToDist(Normalize), dist)
+    let isNormalized = (dist): t => FromDist(#ToBool(IsNormalized), dist)
+    let toPointSet = (dist): t => FromDist(#ToDist(ToPointSet), dist)
+    let toSampleSet = (dist, r): t => FromDist(#ToDist(ToSampleSet(r)), dist)
     let fromSamples = (xs): t => FromSamples(xs)
-    let truncate = (dist, left, right): t => FromDist(ToDist(Truncate(left, right)), dist)
-    let inspect = (dist): t => FromDist(ToDist(Inspect), dist)
-    let klDivergence = (dist1, dist2): t => FromDist(ToScore(KLDivergence(dist2)), dist1)
-    let logScoreWithPointResolution = (~prediction, ~answer, ~prior): t => FromDist(
-      ToScore(LogScore(answer, prior)),
-      prediction,
-    )
-    let scalePower = (dist, n): t => FromDist(ToDist(Scale(#Power, n)), dist)
-    let scaleLogarithm = (dist, n): t => FromDist(ToDist(Scale(#Logarithm, n)), dist)
+    let truncate = (dist, left, right): t => FromDist(#ToDist(Truncate(left, right)), dist)
+    let inspect = (dist): t => FromDist(#ToDist(Inspect), dist)
+    module LogScore = {
+      let distEstimateDistAnswer = (estimate, answer): t => FromDist(
+        #ToScore(LogScore(Score_Dist(answer), None)),
+        estimate,
+      )
+      let distEstimateDistAnswerWithPrior = (estimate, answer, prior): t => FromDist(
+        #ToScore(LogScore(Score_Dist(answer), Some(prior))),
+        estimate,
+      )
+      let distEstimateScalarAnswer = (estimate, answer): t => FromDist(
+        #ToScore(LogScore(Score_Scalar(answer), None)),
+        estimate,
+      )
+      let distEstimateScalarAnswerWithPrior = (estimate, answer, prior): t => FromDist(
+        #ToScore(LogScore(Score_Scalar(answer), Some(prior))),
+        estimate,
+      )
+    }
+    let scaleMultiply = (dist, n): t => FromDist(#ToDist(Scale(#Multiply, n)), dist)
+    let scalePower = (dist, n): t => FromDist(#ToDist(Scale(#Power, n)), dist)
+    let scaleLogarithm = (dist, n): t => FromDist(#ToDist(Scale(#Logarithm, n)), dist)
     let scaleLogarithmWithThreshold = (dist, n, eps): t => FromDist(
-      ToDist(Scale(#LogarithmWithThreshold(eps), n)),
+      #ToDist(Scale(#LogarithmWithThreshold(eps), n)),
       dist,
     )
-    let toString = (dist): t => FromDist(ToString(ToString), dist)
-    let toSparkline = (dist, n): t => FromDist(ToString(ToSparkline(n)), dist)
+    let toString = (dist): t => FromDist(#ToString(ToString), dist)
+    let toSparkline = (dist, n): t => FromDist(#ToString(ToSparkline(n)), dist)
     let algebraicAdd = (dist1, dist2: genericDist): t => FromDist(
-      ToDistCombination(Algebraic(AsDefault), #Add, #Dist(dist2)),
+      #ToDistCombination(Algebraic(AsDefault), #Add, #Dist(dist2)),
       dist1,
     )
     let algebraicMultiply = (dist1, dist2): t => FromDist(
-      ToDistCombination(Algebraic(AsDefault), #Multiply, #Dist(dist2)),
+      #ToDistCombination(Algebraic(AsDefault), #Multiply, #Dist(dist2)),
       dist1,
     )
     let algebraicDivide = (dist1, dist2): t => FromDist(
-      ToDistCombination(Algebraic(AsDefault), #Divide, #Dist(dist2)),
+      #ToDistCombination(Algebraic(AsDefault), #Divide, #Dist(dist2)),
       dist1,
     )
     let algebraicSubtract = (dist1, dist2): t => FromDist(
-      ToDistCombination(Algebraic(AsDefault), #Subtract, #Dist(dist2)),
+      #ToDistCombination(Algebraic(AsDefault), #Subtract, #Dist(dist2)),
       dist1,
     )
     let algebraicLogarithm = (dist1, dist2): t => FromDist(
-      ToDistCombination(Algebraic(AsDefault), #Logarithm, #Dist(dist2)),
+      #ToDistCombination(Algebraic(AsDefault), #Logarithm, #Dist(dist2)),
       dist1,
     )
     let algebraicPower = (dist1, dist2): t => FromDist(
-      ToDistCombination(Algebraic(AsDefault), #Power, #Dist(dist2)),
+      #ToDistCombination(Algebraic(AsDefault), #Power, #Dist(dist2)),
       dist1,
     )
     let pointwiseAdd = (dist1, dist2): t => FromDist(
-      ToDistCombination(Pointwise, #Add, #Dist(dist2)),
+      #ToDistCombination(Pointwise, #Add, #Dist(dist2)),
       dist1,
     )
     let pointwiseMultiply = (dist1, dist2): t => FromDist(
-      ToDistCombination(Pointwise, #Multiply, #Dist(dist2)),
+      #ToDistCombination(Pointwise, #Multiply, #Dist(dist2)),
       dist1,
     )
     let pointwiseDivide = (dist1, dist2): t => FromDist(
-      ToDistCombination(Pointwise, #Divide, #Dist(dist2)),
+      #ToDistCombination(Pointwise, #Divide, #Dist(dist2)),
       dist1,
     )
     let pointwiseSubtract = (dist1, dist2): t => FromDist(
-      ToDistCombination(Pointwise, #Subtract, #Dist(dist2)),
+      #ToDistCombination(Pointwise, #Subtract, #Dist(dist2)),
       dist1,
     )
     let pointwiseLogarithm = (dist1, dist2): t => FromDist(
-      ToDistCombination(Pointwise, #Logarithm, #Dist(dist2)),
+      #ToDistCombination(Pointwise, #Logarithm, #Dist(dist2)),
       dist1,
     )
     let pointwisePower = (dist1, dist2): t => FromDist(
-      ToDistCombination(Pointwise, #Power, #Dist(dist2)),
+      #ToDistCombination(Pointwise, #Power, #Dist(dist2)),
       dist1,
     )
   }

packages/squiggle-lang/src/rescript/Distributions/GenericDist.res

@@ -6,6 +6,11 @@ type toSampleSetFn = t => result<SampleSetDist.t, error>
 type scaleMultiplyFn = (t, float) => result<t, error>
 type pointwiseAddFn = (t, t) => result<t, error>
 
+type env = {
+  sampleCount: int,
+  xyPointLength: int,
+}
+
 let isPointSet = (t: t) =>
   switch t {
   | PointSet(_) => true
@@ -61,46 +66,6 @@ let integralEndY = (t: t): float =>
 
 let isNormalized = (t: t): bool => Js.Math.abs_float(integralEndY(t) -. 1.0) < 1e-7
 
-module Score = {
-  let klDivergence = (prediction, answer, ~toPointSetFn: toPointSetFn): result<float, error> => {
-    let pointSets = E.R.merge(toPointSetFn(prediction), toPointSetFn(answer))
-    pointSets |> E.R2.bind(((predi, ans)) =>
-      PointSetDist.T.klDivergence(predi, ans)->E.R2.errMap(x => DistributionTypes.OperationError(x))
-    )
-  }
-
-  let logScoreWithPointResolution = (
-    ~prediction: DistributionTypes.genericDist,
-    ~answer: float,
-    ~prior: option<DistributionTypes.genericDist>,
-    ~toPointSetFn: toPointSetFn,
-  ): result<float, error> => {
-    switch prior {
-    | Some(prior') =>
-      E.R.merge(toPointSetFn(prior'), toPointSetFn(prediction))->E.R.bind(((
-        prior'',
-        prediction'',
-      )) =>
-        PointSetDist.T.logScoreWithPointResolution(
-          ~prediction=prediction'',
-          ~answer,
-          ~prior=prior''->Some,
-        )->E.R2.errMap(x => DistributionTypes.OperationError(x))
-      )
-    | None =>
-      prediction
-      ->toPointSetFn
-      ->E.R.bind(x =>
-        PointSetDist.T.logScoreWithPointResolution(
-          ~prediction=x,
-          ~answer,
-          ~prior=None,
-        )->E.R2.errMap(x => DistributionTypes.OperationError(x))
-      )
-    }
-  }
-}
-
 let toFloatOperation = (
   t,
   ~toPointSetFn: toPointSetFn,
@@ -171,6 +136,70 @@ let toPointSet = (
   }
 }
 
+module Score = {
+  type genericDistOrScalar = DistributionTypes.DistributionOperation.genericDistOrScalar
+
+  let argsMake = (~esti: t, ~answ: genericDistOrScalar, ~prior: option<t>, ~env: env): result<
+    PointSetDist_Scoring.scoreArgs,
+    error,
+  > => {
+    let toPointSetFn = t =>
+      toPointSet(
+        t,
+        ~xyPointLength=env.xyPointLength,
+        ~sampleCount=env.sampleCount,
+        ~xSelection=#ByWeight,
+        (),
+      )
+    let prior': option<result<PointSetTypes.pointSetDist, error>> = switch prior {
+    | None => None
+    | Some(d) => toPointSetFn(d)->Some
+    }
+    let twoDists = (~toPointSetFn, esti': t, answ': t): result<
+      (PointSetTypes.pointSetDist, PointSetTypes.pointSetDist),
+      error,
+    > => E.R.merge(toPointSetFn(esti'), toPointSetFn(answ'))
+    switch (esti, answ, prior') {
+    | (esti', Score_Dist(answ'), None) =>
+      twoDists(~toPointSetFn, esti', answ')->E.R2.fmap(((esti'', answ'')) =>
+        {estimate: esti'', answer: answ'', prior: None}->PointSetDist_Scoring.DistAnswer
+      )
+    | (esti', Score_Dist(answ'), Some(Ok(prior''))) =>
+      twoDists(~toPointSetFn, esti', answ')->E.R2.fmap(((esti'', answ'')) =>
+        {
+          estimate: esti'',
+          answer: answ'',
+          prior: Some(prior''),
+        }->PointSetDist_Scoring.DistAnswer
+      )
+    | (esti', Score_Scalar(answ'), None) =>
+      toPointSetFn(esti')->E.R2.fmap(esti'' =>
+        {
+          estimate: esti'',
+          answer: answ',
+          prior: None,
+        }->PointSetDist_Scoring.ScalarAnswer
+      )
+    | (esti', Score_Scalar(answ'), Some(Ok(prior''))) =>
+      toPointSetFn(esti')->E.R2.fmap(esti'' =>
+        {
+          estimate: esti'',
+          answer: answ',
+          prior: Some(prior''),
+        }->PointSetDist_Scoring.ScalarAnswer
+      )
+    | (_, _, Some(Error(err))) => err->Error
+    }
+  }
+
+  let logScore = (~estimate: t, ~answer: genericDistOrScalar, ~prior: option<t>, ~env: env): result<
+    float,
+    error,
+  > =>
+    argsMake(~esti=estimate, ~answ=answer, ~prior, ~env)->E.R.bind(x =>
+      x->PointSetDist.logScore->E.R2.errMap(y => DistributionTypes.OperationError(y))
+    )
+}
 /*
   PointSetDist.toSparkline calls "downsampleEquallyOverX", which downsamples it to n=bucketCount.
   It first needs a pointSetDist, so we convert to a pointSetDist. In this process we want the 

packages/squiggle-lang/src/rescript/Distributions/GenericDist.resi

@@ -5,6 +5,9 @@ type toSampleSetFn = t => result<SampleSetDist.t, error>
 type scaleMultiplyFn = (t, float) => result<t, error>
 type pointwiseAddFn = (t, t) => result<t, error>
 
+@genType
+type env = {sampleCount: int, xyPointLength: int}
+
 let sampleN: (t, int) => array<float>
 let sample: t => float
 
@@ -25,12 +28,11 @@ let toFloatOperation: (
 ) => result<float, error>
 
 module Score: {
-  let klDivergence: (t, t, ~toPointSetFn: toPointSetFn) => result<float, error>
-  let logScoreWithPointResolution: (
-    ~prediction: t,
-    ~answer: float,
+  let logScore: (
+    ~estimate: t,
+    ~answer: DistributionTypes.DistributionOperation.genericDistOrScalar,
     ~prior: option<t>,
-    ~toPointSetFn: toPointSetFn,
+    ~env: env,
   ) => result<float, error>
 }