diff --git a/packages/squiggle-lang/__tests__/TS/JS_test.ts b/packages/squiggle-lang/__tests__/TS/JS_test.ts
index 62051261..004d715e 100644
--- a/packages/squiggle-lang/__tests__/TS/JS_test.ts
+++ b/packages/squiggle-lang/__tests__/TS/JS_test.ts
@@ -1,4 +1,4 @@
-import { Distribution, resultMap } from "../../src/js/index";
+import { Distribution, resultMap, defaultBindings } from "../../src/js/index";
 import { testRun, testRunPartial } from "./TestHelpers";
 
 function Ok<b>(x: b) {
@@ -70,20 +70,19 @@ describe("Partials", () => {
 
 describe("Parameters", () => {
   test("Can pass parameters into partials and cells", () => {
-    let bindings = testRunPartial(`y = $x + 2`, {}, { x: 1 }); // y = 3
-    let bindings2 = testRunPartial(`z = $x + y * $a`, bindings, { a: 3 }); // z = 1 + 3 * 3 = 10
-    expect(testRun(`z + $x + $a + y`, bindings2)).toEqual({
+    let bindings = testRunPartial(`y = $x + 2`, defaultBindings, { x: 1 });
+    let bindings2 = testRunPartial(`z = y + $a`, bindings, { a: 3 });
+    expect(testRun(`z`, bindings2)).toEqual({
       tag: "number",
       value: 17,
     });
   });
   test("Complicated deep parameters", () => {
     expect(
-      testRun(
-        `$x.y[0][0].w + $x.z + $u.v`,
-        {},
-        { x: { y: [[{ w: 1 }]], z: 2 }, u: { v: 3 } }
-      )
+      testRun(`$x.y[0][0].w + $x.z + $u.v`, defaultBindings, {
+        x: { y: [[{ w: 1 }]], z: 2 },
+        u: { v: 3 },
+      })
     ).toEqual({
       tag: "number",
       value: 6,
diff --git a/packages/squiggle-lang/src/js/distribution.ts b/packages/squiggle-lang/src/js/distribution.ts
new file mode 100644
index 00000000..603dfaa9
--- /dev/null
+++ b/packages/squiggle-lang/src/js/distribution.ts
@@ -0,0 +1,247 @@
+import * as _ from "lodash";
+import {
+  genericDist,
+  continuousShape,
+  discreteShape,
+  samplingParams,
+  distributionError,
+  toPointSet,
+  distributionErrorToString,
+} from "../rescript/TypescriptInterface.gen";
+import { result, resultMap, Ok } from "./types";
+import {
+  Constructors_mean,
+  Constructors_sample,
+  Constructors_pdf,
+  Constructors_cdf,
+  Constructors_inv,
+  Constructors_normalize,
+  Constructors_isNormalized,
+  Constructors_toPointSet,
+  Constructors_toSampleSet,
+  Constructors_truncate,
+  Constructors_inspect,
+  Constructors_toString,
+  Constructors_toSparkline,
+  Constructors_algebraicAdd,
+  Constructors_algebraicMultiply,
+  Constructors_algebraicDivide,
+  Constructors_algebraicSubtract,
+  Constructors_algebraicLogarithm,
+  Constructors_algebraicPower,
+  Constructors_pointwiseAdd,
+  Constructors_pointwiseMultiply,
+  Constructors_pointwiseDivide,
+  Constructors_pointwiseSubtract,
+  Constructors_pointwiseLogarithm,
+  Constructors_pointwisePower,
+} from "../rescript/Distributions/DistributionOperation/DistributionOperation.gen";
+
+export type point = { x: number; y: number };
+
+function shapePoints(x: continuousShape | discreteShape): point[] {
+  let xs = x.xyShape.xs;
+  let ys = x.xyShape.ys;
+  return _.zipWith(xs, ys, (x, y) => ({ x, y }));
+}
+export type shape = {
+  continuous: point[];
+  discrete: point[];
+};
+
+export class Distribution {
+  t: genericDist;
+  env: samplingParams;
+
+  constructor(t: genericDist, env: samplingParams) {
+    this.t = t;
+    this.env = env;
+    return this;
+  }
+
+  mapResultDist(
+    r: result<genericDist, distributionError>
+  ): result<Distribution, distributionError> {
+    return resultMap(r, (v: genericDist) => new Distribution(v, this.env));
+  }
+
+  mean(): result<number, distributionError> {
+    return Constructors_mean({ env: this.env }, this.t);
+  }
+
+  sample(): result<number, distributionError> {
+    return Constructors_sample({ env: this.env }, this.t);
+  }
+
+  pdf(n: number): result<number, distributionError> {
+    return Constructors_pdf({ env: this.env }, this.t, n);
+  }
+
+  cdf(n: number): result<number, distributionError> {
+    return Constructors_cdf({ env: this.env }, this.t, n);
+  }
+
+  inv(n: number): result<number, distributionError> {
+    return Constructors_inv({ env: this.env }, this.t, n);
+  }
+
+  isNormalized(): result<boolean, distributionError> {
+    return Constructors_isNormalized({ env: this.env }, this.t);
+  }
+
+  normalize(): result<Distribution, distributionError> {
+    return this.mapResultDist(
+      Constructors_normalize({ env: this.env }, this.t)
+    );
+  }
+
+  type() {
+    return this.t.tag;
+  }
+
+  pointSet(): result<shape, distributionError> {
+    let pointSet = toPointSet(
+      this.t,
+      {
+        xyPointLength: this.env.xyPointLength,
+        sampleCount: this.env.sampleCount,
+      },
+      undefined
+    );
+    if (pointSet.tag === "Ok") {
+      let distribution = pointSet.value;
+      if (distribution.tag === "Continuous") {
+        return Ok({
+          continuous: shapePoints(distribution.value),
+          discrete: [],
+        });
+      } else if (distribution.tag === "Discrete") {
+        return Ok({
+          discrete: shapePoints(distribution.value),
+          continuous: [],
+        });
+      } else {
+        return Ok({
+          discrete: shapePoints(distribution.value.discrete),
+          continuous: shapePoints(distribution.value.continuous),
+        });
+      }
+    } else {
+      return pointSet;
+    }
+  }
+
+  toPointSet(): result<Distribution, distributionError> {
+    return this.mapResultDist(
+      Constructors_toPointSet({ env: this.env }, this.t)
+    );
+  }
+
+  toSampleSet(n: number): result<Distribution, distributionError> {
+    return this.mapResultDist(
+      Constructors_toSampleSet({ env: this.env }, this.t, n)
+    );
+  }
+
+  truncate(
+    left: number,
+    right: number
+  ): result<Distribution, distributionError> {
+    return this.mapResultDist(
+      Constructors_truncate({ env: this.env }, this.t, left, right)
+    );
+  }
+
+  inspect(): result<Distribution, distributionError> {
+    return this.mapResultDist(Constructors_inspect({ env: this.env }, this.t));
+  }
+
+  toString(): string {
+    let result = Constructors_toString({ env: this.env }, this.t);
+    if (result.tag === "Ok") {
+      return result.value;
+    } else {
+      return distributionErrorToString(result.value);
+    }
+  }
+
+  toSparkline(n: number): result<string, distributionError> {
+    return Constructors_toSparkline({ env: this.env }, this.t, n);
+  }
+
+  algebraicAdd(d2: Distribution): result<Distribution, distributionError> {
+    return this.mapResultDist(
+      Constructors_algebraicAdd({ env: this.env }, this.t, d2.t)
+    );
+  }
+
+  algebraicMultiply(d2: Distribution): result<Distribution, distributionError> {
+    return this.mapResultDist(
+      Constructors_algebraicMultiply({ env: this.env }, this.t, d2.t)
+    );
+  }
+
+  algebraicDivide(d2: Distribution): result<Distribution, distributionError> {
+    return this.mapResultDist(
+      Constructors_algebraicDivide({ env: this.env }, this.t, d2.t)
+    );
+  }
+
+  algebraicSubtract(d2: Distribution): result<Distribution, distributionError> {
+    return this.mapResultDist(
+      Constructors_algebraicSubtract({ env: this.env }, this.t, d2.t)
+    );
+  }
+
+  algebraicLogarithm(
+    d2: Distribution
+  ): result<Distribution, distributionError> {
+    return this.mapResultDist(
+      Constructors_algebraicLogarithm({ env: this.env }, this.t, d2.t)
+    );
+  }
+
+  algebraicPower(d2: Distribution): result<Distribution, distributionError> {
+    return this.mapResultDist(
+      Constructors_algebraicPower({ env: this.env }, this.t, d2.t)
+    );
+  }
+
+  pointwiseAdd(d2: Distribution): result<Distribution, distributionError> {
+    return this.mapResultDist(
+      Constructors_pointwiseAdd({ env: this.env }, this.t, d2.t)
+    );
+  }
+
+  pointwiseMultiply(d2: Distribution): result<Distribution, distributionError> {
+    return this.mapResultDist(
+      Constructors_pointwiseMultiply({ env: this.env }, this.t, d2.t)
+    );
+  }
+
+  pointwiseDivide(d2: Distribution): result<Distribution, distributionError> {
+    return this.mapResultDist(
+      Constructors_pointwiseDivide({ env: this.env }, this.t, d2.t)
+    );
+  }
+
+  pointwiseSubtract(d2: Distribution): result<Distribution, distributionError> {
+    return this.mapResultDist(
+      Constructors_pointwiseSubtract({ env: this.env }, this.t, d2.t)
+    );
+  }
+
+  pointwiseLogarithm(
+    d2: Distribution
+  ): result<Distribution, distributionError> {
+    return this.mapResultDist(
+      Constructors_pointwiseLogarithm({ env: this.env }, this.t, d2.t)
+    );
+  }
+
+  pointwisePower(d2: Distribution): result<Distribution, distributionError> {
+    return this.mapResultDist(
+      Constructors_pointwisePower({ env: this.env }, this.t, d2.t)
+    );
+  }
+}
diff --git a/packages/squiggle-lang/src/js/index.ts b/packages/squiggle-lang/src/js/index.ts
index 1c0fb4e3..04d6050a 100644
--- a/packages/squiggle-lang/src/js/index.ts
+++ b/packages/squiggle-lang/src/js/index.ts
@@ -1,106 +1,40 @@
 import * as _ from "lodash";
 import {
-  genericDist,
   samplingParams,
   evaluateUsingExternalBindings,
   evaluatePartialUsingExternalBindings,
   externalBindings,
   expressionValue,
   errorValue,
-  distributionError,
-  toPointSet,
-  continuousShape,
-  discreteShape,
-  distributionErrorToString,
-  mixedShape,
-  sampleSetDist,
-  symbolicDist,
 } from "../rescript/TypescriptInterface.gen";
 export {
   makeSampleSetDist,
   errorValueToString,
   distributionErrorToString,
 } from "../rescript/TypescriptInterface.gen";
-import {
-  Constructors_mean,
-  Constructors_sample,
-  Constructors_pdf,
-  Constructors_cdf,
-  Constructors_inv,
-  Constructors_normalize,
-  Constructors_isNormalized,
-  Constructors_toPointSet,
-  Constructors_toSampleSet,
-  Constructors_truncate,
-  Constructors_inspect,
-  Constructors_toString,
-  Constructors_toSparkline,
-  Constructors_algebraicAdd,
-  Constructors_algebraicMultiply,
-  Constructors_algebraicDivide,
-  Constructors_algebraicSubtract,
-  Constructors_algebraicLogarithm,
-  Constructors_algebraicPower,
-  Constructors_pointwiseAdd,
-  Constructors_pointwiseMultiply,
-  Constructors_pointwiseDivide,
-  Constructors_pointwiseSubtract,
-  Constructors_pointwiseLogarithm,
-  Constructors_pointwisePower,
-} from "../rescript/Distributions/DistributionOperation/DistributionOperation.gen";
 export type {
   samplingParams,
   errorValue,
   externalBindings as bindings,
   parameters,
 };
+import {
+  jsValueToBinding,
+  jsValue,
+  rescriptExport,
+  squiggleExpression,
+  convertRawToTypescript,
+} from "./rescript_interop";
+import { result, resultMap, tag, tagged } from "./types";
+import { Distribution } from "./distribution";
+
+export { Distribution, squiggleExpression, result };
 
 export let defaultSamplingInputs: samplingParams = {
   sampleCount: 10000,
   xyPointLength: 10000,
 };
 
-export type result<a, b> =
-  | {
-      tag: "Ok";
-      value: a;
-    }
-  | {
-      tag: "Error";
-      value: b;
-    };
-
-export function resultMap<a, b, c>(
-  r: result<a, c>,
-  mapFn: (x: a) => b
-): result<b, c> {
-  if (r.tag === "Ok") {
-    return { tag: "Ok", value: mapFn(r.value) };
-  } else {
-    return r;
-  }
-}
-
-function Ok<a, b>(x: a): result<a, b> {
-  return { tag: "Ok", value: x };
-}
-
-type tagged<a, b> = { tag: a; value: b };
-
-function tag<a, b>(x: a, y: b): tagged<a, b> {
-  return { tag: x, value: y };
-}
-
-export type squiggleExpression =
-  | tagged<"symbol", string>
-  | tagged<"string", string>
-  | tagged<"call", string>
-  | tagged<"array", squiggleExpression[]>
-  | tagged<"boolean", boolean>
-  | tagged<"distribution", Distribution>
-  | tagged<"number", number>
-  | tagged<"record", { [key: string]: squiggleExpression }>;
-
 export function run(
   squiggleString: string,
   bindings?: externalBindings,
@@ -138,13 +72,13 @@ function mergeParameters(
   bindings: externalBindings,
   parameters: parameters
 ): externalBindings {
-  let transformedParemeters = Object.fromEntries(
+  let transformedParameters = Object.fromEntries(
     Object.entries(parameters).map(([key, value]) => [
       "$" + key,
       jsValueToBinding(value),
     ])
   );
-  return _.merge(bindings, transformedParemeters);
+  return _.merge(bindings, transformedParameters);
 }
 
 type parameters = { [key: string]: jsValue };
@@ -152,28 +86,6 @@ type parameters = { [key: string]: jsValue };
 export let defaultParameters: parameters = {};
 export let defaultBindings: externalBindings = {};
 
-type jsValue =
-  | string
-  | number
-  | jsValue[]
-  | { [key: string]: jsValue }
-  | boolean;
-
-function jsValueToBinding(value: jsValue): rescriptExport {
-  if (typeof value === "boolean") {
-    return { TAG: 1, _0: value as boolean };
-  } else if (typeof value === "string") {
-    return { TAG: 6, _0: value as string };
-  } else if (typeof value === "number") {
-    return { TAG: 4, _0: value as number };
-  } else if (Array.isArray(value)) {
-    return { TAG: 0, _0: value.map(jsValueToBinding) };
-  } else {
-    // Record
-    return { TAG: 5, _0: _.mapValues(value, jsValueToBinding) };
-  }
-}
-
 function createTsExport(
   x: expressionValue,
   sampEnv: samplingParams
@@ -235,328 +147,3 @@ function createTsExport(
   }
 }
 
-// Helper functions to convert the rescript representations that genType doesn't
-// cover
-function convertRawToTypescript(
-  result: rescriptExport,
-  sampEnv: samplingParams
-): squiggleExpression {
-  switch (result.TAG) {
-    case 0: // EvArray
-      return tag(
-        "array",
-        result._0.map((x) => convertRawToTypescript(x, sampEnv))
-      );
-    case 1: // EvBool
-      return tag("boolean", result._0);
-    case 2: // EvCall
-      return tag("call", result._0);
-    case 3: // EvDistribution
-      return tag(
-        "distribution",
-        new Distribution(
-          convertRawDistributionToGenericDist(result._0),
-          sampEnv
-        )
-      );
-    case 4: // EvNumber
-      return tag("number", result._0);
-    case 5: // EvRecord
-      return tag(
-        "record",
-        _.mapValues(result._0, (x) => convertRawToTypescript(x, sampEnv))
-      );
-    case 6: // EvString
-      return tag("string", result._0);
-    case 7: // EvSymbol
-      return tag("symbol", result._0);
-  }
-}
-
-function convertRawDistributionToGenericDist(
-  result: rescriptDist
-): genericDist {
-  switch (result.TAG) {
-    case 0: // Point Set Dist
-      switch (result._0.TAG) {
-        case 0: // Mixed
-          return tag("PointSet", tag("Mixed", result._0._0));
-        case 1: // Discrete
-          return tag("PointSet", tag("Discrete", result._0._0));
-        case 2: // Continuous
-          return tag("PointSet", tag("Continuous", result._0._0));
-      }
-    case 1: // Sample Set Dist
-      return tag("SampleSet", result._0);
-    case 2: // Symbolic Dist
-      return tag("Symbolic", result._0);
-  }
-}
-
-// Raw rescript types.
-type rescriptExport =
-  | {
-      TAG: 0; // EvArray
-      _0: rescriptExport[];
-    }
-  | {
-      TAG: 1; // EvBool
-      _0: boolean;
-    }
-  | {
-      TAG: 2; // EvCall
-      _0: string;
-    }
-  | {
-      TAG: 3; // EvDistribution
-      _0: rescriptDist;
-    }
-  | {
-      TAG: 4; // EvNumber
-      _0: number;
-    }
-  | {
-      TAG: 5; // EvRecord
-      _0: { [key: string]: rescriptExport };
-    }
-  | {
-      TAG: 6; // EvString
-      _0: string;
-    }
-  | {
-      TAG: 7; // EvSymbol
-      _0: string;
-    };
-
-type rescriptDist =
-  | { TAG: 0; _0: rescriptPointSetDist }
-  | { TAG: 1; _0: sampleSetDist }
-  | { TAG: 2; _0: symbolicDist };
-
-type rescriptPointSetDist =
-  | {
-      TAG: 0; // Mixed
-      _0: mixedShape;
-    }
-  | {
-      TAG: 1; // Discrete
-      _0: discreteShape;
-    }
-  | {
-      TAG: 2; // ContinuousShape
-      _0: continuousShape;
-    };
-
-export function resultExn<a, c>(r: result<a, c>): a | c {
-  return r.value;
-}
-
-export type point = { x: number; y: number };
-
-export type shape = {
-  continuous: point[];
-  discrete: point[];
-};
-
-function shapePoints(x: continuousShape | discreteShape): point[] {
-  let xs = x.xyShape.xs;
-  let ys = x.xyShape.ys;
-  return _.zipWith(xs, ys, (x, y) => ({ x, y }));
-}
-
-export class Distribution {
-  t: genericDist;
-  env: samplingParams;
-
-  constructor(t: genericDist, env: samplingParams) {
-    this.t = t;
-    this.env = env;
-    return this;
-  }
-
-  mapResultDist(
-    r: result<genericDist, distributionError>
-  ): result<Distribution, distributionError> {
-    return resultMap(r, (v: genericDist) => new Distribution(v, this.env));
-  }
-
-  mean(): result<number, distributionError> {
-    return Constructors_mean({ env: this.env }, this.t);
-  }
-
-  sample(): result<number, distributionError> {
-    return Constructors_sample({ env: this.env }, this.t);
-  }
-
-  pdf(n: number): result<number, distributionError> {
-    return Constructors_pdf({ env: this.env }, this.t, n);
-  }
-
-  cdf(n: number): result<number, distributionError> {
-    return Constructors_cdf({ env: this.env }, this.t, n);
-  }
-
-  inv(n: number): result<number, distributionError> {
-    return Constructors_inv({ env: this.env }, this.t, n);
-  }
-
-  isNormalized(): result<boolean, distributionError> {
-    return Constructors_isNormalized({ env: this.env }, this.t);
-  }
-
-  normalize(): result<Distribution, distributionError> {
-    return this.mapResultDist(
-      Constructors_normalize({ env: this.env }, this.t)
-    );
-  }
-
-  type() {
-    return this.t.tag;
-  }
-
-  pointSet(): result<shape, distributionError> {
-    let pointSet = toPointSet(
-      this.t,
-      {
-        xyPointLength: this.env.xyPointLength,
-        sampleCount: this.env.sampleCount,
-      },
-      undefined
-    );
-    if (pointSet.tag === "Ok") {
-      let distribution = pointSet.value;
-      if (distribution.tag === "Continuous") {
-        return Ok({
-          continuous: shapePoints(distribution.value),
-          discrete: [],
-        });
-      } else if (distribution.tag === "Discrete") {
-        return Ok({
-          discrete: shapePoints(distribution.value),
-          continuous: [],
-        });
-      } else {
-        return Ok({
-          discrete: shapePoints(distribution.value.discrete),
-          continuous: shapePoints(distribution.value.continuous),
-        });
-      }
-    } else {
-      return pointSet;
-    }
-  }
-
-  toPointSet(): result<Distribution, distributionError> {
-    return this.mapResultDist(
-      Constructors_toPointSet({ env: this.env }, this.t)
-    );
-  }
-
-  toSampleSet(n: number): result<Distribution, distributionError> {
-    return this.mapResultDist(
-      Constructors_toSampleSet({ env: this.env }, this.t, n)
-    );
-  }
-
-  truncate(
-    left: number,
-    right: number
-  ): result<Distribution, distributionError> {
-    return this.mapResultDist(
-      Constructors_truncate({ env: this.env }, this.t, left, right)
-    );
-  }
-
-  inspect(): result<Distribution, distributionError> {
-    return this.mapResultDist(Constructors_inspect({ env: this.env }, this.t));
-  }
-
-  toString(): string {
-    let result = Constructors_toString({ env: this.env }, this.t);
-    if (result.tag === "Ok") {
-      return result.value;
-    } else {
-      return distributionErrorToString(result.value);
-    }
-  }
-
-  toSparkline(n: number): result<string, distributionError> {
-    return Constructors_toSparkline({ env: this.env }, this.t, n);
-  }
-
-  algebraicAdd(d2: Distribution): result<Distribution, distributionError> {
-    return this.mapResultDist(
-      Constructors_algebraicAdd({ env: this.env }, this.t, d2.t)
-    );
-  }
-
-  algebraicMultiply(d2: Distribution): result<Distribution, distributionError> {
-    return this.mapResultDist(
-      Constructors_algebraicMultiply({ env: this.env }, this.t, d2.t)
-    );
-  }
-
-  algebraicDivide(d2: Distribution): result<Distribution, distributionError> {
-    return this.mapResultDist(
-      Constructors_algebraicDivide({ env: this.env }, this.t, d2.t)
-    );
-  }
-
-  algebraicSubtract(d2: Distribution): result<Distribution, distributionError> {
-    return this.mapResultDist(
-      Constructors_algebraicSubtract({ env: this.env }, this.t, d2.t)
-    );
-  }
-
-  algebraicLogarithm(
-    d2: Distribution
-  ): result<Distribution, distributionError> {
-    return this.mapResultDist(
-      Constructors_algebraicLogarithm({ env: this.env }, this.t, d2.t)
-    );
-  }
-
-  algebraicPower(d2: Distribution): result<Distribution, distributionError> {
-    return this.mapResultDist(
-      Constructors_algebraicPower({ env: this.env }, this.t, d2.t)
-    );
-  }
-
-  pointwiseAdd(d2: Distribution): result<Distribution, distributionError> {
-    return this.mapResultDist(
-      Constructors_pointwiseAdd({ env: this.env }, this.t, d2.t)
-    );
-  }
-
-  pointwiseMultiply(d2: Distribution): result<Distribution, distributionError> {
-    return this.mapResultDist(
-      Constructors_pointwiseMultiply({ env: this.env }, this.t, d2.t)
-    );
-  }
-
-  pointwiseDivide(d2: Distribution): result<Distribution, distributionError> {
-    return this.mapResultDist(
-      Constructors_pointwiseDivide({ env: this.env }, this.t, d2.t)
-    );
-  }
-
-  pointwiseSubtract(d2: Distribution): result<Distribution, distributionError> {
-    return this.mapResultDist(
-      Constructors_pointwiseSubtract({ env: this.env }, this.t, d2.t)
-    );
-  }
-
-  pointwiseLogarithm(
-    d2: Distribution
-  ): result<Distribution, distributionError> {
-    return this.mapResultDist(
-      Constructors_pointwiseLogarithm({ env: this.env }, this.t, d2.t)
-    );
-  }
-
-  pointwisePower(d2: Distribution): result<Distribution, distributionError> {
-    return this.mapResultDist(
-      Constructors_pointwisePower({ env: this.env }, this.t, d2.t)
-    );
-  }
-}
diff --git a/packages/squiggle-lang/src/js/rescript_interop.ts b/packages/squiggle-lang/src/js/rescript_interop.ts
new file mode 100644
index 00000000..b017699f
--- /dev/null
+++ b/packages/squiggle-lang/src/js/rescript_interop.ts
@@ -0,0 +1,155 @@
+import * as _ from "lodash";
+import {
+  mixedShape,
+  sampleSetDist,
+  genericDist,
+  samplingParams,
+  symbolicDist,
+  discreteShape,
+  continuousShape,
+} from "../rescript/TypescriptInterface.gen";
+import { Distribution } from "./distribution";
+import { tagged, tag } from "./types";
+// This file is here to compensate for genType not fully recursively converting types
+
+// Raw rescript types.
+export type rescriptExport =
+  | {
+      TAG: 0; // EvArray
+      _0: rescriptExport[];
+    }
+  | {
+      TAG: 1; // EvBool
+      _0: boolean;
+    }
+  | {
+      TAG: 2; // EvCall
+      _0: string;
+    }
+  | {
+      TAG: 3; // EvDistribution
+      _0: rescriptDist;
+    }
+  | {
+      TAG: 4; // EvNumber
+      _0: number;
+    }
+  | {
+      TAG: 5; // EvRecord
+      _0: { [key: string]: rescriptExport };
+    }
+  | {
+      TAG: 6; // EvString
+      _0: string;
+    }
+  | {
+      TAG: 7; // EvSymbol
+      _0: string;
+    };
+
+type rescriptDist =
+  | { TAG: 0; _0: rescriptPointSetDist }
+  | { TAG: 1; _0: sampleSetDist }
+  | { TAG: 2; _0: symbolicDist };
+
+type rescriptPointSetDist =
+  | {
+      TAG: 0; // Mixed
+      _0: mixedShape;
+    }
+  | {
+      TAG: 1; // Discrete
+      _0: discreteShape;
+    }
+  | {
+      TAG: 2; // ContinuousShape
+      _0: continuousShape;
+    };
+
+export type squiggleExpression =
+  | tagged<"symbol", string>
+  | tagged<"string", string>
+  | tagged<"call", string>
+  | tagged<"array", squiggleExpression[]>
+  | tagged<"boolean", boolean>
+  | tagged<"distribution", Distribution>
+  | tagged<"number", number>
+  | tagged<"record", { [key: string]: squiggleExpression }>;
+
+export function convertRawToTypescript(
+  result: rescriptExport,
+  sampEnv: samplingParams
+): squiggleExpression {
+  switch (result.TAG) {
+    case 0: // EvArray
+      return tag(
+        "array",
+        result._0.map((x) => convertRawToTypescript(x, sampEnv))
+      );
+    case 1: // EvBool
+      return tag("boolean", result._0);
+    case 2: // EvCall
+      return tag("call", result._0);
+    case 3: // EvDistribution
+      return tag(
+        "distribution",
+        new Distribution(
+          convertRawDistributionToGenericDist(result._0),
+          sampEnv
+        )
+      );
+    case 4: // EvNumber
+      return tag("number", result._0);
+    case 5: // EvRecord
+      return tag(
+        "record",
+        _.mapValues(result._0, (x) => convertRawToTypescript(x, sampEnv))
+      );
+    case 6: // EvString
+      return tag("string", result._0);
+    case 7: // EvSymbol
+      return tag("symbol", result._0);
+  }
+}
+
+function convertRawDistributionToGenericDist(
+  result: rescriptDist
+): genericDist {
+  switch (result.TAG) {
+    case 0: // Point Set Dist
+      switch (result._0.TAG) {
+        case 0: // Mixed
+          return tag("PointSet", tag("Mixed", result._0._0));
+        case 1: // Discrete
+          return tag("PointSet", tag("Discrete", result._0._0));
+        case 2: // Continuous
+          return tag("PointSet", tag("Continuous", result._0._0));
+      }
+    case 1: // Sample Set Dist
+      return tag("SampleSet", result._0);
+    case 2: // Symbolic Dist
+      return tag("Symbolic", result._0);
+  }
+}
+
+export type jsValue =
+  | string
+  | number
+  | jsValue[]
+  | { [key: string]: jsValue }
+  | boolean;
+
+export function jsValueToBinding(value: jsValue): rescriptExport {
+  if (typeof value === "boolean") {
+    return { TAG: 1, _0: value as boolean };
+  } else if (typeof value === "string") {
+    return { TAG: 6, _0: value as string };
+  } else if (typeof value === "number") {
+    return { TAG: 4, _0: value as number };
+  } else if (Array.isArray(value)) {
+    return { TAG: 0, _0: value.map(jsValueToBinding) };
+  } else {
+    // Record
+    return { TAG: 5, _0: _.mapValues(value, jsValueToBinding) };
+  }
+}
diff --git a/packages/squiggle-lang/src/js/types.ts b/packages/squiggle-lang/src/js/types.ts
new file mode 100644
index 00000000..8851b520
--- /dev/null
+++ b/packages/squiggle-lang/src/js/types.ts
@@ -0,0 +1,30 @@
+export type result<a, b> =
+  | {
+      tag: "Ok";
+      value: a;
+    }
+  | {
+      tag: "Error";
+      value: b;
+    };
+
+export function resultMap<a, b, c>(
+  r: result<a, c>,
+  mapFn: (x: a) => b
+): result<b, c> {
+  if (r.tag === "Ok") {
+    return { tag: "Ok", value: mapFn(r.value) };
+  } else {
+    return r;
+  }
+}
+
+export function Ok<a, b>(x: a): result<a, b> {
+  return { tag: "Ok", value: x };
+}
+
+export type tagged<a, b> = { tag: a; value: b };
+
+export function tag<a, b>(x: a, y: b): tagged<a, b> {
+  return { tag: x, value: y };
+}
diff --git a/packages/squiggle-lang/src/rescript/Utility/E.res b/packages/squiggle-lang/src/rescript/Utility/E.res
index e0bcaf5c..f5b38be7 100644
--- a/packages/squiggle-lang/src/rescript/Utility/E.res
+++ b/packages/squiggle-lang/src/rescript/Utility/E.res
@@ -350,7 +350,7 @@ module JsDate = {
 /* List */
 module L = {
   module Util = {
-    let eq = (a, b) => a == b
+    let eq = \"=="
   }
   let fmap = List.map
   let get = Belt.List.get