Merged with develop

.github/dependabot.yml

@@ -8,6 +8,6 @@ updates:
   - package-ecosystem: "npm" # See documentation for possible values
     directory: "/" # Location of package manifests
     schedule:
-      interval: "daily"
+      interval: "weekly"
     commit-message:
       prefix: "⬆️"

.prettierignore

@@ -11,3 +11,4 @@ packages/squiggle-lang/.nyc_output/
 packages/squiggle-lang/coverage/
 packages/squiggle-lang/.cache/
 packages/website/build/
+packages/squiggle-lang/src/rescript/Reducer/Reducer_Peggy/Reducer_Peggy_GeneratedParser.js

packages/components/package.json

@@ -9,7 +9,7 @@
     "react": "^18.1.0",
     "react-ace": "^10.1.0",
     "react-dom": "^18.1.0",
-    "react-use": "^17.3.2",
+    "react-use": "^17.4.0",
     "react-vega": "^7.5.1",
     "styled-components": "^5.3.5",
     "vega": "^5.22.1",
@@ -18,20 +18,20 @@
   },
   "devDependencies": {
     "@babel/plugin-proposal-private-property-in-object": "^7.17.12",
-    "@storybook/addon-actions": "^6.4.22",
+    "@storybook/addon-actions": "^6.5.3",
-    "@storybook/addon-essentials": "^6.4.22",
+    "@storybook/addon-essentials": "^6.5.4",
-    "@storybook/addon-links": "^6.4.22",
+    "@storybook/addon-links": "^6.5.4",
-    "@storybook/builder-webpack5": "^6.4.22",
+    "@storybook/builder-webpack5": "^6.5.4",
-    "@storybook/manager-webpack5": "^6.4.22",
+    "@storybook/manager-webpack5": "^6.5.4",
-    "@storybook/node-logger": "^6.4.22",
+    "@storybook/node-logger": "^6.5.4",
-    "@storybook/preset-create-react-app": "^4.1.0",
+    "@storybook/preset-create-react-app": "^4.1.1",
-    "@storybook/react": "^6.4.22",
+    "@storybook/react": "^6.5.4",
     "@testing-library/jest-dom": "^5.16.4",
     "@testing-library/react": "^13.2.0",
     "@testing-library/user-event": "^14.2.0",
     "@types/jest": "^27.5.0",
     "@types/lodash": "^4.14.182",
-    "@types/node": "^17.0.34",
+    "@types/node": "^17.0.35",
     "@types/react": "^18.0.9",
     "@types/react-dom": "^18.0.4",
     "@types/styled-components": "^5.1.24",

packages/squiggle-lang/.gitignore

@@ -21,3 +21,4 @@ dist
 _coverage
 coverage
 .nyc_output/
+src/rescript/Reducer/Reducer_Peggy/Reducer_Peggy_GeneratedParser.js

packages/squiggle-lang/.prettierignore

@@ -4,4 +4,5 @@ lib
 *.gen.tsx
 .nyc_output/
 coverage/
-.cache/
+.cache/
+Reducer_Peggy_GeneratedParser.js

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

@@ -16,33 +16,41 @@ testMacro([], exampleExpression, "Ok(1)")
 
 describe("bindStatement", () => {
   // A statement is bound by the bindings created by the previous statement
-  testMacro([], eBindStatement(eBindings([]), exampleStatementY), "Ok((:$setBindings {} :y 1))")
+  testMacro(
+    [],
+    eBindStatement(eBindings([]), exampleStatementY),
+    "Ok((:$_setBindings_$ {} :y 1) context: {})",
+  )
   // Then it answers the bindings for the next statement when reduced
   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((:$setBindings {x: 2} :y 2))",
+    "Ok((:$_setBindings_$ {x: 2} :y 2) context: {x: 2})",
   )
   // An expression does not return a binding, thus error
-  testMacro([], eBindStatement(eBindings([]), exampleExpression), "Error(Assignment expected)")
+  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.))],
     eBindStatementDefault(exampleStatementY),
-    "Ok((:$setBindings {z: 99} :y 1))",
+    "Ok((:$_setBindings_$ {z: 99} :y 1) context: {z: 99})",
   )
 })
 
 describe("bindExpression", () => {
   // x is simply bound in the expression
-  testMacro([], eBindExpression(eBindings([("x", EvNumber(2.))]), eSymbol("x")), "Ok(2)")
+  testMacro(
+    [],
+    eBindExpression(eBindings([("x", EvNumber(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)))",
+    "Ok((:$_exportBindings_$ (:$_setBindings_$ {x: 2} :y 1)) context: {x: 2})",
   )
   // Now let's reduce that expression
   testMacroEval(
@@ -60,37 +68,37 @@ describe("bindExpression", () => {
 
 describe("block", () => {
   // Block with a single expression
-  testMacro([], eBlock(list{exampleExpression}), "Ok((:$$bindExpression 1))")
+  testMacro([], eBlock(list{exampleExpression}), "Ok((:$$_bindExpression_$$ 1))")
   testMacroEval([], eBlock(list{exampleExpression}), "Ok(1)")
   // Block with a single statement
-  testMacro([], eBlock(list{exampleStatementY}), "Ok((:$$bindExpression (:$let :y 1)))")
+  testMacro([], eBlock(list{exampleStatementY}), "Ok((:$$_bindExpression_$$ (:$_let_$ :y 1)))")
   testMacroEval([], eBlock(list{exampleStatementY}), "Ok({y: 1})")
   // Block with a statement and an expression
   testMacro(
     [],
     eBlock(list{exampleStatementY, exampleExpressionY}),
-    "Ok((:$$bindExpression (:$$bindStatement (:$let :y 1)) :y))",
+    "Ok((:$$_bindExpression_$$ (:$$_bindStatement_$$ (:$_let_$ :y 1)) :y))",
   )
   testMacroEval([], eBlock(list{exampleStatementY, exampleExpressionY}), "Ok(1)")
   // Block with a statement and another statement
   testMacro(
     [],
     eBlock(list{exampleStatementY, exampleStatementZ}),
-    "Ok((:$$bindExpression (:$$bindStatement (:$let :y 1)) (:$let :z :y)))",
+    "Ok((:$$_bindExpression_$$ (:$$_bindStatement_$$ (:$_let_$ :y 1)) (:$_let_$ :z :y)))",
   )
   testMacroEval([], eBlock(list{exampleStatementY, exampleStatementZ}), "Ok({y: 1,z: 1})")
   // Block inside a block
   testMacro(
     [],
     eBlock(list{eBlock(list{exampleExpression})}),
-    "Ok((:$$bindExpression (:$$block 1)))",
+    "Ok((:$$_bindExpression_$$ (:$$_block_$$ 1)))",
   )
   testMacroEval([], eBlock(list{eBlock(list{exampleExpression})}), "Ok(1)")
   // Block assigned to a variable
   testMacro(
     [],
     eBlock(list{eLetStatement("z", eBlock(list{eBlock(list{exampleExpressionY})}))}),
-    "Ok((:$$bindExpression (:$let :z (:$$block (:$$block :y)))))",
+    "Ok((:$$_bindExpression_$$ (:$_let_$ :z (:$$_block_$$ (:$$_block_$$ :y)))))",
   )
   testMacroEval(
     [],
@@ -99,7 +107,7 @@ describe("block", () => {
   )
   // Empty block
   testMacro([], eBlock(list{}), "Ok(:undefined block)") //TODO: should be an error
-  //   :$$block (:$$block (:$let :y (:add :x 1)) :y)"
+  //   :$$_block_$$ (:$$_block_$$ (:$_let_$ :y (:add :x 1)) :y)"
   testMacro(
     [],
     eBlock(list{
@@ -108,9 +116,9 @@ describe("block", () => {
         eSymbol("y"),
       }),
     }),
-    "Ok((:$$bindExpression (:$$block (:$let :y (:add :x 1)) :y)))",
+    "Ok((:$$_bindExpression_$$ (:$$_block_$$ (:$_let_$ :y (:add :x 1)) :y)))",
   )
-  MyOnly.testMacroEval(
+  testMacroEval(
     [("x", EvNumber(1.))],
     eBlock(list{
       eBlock(list{
@@ -124,17 +132,17 @@ describe("block", () => {
 
 describe("lambda", () => {
   // assign a lambda to a variable
-  let lambdaExpression = eFunction("$$lambda", list{eArrayString(["y"]), exampleExpressionY})
+  let lambdaExpression = eFunction("$$_lambda_$$", list{eArrayString(["y"]), exampleExpressionY})
-  testMacro([], lambdaExpression, "Ok(lambda(y=>internal))")
+  testMacro([], lambdaExpression, "Ok(lambda(y=>internal code))")
   // call a lambda
   let callLambdaExpression = list{lambdaExpression, eNumber(1.)}->ExpressionT.EList
-  testMacro([], callLambdaExpression, "Ok(((:$$lambda [y] :y) 1))")
+  testMacro([], callLambdaExpression, "Ok(((:$$_lambda_$$ [y] :y) 1))")
   testMacroEval([], callLambdaExpression, "Ok(1)")
   // Parameters shadow the outer scope
   testMacroEval([("y", EvNumber(666.))], callLambdaExpression, "Ok(1)")
   // When not shadowed by the parameters, the outer scope variables are available
   let lambdaExpression = eFunction(
-    "$$lambda",
+    "$$_lambda_$$",
     list{eArrayString(["z"]), eFunction("add", list{eSymbol("y"), eSymbol("z")})},
   )
   let callLambdaExpression = eList(list{lambdaExpression, eNumber(1.)})

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

@@ -26,6 +26,16 @@ describe("builtin", () => {
 describe("builtin exception", () => {
   //It's a pity that MathJs does not return error position
   test("MathJs Exception", () =>
-    expectEvalToBe("testZadanga()", "Error(JS Exception: Error: Undefined function testZadanga)")
+    expectEvalToBe("testZadanga(1)", "Error(JS Exception: Error: Undefined function testZadanga)")
   )
 })
+
+describe("error reporting from collection functions", () => {
+  testEval("arr=[1,2,3]; map(arr, {|x| x*2})", "Ok([2,4,6])")
+  testEval(
+    "arr = [normal(3,2)]; map(arr, zarathsuzaWasHere)",
+    "Error(zarathsuzaWasHere is not defined)",
+  )
+  // FIXME: returns "Error(Function not found: map(Array,Symbol))"
+  // Actually this error is correct but not informative
+})

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

@@ -1,74 +0,0 @@
-module Parse = Reducer_MathJs.Parse
-module Result = Belt.Result
-
-open Jest
-open Expect
-
-let expectParseToBe = (expr, answer) =>
-  Parse.parse(expr)->Result.flatMap(Parse.castNodeType)->Parse.toStringResult->expect->toBe(answer)
-
-let testParse = (expr, answer) => test(expr, () => expectParseToBe(expr, answer))
-
-let testDescriptionParse = (desc, expr, answer) => test(desc, () => expectParseToBe(expr, answer))
-
-module MySkip = {
-  let testParse = (expr, answer) => Skip.test(expr, () => expectParseToBe(expr, answer))
-
-  let testDescriptionParse = (desc, expr, answer) =>
-    Skip.test(desc, () => expectParseToBe(expr, answer))
-}
-
-module MyOnly = {
-  let testParse = (expr, answer) => Only.test(expr, () => expectParseToBe(expr, answer))
-  let testDescriptionParse = (desc, expr, answer) =>
-    Only.test(desc, () => expectParseToBe(expr, answer))
-}
-
-describe("MathJs parse", () => {
-  describe("literals operators parenthesis", () => {
-    testParse("1", "1")
-    testParse("'hello'", "'hello'")
-    testParse("true", "true")
-    testParse("1+2", "add(1, 2)")
-    testParse("add(1,2)", "add(1, 2)")
-    testParse("(1)", "(1)")
-    testParse("(1+2)", "(add(1, 2))")
-  })
-
-  describe("multi-line", () => {
-    testParse("1; 2", "{1; 2}")
-  })
-
-  describe("variables", () => {
-    testParse("x = 1", "x = 1")
-    testParse("x", "x")
-    testParse("x = 1; x", "{x = 1; x}")
-  })
-
-  describe("functions", () => {
-    testParse("identity(x) = x", "identity = (x) => x")
-    testParse("identity(x)", "identity(x)")
-  })
-
-  describe("arrays", () => {
-    testDescriptionParse("empty", "[]", "[]")
-    testDescriptionParse("define", "[0, 1, 2]", "[0, 1, 2]")
-    testDescriptionParse("define with strings", "['hello', 'world']", "['hello', 'world']")
-    testParse("range(0, 4)", "range(0, 4)")
-    testDescriptionParse("index", "([0,1,2])[1]", "([0, 1, 2])[1]")
-  })
-
-  describe("records", () => {
-    testDescriptionParse("define", "{a: 1, b: 2}", "{a: 1, b: 2}")
-    testDescriptionParse("use", "record.property", "record['property']")
-  })
-
-  describe("comments", () => {
-    testDescriptionParse("define", "1 # This is a comment", "1")
-  })
-
-  describe("ternary operator", () => {
-    testParse("1 ? 2 : 3", "ternary(1, 2, 3)")
-    testParse("1 ? 2 : 3 ? 4 : 5", "ternary(1, 2, ternary(3, 4, 5))")
-  })
-})

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

@@ -0,0 +1,373 @@
+module Parse = Reducer_Peggy_Parse
+module Result = Belt.Result
+
+open Jest
+open Expect
+
+let expectParseToBe = (expr, answer) =>
+  Parse.parse(expr)->Parse.toStringResult->expect->toBe(answer)
+
+let testParse = (expr, answer) => test(expr, () => expectParseToBe(expr, answer))
+
+module MySkip = {
+  let testParse = (expr, answer) => Skip.test(expr, () => expectParseToBe(expr, answer))
+
+  let testDescriptionParse = (desc, expr, answer) =>
+    Skip.test(desc, () => expectParseToBe(expr, answer))
+}
+
+module MyOnly = {
+  let testParse = (expr, answer) => Only.test(expr, () => expectParseToBe(expr, answer))
+  let testDescriptionParse = (desc, expr, answer) =>
+    Only.test(desc, () => expectParseToBe(expr, answer))
+}
+
+describe("Peggy parse", () => {
+  describe("float", () => {
+    testParse("1.", "{1}")
+    testParse("1.1", "{1.1}")
+    testParse(".1", "{0.1}")
+    testParse("0.1", "{0.1}")
+    testParse("1e1", "{10}")
+    testParse("1e-1", "{0.1}")
+    testParse(".1e1", "{1}")
+    testParse("0.1e1", "{1}")
+  })
+
+  describe("literals operators parenthesis", () => {
+    // Note that there is always an outer block. Otherwise, external bindings are ignrored at the first statement
+    testParse("1", "{1}")
+    testParse("'hello'", "{'hello'}")
+    testParse("true", "{true}")
+    testParse("1+2", "{(::add 1 2)}")
+    testParse("add(1,2)", "{(::add 1 2)}")
+    testParse("(1)", "{1}")
+    testParse("(1+2)", "{(::add 1 2)}")
+  })
+
+  describe("unary", () => {
+    testParse("-1", "{(::unaryMinus 1)}")
+    testParse("!true", "{(::not true)}")
+    testParse("1 + -1", "{(::add 1 (::unaryMinus 1))}")
+    testParse("-a[0]", "{(::unaryMinus (::$_atIndex_$ :a 0))}")
+    testParse("!a[0]", "{(::not (::$_atIndex_$ :a 0))}")
+  })
+
+  describe("multiplicative", () => {
+    testParse("1 * 2", "{(::multiply 1 2)}")
+    testParse("1 / 2", "{(::divide 1 2)}")
+    testParse("1 * 2 * 3", "{(::multiply (::multiply 1 2) 3)}")
+    testParse("1 * 2 / 3", "{(::divide (::multiply 1 2) 3)}")
+    testParse("1 / 2 * 3", "{(::multiply (::divide 1 2) 3)}")
+    testParse("1 / 2 / 3", "{(::divide (::divide 1 2) 3)}")
+    testParse("1 * 2 + 3 * 4", "{(::add (::multiply 1 2) (::multiply 3 4))}")
+    testParse("1 * 2 - 3 * 4", "{(::subtract (::multiply 1 2) (::multiply 3 4))}")
+    testParse("1 * 2 .+ 3 * 4", "{(::dotAdd (::multiply 1 2) (::multiply 3 4))}")
+    testParse("1 * 2 .- 3 * 4", "{(::dotSubtract (::multiply 1 2) (::multiply 3 4))}")
+    testParse("1 * 2 + 3 .* 4", "{(::add (::multiply 1 2) (::dotMultiply 3 4))}")
+    testParse("1 * 2 + 3 / 4", "{(::add (::multiply 1 2) (::divide 3 4))}")
+    testParse("1 * 2 + 3 ./ 4", "{(::add (::multiply 1 2) (::dotDivide 3 4))}")
+    testParse("1 * 2 - 3 .* 4", "{(::subtract (::multiply 1 2) (::dotMultiply 3 4))}")
+    testParse("1 * 2 - 3 / 4", "{(::subtract (::multiply 1 2) (::divide 3 4))}")
+    testParse("1 * 2 - 3 ./ 4", "{(::subtract (::multiply 1 2) (::dotDivide 3 4))}")
+    testParse("1 * 2 - 3 * 4^5", "{(::subtract (::multiply 1 2) (::multiply 3 (::pow 4 5)))}")
+    testParse(
+      "1 * 2 - 3 * 4^5^6",
+      "{(::subtract (::multiply 1 2) (::multiply 3 (::pow (::pow 4 5) 6)))}",
+    )
+    testParse("1 * -a[-2]", "{(::multiply 1 (::unaryMinus (::$_atIndex_$ :a (::unaryMinus 2))))}")
+  })
+
+  describe("multi-line", () => {
+    testParse("x=1; 2", "{:x = {1}; 2}")
+    testParse("x=1; y=2", "{:x = {1}; :y = {2}}")
+  })
+
+  describe("variables", () => {
+    testParse("x = 1", "{:x = {1}}")
+    testParse("x", "{:x}")
+    testParse("x = 1; x", "{:x = {1}; :x}")
+  })
+
+  describe("functions", () => {
+    testParse("identity(x) = x", "{:identity = {|:x| {:x}}}") // Function definitions become lambda assignments
+    testParse("identity(x)", "{(::identity :x)}")
+  })
+
+  describe("arrays", () => {
+    testParse("[]", "{(::$_constructArray_$ ())}")
+    testParse("[0, 1, 2]", "{(::$_constructArray_$ (0 1 2))}")
+    testParse("['hello', 'world']", "{(::$_constructArray_$ ('hello' 'world'))}")
+    testParse("([0,1,2])[1]", "{(::$_atIndex_$ (::$_constructArray_$ (0 1 2)) 1)}")
+  })
+
+  describe("records", () => {
+    testParse("{a: 1, b: 2}", "{(::$_constructRecord_$ ('a': 1 'b': 2))}")
+    testParse("{1+0: 1, 2+0: 2}", "{(::$_constructRecord_$ ((::add 1 0): 1 (::add 2 0): 2))}") // key can be any expression
+    testParse("record.property", "{(::$_atIndex_$ :record 'property')}")
+  })
+
+  describe("post operators", () => {
+    //function call, array and record access are post operators with higher priority than unary operators
+    testParse("a==!b(1)", "{(::equal :a (::not (::b 1)))}")
+    testParse("a==!b[1]", "{(::equal :a (::not (::$_atIndex_$ :b 1)))}")
+    testParse("a==!b.one", "{(::equal :a (::not (::$_atIndex_$ :b 'one')))}")
+  })
+
+  describe("comments", () => {
+    testParse("1 # This is a line comment", "{1}")
+    testParse("1 // This is a line comment", "{1}")
+    testParse("1 /* This is a multi line comment */", "{1}")
+    testParse("/* This is a multi line comment */ 1", "{1}")
+    testParse(
+      `
+    /* This is 
+    a multi line 
+    comment */
+    1`,
+      "{1}",
+    )
+  })
+
+  describe("ternary operator", () => {
+    testParse("true ? 2 : 3", "{(::$$_ternary_$$ true 2 3)}")
+    testParse(
+      "false ? 2 : false ? 4 : 5",
+      "{(::$$_ternary_$$ false 2 (::$$_ternary_$$ false 4 5))}",
+    ) // nested ternary
+  })
+
+  describe("if then else", () => {
+    testParse("if true then 2 else 3", "{(::$$_ternary_$$ true {2} {3})}")
+    testParse("if false then {2} else {3}", "{(::$$_ternary_$$ false {2} {3})}")
+    testParse(
+      "if false then {2} else if false then {4} else {5}",
+      "{(::$$_ternary_$$ false {2} (::$$_ternary_$$ false {4} {5}))}",
+    ) //nested if
+  })
+
+  describe("logical", () => {
+    testParse("true || false", "{(::or true false)}")
+    testParse("true && false", "{(::and true false)}")
+    testParse("a * b + c", "{(::add (::multiply :a :b) :c)}") // for comparison
+    testParse("a && b || c", "{(::or (::and :a :b) :c)}")
+    testParse("a && b || c && d", "{(::or (::and :a :b) (::and :c :d))}")
+    testParse("a && !b || c", "{(::or (::and :a (::not :b)) :c)}")
+    testParse("a && b==c || d", "{(::or (::and :a (::equal :b :c)) :d)}")
+    testParse("a && b!=c || d", "{(::or (::and :a (::unequal :b :c)) :d)}")
+    testParse("a && !(b==c) || d", "{(::or (::and :a (::not (::equal :b :c))) :d)}")
+    testParse("a && b>=c || d", "{(::or (::and :a (::largerEq :b :c)) :d)}")
+    testParse("a && !(b>=c) || d", "{(::or (::and :a (::not (::largerEq :b :c))) :d)}")
+    testParse("a && b<=c || d", "{(::or (::and :a (::smallerEq :b :c)) :d)}")
+    testParse("a && b>c || d", "{(::or (::and :a (::larger :b :c)) :d)}")
+    testParse("a && b<c || d", "{(::or (::and :a (::smaller :b :c)) :d)}")
+    testParse("a && b<c[i] || d", "{(::or (::and :a (::smaller :b (::$_atIndex_$ :c :i))) :d)}")
+    testParse("a && b<c.i || d", "{(::or (::and :a (::smaller :b (::$_atIndex_$ :c 'i'))) :d)}")
+    testParse("a && b<c(i) || d", "{(::or (::and :a (::smaller :b (::c :i))) :d)}")
+    testParse("a && b<1+2 || d", "{(::or (::and :a (::smaller :b (::add 1 2))) :d)}")
+    testParse(
+      "a && b<1+2*3 || d",
+      "{(::or (::and :a (::smaller :b (::add 1 (::multiply 2 3)))) :d)}",
+    )
+    testParse(
+      "a && b<1+2*-3+4 || d",
+      "{(::or (::and :a (::smaller :b (::add (::add 1 (::multiply 2 (::unaryMinus 3))) 4))) :d)}",
+    )
+    testParse(
+      "a && b<1+2*3 || d ? true : false",
+      "{(::$$_ternary_$$ (::or (::and :a (::smaller :b (::add 1 (::multiply 2 3)))) :d) true false)}",
+    )
+  })
+
+  describe("pipe", () => {
+    testParse("1 -> add(2)", "{(::add 1 2)}")
+    testParse("-1 -> add(2)", "{(::add (::unaryMinus 1) 2)}")
+    testParse("-a[1] -> add(2)", "{(::add (::unaryMinus (::$_atIndex_$ :a 1)) 2)}")
+    testParse("-f(1) -> add(2)", "{(::add (::unaryMinus (::f 1)) 2)}")
+    testParse("1 + 2 -> add(3)", "{(::add 1 (::add 2 3))}")
+    testParse("1 -> add(2) * 3", "{(::multiply (::add 1 2) 3)}")
+    testParse("1 -> subtract(2)", "{(::subtract 1 2)}")
+    testParse("-1 -> subtract(2)", "{(::subtract (::unaryMinus 1) 2)}")
+    testParse("1 -> subtract(2) * 3", "{(::multiply (::subtract 1 2) 3)}")
+  })
+
+  describe("elixir pipe", () => {
+    //handled together with -> so there is no need for seperate tests
+    testParse("1 |> add(2)", "{(::add 1 2)}")
+  })
+
+  describe("to", () => {
+    testParse("1 to 2", "{(::credibleIntervalToDistribution 1 2)}")
+    testParse("-1 to -2", "{(::credibleIntervalToDistribution (::unaryMinus 1) (::unaryMinus 2))}") // lower than unary
+    testParse(
+      "a[1] to a[2]",
+      "{(::credibleIntervalToDistribution (::$_atIndex_$ :a 1) (::$_atIndex_$ :a 2))}",
+    ) // lower than post
+    testParse(
+      "a.p1 to a.p2",
+      "{(::credibleIntervalToDistribution (::$_atIndex_$ :a 'p1') (::$_atIndex_$ :a 'p2'))}",
+    ) // lower than post
+    testParse("1 to 2 + 3", "{(::add (::credibleIntervalToDistribution 1 2) 3)}") // higher than binary operators
+    testParse(
+      "1->add(2) to 3->add(4) -> add(4)",
+      "{(::credibleIntervalToDistribution (::add 1 2) (::add (::add 3 4) 4))}",
+    ) // lower than chain
+  })
+
+  describe("inner block", () => {
+    // inner blocks are 0 argument lambdas. They can be used whenever a value is required.
+    // Like lambdas they have a local scope.
+    testParse("x={y=1; y}; x", "{:x = {:y = {1}; :y}; :x}")
+  })
+
+  describe("lambda", () => {
+    testParse("{|x| x}", "{{|:x| {:x}}}")
+    testParse("f={|x| x}", "{:f = {{|:x| {:x}}}}")
+    testParse("f(x)=x", "{:f = {|:x| {:x}}}") // Function definitions are lambda assignments
+    testParse("f(x)=x ? 1 : 0", "{:f = {|:x| {(::$$_ternary_$$ :x 1 0)}}}") // Function definitions are lambda assignments
+  })
+
+  describe("Using lambda as value", () => {
+    testParse(
+      "myadd(x,y)=x+y; z=myadd; z",
+      "{:myadd = {|:x,:y| {(::add :x :y)}}; :z = {:myadd}; :z}",
+    )
+    testParse(
+      "myadd(x,y)=x+y; z=[myadd]; z",
+      "{:myadd = {|:x,:y| {(::add :x :y)}}; :z = {(::$_constructArray_$ (:myadd))}; :z}",
+    )
+    testParse(
+      "myaddd(x,y)=x+y; z={x: myaddd}; z",
+      "{:myaddd = {|:x,:y| {(::add :x :y)}}; :z = {(::$_constructRecord_$ ('x': :myaddd))}; :z}",
+    )
+    testParse("f({|x| x+1})", "{(::f {|:x| {(::add :x 1)}})}")
+    testParse("map(arr, {|x| x+1})", "{(::map :arr {|:x| {(::add :x 1)}})}")
+    testParse(
+      "map([1,2,3], {|x| x+1})",
+      "{(::map (::$_constructArray_$ (1 2 3)) {|:x| {(::add :x 1)}})}",
+    )
+    testParse(
+      "[1,2,3]->map({|x| x+1})",
+      "{(::map (::$_constructArray_$ (1 2 3)) {|:x| {(::add :x 1)}})}",
+    )
+  })
+})
+
+describe("parsing new line", () => {
+  testParse(
+    `
+  a + 
+  b`,
+    "{(::add :a :b)}",
+  )
+  testParse(
+    `
+  x=
+  1`,
+    "{:x = {1}}",
+  )
+  testParse(
+    `
+  x=1
+  y=2`,
+    "{:x = {1}; :y = {2}}",
+  )
+  testParse(
+    `
+  x={
+   y=2;
+   y }
+  x`,
+    "{:x = {:y = {2}; :y}; :x}",
+  )
+  testParse(
+    `
+  x={
+   y=2
+   y }
+  x`,
+    "{:x = {:y = {2}; :y}; :x}",
+  )
+  testParse(
+    `
+  x={
+   y=2
+   y 
+   }
+  x`,
+    "{:x = {:y = {2}; :y}; :x}",
+  )
+  testParse(
+    `
+  x=1
+  y=2
+  z=3
+  `,
+    "{:x = {1}; :y = {2}; :z = {3}}",
+  )
+  testParse(
+    `
+  f={
+    x=1
+    y=2
+    z=3
+    x+y+z
+  }
+  `,
+    "{:f = {:x = {1}; :y = {2}; :z = {3}; (::add (::add :x :y) :z)}}",
+  )
+  testParse(
+    `
+  f={
+    x=1
+    y=2
+    z=3
+    x+y+z
+  }
+  g=f+4
+  g
+  `,
+    "{:f = {:x = {1}; :y = {2}; :z = {3}; (::add (::add :x :y) :z)}; :g = {(::add :f 4)}; :g}",
+  )
+  testParse(
+    `
+  f =
+    {
+      x=1; //x
+      y=2  //y
+      z=
+        3
+      x+
+        y+
+        z
+    }
+  g =
+    f +
+      4
+  g ->
+    h ->
+    p ->
+    q 
+  `,
+    "{:f = {:x = {1}; :y = {2}; :z = {3}; (::add (::add :x :y) :z)}; :g = {(::add :f 4)}; (::q (::p (::h :g)))}",
+  )
+  testParse(
+    `
+    a |>
+    b |>
+    c |>
+    d 
+  `,
+    "{(::d (::c (::b :a)))}",
+  )
+  testParse(
+    `
+    a |>
+    b |>
+    c |>
+    d +
+    e
+  `,
+    "{(::add (::d (::c (::b :a))) :e)}",
+  )
+})

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

@@ -0,0 +1,220 @@
+module Expression = Reducer_Expression
+module ExpressionT = Reducer_Expression_T
+module ExpressionValue = ReducerInterface_ExpressionValue
+module Parse = Reducer_Peggy_Parse
+module ToExpression = Reducer_Peggy_ToExpression
+module Result = Belt.Result
+
+open Jest
+open Expect
+
+let expectToExpressionToBe = (expr, answer, ~v="_", ()) => {
+  let rExpr = Parse.parse(expr)->Result.map(ToExpression.fromNode)
+  let a1 = rExpr->ExpressionT.toStringResultOkless
+  if v == "_" {
+    a1->expect->toBe(answer)
+  } else {
+    let a2 =
+      rExpr
+      ->Result.flatMap(expr =>
+        Expression.reduceExpression(expr, Belt.Map.String.empty, ExpressionValue.defaultEnvironment)
+      )
+      ->ExpressionValue.toStringResultOkless
+    (a1, a2)->expect->toEqual((answer, v))
+  }
+}
+
+let testToExpression = (expr, answer, ~v="_", ()) =>
+  test(expr, () => expectToExpressionToBe(expr, answer, ~v, ()))
+
+module MySkip = {
+  let testToExpression = (expr, answer, ~v="_", ()) =>
+    Skip.test(expr, () => expectToExpressionToBe(expr, answer, ~v, ()))
+}
+
+module MyOnly = {
+  let testToExpression = (expr, answer, ~v="_", ()) =>
+    Only.test(expr, () => expectToExpressionToBe(expr, answer, ~v, ()))
+}
+
+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
+    testToExpression("1", "(:$$_block_$$ 1)", ~v="1", ())
+    testToExpression("'hello'", "(:$$_block_$$ 'hello')", ~v="'hello'", ())
+    testToExpression("true", "(:$$_block_$$ true)", ~v="true", ())
+    testToExpression("1+2", "(:$$_block_$$ (:add 1 2))", ~v="3", ())
+    testToExpression("add(1,2)", "(:$$_block_$$ (:add 1 2))", ~v="3", ())
+    testToExpression("(1)", "(:$$_block_$$ 1)", ())
+    testToExpression("(1+2)", "(:$$_block_$$ (:add 1 2))", ())
+  })
+
+  describe("unary", () => {
+    testToExpression("-1", "(:$$_block_$$ (:unaryMinus 1))", ~v="-1", ())
+    testToExpression("!true", "(:$$_block_$$ (:not true))", ~v="false", ())
+    testToExpression("1 + -1", "(:$$_block_$$ (:add 1 (:unaryMinus 1)))", ~v="0", ())
+    testToExpression("-a[0]", "(:$$_block_$$ (:unaryMinus (:$_atIndex_$ :a 0)))", ())
+  })
+
+  describe("multi-line", () => {
+    testToExpression("x=1; 2", "(:$$_block_$$ (:$_let_$ :x (:$$_block_$$ 1)) 2)", ~v="2", ())
+    testToExpression(
+      "x=1; y=2",
+      "(:$$_block_$$ (:$_let_$ :x (:$$_block_$$ 1)) (:$_let_$ :y (:$$_block_$$ 2)))",
+      ~v="{x: 1,y: 2}",
+      (),
+    )
+  })
+
+  describe("variables", () => {
+    testToExpression("x = 1", "(:$$_block_$$ (:$_let_$ :x (:$$_block_$$ 1)))", ~v="{x: 1}", ())
+    testToExpression("x", "(:$$_block_$$ :x)", ~v=":x", ()) //TODO: value should return error
+    testToExpression("x = 1; x", "(:$$_block_$$ (:$_let_$ :x (:$$_block_$$ 1)) :x)", ~v="1", ())
+  })
+
+  describe("functions", () => {
+    testToExpression(
+      "identity(x) = x",
+      "(:$$_block_$$ (:$_let_$ :identity (:$$_lambda_$$ [x] (:$$_block_$$ :x))))",
+      ~v="{identity: lambda(x=>internal code)}",
+      (),
+    ) // Function definitions become lambda assignments
+    testToExpression("identity(x)", "(:$$_block_$$ (:identity :x))", ()) // Note value returns error properly
+    testToExpression(
+      "f(x) = x> 2 ? 0 : 1; f(3)",
+      "(:$$_block_$$ (:$_let_$ :f (:$$_lambda_$$ [x] (:$$_block_$$ (:$$_ternary_$$ (:larger :x 2) 0 1)))) (:f 3))",
+      ~v="0",
+      (),
+    )
+  })
+
+  describe("arrays", () => {
+    testToExpression("[]", "(:$$_block_$$ (:$_constructArray_$ ()))", ~v="[]", ())
+    testToExpression("[0, 1, 2]", "(:$$_block_$$ (:$_constructArray_$ (0 1 2)))", ~v="[0,1,2]", ())
+    testToExpression(
+      "['hello', 'world']",
+      "(:$$_block_$$ (:$_constructArray_$ ('hello' 'world')))",
+      ~v="['hello','world']",
+      (),
+    )
+    testToExpression(
+      "([0,1,2])[1]",
+      "(:$$_block_$$ (:$_atIndex_$ (:$_constructArray_$ (0 1 2)) 1))",
+      ~v="1",
+      (),
+    )
+  })
+
+  describe("records", () => {
+    testToExpression(
+      "{a: 1, b: 2}",
+      "(:$$_block_$$ (:$_constructRecord_$ (('a' 1) ('b' 2))))",
+      ~v="{a: 1,b: 2}",
+      (),
+    )
+    testToExpression(
+      "{1+0: 1, 2+0: 2}",
+      "(:$$_block_$$ (:$_constructRecord_$ (((:add 1 0) 1) ((:add 2 0) 2))))",
+      (),
+    ) // key can be any expression
+    testToExpression("record.property", "(:$$_block_$$ (:$_atIndex_$ :record 'property'))", ())
+    testToExpression(
+      "record={property: 1}; record.property",
+      "(:$$_block_$$ (:$_let_$ :record (:$$_block_$$ (:$_constructRecord_$ (('property' 1))))) (:$_atIndex_$ :record 'property'))",
+      ~v="1",
+      (),
+    )
+  })
+
+  describe("comments", () => {
+    testToExpression("1 # This is a line comment", "(:$$_block_$$ 1)", ~v="1", ())
+    testToExpression("1 // This is a line comment", "(:$$_block_$$ 1)", ~v="1", ())
+    testToExpression("1 /* This is a multi line comment */", "(:$$_block_$$ 1)", ~v="1", ())
+    testToExpression("/* This is a multi line comment */ 1", "(:$$_block_$$ 1)", ~v="1", ())
+  })
+
+  describe("ternary operator", () => {
+    testToExpression("true ? 1 : 0", "(:$$_block_$$ (:$$_ternary_$$ true 1 0))", ~v="1", ())
+    testToExpression("false ? 1 : 0", "(:$$_block_$$ (:$$_ternary_$$ false 1 0))", ~v="0", ())
+    testToExpression(
+      "true ? 1 : false ? 2 : 0",
+      "(:$$_block_$$ (:$$_ternary_$$ true 1 (:$$_ternary_$$ false 2 0)))",
+      ~v="1",
+      (),
+    ) // nested ternary
+    testToExpression(
+      "false ? 1 : false ? 2 : 0",
+      "(:$$_block_$$ (:$$_ternary_$$ false 1 (:$$_ternary_$$ false 2 0)))",
+      ~v="0",
+      (),
+    ) // nested ternary
+  })
+
+  describe("if then else", () => {
+    testToExpression(
+      "if true then 2 else 3",
+      "(:$$_block_$$ (:$$_ternary_$$ true (:$$_block_$$ 2) (:$$_block_$$ 3)))",
+      (),
+    )
+    testToExpression(
+      "if true then {2} else {3}",
+      "(:$$_block_$$ (:$$_ternary_$$ true (:$$_block_$$ 2) (:$$_block_$$ 3)))",
+      (),
+    )
+    testToExpression(
+      "if false then {2} else if false then {4} else {5}",
+      "(:$$_block_$$ (:$$_ternary_$$ false (:$$_block_$$ 2) (:$$_ternary_$$ false (:$$_block_$$ 4) (:$$_block_$$ 5))))",
+      (),
+    ) //nested if
+  })
+
+  describe("pipe", () => {
+    testToExpression("1 -> add(2)", "(:$$_block_$$ (:add 1 2))", ~v="3", ())
+    testToExpression("-1 -> add(2)", "(:$$_block_$$ (:add (:unaryMinus 1) 2))", ~v="1", ()) // note that unary has higher priority naturally
+    testToExpression("1 -> add(2) * 3", "(:$$_block_$$ (:multiply (:add 1 2) 3))", ~v="9", ())
+  })
+
+  describe("elixir pipe", () => {
+    testToExpression("1 |> add(2)", "(:$$_block_$$ (:add 1 2))", ~v="3", ())
+  })
+
+  // see testParse for priorities of to and credibleIntervalToDistribution
+
+  describe("inner block", () => {
+    // inner blocks are 0 argument lambdas. They can be used whenever a value is required.
+    // Like lambdas they have a local scope.
+    testToExpression(
+      "y=99; x={y=1; y}",
+      "(:$$_block_$$ (:$_let_$ :y (:$$_block_$$ 99)) (:$_let_$ :x (:$$_block_$$ (:$_let_$ :y (:$$_block_$$ 1)) :y)))",
+      ~v="{x: 1,y: 99}",
+      (),
+    )
+  })
+
+  describe("lambda", () => {
+    testToExpression(
+      "{|x| x}",
+      "(:$$_block_$$ (:$$_lambda_$$ [x] (:$$_block_$$ :x)))",
+      ~v="lambda(x=>internal code)",
+      (),
+    )
+    testToExpression(
+      "f={|x| x}",
+      "(:$$_block_$$ (:$_let_$ :f (:$$_block_$$ (:$$_lambda_$$ [x] (:$$_block_$$ :x)))))",
+      ~v="{f: lambda(x=>internal code)}",
+      (),
+    )
+    testToExpression(
+      "f(x)=x",
+      "(:$$_block_$$ (:$_let_$ :f (:$$_lambda_$$ [x] (:$$_block_$$ :x))))",
+      ~v="{f: lambda(x=>internal code)}",
+      (),
+    ) // Function definitions are lambda assignments
+    testToExpression(
+      "f(x)=x ? 1 : 0",
+      "(:$$_block_$$ (:$_let_$ :f (:$$_lambda_$$ [x] (:$$_block_$$ (:$$_ternary_$$ :x 1 0)))))",
+      ~v="{f: lambda(x=>internal code)}",
+      (),
+    )
+  })
+})

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

@@ -19,6 +19,9 @@ let expectParseToBe = (expr: string, answer: string) =>
 let expectEvalToBe = (expr: string, answer: string) =>
   Reducer.evaluate(expr)->ExpressionValue.toStringResult->expect->toBe(answer)
 
+let expectEvalError = (expr: string) =>
+  Reducer.evaluate(expr)->ExpressionValue.toStringResult->expect->toMatch("Error\(")
+
 let expectEvalBindingsToBe = (expr: string, bindings: Reducer.externalBindings, answer: string) =>
   Reducer.evaluateUsingOptions(expr, ~externalBindings=Some(bindings), ~environment=None)
   ->ExpressionValue.toStringResult
@@ -29,6 +32,7 @@ let testParseToBe = (expr, answer) => test(expr, () => expectParseToBe(expr, ans
 let testDescriptionParseToBe = (desc, expr, answer) =>
   test(desc, () => expectParseToBe(expr, answer))
 
+let testEvalError = expr => test(expr, () => expectEvalError(expr))
 let testEvalToBe = (expr, answer) => test(expr, () => expectEvalToBe(expr, answer))
 let testDescriptionEvalToBe = (desc, expr, answer) => test(desc, () => expectEvalToBe(expr, answer))
 let testEvalBindingsToBe = (expr, bindingsList, answer) =>

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

@@ -2,62 +2,10 @@
 open Jest
 open Reducer_TestHelpers
 
-// describe("Parse for Bindings", () => {
-//   testParseOuterToBe("x", "Ok((:$$bindExpression (:$$bindings) :x))")
-//   testParseOuterToBe("x+1", "Ok((:$$bindExpression (:$$bindings) (:add :x 1)))")
-//   testParseOuterToBe(
-//     "y = x+1; y",
-//     "Ok((:$$bindExpression (:$$bindStatement (:$$bindings) (:$let :y (:add :x 1))) :y))",
-//   )
-// })
-
-// describe("Parse Partial", () => {
-//   testParsePartialToBe(
-//     "x",
-//     "Ok((:$$bindExpression (:$$bindStatement (:$$bindings) :x) (:$exportVariablesExpression)))",
-//   )
-//   testParsePartialToBe(
-//     "y=x",
-//     "Ok((:$$bindExpression (:$$bindStatement (:$$bindings) (:$let :y :x)) (:$exportVariablesExpression)))",
-//   )
-//   testParsePartialToBe(
-//     "y=x+1",
-//     "Ok((:$$bindExpression (:$$bindStatement (:$$bindings) (:$let :y (:add :x 1))) (:$exportVariablesExpression)))",
-//   )
-//   testParsePartialToBe(
-//     "y = x+1; z = y",
-//     "Ok((:$$bindExpression (:$$bindStatement (:$$bindStatement (:$$bindings) (:$let :y (:add :x 1))) (:$let :z :y)) (:$exportVariablesExpression)))",
-//   )
-// })
-
 describe("Eval with Bindings", () => {
   testEvalBindingsToBe("x", list{("x", ExpressionValue.EvNumber(1.))}, "Ok(1)")
   testEvalBindingsToBe("x+1", list{("x", ExpressionValue.EvNumber(1.))}, "Ok(2)")
-  testParseToBe("y = x+1; y", "Ok((:$$block (:$$block (:$let :y (:add :x 1)) :y)))")
+  testParseToBe("y = x+1; y", "Ok((:$$_block_$$ (:$_let_$ :y (:$$_block_$$ (: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})")
 })
-
-/*
-    Partial code is a partial code fragment that is cut out from a larger code.
-    Therefore it does not end with an expression.
-*/
-// describe("Eval Partial", () => {
-//   testEvalPartialBindingsToBe(
-//     //   A partial cannot end with an expression
-//     "x",
-//     list{("x", ExpressionValue.EvNumber(1.))},
-//     "Error(Assignment expected)",
-//   )
-//   testEvalPartialBindingsToBe("y=x", list{("x", ExpressionValue.EvNumber(1.))}, "Ok({x: 1,y: 1})")
-//   testEvalPartialBindingsToBe(
-//     "y=x+1",
-//     list{("x", ExpressionValue.EvNumber(1.))},
-//     "Ok({x: 1,y: 2})",
-//   )
-//   testEvalPartialBindingsToBe(
-//     "y = x+1; z = y",
-//     list{("x", ExpressionValue.EvNumber(1.))},
-//     "Ok({x: 1,y: 2,z: 2})",
-//   )
-// })

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

@@ -2,8 +2,11 @@ open Jest
 open Reducer_TestHelpers
 
 describe("Parse function assignment", () => {
-  testParseToBe("f(x)=x", "Ok((:$$block (:$let :f (:$$lambda [x] (:$$block :x)))))")
+  testParseToBe("f(x)=x", "Ok((:$$_block_$$ (:$_let_$ :f (:$$_lambda_$$ [x] (:$$_block_$$ :x)))))")
-  testParseToBe("f(x)=2*x", "Ok((:$$block (:$let :f (:$$lambda [x] (:$$block (:multiply 2 :x))))))")
+  testParseToBe(
+    "f(x)=2*x",
+    "Ok((:$$_block_$$ (:$_let_$ :f (:$$_lambda_$$ [x] (:$$_block_$$ (:multiply 2 :x))))))",
+  )
   //MathJs does not allow blocks in function definitions
 })
 

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

@@ -25,7 +25,7 @@ describe("Arity check", () => {
   )
   testEvalToBe("f(x)=x; f(f)", "Ok(lambda(x=>internal code))")
   testEvalToBe(
-    "f(x,y)=x(y); f(z)",
+    "f(x,y)=x(y); f(1)",
     "Error(2 arguments expected. Instead 1 argument(s) were passed.)",
   )
 })
@@ -51,7 +51,7 @@ describe("call and bindings", () => {
   )
   testParseToBe(
     "f=99; g(x)=f; g(2)",
-    "Ok((:$$block (:$$block (:$let :f 99) (:$let :g (:$$lambda [x] (:$$block :f))) (:g 2))))",
+    "Ok((:$$_block_$$ (:$_let_$ :f (:$$_block_$$ 99)) (:$_let_$ :g (:$$_lambda_$$ [x] (:$$_block_$$ :f))) (:g 2)))",
   )
   testEvalToBe("f=99; g(x)=f; g(2)", "Ok(99)")
   testEvalToBe("f(x)=x; g(x)=f(x); g(2)", "Ok(2)")
@@ -63,15 +63,28 @@ describe("call and bindings", () => {
 })
 
 describe("function tricks", () => {
-  testParseToBe(
+  testEvalError("f(x)=f(y)=2; f(2)") //Error because chain assignment is not allowed
-    "f(x)=f(y)=2; f(2)",
-    "Ok((:$$block (:$$block (:$let :f (:$$lambda [x] (:$$block (:$let :f (:$$lambda [y] (:$$block 2)))))) (:f 2))))",
-  )
-  testEvalToBe("f(x)=f(y)=2; f(2)", "Ok({f: lambda(y=>internal code),x: 2})")
   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})")
   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
-  MySkip.testEvalToBe("myadd(x,y)=x+y; z=[add]; z[0](3,2)", "????") //TODO: to fix with new parser
+  testEvalToBe("myadd(x,y)=x+y; z=myadd; z", "Ok(lambda(x,y=>internal code))")
-  MySkip.testEvalToBe("myaddd(x,y)=x+y; z={x: add}; z.x(3,2)", "????") //TODO: to fix with new parser
+  testEvalToBe("myadd(x,y)=x+y; z=myadd; z(1, 1)", "Ok(2)")
+})
+
+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)]})",
+  )
+  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)")
+  testEvalToBe("myaddd(x,y)=x+y; z={x: myaddd}; z", "Ok({x: lambda(x,y=>internal code)})")
+  testEvalToBe("myaddd(x,y)=x+y; z={x: myaddd}; z.x", "Ok(lambda(x,y=>internal code))")
+  testEvalToBe("myaddd(x,y)=x+y; z={x: myaddd}; z.x(3,2)", "Ok(5)")
+})
+
+describe("ternary and bindings", () => {
+  testEvalToBe("f(x)=x ? 1 : 0; f(true)", "Ok(1)")
+  testEvalToBe("f(x)=x>2 ? 1 : 0; f(3)", "Ok(1)")
 })

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

@@ -2,7 +2,7 @@ open Jest
 open Reducer_TestHelpers
 
 describe("Parse ternary operator", () => {
-  testParseToBe("true ? 'YES' : 'NO'", "Ok((:$$block (:$$ternary true 'YES' 'NO')))")
+  testParseToBe("true ? 'YES' : 'NO'", "Ok((:$$_block_$$ (:$$_ternary_$$ true 'YES' 'NO')))")
 })
 
 describe("Evaluate ternary operator", () => {

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

@@ -1,55 +1,9 @@
 open Jest
 open Reducer_TestHelpers
 
-describe("reducer using mathjs parse", () => {
-  // Test the MathJs parser compatibility
-  // Those tests toString that there is a semantic mapping from MathJs to Expression
-  // Reducer.parse is called by Reducer.eval
-  // See https://mathjs.org/docs/expressions/syntax.html
-  // See https://mathjs.org/docs/reference/functions.html
-  // Those tests toString that we are converting mathjs parse tree to what we need
-
-  describe("expressions", () => {
-    testParseToBe("1", "Ok((:$$block 1))")
-    testParseToBe("(1)", "Ok((:$$block 1))")
-    testParseToBe("1+2", "Ok((:$$block (:add 1 2)))")
-    testParseToBe("1+2*3", "Ok((:$$block (:add 1 (:multiply 2 3))))")
-  })
-  describe("arrays", () => {
-    //Note. () is a empty list in Lisp
-    //  The only builtin structure in Lisp is list. There are no arrays
-    //  [1,2,3] becomes (1 2 3)
-    testDescriptionParseToBe("empty", "[]", "Ok((:$$block ()))")
-    testParseToBe("[1, 2, 3]", "Ok((:$$block (1 2 3)))")
-    testParseToBe("['hello', 'world']", "Ok((:$$block ('hello' 'world')))")
-    testDescriptionParseToBe("index", "([0,1,2])[1]", "Ok((:$$block (:$atIndex (0 1 2) (1))))")
-  })
-  describe("records", () => {
-    testDescriptionParseToBe(
-      "define",
-      "{a: 1, b: 2}",
-      "Ok((:$$block (:$constructRecord (('a' 1) ('b' 2)))))",
-    )
-    testDescriptionParseToBe(
-      "use",
-      "{a: 1, b: 2}.a",
-      "Ok((:$$block (:$atIndex (:$constructRecord (('a' 1) ('b' 2))) ('a'))))",
-    )
-  })
-  describe("multi-line", () => {
-    testParseToBe("1; 2", "Ok((:$$block (:$$block 1 2)))")
-    testParseToBe("1+1; 2+1", "Ok((:$$block (:$$block (:add 1 1) (:add 2 1))))")
-  })
-  describe("assignment", () => {
-    testParseToBe("x=1; x", "Ok((:$$block (:$$block (:$let :x 1) :x)))")
-    testParseToBe("x=1+1; x+1", "Ok((:$$block (:$$block (:$let :x (:add 1 1)) (:add :x 1))))")
-  })
-})
-
 describe("eval", () => {
   // All MathJs operators and functions are builtin for string, float and boolean
   // .e.g + - / * > >= < <= == /= not and or
-  // See https://mathjs.org/docs/expressions/syntax.html
   // See https://mathjs.org/docs/reference/functions.html
   describe("expressions", () => {
     testEvalToBe("1", "Ok(1)")
@@ -70,20 +24,21 @@ describe("eval", () => {
   })
   describe("records", () => {
     test("define", () => expectEvalToBe("{a: 1, b: 2}", "Ok({a: 1,b: 2})"))
-    test("index", () => expectEvalToBe("{a: 1}.a", "Ok(1)"))
+    test("index", () => expectEvalToBe("r = {a: 1}; r.a", "Ok(1)"))
-    test("index not found", () => expectEvalToBe("{a: 1}.b", "Error(Record property not found: b)"))
+    test("index", () => expectEvalToBe("r = {a: 1}; r.b", "Error(Record property not found: b)"))
+    testEvalError("{a: 1}.b") // invalid syntax
   })
 
   describe("multi-line", () => {
-    testEvalToBe("1; 2", "Error(Assignment expected)")
+    testEvalError("1; 2")
-    testEvalToBe("1+1; 2+1", "Error(Assignment expected)")
+    testEvalError("1+1; 2+1")
   })
   describe("assignment", () => {
     testEvalToBe("x=1; x", "Ok(1)")
     testEvalToBe("x=1+1; x+1", "Ok(3)")
     testEvalToBe("x=1; y=x+1; y+1", "Ok(3)")
-    testEvalToBe("1; x=1", "Error(Assignment expected)")
+    testEvalError("1; x=1")
-    testEvalToBe("1; 1", "Error(Assignment expected)")
+    testEvalError("1; 1")
     testEvalToBe("x=1; x=1", "Ok({x: 1})")
   })
 })
@@ -94,9 +49,9 @@ describe("test exceptions", () => {
     "javascriptraise('div by 0')",
     "Error(JS Exception: Error: 'div by 0')",
   )
-  testDescriptionEvalToBe(
+  // testDescriptionEvalToBe(
-    "rescript exception",
+  //   "rescript exception",
-    "rescriptraise()",
+  //   "rescriptraise()",
-    "Error(TODO: unhandled rescript exception)",
+  //   "Error(TODO: unhandled rescript exception)",
-  )
+  // )
 })

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

@@ -123,34 +123,37 @@ describe("eval on distribution functions", () => {
 
 describe("parse on distribution functions", () => {
   describe("power", () => {
-    testParse("normal(5,2) ^ normal(5,1)", "Ok((:$$block (:pow (:normal 5 2) (:normal 5 1))))")
+    testParse("normal(5,2) ^ normal(5,1)", "Ok((:$$_block_$$ (:pow (:normal 5 2) (:normal 5 1))))")
-    testParse("3 ^ normal(5,1)", "Ok((:$$block (:pow 3 (:normal 5 1))))")
+    testParse("3 ^ normal(5,1)", "Ok((:$$_block_$$ (:pow 3 (:normal 5 1))))")
-    testParse("normal(5,2) ^ 3", "Ok((:$$block (:pow (:normal 5 2) 3)))")
+    testParse("normal(5,2) ^ 3", "Ok((:$$_block_$$ (:pow (:normal 5 2) 3)))")
   })
   describe("subtraction", () => {
-    testParse("10 - normal(5,1)", "Ok((:$$block (:subtract 10 (:normal 5 1))))")
+    testParse("10 - normal(5,1)", "Ok((:$$_block_$$ (:subtract 10 (:normal 5 1))))")
-    testParse("normal(5,1) - 10", "Ok((:$$block (:subtract (:normal 5 1) 10)))")
+    testParse("normal(5,1) - 10", "Ok((:$$_block_$$ (:subtract (:normal 5 1) 10)))")
   })
   describe("pointwise arithmetic expressions", () => {
     testParse(~skip=true, "normal(5,2) .+ normal(5,1)", "Ok((:dotAdd (:normal 5 2) (:normal 5 1)))")
     testParse(
       ~skip=true,
       "normal(5,2) .- normal(5,1)",
-      "Ok((:$$block (:dotSubtract (:normal 5 2) (:normal 5 1))))",
+      "Ok((:$$_block_$$ (:dotSubtract (:normal 5 2) (:normal 5 1))))",
-      // TODO: !!! returns "Ok((:$$block (:dotPow (:normal 5 2) (:normal 5 1))))"
+      // TODO: !!! returns "Ok((:$$_block_$$ (:dotPow (:normal 5 2) (:normal 5 1))))"
     )
     testParse(
       "normal(5,2) .* normal(5,1)",
-      "Ok((:$$block (:dotMultiply (:normal 5 2) (:normal 5 1))))",
+      "Ok((:$$_block_$$ (:dotMultiply (:normal 5 2) (:normal 5 1))))",
     )
     testParse(
       "normal(5,2) ./ normal(5,1)",
-      "Ok((:$$block (:dotDivide (:normal 5 2) (:normal 5 1))))",
+      "Ok((:$$_block_$$ (:dotDivide (:normal 5 2) (:normal 5 1))))",
+    )
+    testParse(
+      "normal(5,2) .^ normal(5,1)",
+      "Ok((:$$_block_$$ (:dotPow (:normal 5 2) (:normal 5 1))))",
     )
-    testParse("normal(5,2) .^ normal(5,1)", "Ok((:$$block (:dotPow (:normal 5 2) (:normal 5 1))))")
   })
   describe("equality", () => {
-    testParse("5 == normal(5,2)", "Ok((:$$block (:equal 5 (:normal 5 2))))")
+    testParse("5 == normal(5,2)", "Ok((:$$_block_$$ (:equal 5 (:normal 5 2))))")
   })
   describe("pointwise adding two normals", () => {
     testParse(~skip=true, "normal(5,2) .+ normal(5,1)", "Ok((:dotAdd (:normal 5 2) (:normal 5 1)))")

packages/squiggle-lang/package.json

@@ -4,7 +4,9 @@
   "homepage": "https://squiggle-language.com",
   "license": "MIT",
   "scripts": {
-    "build": "yarn build:rescript && yarn build:typescript",
+    "peggy": "peggy --cache",
+    "build": "yarn build:peggy && yarn build:rescript && yarn build:typescript",
+    "build:peggy": "find . -type f -name *.peggy -exec yarn peggy {} \\;",
     "build:rescript": "rescript build -with-deps",
     "build:typescript": "tsc",
     "bundle": "webpack",
@@ -54,11 +56,12 @@
     "lodash": "^4.17.21",
     "moduleserve": "^0.9.1",
     "nyc": "^15.1.0",
+    "peggy": "^1.2.0",
     "reanalyze": "^2.19.0",
     "rescript-fast-check": "^1.1.1",
     "ts-jest": "^27.1.4",
     "ts-loader": "^9.3.0",
-    "ts-node": "^10.7.0",
+    "ts-node": "^10.8.0",
     "typescript": "^4.6.3",
     "webpack": "^5.72.1",
     "webpack-cli": "^4.9.2"

packages/squiggle-lang/src/rescript/FunctionRegistry/FunctionRegistry_Library.res

@@ -44,6 +44,9 @@ let registry = [
   ),
   Function.make(
     ~name="To",
-    ~definitions=[TwoArgDist.make("to", twoArgs(SymbolicDist.From90thPercentile.make))],
+    ~definitions=[TwoArgDist.make("to", twoArgs(SymbolicDist.From90thPercentile.make)), 
+    TwoArgDist.make("credibleIntervalToDistribution", twoArgs(SymbolicDist.From90thPercentile.make))
+    ],
+
   ),
 ]

packages/squiggle-lang/src/rescript/Reducer/Reducer_Dispatch/Reducer_Dispatch_BuiltIn.res

@@ -13,6 +13,8 @@ open Reducer_ErrorValue
   DO NOT try to add external function mapping here!
 */
 
+//TODO: pow to xor
+
 exception TestRescriptException
 
 let callInternal = (call: functionCall, environment, reducer: ExpressionT.reducerFn): result<
@@ -128,12 +130,12 @@ let callInternal = (call: functionCall, environment, reducer: ExpressionT.reduce
   }
 
   switch call {
-  | ("$atIndex", [EvArray(aValueArray), EvArray([EvNumber(fIndex)])]) =>
+  | ("$_atIndex_$", [EvArray(aValueArray), EvNumber(fIndex)]) => arrayAtIndex(aValueArray, fIndex)
-    arrayAtIndex(aValueArray, fIndex)
+  | ("$_atIndex_$", [EvRecord(dict), EvString(sIndex)]) => recordAtIndex(dict, sIndex)
-  | ("$atIndex", [EvRecord(dict), EvArray([EvString(sIndex)])]) => recordAtIndex(dict, sIndex)
+  | ("$_constructArray_$", [EvArray(aValueArray)]) => EvArray(aValueArray)->Ok
-  | ("$constructRecord", [EvArray(arrayOfPairs)]) => constructRecord(arrayOfPairs)
+  | ("$_constructRecord_$", [EvArray(arrayOfPairs)]) => constructRecord(arrayOfPairs)
-  | ("$exportBindings", [EvRecord(externalBindings)]) => doExportBindings(externalBindings)
+  | ("$_exportBindings_$", [EvRecord(externalBindings)]) => doExportBindings(externalBindings)
-  | ("$setBindings", [EvRecord(externalBindings), EvSymbol(symbol), value]) =>
+  | ("$_setBindings_$", [EvRecord(externalBindings), EvSymbol(symbol), value]) =>
     doSetBindings(externalBindings, symbol, value)
   | ("inspect", [value, EvString(label)]) => inspectLabel(value, label)
   | ("inspect", [value]) => inspect(value)
@@ -147,7 +149,15 @@ let callInternal = (call: functionCall, environment, reducer: ExpressionT.reduce
   | ("reduceReverse", [EvArray(aValueArray), initialValue, EvLambda(aLambdaValue)]) =>
     doReduceReverseArray(aValueArray, initialValue, aLambdaValue)
   | ("reverse", [EvArray(aValueArray)]) => aValueArray->Belt.Array.reverse->EvArray->Ok
-  | call => callMathJs(call)
+  | (_, [EvBool(_)])
+  | (_, [EvNumber(_)])
+  | (_, [EvString(_)])
+  | (_, [EvBool(_), EvBool(_)])
+  | (_, [EvNumber(_), EvNumber(_)])
+  | (_, [EvString(_), EvString(_)]) =>
+    callMathJs(call)
+  | call =>
+    Error(REFunctionNotFound(call->functionCallToCallSignature->functionCallSignatureToString)) // Report full type signature as error
   }
 }
 

packages/squiggle-lang/src/rescript/Reducer/Reducer_Dispatch/Reducer_Dispatch_BuiltInMacros.res

@@ -4,6 +4,7 @@
   Macros are used to define language building blocks. They are like Lisp macros.
 */
 module Bindings = Reducer_Expression_Bindings
+module ExpressionBuilder = Reducer_Expression_ExpressionBuilder
 module ExpressionT = Reducer_Expression_T
 module ExpressionValue = ReducerInterface.ExpressionValue
 module ExpressionWithContext = Reducer_ExpressionWithContext
@@ -24,7 +25,7 @@ let dispatchMacroCall = (
 ): result<expressionWithContext, errorValue> => {
   let doBindStatement = (bindingExpr: expression, statement: expression, environment) =>
     switch statement {
-    | ExpressionT.EList(list{ExpressionT.EValue(EvCall("$let")), symbolExpr, statement}) => {
+    | ExpressionT.EList(list{ExpressionT.EValue(EvCall("$_let_$")), symbolExpr, statement}) => {
         let rExternalBindingsValue = reduceExpression(bindingExpr, bindings, environment)
 
         rExternalBindingsValue->Result.flatMap(externalBindingsValue => {
@@ -33,7 +34,7 @@ let dispatchMacroCall = (
           // Js.log(
           //   `bindStatement ${Bindings.toString(newBindings)}<==${ExpressionT.toString(
           //       bindingExpr,
-          //     )} statement: $let ${ExpressionT.toString(symbolExpr)}=${ExpressionT.toString(
+          //     )} statement: $_let_$ ${ExpressionT.toString(symbolExpr)}=${ExpressionT.toString(
           //       statement,
           //     )}`,
           // )
@@ -42,7 +43,7 @@ let dispatchMacroCall = (
           rNewStatement->Result.map(newStatement =>
             ExpressionWithContext.withContext(
               eFunction(
-                "$setBindings",
+                "$_setBindings_$",
                 list{newBindings->Bindings.toExternalBindings->eRecord, symbolExpr, newStatement},
               ),
               newBindings,
@@ -58,7 +59,7 @@ let dispatchMacroCall = (
     errorValue,
   > =>
     switch statement {
-    | ExpressionT.EList(list{ExpressionT.EValue(EvCall("$let")), symbolExpr, statement}) => {
+    | ExpressionT.EList(list{ExpressionT.EValue(EvCall("$_let_$")), symbolExpr, statement}) => {
         let rExternalBindingsValue = reduceExpression(bindingExpr, bindings, environment)
 
         rExternalBindingsValue->Result.flatMap(externalBindingsValue => {
@@ -67,10 +68,10 @@ let dispatchMacroCall = (
           rNewStatement->Result.map(newStatement =>
             ExpressionWithContext.withContext(
               eFunction(
-                "$exportBindings",
+                "$_exportBindings_$",
                 list{
                   eFunction(
-                    "$setBindings",
+                    "$_setBindings_$",
                     list{
                       newBindings->Bindings.toExternalBindings->eRecord,
                       symbolExpr,
@@ -139,7 +140,8 @@ let dispatchMacroCall = (
     bindings: ExpressionT.bindings,
     environment,
   ): result<expressionWithContext, errorValue> => {
-    let rCondition = reduceExpression(condition, bindings, environment)
+    let blockCondition = ExpressionBuilder.eBlock(list{condition})
+    let rCondition = reduceExpression(blockCondition, bindings, environment)
     rCondition->Result.flatMap(conditionValue =>
       switch conditionValue {
       | ExpressionValue.EvBool(false) => ExpressionWithContext.noContext(ifFalse)->Ok
@@ -155,31 +157,32 @@ let dispatchMacroCall = (
   > =>
     switch aList {
     | list{
-        ExpressionT.EValue(EvCall("$$bindStatement")),
+        ExpressionT.EValue(EvCall("$$_bindStatement_$$")),
         bindingExpr: ExpressionT.expression,
         statement,
       } =>
       doBindStatement(bindingExpr, statement, environment)
-    | list{ExpressionT.EValue(EvCall("$$bindStatement")), statement} =>
+    | list{ExpressionT.EValue(EvCall("$$_bindStatement_$$")), statement} =>
       // bindings of the context are used when there is no binding expression
       doBindStatement(eRecord(Bindings.toExternalBindings(bindings)), statement, environment)
     | list{
-        ExpressionT.EValue(EvCall("$$bindExpression")),
+        ExpressionT.EValue(EvCall("$$_bindExpression_$$")),
         bindingExpr: ExpressionT.expression,
         expression,
       } =>
       doBindExpression(bindingExpr, expression, environment)
-    | list{ExpressionT.EValue(EvCall("$$bindExpression")), expression} =>
+    | list{ExpressionT.EValue(EvCall("$$_bindExpression_$$")), expression} =>
       // bindings of the context are used when there is no binding expression
       doBindExpression(eRecord(Bindings.toExternalBindings(bindings)), expression, environment)
-    | list{ExpressionT.EValue(EvCall("$$block")), ...exprs} => doBlock(exprs, bindings, environment)
+    | list{ExpressionT.EValue(EvCall("$$_block_$$")), ...exprs} =>
+      doBlock(exprs, bindings, environment)
     | list{
-        ExpressionT.EValue(EvCall("$$lambda")),
+        ExpressionT.EValue(EvCall("$$_lambda_$$")),
         ExpressionT.EValue(EvArrayString(parameters)),
         lambdaDefinition,
       } =>
       doLambdaDefinition(bindings, parameters, lambdaDefinition)
-    | list{ExpressionT.EValue(EvCall("$$ternary")), condition, ifTrue, ifFalse} =>
+    | list{ExpressionT.EValue(EvCall("$$_ternary_$$")), condition, ifTrue, ifFalse} =>
       doTernary(condition, ifTrue, ifFalse, bindings, environment)
     | _ => ExpressionWithContext.noContext(ExpressionT.EList(aList))->Ok
     }

packages/squiggle-lang/src/rescript/Reducer/Reducer_ErrorValue.res

@@ -7,6 +7,7 @@ type errorValue =
   | REOperationError(Operation.operationError)
   | REExpressionExpected
   | REFunctionExpected(string)
+  | REFunctionNotFound(string)
   | REJavaScriptExn(option<string>, option<string>) // Javascript Exception
   | REMacroNotFound(string)
   | RENotAFunction(string)
@@ -29,6 +30,7 @@ let errorToString = err =>
   | REAssignmentExpected => "Assignment expected"
   | REExpressionExpected => "Expression expected"
   | REFunctionExpected(msg) => `Function expected: ${msg}`
+  | REFunctionNotFound(msg) => `Function not found: ${msg}`
   | REDistributionError(err) => `Distribution Math Error: ${DistributionTypes.Error.toString(err)}`
   | REOperationError(err) => `Math Error: ${Operation.Error.toString(err)}`
   | REJavaScriptExn(omsg, oname) => {

packages/squiggle-lang/src/rescript/Reducer/Reducer_Expression/Reducer_Expression.res

@@ -18,13 +18,10 @@ type internalCode = ReducerInterface_ExpressionValue.internalCode
 type t = expression
 
 /*
-  Converts a MathJs code to expression
+  Converts a Squigle code to expression
 */
-let parse_ = (expr: string, parser, converter): result<t, errorValue> =>
+let parse = (peggyCode: string): result<t, errorValue> =>
-  expr->parser->Result.flatMap(node => converter(node))
+  peggyCode->Reducer_Peggy_Parse.parse->Result.map(Reducer_Peggy_ToExpression.fromNode)
-
-let parse = (mathJsCode: string): result<t, errorValue> =>
-  mathJsCode->parse_(MathJs.Parse.parse, MathJs.ToExpression.fromNode)
 
 /*
   Recursively evaluate/reduce the expression (Lisp AST)
@@ -77,11 +74,30 @@ and reduceValueList = (valueList: list<expressionValue>, environment): result<
   'e,
 > =>
   switch valueList {
-  | list{EvCall(fName), ...args} =>
+  | list{EvCall(fName), ...args} => {
-    (fName, args->Belt.List.toArray)->BuiltIn.dispatch(environment, reduceExpression)
+      let rCheckedArgs = switch fName == "$_setBindings_$" {
+      | false => args->Lambda.checkIfReduced
+      | true => args->Ok
+      }
 
+      rCheckedArgs->Result.flatMap(checkedArgs =>
+        (fName, checkedArgs->Belt.List.toArray)->BuiltIn.dispatch(environment, reduceExpression)
+      )
+    }
+  | list{EvLambda(_)} =>
+    // TODO: remove on solving issue#558
+    valueList
+    ->Lambda.checkIfReduced
+    ->Result.flatMap(reducedValueList =>
+      reducedValueList->Belt.List.toArray->ExpressionValue.EvArray->Ok
+    )
   | list{EvLambda(lamdaCall), ...args} =>
-    Lambda.doLambdaCall(lamdaCall, args, environment, reduceExpression)
+    args
+    ->Lambda.checkIfReduced
+    ->Result.flatMap(checkedArgs =>
+      Lambda.doLambdaCall(lamdaCall, checkedArgs, environment, reduceExpression)
+    )
+
   | _ =>
     valueList
     ->Lambda.checkIfReduced
@@ -116,7 +132,7 @@ let evaluateUsingOptions = (
 }
 
 /*
-  Evaluates MathJs code and bindings via Reducer and answers the result
+  Evaluates Squiggle code and bindings via Reducer and answers the result
 */
 let evaluate = (code: string): result<expressionValue, errorValue> => {
   evaluateUsingOptions(~environment=None, ~externalBindings=None, code)

packages/squiggle-lang/src/rescript/Reducer/Reducer_Expression/Reducer_Expression_ExpressionBuilder.res

@@ -48,19 +48,19 @@ let eSymbol = (name: string): expression => name->BExpressionValue.EvSymbol->BEx
 
 let eList = (list: list<expression>): expression => list->BExpressionT.EList
 
-let eBlock = (exprs: list<expression>): expression => eFunction("$$block", exprs)
+let eBlock = (exprs: list<expression>): expression => eFunction("$$_block_$$", exprs)
 
 let eLetStatement = (symbol: string, valueExpression: expression): expression =>
-  eFunction("$let", list{eSymbol(symbol), valueExpression})
+  eFunction("$_let_$", list{eSymbol(symbol), valueExpression})
 
 let eBindStatement = (bindingExpr: expression, letStatement: expression): expression =>
-  eFunction("$$bindStatement", list{bindingExpr, letStatement})
+  eFunction("$$_bindStatement_$$", list{bindingExpr, letStatement})
 
 let eBindStatementDefault = (letStatement: expression): expression =>
-  eFunction("$$bindStatement", list{letStatement})
+  eFunction("$$_bindStatement_$$", list{letStatement})
 
 let eBindExpression = (bindingExpr: expression, expression: expression): expression =>
-  eFunction("$$bindExpression", list{bindingExpr, expression})
+  eFunction("$$_bindExpression_$$", list{bindingExpr, expression})
 
 let eBindExpressionDefault = (expression: expression): expression =>
-  eFunction("$$bindExpression", list{expression})
+  eFunction("$$_bindExpression_$$", list{expression})

packages/squiggle-lang/src/rescript/Reducer/Reducer_Expression/Reducer_Expression_T.res

@@ -42,6 +42,12 @@ let toStringResult = codeResult =>
   | Error(m) => `Error(${Reducer_ErrorValue.errorToString(m)})`
   }
 
+let toStringResultOkless = codeResult =>
+  switch codeResult {
+  | Ok(a) => toString(a)
+  | Error(m) => `Error(${Reducer_ErrorValue.errorToString(m)})`
+  }
+
 let inspect = (expr: expression): expression => {
   Js.log(toString(expr))
   expr

packages/squiggle-lang/src/rescript/Reducer/Reducer_MathJs/Reducer_MathJs.res

@@ -1,3 +1 @@
 module Eval = Reducer_MathJs_Eval
-module Parse = Reducer_MathJs_Parse
-module ToExpression = Reducer_MathJs_ToExpression

packages/squiggle-lang/src/rescript/Reducer/Reducer_MathJs/Reducer_MathJs_Parse.res

@@ -1,182 +0,0 @@
-/*
-  MathJs Nodes
-  We make MathJs Nodes strong-typed
-*/
-module Extra = Reducer_Extra
-open Reducer_ErrorValue
-
-type node = {"type": string, "isNode": bool, "comment": string}
-type arrayNode = {...node, "items": array<node>}
-type block = {"node": node}
-type blockNode = {...node, "blocks": array<block>}
-type conditionalNode = {...node, "condition": node, "trueExpr": node, "falseExpr": node}
-type constantNode = {...node, "value": unit}
-type functionAssignmentNode = {...node, "name": string, "params": array<string>, "expr": node}
-type indexNode = {...node, "dimensions": array<node>}
-type objectNode = {...node, "properties": Js.Dict.t<node>}
-type accessorNode = {...node, "object": node, "index": indexNode, "name": string}
-type parenthesisNode = {...node, "content": node}
-//rangeNode
-//relationalNode
-type symbolNode = {...node, "name": string}
-type functionNode = {...node, "fn": unit, "args": array<node>}
-type operatorNode = {...functionNode, "op": string}
-type assignmentNode = {...node, "object": symbolNode, "value": node}
-type assignmentNodeWAccessor = {...node, "object": accessorNode, "value": node}
-type assignmentNodeWIndex = {...assignmentNodeWAccessor, "index": Js.null<indexNode>}
-
-external castAccessorNode: node => accessorNode = "%identity"
-external castArrayNode: node => arrayNode = "%identity"
-external castAssignmentNode: node => assignmentNode = "%identity"
-external castAssignmentNodeWAccessor: node => assignmentNodeWAccessor = "%identity"
-external castAssignmentNodeWIndex: node => assignmentNodeWIndex = "%identity"
-external castBlockNode: node => blockNode = "%identity"
-external castConditionalNode: node => conditionalNode = "%identity"
-external castConstantNode: node => constantNode = "%identity"
-external castFunctionAssignmentNode: node => functionAssignmentNode = "%identity"
-external castFunctionNode: node => functionNode = "%identity"
-external castIndexNode: node => indexNode = "%identity"
-external castObjectNode: node => objectNode = "%identity"
-external castOperatorNode: node => operatorNode = "%identity"
-external castOperatorNodeToFunctionNode: operatorNode => functionNode = "%identity"
-external castParenthesisNode: node => parenthesisNode = "%identity"
-external castSymbolNode: node => symbolNode = "%identity"
-
-/*
-  MathJs Parser
-*/
-@module("mathjs") external parse__: string => node = "parse"
-
-let parse = (expr: string): result<node, errorValue> =>
-  try {
-    Ok(parse__(expr))
-  } catch {
-  | Js.Exn.Error(obj) => REJavaScriptExn(Js.Exn.message(obj), Js.Exn.name(obj))->Error
-  }
-
-type mathJsNode =
-  | MjAccessorNode(accessorNode)
-  | MjArrayNode(arrayNode)
-  | MjAssignmentNode(assignmentNode)
-  | MjBlockNode(blockNode)
-  | MjConditionalNode(conditionalNode)
-  | MjConstantNode(constantNode)
-  | MjFunctionAssignmentNode(functionAssignmentNode)
-  | MjFunctionNode(functionNode)
-  | MjIndexNode(indexNode)
-  | MjObjectNode(objectNode)
-  | MjOperatorNode(operatorNode)
-  | MjParenthesisNode(parenthesisNode)
-  | MjSymbolNode(symbolNode)
-
-let castNodeType = (node: node) => {
-  let decideAssignmentNode = node => {
-    let iNode = node->castAssignmentNodeWIndex
-    if Js.null == iNode["index"] && iNode["object"]["type"] == "SymbolNode" {
-      node->castAssignmentNode->MjAssignmentNode->Ok
-    } else {
-      RESyntaxError("Assignment to index or property not supported")->Error
-    }
-  }
-
-  switch node["type"] {
-  | "AccessorNode" => node->castAccessorNode->MjAccessorNode->Ok
-  | "ArrayNode" => node->castArrayNode->MjArrayNode->Ok
-  | "AssignmentNode" => node->decideAssignmentNode
-  | "BlockNode" => node->castBlockNode->MjBlockNode->Ok
-  | "ConditionalNode" => node->castConditionalNode->MjConditionalNode->Ok
-  | "ConstantNode" => node->castConstantNode->MjConstantNode->Ok
-  | "FunctionAssignmentNode" => node->castFunctionAssignmentNode->MjFunctionAssignmentNode->Ok
-  | "FunctionNode" => node->castFunctionNode->MjFunctionNode->Ok
-  | "IndexNode" => node->castIndexNode->MjIndexNode->Ok
-  | "ObjectNode" => node->castObjectNode->MjObjectNode->Ok
-  | "OperatorNode" => node->castOperatorNode->MjOperatorNode->Ok
-  | "ParenthesisNode" => node->castParenthesisNode->MjParenthesisNode->Ok
-  | "SymbolNode" => node->castSymbolNode->MjSymbolNode->Ok
-  | _ => RETodo(`Argg, unhandled MathJsNode: ${node["type"]}`)->Error
-  }
-}
-
-external unitAsSymbolNode: unit => symbolNode = "%identity"
-external unitAsString: unit => string = "%identity"
-
-let nameOfFunctionNode = (fNode: functionNode): string => {
-  let name = fNode["fn"]
-  if Js.typeof(name) == "string" {
-    name->unitAsString
-  } else {
-    (name->unitAsSymbolNode)["name"]
-  }
-}
-
-let rec toString = (mathJsNode: mathJsNode): string => {
-  let toStringValue = (a: 'a): string =>
-    if Js.typeof(a) == "string" {
-      `'${Js.String.make(a)}'`
-    } else {
-      Js.String.make(a)
-    }
-
-  let toStringNodeArray = (nodeArray: array<node>): string =>
-    nodeArray
-    ->Belt.Array.map(a => toStringMathJsNode(a))
-    ->Extra.Array.interperse(", ")
-    ->Js.String.concatMany("")
-
-  let toStringFunctionAssignmentNode = (faNode: functionAssignmentNode): string => {
-    let paramNames = Js.Array2.toString(faNode["params"])
-    `${faNode["name"]} = (${paramNames}) => ${toStringMathJsNode(faNode["expr"])}`
-  }
-  let toStringFunctionNode = (fnode: functionNode): string =>
-    `${fnode->nameOfFunctionNode}(${fnode["args"]->toStringNodeArray})`
-
-  let toStringObjectEntry = ((key: string, value: node)): string =>
-    `${key}: ${value->toStringMathJsNode}`
-
-  let toStringObjectNode = (oNode: objectNode): string =>
-    `{${oNode["properties"]
-      ->Js.Dict.entries
-      ->Belt.Array.map(entry => entry->toStringObjectEntry)
-      ->Extra.Array.interperse(", ")
-      ->Js.String.concatMany("")}}`
-
-  let toStringIndexNode = (iNode: indexNode): string =>
-    iNode["dimensions"]
-    ->Belt.Array.map(each => toStringResult(each->castNodeType))
-    ->Js.String.concatMany("")
-
-  let toStringSymbolNode = (sNode: symbolNode): string => sNode["name"]
-
-  let toStringBlocks = (blocks: array<block>): string =>
-    blocks
-    ->Belt.Array.map(each => each["node"]->castNodeType->toStringResult)
-    ->Extra.Array.interperse("; ")
-    ->Js.String.concatMany("")
-
-  switch mathJsNode {
-  | MjAccessorNode(aNode) =>
-    `${aNode["object"]->toStringMathJsNode}[${aNode["index"]->toStringIndexNode}]`
-  | MjArrayNode(aNode) => `[${aNode["items"]->toStringNodeArray}]`
-  | MjAssignmentNode(aNode) =>
-    `${aNode["object"]->toStringSymbolNode} = ${aNode["value"]->toStringMathJsNode}`
-  | MjBlockNode(bNode) => `{${bNode["blocks"]->toStringBlocks}}`
-  | MjConditionalNode(cNode) =>
-    `ternary(${toStringMathJsNode(cNode["condition"])}, ${toStringMathJsNode(
-        cNode["trueExpr"],
-      )}, ${toStringMathJsNode(cNode["falseExpr"])})`
-  | MjConstantNode(cNode) => cNode["value"]->toStringValue
-  | MjFunctionAssignmentNode(faNode) => faNode->toStringFunctionAssignmentNode
-  | MjFunctionNode(fNode) => fNode->toStringFunctionNode
-  | MjIndexNode(iNode) => iNode->toStringIndexNode
-  | MjObjectNode(oNode) => oNode->toStringObjectNode
-  | MjOperatorNode(opNode) => opNode->castOperatorNodeToFunctionNode->toStringFunctionNode
-  | MjParenthesisNode(pNode) => `(${toStringMathJsNode(pNode["content"])})`
-  | MjSymbolNode(sNode) => sNode->toStringSymbolNode
-  }
-}
-and toStringResult = (rMathJsNode: result<mathJsNode, errorValue>): string =>
-  switch rMathJsNode {
-  | Error(e) => errorToString(e)
-  | Ok(mathJsNode) => toString(mathJsNode)
-  }
-and toStringMathJsNode = node => node->castNodeType->toStringResult

packages/squiggle-lang/src/rescript/Reducer/Reducer_MathJs/Reducer_MathJs_ToExpression.res

@@ -1,154 +0,0 @@
-/* * WARNING. DO NOT EDIT, BEAUTIFY, COMMENT ON OR REFACTOR THIS CODE. 
-We will stop using MathJs parser and
-this whole file will go to trash
-**/
-module ErrorValue = Reducer_ErrorValue
-module ExpressionBuilder = Reducer_Expression_ExpressionBuilder
-module ExpressionT = Reducer_Expression_T
-module ExpressionValue = ReducerInterface.ExpressionValue
-module JavaScript = Reducer_Js
-module Parse = Reducer_MathJs_Parse
-module Result = Belt.Result
-
-type errorValue = ErrorValue.errorValue
-type expression = ExpressionT.expression
-type expressionValue = ExpressionValue.expressionValue
-
-let blockToNode = block => block["node"]
-
-let rec fromInnerNode = (mathJsNode: Parse.node): result<expression, errorValue> =>
-  Parse.castNodeType(mathJsNode)->Result.flatMap(typedMathJsNode => {
-    let fromNodeList = (nodeList: list<Parse.node>): result<list<expression>, 'e> =>
-      Belt.List.reduceReverse(nodeList, Ok(list{}), (racc, currNode) =>
-        racc->Result.flatMap(acc =>
-          fromInnerNode(currNode)->Result.map(currCode => list{currCode, ...acc})
-        )
-      )
-
-    let caseFunctionNode = fNode => {
-      let rLispArgs = fNode["args"]->Belt.List.fromArray->fromNodeList
-      rLispArgs->Result.map(lispArgs =>
-        ExpressionBuilder.eFunction(fNode->Parse.nameOfFunctionNode, lispArgs)
-      )
-    }
-
-    let caseObjectNode = oNode => {
-      let fromObjectEntries = entryList => {
-        let rargs = Belt.List.reduceReverse(entryList, Ok(list{}), (
-          racc,
-          (key: string, value: Parse.node),
-        ) =>
-          racc->Result.flatMap(acc =>
-            fromInnerNode(value)->Result.map(valueExpression => {
-              let entryCode =
-                list{ExpressionBuilder.eString(key), valueExpression}->ExpressionT.EList
-              list{entryCode, ...acc}
-            })
-          )
-        )
-        rargs->Result.flatMap(args =>
-          ExpressionBuilder.eFunction("$constructRecord", list{ExpressionT.EList(args)})->Ok
-        ) // $constructRecord gets a single argument: List of key-value paiers
-      }
-
-      oNode["properties"]->Js.Dict.entries->Belt.List.fromArray->fromObjectEntries
-    }
-
-    let caseIndexNode = iNode => {
-      let rpropertyCodeList = Belt.List.reduceReverse(
-        iNode["dimensions"]->Belt.List.fromArray,
-        Ok(list{}),
-        (racc, currentPropertyMathJsNode) =>
-          racc->Result.flatMap(acc =>
-            fromInnerNode(currentPropertyMathJsNode)->Result.map(propertyCode => list{
-              propertyCode,
-              ...acc,
-            })
-          ),
-      )
-      rpropertyCodeList->Result.map(propertyCodeList => ExpressionT.EList(propertyCodeList))
-    }
-
-    let caseAccessorNode = (objectNode, indexNode) => {
-      caseIndexNode(indexNode)->Result.flatMap(indexCode => {
-        fromInnerNode(objectNode)->Result.flatMap(objectCode =>
-          ExpressionBuilder.eFunction("$atIndex", list{objectCode, indexCode})->Ok
-        )
-      })
-    }
-
-    let caseBlock = (nodesArray: array<Parse.node>): result<expression, errorValue> => {
-      let rStatements: result<list<expression>, 'a> =
-        nodesArray
-        ->Belt.List.fromArray
-        ->Belt.List.reduceReverse(Ok(list{}), (racc, currNode) =>
-          racc->Result.flatMap(acc =>
-            fromInnerNode(currNode)->Result.map(currCode => list{currCode, ...acc})
-          )
-        )
-      rStatements->Result.map(statements => ExpressionBuilder.eBlock(statements))
-    }
-
-    let caseAssignmentNode = aNode => {
-      let symbolName = aNode["object"]["name"]
-      let rValueExpression = fromInnerNode(aNode["value"])
-      rValueExpression->Result.map(valueExpression =>
-        ExpressionBuilder.eLetStatement(symbolName, valueExpression)
-      )
-    }
-
-    let caseFunctionAssignmentNode = faNode => {
-      let symbol = faNode["name"]->ExpressionBuilder.eSymbol
-      let rValueExpression = fromInnerNode(faNode["expr"])
-
-      rValueExpression->Result.flatMap(valueExpression => {
-        let lispParams = ExpressionBuilder.eArrayString(faNode["params"])
-        let valueBlock = ExpressionBuilder.eBlock(list{valueExpression})
-        let lambda = ExpressionBuilder.eFunction("$$lambda", list{lispParams, valueBlock})
-        ExpressionBuilder.eFunction("$let", list{symbol, lambda})->Ok
-      })
-    }
-
-    let caseArrayNode = aNode => {
-      aNode["items"]->Belt.List.fromArray->fromNodeList->Result.map(list => ExpressionT.EList(list))
-    }
-
-    let caseConditionalNode = cndNode => {
-      let rCondition = fromInnerNode(cndNode["condition"])
-      let rTrueExpr = fromInnerNode(cndNode["trueExpr"])
-      let rFalse = fromInnerNode(cndNode["falseExpr"])
-
-      rCondition->Result.flatMap(condition =>
-        rTrueExpr->Result.flatMap(trueExpr =>
-          rFalse->Result.flatMap(falseExpr =>
-            ExpressionBuilder.eFunction("$$ternary", list{condition, trueExpr, falseExpr})->Ok
-          )
-        )
-      )
-    }
-
-    let rFinalExpression: result<expression, errorValue> = switch typedMathJsNode {
-    | MjAccessorNode(aNode) => caseAccessorNode(aNode["object"], aNode["index"])
-    | MjArrayNode(aNode) => caseArrayNode(aNode)
-    | MjAssignmentNode(aNode) => caseAssignmentNode(aNode)
-    | MjSymbolNode(sNode) => {
-        let expr: expression = ExpressionBuilder.eSymbol(sNode["name"])
-        let rExpr: result<expression, errorValue> = expr->Ok
-        rExpr
-      }
-    | MjBlockNode(bNode) => bNode["blocks"]->Js.Array2.map(blockToNode)->caseBlock
-    | MjConditionalNode(cndNode) => caseConditionalNode(cndNode)
-    | MjConstantNode(cNode) =>
-      cNode["value"]->JavaScript.Gate.jsToEv->Result.flatMap(v => v->ExpressionT.EValue->Ok)
-    | MjFunctionAssignmentNode(faNode) => caseFunctionAssignmentNode(faNode)
-    | MjFunctionNode(fNode) => fNode->caseFunctionNode
-    | MjIndexNode(iNode) => caseIndexNode(iNode)
-    | MjObjectNode(oNode) => caseObjectNode(oNode)
-    | MjOperatorNode(opNode) => opNode->Parse.castOperatorNodeToFunctionNode->caseFunctionNode
-    | MjParenthesisNode(pNode) => pNode["content"]->fromInnerNode
-    }
-    rFinalExpression
-  })
-
-let fromNode = (node: Parse.node): result<expression, errorValue> =>
-  fromInnerNode(node)->Result.map(expr => ExpressionBuilder.eBlock(list{expr}))

packages/squiggle-lang/src/rescript/Reducer/Reducer_Peggy/Reducer_Peggy_GeneratedParser.peggy

@@ -0,0 +1,346 @@
+// Try in https://peggyjs.org/online
+
+{{
+  var toFunction = {
+    '-': 'subtract',
+    '->': 'pipe',
+    '!=': 'unequal',
+    '.-': 'dotSubtract',
+    '.*': 'dotMultiply',
+    './': 'dotDivide',
+    '.^': 'dotPow',
+    '.+': 'dotAdd',
+    '*': 'multiply',
+    '/': 'divide',
+    '&&': 'and',
+    '^': 'pow', // or xor
+    '+': 'add',
+    '<': 'smaller',
+    '<=': 'smallerEq',
+    '==': 'equal',
+    '>': 'larger',
+    '>=': 'largerEq',
+    '||': 'or',
+    'to': 'credibleIntervalToDistribution',
+  } 
+
+  var unaryToFunction = {
+    '-': 'unaryMinus', 
+    '!': 'not',
+    '.-': 'unaryDotMinus',
+  }
+
+  var postOperatorToFunction = {
+    '.': '$_atIndex_$',
+    '()': '$$_applyAll_$$',
+    '[]': '$_atIndex_$',
+  }
+
+  function nodeBlock(statements) {return{type: 'Block', statements: statements}}
+  function nodeBoolean(value) {return {type: 'Boolean', value: value}}
+  function nodeCallIndentifier(value) {return {type: 'CallIdentifier', value: value}}
+  function nodeExpression(args) {return {type: 'Expression', nodes: args}}
+  function nodeFloat(value) {return {type: 'Float', value: value}}
+  function makeFunctionCall(fn, args) {
+    if (fn === '$$_applyAll_$$') {
+      // Any list of values is applied from left to right anyway. 
+      // Like in Haskell and Lisp.
+      // So we remove the redundant $$_applyAll_$$.
+      if (args[0].type === "Identifier") {args[0].type = "CallIdentifier"}
+      return nodeExpression(args) 
+    } else {
+      return nodeExpression([nodeCallIndentifier(fn), ...args]) 
+    }
+  }
+  function nodeIdentifier(value) {return {type: 'Identifier', value: value}}
+  function nodeInteger(value) {return {type: 'Integer', value: value}}
+  function nodeKeyValue(key, value) { 
+    if (key.type === 'Identifier') {key.type = 'String'}
+    return {type: 'KeyValue', key: key, value: value}}  
+  function nodeLambda(args, body) {return {type: 'Lambda', args: args, body: body}}
+  function nodeLetStatment(variable, value) {return {type: 'LetStatement', variable: variable, value: value}}
+  function nodeString(value) {return {type: 'String', value: value}}
+  function nodeTernary(condition, trueExpression, falseExpression) {return {type: 'Ternary', condition: condition, trueExpression: trueExpression, falseExpression: falseExpression}}
+}}
+
+start
+  = _nl start:outerBlock _nl finalComment?  {return start}
+
+zeroOMoreArgumentsBlockOrExpression = innerBlockOrExpression / lambda
+
+outerBlock 
+	= statements:array_statements  finalExpression: (statementSeparator @expression)?
+    { if (finalExpression != null) { statements.push(finalExpression) }
+        return nodeBlock(statements) }
+  / finalExpression: expression
+    { return nodeBlock([finalExpression])}
+    
+innerBlockOrExpression  
+  = quotedInnerBlock
+  / finalExpression: expression
+    { return nodeBlock([finalExpression])}
+
+quotedInnerBlock  
+  = '{' _nl statements:array_statements  finalExpression: (statementSeparator @expression)  _nl '}'
+	  { statements.push(finalExpression) 
+    	return nodeBlock(statements) }
+  / '{' _nl finalExpression: expression  _nl '}'
+	  { return nodeBlock([finalExpression]) }
+
+array_statements
+  = head:statement tail:(statementSeparator @array_statements )
+    { return [head, ...tail] }
+  / head:statement
+  	{ return [head] }
+
+statement 
+  = letStatement
+  / defunStatement
+
+letStatement 
+  = variable:identifier _ assignmentOp _nl value:zeroOMoreArgumentsBlockOrExpression
+  { return nodeLetStatment(variable, value) }
+
+defunStatement
+  = variable:identifier '(' _nl args:array_parameters _nl ')' _ assignmentOp _nl body:innerBlockOrExpression
+    { var value = nodeLambda(args, body)
+      return nodeLetStatment(variable, value) }
+
+  assignmentOp "assignment" = '='
+
+array_parameters 
+  = head:dollarIdentifier tail:(_ ',' _nl @dollarIdentifier)* 
+  { return [head, ...tail]; }
+
+expression = ifthenelse / ternary / logicalAdditive
+
+ifthenelse 
+  = 'if' __nl condition:logicalAdditive 
+  	__nl 'then' __nl trueExpression:innerBlockOrExpression 
+    __nl 'else' __nl falseExpression:(ifthenelse/innerBlockOrExpression)
+    { return nodeTernary(condition, trueExpression, falseExpression) }
+  
+ternary 
+  = condition:logicalAdditive _ '?' _nl trueExpression:logicalAdditive _ ':' _nl falseExpression:(ternary/logicalAdditive)
+    { return nodeTernary(condition, trueExpression, falseExpression) }
+
+logicalAdditive
+  = head:logicalMultiplicative tail:(_ operator:logicalAdditiveOp _nl arg:logicalMultiplicative {return {operator: operator, right: arg}})* 
+  { return tail.reduce(function(result, element) {
+      return makeFunctionCall(toFunction[element.operator], [result, element.right])
+    }, head)}
+
+  logicalAdditiveOp "operator" = '||'
+
+// start binary operators
+logicalMultiplicative
+  = head:equality tail:(_ operator:logicalMultiplicativeOp _nl arg:equality {return {operator: operator, right: arg}})* 
+  { return tail.reduce(function(result, element) {
+      return makeFunctionCall(toFunction[element.operator], [result, element.right])
+    }, head)}
+
+  logicalMultiplicativeOp "operator" = '&&'
+
+equality
+  = left:relational _ operator:equalityOp _nl right:relational 
+  { return makeFunctionCall(toFunction[operator], [left, right])}
+  / relational  
+ 
+ equalityOp "operator" = '=='/'!='
+
+relational
+  = left:additive _ operator:relationalOp _nl right:additive 
+  { return makeFunctionCall(toFunction[operator], [left, right])}
+  / additive
+
+  relationalOp "operator" = '<='/'<'/'>='/'>'
+
+additive
+  = head:multiplicative tail:(_ operator:additiveOp _nl arg:multiplicative {return {operator: operator, right: arg}})* 
+  { return tail.reduce(function(result, element) {
+      return makeFunctionCall(toFunction[element.operator], [result, element.right])
+    }, head)}
+
+  additiveOp "operator" = '+' / '-' / '.+' / '.-'
+
+multiplicative
+  = head:power tail:(_ operator:multiplicativeOp _nl arg:power {return {operator: operator, right: arg}})* 
+  { return tail.reduce(function(result, element) {
+      return makeFunctionCall(toFunction[element.operator], [result, element.right])
+    }, head)}
+
+  multiplicativeOp "operator" = '*' / '/' / '.*' / './'
+
+power
+  = head:credibleInterval tail:(_ operator:powerOp _nl arg:credibleInterval {return {operator: operator, right: arg}})* 
+  { return tail.reduce(function(result, element) {
+      return makeFunctionCall(toFunction[element.operator], [result, element.right])
+    }, head)}
+
+  powerOp "operator" = '^' / '.^'
+
+credibleInterval
+  = head:chainFunctionCall tail:(__ operator:credibleIntervalOp __nl arg:chainFunctionCall {return {operator: operator, right: arg}})* 
+  { return tail.reduce(function(result, element) {
+      return makeFunctionCall(toFunction[element.operator], [result, element.right])
+    }, head)}
+
+    credibleIntervalOp "operator" = 'to'
+
+chainFunctionCall
+  = head:unary tail:(_ ('->'/'|>') _nl chained:chainedFunction {return chained})* 
+  { return tail.reduce(function(result, element) {
+      return makeFunctionCall(element.fnName, [result, ...element.args])
+    }, head)}
+
+  chainedFunction
+    = fn:dollarIdentifier '(' _nl args:array_functionArguments _nl ')' 
+      { return {fnName: fn.value, args: args}}
+      / fn:dollarIdentifier '(' _nl ')' 
+      { return {fnName: fn.value, args: []}}
+      / fn:dollarIdentifier
+      { return {fnName: fn.value, args: []}}
+
+// end of binary operators
+
+unary
+  = unaryOperator:unaryOperator _nl right:(unary/postOperator)
+  { return makeFunctionCall(unaryToFunction[unaryOperator], [right])}
+  / postOperator
+  
+  unaryOperator "unary operator"
+  = ('-' / '.-' / '!' ) 
+
+postOperator = indexedValue
+
+indexedValue
+  = collectionElement
+  / recordElement
+  / atom
+
+  collectionElement
+    = head:atom &('['/'('/'.')
+      tail:(
+        _ '[' _nl arg:expression  _nl ']' {return {fn: postOperatorToFunction['[]'], args: [arg]}}
+      / _ '(' _nl args:array_functionArguments  _nl ')' {return {fn: postOperatorToFunction['()'], args: args}}
+      / '.' arg:$dollarIdentifier {return {fn: postOperatorToFunction['[]'], args: [nodeString(arg)]}}
+      )* 
+    { return tail.reduce(function(result, element) {
+        return makeFunctionCall(element.fn, [result, ...element.args])
+      }, head)}
+
+    array_functionArguments 
+      = head:expression tail:(_ ',' _nl @expression)* 
+      { return [head, ...tail]; }
+
+recordElement
+  = head:dollarIdentifier &'.' 
+    tail:(_ '.' _nl arg:$dollarIdentifier {return {fn: postOperatorToFunction['.'],  args: [nodeString(arg)]}})* 
+  { return tail.reduce(function(result, element) {
+      return makeFunctionCall(element.fn, [result, ...element.args])
+    }, head)}
+
+atom
+  = '(' _nl expression:expression _nl ')' {return expression}
+  / basicValue
+
+basicValue = valueConstructor / basicLiteral
+ 
+basicLiteral
+  = string
+  / float
+  / integer
+  / boolean
+  / dollarIdentifier
+
+identifier 'identifier'
+  = ([_a-z]+[_a-z0-9]i*) {return nodeIdentifier(text())} 
+
+dollarIdentifier '$identifier'
+  = ([\$_a-z]+[\$_a-z0-9]i*) {return nodeIdentifier(text())} 
+
+string 'string'
+  = characters:("'" @([^'])* "'") {return nodeString(characters.join(''))} 
+  / characters:('"' @([^"])* '"') {return nodeString(characters.join(''))}
+
+integer 'integer'
+  = d+ !"\." ![e]i
+  { return nodeInteger(parseInt(text()))} 
+  
+float 'float'
+  = $(((d+ "\." d*) / ("\." d+)) floatExponent? / d+ floatExponent)
+  { return nodeFloat(parseFloat(text()))} 
+
+	floatExponent = [e]i '-'? d+
+	d = [0-9]
+    
+boolean 'boolean'
+  = ('true'/'false') 
+  { return nodeBoolean(text() === 'true')}   
+
+valueConstructor
+  = recordConstructor
+  / arrayConstructor
+  / lambda
+  / quotedInnerBlock 
+
+lambda  
+  = '{' _nl '|' _nl args:array_parameters _nl '|' _nl statements:array_statements  finalExpression: (statementSeparator @expression)  _nl '}'
+	  { statements.push(finalExpression) 
+    	return nodeLambda(args, nodeBlock(statements)) }
+  / '{' _nl '|' _nl args:array_parameters _nl '|' _nl finalExpression: expression  _nl '}'
+	  { return nodeLambda(args, nodeBlock([finalExpression])) }
+
+arrayConstructor 'array'
+  = '[' _nl ']'
+    { return makeFunctionCall('$_constructArray_$', [nodeExpression([])])}
+  / '[' _nl args:array_elements _nl ']' 
+    { return makeFunctionCall('$_constructArray_$', [nodeExpression(args)])}
+
+  array_elements 
+    = head:expression tail:(_ ',' _nl @expression)* 
+    { return [head, ...tail]; }
+
+recordConstructor  'record'
+  = '{' _nl args:array_recordArguments _nl '}' 
+  { return makeFunctionCall('$_constructRecord_$', [nodeExpression(args)])}
+
+  array_recordArguments 
+    = head:keyValuePair tail:(_ ',' _nl @keyValuePair)* 
+    { return [head, ...tail]; }
+
+  keyValuePair 
+    = key:expression _ ':' _nl value:expression 
+    { return nodeKeyValue(key, value)}
+    
+_ 'whitespace'
+  = whiteSpaceCharactersOrComment*
+
+_nl 'optional whitespace or newline'
+  = (whiteSpaceCharactersOrComment / commentOrNewLine)*
+
+__ 'whitespace'
+  = whiteSpaceCharactersOrComment+
+
+__nl 'whitespace or newline'
+  = (whiteSpaceCharactersOrComment / commentOrNewLine )+
+
+statementSeparator 'statement separator'
+	= _ (';'/ commentOrNewLine)+ _nl
+
+  commentOrNewLine = finalComment? newLine 
+
+    finalComment "line comment"
+      = _ ('//'/'#') @([^\r\n]*) 
+
+  whiteSpaceCharactersOrComment = whiteSpaceCharacters / delimitedComment
+
+    delimitedComment  "comment"
+      = '/*' @([^*]*) '*/'
+
+    whiteSpaceCharacters = [ \t]
+
+    newLine "newline"
+      = [\n\r]
+
+  

packages/squiggle-lang/src/rescript/Reducer/Reducer_Peggy/Reducer_Peggy_Parse.res

@@ -0,0 +1,109 @@
+module Extra = Reducer_Extra
+open Reducer_ErrorValue
+
+type node = {"type": string}
+
+@module("./Reducer_Peggy_GeneratedParser.js") external parse__: string => node = "parse"
+
+let parse = (expr: string): result<node, errorValue> =>
+  try {
+    Ok(parse__(expr))
+  } catch {
+  | Js.Exn.Error(obj) => REJavaScriptExn(Js.Exn.message(obj), Js.Exn.name(obj))->Error
+  }
+
+type nodeBlock = {...node, "statements": array<node>}
+type nodeBoolean = {...node, "value": bool}
+type nodeCallIdentifier = {...node, "value": string}
+type nodeExpression = {...node, "nodes": array<node>}
+type nodeFloat = {...node, "value": float}
+type nodeIdentifier = {...node, "value": string}
+type nodeInteger = {...node, "value": int}
+type nodeKeyValue = {...node, "key": node, "value": node}
+type nodeLambda = {...node, "args": array<nodeIdentifier>, "body": nodeBlock}
+type nodeLetStatement = {...node, "variable": nodeIdentifier, "value": node}
+type nodeString = {...node, "value": string}
+type nodeTernary = {...node, "condition": node, "trueExpression": node, "falseExpression": node}
+
+type peggyNode =
+  | PgNodeBlock(nodeBlock)
+  | PgNodeBoolean(nodeBoolean)
+  | PgNodeCallIdentifier(nodeCallIdentifier)
+  | PgNodeExpression(nodeExpression)
+  | PgNodeFloat(nodeFloat)
+  | PgNodeIdentifier(nodeIdentifier)
+  | PgNodeInteger(nodeInteger)
+  | PgNodeKeyValue(nodeKeyValue)
+  | PgNodeLambda(nodeLambda)
+  | PgNodeLetStatement(nodeLetStatement)
+  | PgNodeString(nodeString)
+  | PgNodeTernary(nodeTernary)
+
+external castNodeBlock: node => nodeBlock = "%identity"
+external castNodeBoolean: node => nodeBoolean = "%identity"
+external castNodeCallIdentifier: node => nodeCallIdentifier = "%identity"
+external castNodeExpression: node => nodeExpression = "%identity"
+external castNodeFloat: node => nodeFloat = "%identity"
+external castNodeIdentifier: node => nodeIdentifier = "%identity"
+external castNodeInteger: node => nodeInteger = "%identity"
+external castNodeKeyValue: node => nodeKeyValue = "%identity"
+external castNodeLambda: node => nodeLambda = "%identity"
+external castNodeLetStatement: node => nodeLetStatement = "%identity"
+external castNodeString: node => nodeString = "%identity"
+external castNodeTernary: node => nodeTernary = "%identity"
+
+exception UnsupportedPeggyNodeType(string) // This should never happen; programming error
+let castNodeType = (node: node) =>
+  switch node["type"] {
+  | "Block" => node->castNodeBlock->PgNodeBlock
+  | "Boolean" => node->castNodeBoolean->PgNodeBoolean
+  | "CallIdentifier" => node->castNodeCallIdentifier->PgNodeCallIdentifier
+  | "Expression" => node->castNodeExpression->PgNodeExpression
+  | "Float" => node->castNodeFloat->PgNodeFloat
+  | "Identifier" => node->castNodeIdentifier->PgNodeIdentifier
+  | "Integer" => node->castNodeInteger->PgNodeInteger
+  | "KeyValue" => node->castNodeKeyValue->PgNodeKeyValue
+  | "Lambda" => node->castNodeLambda->PgNodeLambda
+  | "LetStatement" => node->castNodeLetStatement->PgNodeLetStatement
+  | "String" => node->castNodeString->PgNodeString
+  | "Ternary" => node->castNodeTernary->PgNodeTernary
+  | _ => raise(UnsupportedPeggyNodeType(node["type"]))
+  }
+
+let rec pgToString = (peggyNode: peggyNode): string => {
+  let argsToString = (args: array<nodeIdentifier>): string =>
+    args->Js.Array2.map(arg => PgNodeIdentifier(arg)->pgToString)->Js.Array2.toString
+
+  let nodesToStringUsingSeparator = (nodes: array<node>, separator: string): string =>
+    nodes->Js.Array2.map(toString)->Extra.Array.interperse(separator)->Js.String.concatMany("")
+
+  switch peggyNode {
+  | PgNodeBlock(node) => "{" ++ node["statements"]->nodesToStringUsingSeparator("; ") ++ "}"
+  | PgNodeBoolean(node) => node["value"]->Js.String.make
+  | PgNodeCallIdentifier(node) => `::${Js.String.make(node["value"])}` // This is an identifier also but for function names
+  | PgNodeExpression(node) => "(" ++ node["nodes"]->nodesToStringUsingSeparator(" ") ++ ")"
+  | PgNodeFloat(node) => node["value"]->Js.String.make
+  | PgNodeIdentifier(node) => `:${node["value"]}`
+  | PgNodeInteger(node) => node["value"]->Js.String.make
+  | PgNodeKeyValue(node) => toString(node["key"]) ++ ": " ++ toString(node["value"])
+  | PgNodeLambda(node) =>
+    "{|" ++ node["args"]->argsToString ++ "| " ++ pgToString(PgNodeBlock(node["body"])) ++ "}"
+  | PgNodeLetStatement(node) =>
+    pgToString(PgNodeIdentifier(node["variable"])) ++ " = " ++ toString(node["value"])
+  | PgNodeString(node) => `'${node["value"]->Js.String.make}'`
+  | PgNodeTernary(node) =>
+    "(::$$_ternary_$$ " ++
+    toString(node["condition"]) ++
+    " " ++
+    toString(node["trueExpression"]) ++
+    " " ++
+    toString(node["falseExpression"]) ++ ")"
+  }
+}
+and toString = (node: node): string => node->castNodeType->pgToString
+
+let toStringResult = (rNode: result<node, errorValue>): string =>
+  switch rNode {
+  | Ok(node) => toString(node)
+  | Error(error) => `Error(${errorToString(error)})`
+  }

packages/squiggle-lang/src/rescript/Reducer/Reducer_Peggy/Reducer_Peggy_ToExpression.res

@@ -0,0 +1,48 @@
+module ExpressionBuilder = Reducer_Expression_ExpressionBuilder
+module ExpressionT = Reducer_Expression_T
+module Parse = Reducer_Peggy_Parse
+
+type expression = ExpressionT.expression
+
+let rec fromNode = (node: Parse.node): expression => {
+  let caseBlock = nodeBlock =>
+    ExpressionBuilder.eBlock(nodeBlock["statements"]->Js.Array2.map(fromNode)->Belt.List.fromArray)
+
+  let caseLambda = (nodeLambda: Parse.nodeLambda): expression => {
+    let args =
+      nodeLambda["args"]
+      ->Js.Array2.map((argNode: Parse.nodeIdentifier) => argNode["value"])
+      ->ExpressionBuilder.eArrayString
+    let body = nodeLambda["body"]->caseBlock
+    ExpressionBuilder.eFunction("$$_lambda_$$", list{args, body})
+  }
+
+  switch Parse.castNodeType(node) {
+  | PgNodeBlock(nodeBlock) => caseBlock(nodeBlock)
+  | PgNodeBoolean(nodeBoolean) => ExpressionBuilder.eBool(nodeBoolean["value"])
+  | PgNodeCallIdentifier(nodeCallIdentifier) => ExpressionBuilder.eCall(nodeCallIdentifier["value"])
+  | PgNodeExpression(nodeExpression) =>
+    ExpressionT.EList(nodeExpression["nodes"]->Js.Array2.map(fromNode)->Belt.List.fromArray)
+  | PgNodeFloat(nodeFloat) => ExpressionBuilder.eNumber(nodeFloat["value"])
+  | PgNodeIdentifier(nodeIdentifier) => ExpressionBuilder.eSymbol(nodeIdentifier["value"])
+  | PgNodeInteger(nodeInteger) => ExpressionBuilder.eNumber(Belt.Int.toFloat(nodeInteger["value"]))
+  | PgNodeKeyValue(nodeKeyValue) =>
+    ExpressionT.EList(list{fromNode(nodeKeyValue["key"]), fromNode(nodeKeyValue["value"])})
+  | PgNodeLambda(nodeLambda) => caseLambda(nodeLambda)
+  | PgNodeLetStatement(nodeLetStatement) =>
+    ExpressionBuilder.eLetStatement(
+      nodeLetStatement["variable"]["value"],
+      fromNode(nodeLetStatement["value"]),
+    )
+  | PgNodeString(nodeString) => ExpressionBuilder.eString(nodeString["value"])
+  | PgNodeTernary(nodeTernary) =>
+    ExpressionBuilder.eFunction(
+      "$$_ternary_$$",
+      list{
+        fromNode(nodeTernary["condition"]),
+        fromNode(nodeTernary["trueExpression"]),
+        fromNode(nodeTernary["falseExpression"]),
+      },
+    )
+  }
+}

packages/squiggle-lang/src/rescript/ReducerInterface/ReducerInterface_ExpressionValue.res

@@ -87,6 +87,12 @@ let toStringResult = x =>
   | Error(m) => `Error(${ErrorValue.errorToString(m)})`
   }
 
+let toStringResultOkless = (codeResult: result<expressionValue, ErrorValue.errorValue>): string =>
+  switch codeResult {
+  | Ok(a) => toString(a)
+  | Error(m) => `Error(${ErrorValue.errorToString(m)})`
+  }
+
 let toStringResultRecord = x =>
   switch x {
   | Ok(a) => `Ok(${toStringRecord(a)})`
@@ -98,3 +104,57 @@ type environment = DistributionOperation.env
 
 @genType
 let defaultEnvironment: environment = DistributionOperation.defaultEnv
+
+type expressionValueType =
+  | EvtArray
+  | EvtArrayString
+  | EvtBool
+  | EvtCall
+  | EvtDistribution
+  | EvtLambda
+  | EvtNumber
+  | EvtRecord
+  | EvtString
+  | EvtSymbol
+
+type functionCallSignature = CallSignature(string, array<expressionValueType>)
+type functionDefinitionSignature =
+  FunctionDefinitionSignature(functionCallSignature, expressionValueType)
+
+let valueToValueType = value =>
+  switch value {
+  | EvArray(_) => EvtArray
+  | EvArrayString(_) => EvtArray
+  | EvBool(_) => EvtBool
+  | EvCall(_) => EvtCall
+  | EvDistribution(_) => EvtDistribution
+  | EvLambda(_) => EvtLambda
+  | EvNumber(_) => EvtNumber
+  | EvRecord(_) => EvtRecord
+  | EvString(_) => EvtArray
+  | EvSymbol(_) => EvtSymbol
+  }
+
+let functionCallToCallSignature = (functionCall: functionCall): functionCallSignature => {
+  let (fn, args) = functionCall
+  CallSignature(fn, args->Js.Array2.map(valueToValueType))
+}
+
+let valueTypeToString = (valueType: expressionValueType): string =>
+  switch valueType {
+  | EvtArray => `Array`
+  | EvtArrayString => `ArrayString`
+  | EvtBool => `Bool`
+  | EvtCall => `Call`
+  | EvtDistribution => `Distribution`
+  | EvtLambda => `Lambda`
+  | EvtNumber => `Number`
+  | EvtRecord => `Record`
+  | EvtString => `String`
+  | EvtSymbol => `Symbol`
+  }
+
+let functionCallSignatureToString = (functionCallSignature: functionCallSignature): string => {
+  let CallSignature(fn, args) = functionCallSignature
+  `${fn}(${args->Js.Array2.map(valueTypeToString)->Js.Array2.toString})`
+}