project

test

remove setResult

parse end of outerblock

test end of outer block

compiles

testing

bindings tested

todo chain bindings

topological sort

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

@@ -1,10 +1,14 @@
-module ExpressionValue = ReducerInterface.ExternalExpressionValue
+module ExpressionValue = ReducerInterface.InternalExpressionValue
+module Expression = Reducer_Expression
 
 open Jest
 open Expect
 
-let expectEvalToBe = (expr: string, answer: string) =>
-  Reducer.evaluate(expr)->ExpressionValue.toStringResult->expect->toBe(answer)
+let expectEvalToBe = (sourceCode: string, answer: string) =>
+  Expression.BackCompatible.evaluateString(sourceCode)
+  ->ExpressionValue.toStringResult
+  ->expect
+  ->toBe(answer)
 
 let testEval = (expr, answer) => test(expr, () => expectEvalToBe(expr, answer))
 

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

@@ -3,241 +3,346 @@ open Reducer_Peggy_TestHelpers
 
 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}")
+    testParse("1.", "{(::$_endOfOuterBlock_$ () 1)}")
+    testParse("1.1", "{(::$_endOfOuterBlock_$ () 1.1)}")
+    testParse(".1", "{(::$_endOfOuterBlock_$ () 0.1)}")
+    testParse("0.1", "{(::$_endOfOuterBlock_$ () 0.1)}")
+    testParse("1e1", "{(::$_endOfOuterBlock_$ () 10)}")
+    testParse("1e-1", "{(::$_endOfOuterBlock_$ () 0.1)}")
+    testParse(".1e1", "{(::$_endOfOuterBlock_$ () 1)}")
+    testParse("0.1e1", "{(::$_endOfOuterBlock_$ () 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)}")
+    testParse("1", "{(::$_endOfOuterBlock_$ () 1)}")
+    testParse("'hello'", "{(::$_endOfOuterBlock_$ () 'hello')}")
+    testParse("true", "{(::$_endOfOuterBlock_$ () true)}")
+    testParse("1+2", "{(::$_endOfOuterBlock_$ () (::add 1 2))}")
+    testParse("add(1,2)", "{(::$_endOfOuterBlock_$ () (::add 1 2))}")
+    testParse("(1)", "{(::$_endOfOuterBlock_$ () 1)}")
+    testParse("(1+2)", "{(::$_endOfOuterBlock_$ () (::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))}")
+    testParse("-1", "{(::$_endOfOuterBlock_$ () (::unaryMinus 1))}")
+    testParse("!true", "{(::$_endOfOuterBlock_$ () (::not true))}")
+    testParse("1 + -1", "{(::$_endOfOuterBlock_$ () (::add 1 (::unaryMinus 1)))}")
+    testParse("-a[0]", "{(::$_endOfOuterBlock_$ () (::unaryMinus (::$_atIndex_$ :a 0)))}")
+    testParse("!a[0]", "{(::$_endOfOuterBlock_$ () (::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", "{(::$_endOfOuterBlock_$ () (::multiply 1 2))}")
+    testParse("1 / 2", "{(::$_endOfOuterBlock_$ () (::divide 1 2))}")
+    testParse("1 * 2 * 3", "{(::$_endOfOuterBlock_$ () (::multiply (::multiply 1 2) 3))}")
+    testParse("1 * 2 / 3", "{(::$_endOfOuterBlock_$ () (::divide (::multiply 1 2) 3))}")
+    testParse("1 / 2 * 3", "{(::$_endOfOuterBlock_$ () (::multiply (::divide 1 2) 3))}")
+    testParse("1 / 2 / 3", "{(::$_endOfOuterBlock_$ () (::divide (::divide 1 2) 3))}")
+    testParse(
+      "1 * 2 + 3 * 4",
+      "{(::$_endOfOuterBlock_$ () (::add (::multiply 1 2) (::multiply 3 4)))}",
+    )
+    testParse(
+      "1 * 2 - 3 * 4",
+      "{(::$_endOfOuterBlock_$ () (::subtract (::multiply 1 2) (::multiply 3 4)))}",
+    )
+    testParse(
+      "1 * 2 .+ 3 * 4",
+      "{(::$_endOfOuterBlock_$ () (::dotAdd (::multiply 1 2) (::multiply 3 4)))}",
+    )
+    testParse(
+      "1 * 2 .- 3 * 4",
+      "{(::$_endOfOuterBlock_$ () (::dotSubtract (::multiply 1 2) (::multiply 3 4)))}",
+    )
+    testParse(
+      "1 * 2 + 3 .* 4",
+      "{(::$_endOfOuterBlock_$ () (::add (::multiply 1 2) (::dotMultiply 3 4)))}",
+    )
+    testParse(
+      "1 * 2 + 3 / 4",
+      "{(::$_endOfOuterBlock_$ () (::add (::multiply 1 2) (::divide 3 4)))}",
+    )
+    testParse(
+      "1 * 2 + 3 ./ 4",
+      "{(::$_endOfOuterBlock_$ () (::add (::multiply 1 2) (::dotDivide 3 4)))}",
+    )
+    testParse(
+      "1 * 2 - 3 .* 4",
+      "{(::$_endOfOuterBlock_$ () (::subtract (::multiply 1 2) (::dotMultiply 3 4)))}",
+    )
+    testParse(
+      "1 * 2 - 3 / 4",
+      "{(::$_endOfOuterBlock_$ () (::subtract (::multiply 1 2) (::divide 3 4)))}",
+    )
+    testParse(
+      "1 * 2 - 3 ./ 4",
+      "{(::$_endOfOuterBlock_$ () (::subtract (::multiply 1 2) (::dotDivide 3 4)))}",
+    )
+    testParse(
+      "1 * 2 - 3 * 4^5",
+      "{(::$_endOfOuterBlock_$ () (::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)))}",
+      "{(::$_endOfOuterBlock_$ () (::subtract (::multiply 1 2) (::multiply 3 (::pow (::pow 4 5) 6))))}",
+    )
+    testParse(
+      "1 * -a[-2]",
+      "{(::$_endOfOuterBlock_$ () (::multiply 1 (::unaryMinus (::$_atIndex_$ :a (::unaryMinus 2)))))}",
     )
-    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}}")
+    testParse("x=1; 2", "{:x = {1}; (::$_endOfOuterBlock_$ () 2)}")
+    testParse("x=1; y=2", "{:x = {1}; :y = {2}; (::$_endOfOuterBlock_$ () ())}")
   })
 
   describe("variables", () => {
-    testParse("x = 1", "{:x = {1}}")
-    testParse("x", "{:x}")
-    testParse("x = 1; x", "{:x = {1}; :x}")
+    testParse("x = 1", "{:x = {1}; (::$_endOfOuterBlock_$ () ())}")
+    testParse("x", "{(::$_endOfOuterBlock_$ () :x)}")
+    testParse("x = 1; x", "{:x = {1}; (::$_endOfOuterBlock_$ () :x)}")
   })
 
   describe("functions", () => {
-    testParse("identity(x) = x", "{:identity = {|:x| {:x}}}") // Function definitions become lambda assignments
-    testParse("identity(x)", "{(::identity :x)}")
+    testParse("identity(x) = x", "{:identity = {|:x| {:x}}; (::$_endOfOuterBlock_$ () ())}") // Function definitions become lambda assignments
+    testParse("identity(x)", "{(::$_endOfOuterBlock_$ () (::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)}")
+    testParse("[]", "{(::$_endOfOuterBlock_$ () (::$_constructArray_$ ()))}")
+    testParse("[0, 1, 2]", "{(::$_endOfOuterBlock_$ () (::$_constructArray_$ (0 1 2)))}")
+    testParse(
+      "['hello', 'world']",
+      "{(::$_endOfOuterBlock_$ () (::$_constructArray_$ ('hello' 'world')))}",
+    )
+    testParse(
+      "([0,1,2])[1]",
+      "{(::$_endOfOuterBlock_$ () (::$_atIndex_$ (::$_constructArray_$ (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')}")
+    testParse(
+      "{a: 1, b: 2}",
+      "{(::$_endOfOuterBlock_$ () (::$_constructRecord_$ ('a': 1 'b': 2)))}",
+    )
+    testParse(
+      "{1+0: 1, 2+0: 2}",
+      "{(::$_endOfOuterBlock_$ () (::$_constructRecord_$ ((::add 1 0): 1 (::add 2 0): 2)))}",
+    ) // key can be any expression
+    testParse("record.property", "{(::$_endOfOuterBlock_$ () (::$_atIndex_$ :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')))}")
+    testParse("a==!b(1)", "{(::$_endOfOuterBlock_$ () (::equal :a (::not (::b 1))))}")
+    testParse("a==!b[1]", "{(::$_endOfOuterBlock_$ () (::equal :a (::not (::$_atIndex_$ :b 1))))}")
+    testParse(
+      "a==!b.one",
+      "{(::$_endOfOuterBlock_$ () (::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("1 # This is a line comment", "{(::$_endOfOuterBlock_$ () 1)}")
+    testParse("1 // This is a line comment", "{(::$_endOfOuterBlock_$ () 1)}")
+    testParse("1 /* This is a multi line comment */", "{(::$_endOfOuterBlock_$ () 1)}")
+    testParse("/* This is a multi line comment */ 1", "{(::$_endOfOuterBlock_$ () 1)}")
     testParse(
       `
   /* This is 
   a multi line 
   comment */
   1`,
-      "{1}",
+      "{(::$_endOfOuterBlock_$ () 1)}",
     )
   })
 
   describe("ternary operator", () => {
-    testParse("true ? 2 : 3", "{(::$$_ternary_$$ true 2 3)}")
+    testParse("true ? 2 : 3", "{(::$_endOfOuterBlock_$ () (::$$_ternary_$$ true 2 3))}")
     testParse(
       "false ? 2 : false ? 4 : 5",
-      "{(::$$_ternary_$$ false 2 (::$$_ternary_$$ false 4 5))}",
+      "{(::$_endOfOuterBlock_$ () (::$$_ternary_$$ 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 true then 2 else 3",
+      "{(::$_endOfOuterBlock_$ () (::$$_ternary_$$ true {2} {3}))}",
+    )
+    testParse(
+      "if false then {2} else {3}",
+      "{(::$_endOfOuterBlock_$ () (::$$_ternary_$$ false {2} {3}))}",
+    )
     testParse(
       "if false then {2} else if false then {4} else {5}",
-      "{(::$$_ternary_$$ false {2} (::$$_ternary_$$ false {4} {5}))}",
+      "{(::$_endOfOuterBlock_$ () (::$$_ternary_$$ 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("true || false", "{(::$_endOfOuterBlock_$ () (::or true false))}")
+    testParse("true && false", "{(::$_endOfOuterBlock_$ () (::and true false))}")
+    testParse("a * b + c", "{(::$_endOfOuterBlock_$ () (::add (::multiply :a :b) :c))}") // for comparison
+    testParse("a && b || c", "{(::$_endOfOuterBlock_$ () (::or (::and :a :b) :c))}")
+    testParse("a && b || c && d", "{(::$_endOfOuterBlock_$ () (::or (::and :a :b) (::and :c :d)))}")
+    testParse("a && !b || c", "{(::$_endOfOuterBlock_$ () (::or (::and :a (::not :b)) :c))}")
+    testParse("a && b==c || d", "{(::$_endOfOuterBlock_$ () (::or (::and :a (::equal :b :c)) :d))}")
+    testParse(
+      "a && b!=c || d",
+      "{(::$_endOfOuterBlock_$ () (::or (::and :a (::unequal :b :c)) :d))}",
+    )
+    testParse(
+      "a && !(b==c) || d",
+      "{(::$_endOfOuterBlock_$ () (::or (::and :a (::not (::equal :b :c))) :d))}",
+    )
+    testParse(
+      "a && b>=c || d",
+      "{(::$_endOfOuterBlock_$ () (::or (::and :a (::largerEq :b :c)) :d))}",
+    )
+    testParse(
+      "a && !(b>=c) || d",
+      "{(::$_endOfOuterBlock_$ () (::or (::and :a (::not (::largerEq :b :c))) :d))}",
+    )
+    testParse(
+      "a && b<=c || d",
+      "{(::$_endOfOuterBlock_$ () (::or (::and :a (::smallerEq :b :c)) :d))}",
+    )
+    testParse("a && b>c || d", "{(::$_endOfOuterBlock_$ () (::or (::and :a (::larger :b :c)) :d))}")
+    testParse(
+      "a && b<c || d",
+      "{(::$_endOfOuterBlock_$ () (::or (::and :a (::smaller :b :c)) :d))}",
+    )
+    testParse(
+      "a && b<c[i] || d",
+      "{(::$_endOfOuterBlock_$ () (::or (::and :a (::smaller :b (::$_atIndex_$ :c :i))) :d))}",
+    )
+    testParse(
+      "a && b<c.i || d",
+      "{(::$_endOfOuterBlock_$ () (::or (::and :a (::smaller :b (::$_atIndex_$ :c 'i'))) :d))}",
+    )
+    testParse(
+      "a && b<c(i) || d",
+      "{(::$_endOfOuterBlock_$ () (::or (::and :a (::smaller :b (::c :i))) :d))}",
+    )
+    testParse(
+      "a && b<1+2 || d",
+      "{(::$_endOfOuterBlock_$ () (::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)}",
+      "{(::$_endOfOuterBlock_$ () (::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)}",
+      "{(::$_endOfOuterBlock_$ () (::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)}",
+      "{(::$_endOfOuterBlock_$ () (::$$_ternary_$$ (::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)}")
+    testParse("1 -> add(2)", "{(::$_endOfOuterBlock_$ () (::add 1 2))}")
+    testParse("-1 -> add(2)", "{(::$_endOfOuterBlock_$ () (::add (::unaryMinus 1) 2))}")
+    testParse(
+      "-a[1] -> add(2)",
+      "{(::$_endOfOuterBlock_$ () (::add (::unaryMinus (::$_atIndex_$ :a 1)) 2))}",
+    )
+    testParse("-f(1) -> add(2)", "{(::$_endOfOuterBlock_$ () (::add (::unaryMinus (::f 1)) 2))}")
+    testParse("1 + 2 -> add(3)", "{(::$_endOfOuterBlock_$ () (::add 1 (::add 2 3)))}")
+    testParse("1 -> add(2) * 3", "{(::$_endOfOuterBlock_$ () (::multiply (::add 1 2) 3))}")
+    testParse("1 -> subtract(2)", "{(::$_endOfOuterBlock_$ () (::subtract 1 2))}")
+    testParse("-1 -> subtract(2)", "{(::$_endOfOuterBlock_$ () (::subtract (::unaryMinus 1) 2))}")
+    testParse(
+      "1 -> subtract(2) * 3",
+      "{(::$_endOfOuterBlock_$ () (::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)}")
+    testParse("1 |> add(2)", "{(::$_endOfOuterBlock_$ () (::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("1 to 2", "{(::$_endOfOuterBlock_$ () (::credibleIntervalToDistribution 1 2))}")
+    testParse(
+      "-1 to -2",
+      "{(::$_endOfOuterBlock_$ () (::credibleIntervalToDistribution (::unaryMinus 1) (::unaryMinus 2)))}",
+    ) // lower than unary
     testParse(
       "a[1] to a[2]",
-      "{(::credibleIntervalToDistribution (::$_atIndex_$ :a 1) (::$_atIndex_$ :a 2))}",
+      "{(::$_endOfOuterBlock_$ () (::credibleIntervalToDistribution (::$_atIndex_$ :a 1) (::$_atIndex_$ :a 2)))}",
     ) // lower than post
     testParse(
       "a.p1 to a.p2",
-      "{(::credibleIntervalToDistribution (::$_atIndex_$ :a 'p1') (::$_atIndex_$ :a 'p2'))}",
+      "{(::$_endOfOuterBlock_$ () (::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 to 2 + 3",
+      "{(::$_endOfOuterBlock_$ () (::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))}",
+      "{(::$_endOfOuterBlock_$ () (::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}")
+    testParse("x={y=1; y}; x", "{:x = {:y = {1}; :y}; (::$_endOfOuterBlock_$ () :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
+    testParse("{|x| x}", "{(::$_endOfOuterBlock_$ () {|:x| {:x}})}")
+    testParse("f={|x| x}", "{:f = {{|:x| {:x}}}; (::$_endOfOuterBlock_$ () ())}")
+    testParse("f(x)=x", "{:f = {|:x| {:x}}; (::$_endOfOuterBlock_$ () ())}") // Function definitions are lambda assignments
+    testParse(
+      "f(x)=x ? 1 : 0",
+      "{:f = {|:x| {(::$$_ternary_$$ :x 1 0)}}; (::$_endOfOuterBlock_$ () ())}",
+    ) // 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}",
+      "{:myadd = {|:x,:y| {(::add :x :y)}}; :z = {:myadd}; (::$_endOfOuterBlock_$ () :z)}",
     )
     testParse(
       "myadd(x,y)=x+y; z=[myadd]; z",
-      "{:myadd = {|:x,:y| {(::add :x :y)}}; :z = {(::$_constructArray_$ (:myadd))}; :z}",
+      "{:myadd = {|:x,:y| {(::add :x :y)}}; :z = {(::$_constructArray_$ (:myadd))}; (::$_endOfOuterBlock_$ () :z)}",
     )
     testParse(
       "myaddd(x,y)=x+y; z={x: myaddd}; z",
-      "{:myaddd = {|:x,:y| {(::add :x :y)}}; :z = {(::$_constructRecord_$ ('x': :myaddd))}; :z}",
+      "{:myaddd = {|:x,:y| {(::add :x :y)}}; :z = {(::$_constructRecord_$ ('x': :myaddd))}; (::$_endOfOuterBlock_$ () :z)}",
+    )
+    testParse("f({|x| x+1})", "{(::$_endOfOuterBlock_$ () (::f {|:x| {(::add :x 1)}}))}")
+    testParse(
+      "map(arr, {|x| x+1})",
+      "{(::$_endOfOuterBlock_$ () (::map :arr {|:x| {(::add :x 1)}}))}",
     )
-    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)}})}",
+      "{(::$_endOfOuterBlock_$ () (::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)}})}",
+      "{(::$_endOfOuterBlock_$ () (::map (::$_constructArray_$ (1 2 3)) {|:x| {(::add :x 1)}}))}",
     )
   })
   describe("unit", () => {
-    testParse("1m", "{(::fromUnit_m 1)}")
-    testParse("1M", "{(::fromUnit_M 1)}")
-    testParse("1m+2cm", "{(::add (::fromUnit_m 1) (::fromUnit_cm 2))}")
+    testParse("1m", "{(::$_endOfOuterBlock_$ () (::fromUnit_m 1))}")
+    testParse("1M", "{(::$_endOfOuterBlock_$ () (::fromUnit_M 1))}")
+    testParse("1m+2cm", "{(::$_endOfOuterBlock_$ () (::add (::fromUnit_m 1) (::fromUnit_cm 2)))}")
   })
   describe("Module", () => {
-    testParse("x", "{:x}")
-    testParse("Math.pi", "{:Math.pi}")
+    testParse("x", "{(::$_endOfOuterBlock_$ () :x)}")
+    testParse("Math.pi", "{(::$_endOfOuterBlock_$ () :Math.pi)}")
   })
 })
 
@@ -246,19 +351,19 @@ describe("parsing new line", () => {
     `
  a + 
  b`,
-    "{(::add :a :b)}",
+    "{(::$_endOfOuterBlock_$ () (::add :a :b))}",
   )
   testParse(
     `
  x=
  1`,
-    "{:x = {1}}",
+    "{:x = {1}; (::$_endOfOuterBlock_$ () ())}",
   )
   testParse(
     `
  x=1
  y=2`,
-    "{:x = {1}; :y = {2}}",
+    "{:x = {1}; :y = {2}; (::$_endOfOuterBlock_$ () ())}",
   )
   testParse(
     `
@@ -266,7 +371,7 @@ describe("parsing new line", () => {
   y=2;
   y }
  x`,
-    "{:x = {:y = {2}; :y}; :x}",
+    "{:x = {:y = {2}; :y}; (::$_endOfOuterBlock_$ () :x)}",
   )
   testParse(
     `
@@ -274,7 +379,7 @@ describe("parsing new line", () => {
   y=2
   y }
  x`,
-    "{:x = {:y = {2}; :y}; :x}",
+    "{:x = {:y = {2}; :y}; (::$_endOfOuterBlock_$ () :x)}",
   )
   testParse(
     `
@@ -283,7 +388,7 @@ describe("parsing new line", () => {
   y 
   }
  x`,
-    "{:x = {:y = {2}; :y}; :x}",
+    "{:x = {:y = {2}; :y}; (::$_endOfOuterBlock_$ () :x)}",
   )
   testParse(
     `
@@ -291,7 +396,7 @@ describe("parsing new line", () => {
  y=2
  z=3
  `,
-    "{:x = {1}; :y = {2}; :z = {3}}",
+    "{:x = {1}; :y = {2}; :z = {3}; (::$_endOfOuterBlock_$ () ())}",
   )
   testParse(
     `
@@ -302,7 +407,7 @@ describe("parsing new line", () => {
   x+y+z
  }
  `,
-    "{:f = {:x = {1}; :y = {2}; :z = {3}; (::add (::add :x :y) :z)}}",
+    "{:f = {:x = {1}; :y = {2}; :z = {3}; (::add (::add :x :y) :z)}; (::$_endOfOuterBlock_$ () ())}",
   )
   testParse(
     `
@@ -315,7 +420,7 @@ describe("parsing new line", () => {
  g=f+4
  g
  `,
-    "{:f = {:x = {1}; :y = {2}; :z = {3}; (::add (::add :x :y) :z)}; :g = {(::add :f 4)}; :g}",
+    "{:f = {:x = {1}; :y = {2}; :z = {3}; (::add (::add :x :y) :z)}; :g = {(::add :f 4)}; (::$_endOfOuterBlock_$ () :g)}",
   )
   testParse(
     `
@@ -337,7 +442,7 @@ describe("parsing new line", () => {
   p ->
   q 
  `,
-    "{:f = {:x = {1}; :y = {2}; :z = {3}; (::add (::add :x :y) :z)}; :g = {(::add :f 4)}; (::q (::p (::h :g)))}",
+    "{:f = {:x = {1}; :y = {2}; :z = {3}; (::add (::add :x :y) :z)}; :g = {(::add :f 4)}; (::$_endOfOuterBlock_$ () (::q (::p (::h :g))))}",
   )
   testParse(
     `
@@ -346,7 +451,7 @@ describe("parsing new line", () => {
   c |>
   d 
  `,
-    "{(::d (::c (::b :a)))}",
+    "{(::$_endOfOuterBlock_$ () (::d (::c (::b :a))))}",
   )
   testParse(
     `
@@ -356,6 +461,6 @@ describe("parsing new line", () => {
   d +
   e
  `,
-    "{(::add (::d (::c (::b :a))) :e)}",
+    "{(::$_endOfOuterBlock_$ () (::add (::d (::c (::b :a))) :e))}",
   )
 })

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

@@ -3,77 +3,83 @@ open Reducer_Peggy_TestHelpers
 
 describe("Peggy parse type", () => {
   describe("type of", () => {
-    testParse("p: number", "{(::$_typeOf_$ :p #number)}")
+    testParse("p: number", "{(::$_typeOf_$ :p #number); (::$_endOfOuterBlock_$ () ())}")
   })
   describe("type alias", () => {
-    testParse("type index=number", "{(::$_typeAlias_$ #index #number)}")
+    testParse(
+      "type index=number",
+      "{(::$_typeAlias_$ #index #number); (::$_endOfOuterBlock_$ () ())}",
+    )
   })
   describe("type or", () => {
     testParse(
       "answer: number|string",
-      "{(::$_typeOf_$ :answer (::$_typeOr_$ (::$_constructArray_$ (#number #string))))}",
+      "{(::$_typeOf_$ :answer (::$_typeOr_$ (::$_constructArray_$ (#number #string)))); (::$_endOfOuterBlock_$ () ())}",
     )
   })
   describe("type function", () => {
     testParse(
       "f: number=>number=>number",
-      "{(::$_typeOf_$ :f (::$_typeFunction_$ (::$_constructArray_$ (#number #number #number))))}",
+      "{(::$_typeOf_$ :f (::$_typeFunction_$ (::$_constructArray_$ (#number #number #number)))); (::$_endOfOuterBlock_$ () ())}",
     )
   })
   describe("high priority contract", () => {
     testParse(
       "answer: number<-min<-max(100)|string",
-      "{(::$_typeOf_$ :answer (::$_typeOr_$ (::$_constructArray_$ ((::$_typeModifier_max_$ (::$_typeModifier_min_$ #number) 100) #string))))}",
+      "{(::$_typeOf_$ :answer (::$_typeOr_$ (::$_constructArray_$ ((::$_typeModifier_max_$ (::$_typeModifier_min_$ #number) 100) #string)))); (::$_endOfOuterBlock_$ () ())}",
     )
     testParse(
       "answer: number<-memberOf([1,3,5])",
-      "{(::$_typeOf_$ :answer (::$_typeModifier_memberOf_$ #number (::$_constructArray_$ (1 3 5))))}",
+      "{(::$_typeOf_$ :answer (::$_typeModifier_memberOf_$ #number (::$_constructArray_$ (1 3 5)))); (::$_endOfOuterBlock_$ () ())}",
     )
   })
   describe("low priority contract", () => {
     testParse(
       "answer: number | string $ opaque",
-      "{(::$_typeOf_$ :answer (::$_typeModifier_opaque_$ (::$_typeOr_$ (::$_constructArray_$ (#number #string)))))}",
+      "{(::$_typeOf_$ :answer (::$_typeModifier_opaque_$ (::$_typeOr_$ (::$_constructArray_$ (#number #string))))); (::$_endOfOuterBlock_$ () ())}",
     )
   })
   describe("type array", () => {
-    testParse("answer: [number]", "{(::$_typeOf_$ :answer (::$_typeArray_$ #number))}")
+    testParse(
+      "answer: [number]",
+      "{(::$_typeOf_$ :answer (::$_typeArray_$ #number)); (::$_endOfOuterBlock_$ () ())}",
+    )
   })
   describe("type record", () => {
     testParse(
       "answer: {a: number, b: string}",
-      "{(::$_typeOf_$ :answer (::$_typeRecord_$ (::$_constructRecord_$ ('a': #number 'b': #string))))}",
+      "{(::$_typeOf_$ :answer (::$_typeRecord_$ (::$_constructRecord_$ ('a': #number 'b': #string)))); (::$_endOfOuterBlock_$ () ())}",
     )
   })
   describe("type constructor", () => {
     testParse(
       "answer: Age(number)",
-      "{(::$_typeOf_$ :answer (::$_typeConstructor_$ #Age (::$_constructArray_$ (#number))))}",
+      "{(::$_typeOf_$ :answer (::$_typeConstructor_$ #Age (::$_constructArray_$ (#number)))); (::$_endOfOuterBlock_$ () ())}",
     )
     testParse(
       "answer: Complex(number, number)",
-      "{(::$_typeOf_$ :answer (::$_typeConstructor_$ #Complex (::$_constructArray_$ (#number #number))))}",
+      "{(::$_typeOf_$ :answer (::$_typeConstructor_$ #Complex (::$_constructArray_$ (#number #number)))); (::$_endOfOuterBlock_$ () ())}",
     )
     testParse(
       "answer: Person({age: number, name: string})",
-      "{(::$_typeOf_$ :answer (::$_typeConstructor_$ #Person (::$_constructArray_$ ((::$_typeRecord_$ (::$_constructRecord_$ ('age': #number 'name': #string)))))))}",
+      "{(::$_typeOf_$ :answer (::$_typeConstructor_$ #Person (::$_constructArray_$ ((::$_typeRecord_$ (::$_constructRecord_$ ('age': #number 'name': #string))))))); (::$_endOfOuterBlock_$ () ())}",
     )
     testParse(
       "weekend: Saturday | Sunday",
-      "{(::$_typeOf_$ :weekend (::$_typeOr_$ (::$_constructArray_$ ((::$_typeConstructor_$ #Saturday (::$_constructArray_$ ())) (::$_typeConstructor_$ #Sunday (::$_constructArray_$ ()))))))}",
+      "{(::$_typeOf_$ :weekend (::$_typeOr_$ (::$_constructArray_$ ((::$_typeConstructor_$ #Saturday (::$_constructArray_$ ())) (::$_typeConstructor_$ #Sunday (::$_constructArray_$ ())))))); (::$_endOfOuterBlock_$ () ())}",
     )
   })
   describe("type parenthesis", () => {
     //$ is introduced to avoid parenthesis
     testParse(
       "answer: (number|string)<-opaque",
-      "{(::$_typeOf_$ :answer (::$_typeModifier_opaque_$ (::$_typeOr_$ (::$_constructArray_$ (#number #string)))))}",
+      "{(::$_typeOf_$ :answer (::$_typeModifier_opaque_$ (::$_typeOr_$ (::$_constructArray_$ (#number #string))))); (::$_endOfOuterBlock_$ () ())}",
     )
   })
   describe("squiggle expressions in type contracts", () => {
     testParse(
       "odds1 = [1,3,5]; odds2 = [7, 9]; type odds = number<-memberOf(concat(odds1, odds2))",
-      "{:odds1 = {(::$_constructArray_$ (1 3 5))}; :odds2 = {(::$_constructArray_$ (7 9))}; (::$_typeAlias_$ #odds (::$_typeModifier_memberOf_$ #number (::concat :odds1 :odds2)))}",
+      "{:odds1 = {(::$_constructArray_$ (1 3 5))}; :odds2 = {(::$_constructArray_$ (7 9))}; (::$_typeAlias_$ #odds (::$_typeModifier_memberOf_$ #number (::concat :odds1 :odds2))); (::$_endOfOuterBlock_$ () ())}",
     )
   })
 })

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

@@ -23,13 +23,7 @@ let expectToExpressionToBe = (expr, answer, ~v="_", ()) => {
   } else {
     let a2 =
       rExpr
-      ->Result.flatMap(expr =>
-        Expression.reduceExpression(
-          expr,
-          ReducerInterface_StdLib.internalStdLib,
-          ExpressionValue.defaultEnvironment,
-        )
-      )
+      ->Result.flatMap(expr => Expression.BackCompatible.evaluate(expr))
       ->Reducer_Helpers.rRemoveDefaultsInternal
       ->ExpressionValue.toStringResultOkless
     (a1, a2)->expect->toEqual((answer, v))

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

@@ -0,0 +1,23 @@
+module Bindings = Reducer_Bindings
+module InternalExpressionValue = ReducerInterface_InternalExpressionValue
+
+open Jest
+open Reducer_Peggy_TestHelpers
+
+describe("Peggy Outer Block", () => {
+  testToExpression("1", "{(:$_endOfOuterBlock_$ () 1)}", ~v="1", ())
+  testToExpression("x=1", "{(:$_let_$ :x {1}); (:$_endOfOuterBlock_$ () ())}", ~v="()", ())
+  testToExpression(
+    "x=1; y=2",
+    "{(:$_let_$ :x {1}); (:$_let_$ :y {2}); (:$_endOfOuterBlock_$ () ())}",
+    ~v="()",
+    (),
+  )
+  testToExpression("x=1; 2", "{(:$_let_$ :x {1}); (:$_endOfOuterBlock_$ () 2)}", ~v="2", ())
+  testToExpression(
+    "x={a=1; a}; x",
+    "{(:$_let_$ :x {(:$_let_$ :a {1}); :a}); (:$_endOfOuterBlock_$ () :x)}",
+    ~v="1",
+    (),
+  )
+})

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

@@ -7,101 +7,138 @@ open Reducer_Peggy_TestHelpers
 describe("Peggy to Expression", () => {
   describe("literals operators parenthesis", () => {
     // Note that there is always an outer block. Otherwise, external bindings are ignored at the first statement
-    testToExpression("1", "{1}", ~v="1", ())
-    testToExpression("'hello'", "{'hello'}", ~v="'hello'", ())
-    testToExpression("true", "{true}", ~v="true", ())
-    testToExpression("1+2", "{(:add 1 2)}", ~v="3", ())
-    testToExpression("add(1,2)", "{(:add 1 2)}", ~v="3", ())
-    testToExpression("(1)", "{1}", ())
-    testToExpression("(1+2)", "{(:add 1 2)}", ())
+    testToExpression("1", "{(:$_endOfOuterBlock_$ () 1)}", ~v="1", ())
+    testToExpression("'hello'", "{(:$_endOfOuterBlock_$ () 'hello')}", ~v="'hello'", ())
+    testToExpression("true", "{(:$_endOfOuterBlock_$ () true)}", ~v="true", ())
+    testToExpression("1+2", "{(:$_endOfOuterBlock_$ () (:add 1 2))}", ~v="3", ())
+    testToExpression("add(1,2)", "{(:$_endOfOuterBlock_$ () (:add 1 2))}", ~v="3", ())
+    testToExpression("(1)", "{(:$_endOfOuterBlock_$ () 1)}", ())
+    testToExpression("(1+2)", "{(:$_endOfOuterBlock_$ () (:add 1 2))}", ())
   })
 
   describe("unary", () => {
-    testToExpression("-1", "{(:unaryMinus 1)}", ~v="-1", ())
-    testToExpression("!true", "{(:not true)}", ~v="false", ())
-    testToExpression("1 + -1", "{(:add 1 (:unaryMinus 1))}", ~v="0", ())
-    testToExpression("-a[0]", "{(:unaryMinus (:$_atIndex_$ :a 0))}", ())
+    testToExpression("-1", "{(:$_endOfOuterBlock_$ () (:unaryMinus 1))}", ~v="-1", ())
+    testToExpression("!true", "{(:$_endOfOuterBlock_$ () (:not true))}", ~v="false", ())
+    testToExpression("1 + -1", "{(:$_endOfOuterBlock_$ () (:add 1 (:unaryMinus 1)))}", ~v="0", ())
+    testToExpression("-a[0]", "{(:$_endOfOuterBlock_$ () (:unaryMinus (:$_atIndex_$ :a 0)))}", ())
   })
 
   describe("multi-line", () => {
-    testToExpression("x=1; 2", "{(:$_let_$ :x {1}); 2}", ~v="2", ())
-    testToExpression("x=1; y=2", "{(:$_let_$ :x {1}); (:$_let_$ :y {2})}", ~v="@{x: 1,y: 2}", ())
+    testToExpression("x=1; 2", "{(:$_let_$ :x {1}); (:$_endOfOuterBlock_$ () 2)}", ~v="2", ())
+    testToExpression(
+      "x=1; y=2",
+      "{(:$_let_$ :x {1}); (:$_let_$ :y {2}); (:$_endOfOuterBlock_$ () ())}",
+      (),
+    )
   })
 
   describe("variables", () => {
-    testToExpression("x = 1", "{(:$_let_$ :x {1})}", ~v="@{x: 1}", ())
-    testToExpression("x", "{:x}", ~v=":x", ()) //TODO: value should return error
-    testToExpression("x = 1; x", "{(:$_let_$ :x {1}); :x}", ~v="1", ())
+    testToExpression("x = 1", "{(:$_let_$ :x {1}); (:$_endOfOuterBlock_$ () ())}", ())
+    testToExpression("x", "{(:$_endOfOuterBlock_$ () :x)}", ~v="Error(x is not defined)", ()) //TODO: value should return error
+    testToExpression("x = 1; x", "{(:$_let_$ :x {1}); (:$_endOfOuterBlock_$ () :x)}", ~v="1", ())
   })
 
   describe("functions", () => {
     testToExpression(
       "identity(x) = x",
-      "{(:$_let_$ :identity (:$$_lambda_$$ [x] {:x}))}",
-      ~v="@{identity: lambda(x=>internal code)}",
+      "{(:$_let_$ :identity (:$$_lambda_$$ [x] {:x})); (:$_endOfOuterBlock_$ () ())}",
       (),
     ) // Function definitions become lambda assignments
-    testToExpression("identity(x)", "{(:identity :x)}", ()) // Note value returns error properly
+    testToExpression("identity(x)", "{(:$_endOfOuterBlock_$ () (:identity :x))}", ()) // Note value returns error properly
     testToExpression(
       "f(x) = x> 2 ? 0 : 1; f(3)",
-      "{(:$_let_$ :f (:$$_lambda_$$ [x] {(:$$_ternary_$$ (:larger :x 2) 0 1)})); (:f 3)}",
+      "{(:$_let_$ :f (:$$_lambda_$$ [x] {(:$$_ternary_$$ (:larger :x 2) 0 1)})); (:$_endOfOuterBlock_$ () (:f 3))}",
       ~v="0",
       (),
     )
   })
 
   describe("arrays", () => {
-    testToExpression("[]", "{(:$_constructArray_$ ())}", ~v="[]", ())
-    testToExpression("[0, 1, 2]", "{(:$_constructArray_$ (0 1 2))}", ~v="[0,1,2]", ())
+    testToExpression("[]", "{(:$_endOfOuterBlock_$ () (:$_constructArray_$ ()))}", ~v="[]", ())
+    testToExpression(
+      "[0, 1, 2]",
+      "{(:$_endOfOuterBlock_$ () (:$_constructArray_$ (0 1 2)))}",
+      ~v="[0,1,2]",
+      (),
+    )
     testToExpression(
       "['hello', 'world']",
-      "{(:$_constructArray_$ ('hello' 'world'))}",
+      "{(:$_endOfOuterBlock_$ () (:$_constructArray_$ ('hello' 'world')))}",
       ~v="['hello','world']",
       (),
     )
-    testToExpression("([0,1,2])[1]", "{(:$_atIndex_$ (:$_constructArray_$ (0 1 2)) 1)}", ~v="1", ())
+    testToExpression(
+      "([0,1,2])[1]",
+      "{(:$_endOfOuterBlock_$ () (:$_atIndex_$ (:$_constructArray_$ (0 1 2)) 1))}",
+      ~v="1",
+      (),
+    )
   })
 
   describe("records", () => {
     testToExpression(
       "{a: 1, b: 2}",
-      "{(:$_constructRecord_$ (('a' 1) ('b' 2)))}",
+      "{(:$_endOfOuterBlock_$ () (:$_constructRecord_$ (('a' 1) ('b' 2))))}",
       ~v="{a: 1,b: 2}",
       (),
     )
     testToExpression(
       "{1+0: 1, 2+0: 2}",
-      "{(:$_constructRecord_$ (((:add 1 0) 1) ((:add 2 0) 2)))}",
+      "{(:$_endOfOuterBlock_$ () (:$_constructRecord_$ (((:add 1 0) 1) ((:add 2 0) 2))))}",
       (),
     ) // key can be any expression
-    testToExpression("record.property", "{(:$_atIndex_$ :record 'property')}", ())
+    testToExpression(
+      "record.property",
+      "{(:$_endOfOuterBlock_$ () (:$_atIndex_$ :record 'property'))}",
+      (),
+    )
     testToExpression(
       "record={property: 1}; record.property",
-      "{(:$_let_$ :record {(:$_constructRecord_$ (('property' 1)))}); (:$_atIndex_$ :record 'property')}",
+      "{(:$_let_$ :record {(:$_constructRecord_$ (('property' 1)))}); (:$_endOfOuterBlock_$ () (:$_atIndex_$ :record 'property'))}",
       ~v="1",
       (),
     )
   })
 
   describe("comments", () => {
-    testToExpression("1 # This is a line comment", "{1}", ~v="1", ())
-    testToExpression("1 // This is a line comment", "{1}", ~v="1", ())
-    testToExpression("1 /* This is a multi line comment */", "{1}", ~v="1", ())
-    testToExpression("/* This is a multi line comment */ 1", "{1}", ~v="1", ())
+    testToExpression("1 # This is a line comment", "{(:$_endOfOuterBlock_$ () 1)}", ~v="1", ())
+    testToExpression("1 // This is a line comment", "{(:$_endOfOuterBlock_$ () 1)}", ~v="1", ())
+    testToExpression(
+      "1 /* This is a multi line comment */",
+      "{(:$_endOfOuterBlock_$ () 1)}",
+      ~v="1",
+      (),
+    )
+    testToExpression(
+      "/* This is a multi line comment */ 1",
+      "{(:$_endOfOuterBlock_$ () 1)}",
+      ~v="1",
+      (),
+    )
   })
 
   describe("ternary operator", () => {
-    testToExpression("true ? 1 : 0", "{(:$$_ternary_$$ true 1 0)}", ~v="1", ())
-    testToExpression("false ? 1 : 0", "{(:$$_ternary_$$ false 1 0)}", ~v="0", ())
+    testToExpression(
+      "true ? 1 : 0",
+      "{(:$_endOfOuterBlock_$ () (:$$_ternary_$$ true 1 0))}",
+      ~v="1",
+      (),
+    )
+    testToExpression(
+      "false ? 1 : 0",
+      "{(:$_endOfOuterBlock_$ () (:$$_ternary_$$ false 1 0))}",
+      ~v="0",
+      (),
+    )
     testToExpression(
       "true ? 1 : false ? 2 : 0",
-      "{(:$$_ternary_$$ true 1 (:$$_ternary_$$ false 2 0))}",
+      "{(:$_endOfOuterBlock_$ () (:$$_ternary_$$ true 1 (:$$_ternary_$$ false 2 0)))}",
       ~v="1",
       (),
     ) // nested ternary
     testToExpression(
       "false ? 1 : false ? 2 : 0",
-      "{(:$$_ternary_$$ false 1 (:$$_ternary_$$ false 2 0))}",
+      "{(:$_endOfOuterBlock_$ () (:$$_ternary_$$ false 1 (:$$_ternary_$$ false 2 0)))}",
       ~v="0",
       (),
     ) // nested ternary
@@ -109,21 +146,21 @@ describe("Peggy to Expression", () => {
       testToExpression(
         // expression binding
         "f(a) = a > 5 ? 1 : 0; f(6)",
-        "{(:$_let_$ :f (:$$_lambda_$$ [a] {(:$$_ternary_$$ (:larger :a 5) 1 0)})); (:f 6)}",
+        "{(:$_let_$ :f (:$$_lambda_$$ [a] {(:$$_ternary_$$ (:larger :a 5) 1 0)})); (:$_endOfOuterBlock_$ () (:f 6))}",
         ~v="1",
         (),
       )
       testToExpression(
         // when true binding
         "f(a) = a > 5 ? a : 0; f(6)",
-        "{(:$_let_$ :f (:$$_lambda_$$ [a] {(:$$_ternary_$$ (:larger :a 5) :a 0)})); (:f 6)}",
+        "{(:$_let_$ :f (:$$_lambda_$$ [a] {(:$$_ternary_$$ (:larger :a 5) :a 0)})); (:$_endOfOuterBlock_$ () (:f 6))}",
         ~v="6",
         (),
       )
       testToExpression(
         // when false binding
         "f(a) = a < 5 ? 1 : a; f(6)",
-        "{(:$_let_$ :f (:$$_lambda_$$ [a] {(:$$_ternary_$$ (:smaller :a 5) 1 :a)})); (:f 6)}",
+        "{(:$_let_$ :f (:$$_lambda_$$ [a] {(:$$_ternary_$$ (:smaller :a 5) 1 :a)})); (:$_endOfOuterBlock_$ () (:f 6))}",
         ~v="6",
         (),
       )
@@ -131,23 +168,41 @@ describe("Peggy to Expression", () => {
   })
 
   describe("if then else", () => {
-    testToExpression("if true then 2 else 3", "{(:$$_ternary_$$ true {2} {3})}", ())
-    testToExpression("if true then {2} else {3}", "{(:$$_ternary_$$ true {2} {3})}", ())
+    testToExpression(
+      "if true then 2 else 3",
+      "{(:$_endOfOuterBlock_$ () (:$$_ternary_$$ true {2} {3}))}",
+      (),
+    )
+    testToExpression(
+      "if true then {2} else {3}",
+      "{(:$_endOfOuterBlock_$ () (:$$_ternary_$$ true {2} {3}))}",
+      (),
+    )
     testToExpression(
       "if false then {2} else if false then {4} else {5}",
-      "{(:$$_ternary_$$ false {2} (:$$_ternary_$$ false {4} {5}))}",
+      "{(:$_endOfOuterBlock_$ () (:$$_ternary_$$ false {2} (:$$_ternary_$$ false {4} {5})))}",
       (),
     ) //nested if
   })
 
   describe("pipe", () => {
-    testToExpression("1 -> add(2)", "{(:add 1 2)}", ~v="3", ())
-    testToExpression("-1 -> add(2)", "{(:add (:unaryMinus 1) 2)}", ~v="1", ()) // note that unary has higher priority naturally
-    testToExpression("1 -> add(2) * 3", "{(:multiply (:add 1 2) 3)}", ~v="9", ())
+    testToExpression("1 -> add(2)", "{(:$_endOfOuterBlock_$ () (:add 1 2))}", ~v="3", ())
+    testToExpression(
+      "-1 -> add(2)",
+      "{(:$_endOfOuterBlock_$ () (:add (:unaryMinus 1) 2))}",
+      ~v="1",
+      (),
+    ) // note that unary has higher priority naturally
+    testToExpression(
+      "1 -> add(2) * 3",
+      "{(:$_endOfOuterBlock_$ () (:multiply (:add 1 2) 3))}",
+      ~v="9",
+      (),
+    )
   })
 
   describe("elixir pipe", () => {
-    testToExpression("1 |> add(2)", "{(:add 1 2)}", ~v="3", ())
+    testToExpression("1 |> add(2)", "{(:$_endOfOuterBlock_$ () (:add 1 2))}", ~v="3", ())
   })
 
   // see testParse for priorities of to and credibleIntervalToDistribution
@@ -157,30 +212,31 @@ describe("Peggy to Expression", () => {
     // Like lambdas they have a local scope.
     testToExpression(
       "y=99; x={y=1; y}",
-      "{(:$_let_$ :y {99}); (:$_let_$ :x {(:$_let_$ :y {1}); :y})}",
-      ~v="@{x: 1,y: 99}",
+      "{(:$_let_$ :y {99}); (:$_let_$ :x {(:$_let_$ :y {1}); :y}); (:$_endOfOuterBlock_$ () ())}",
       (),
     )
   })
 
   describe("lambda", () => {
-    testToExpression("{|x| x}", "{(:$$_lambda_$$ [x] {:x})}", ~v="lambda(x=>internal code)", ())
+    testToExpression(
+      "{|x| x}",
+      "{(:$_endOfOuterBlock_$ () (:$$_lambda_$$ [x] {:x}))}",
+      ~v="lambda(x=>internal code)",
+      (),
+    )
     testToExpression(
       "f={|x| x}",
-      "{(:$_let_$ :f {(:$$_lambda_$$ [x] {:x})})}",
-      ~v="@{f: lambda(x=>internal code)}",
+      "{(:$_let_$ :f {(:$$_lambda_$$ [x] {:x})}); (:$_endOfOuterBlock_$ () ())}",
       (),
     )
     testToExpression(
       "f(x)=x",
-      "{(:$_let_$ :f (:$$_lambda_$$ [x] {:x}))}",
-      ~v="@{f: lambda(x=>internal code)}",
+      "{(:$_let_$ :f (:$$_lambda_$$ [x] {:x})); (:$_endOfOuterBlock_$ () ())}",
       (),
     ) // Function definitions are lambda assignments
     testToExpression(
       "f(x)=x ? 1 : 0",
-      "{(:$_let_$ :f (:$$_lambda_$$ [x] {(:$$_ternary_$$ :x 1 0)}))}",
-      ~v="@{f: lambda(x=>internal code)}",
+      "{(:$_let_$ :f (:$$_lambda_$$ [x] {(:$$_ternary_$$ :x 1 0)})); (:$_endOfOuterBlock_$ () ())}",
       (),
     )
   })
@@ -194,6 +250,6 @@ describe("Peggy to Expression", () => {
     //  ->expect
     //  ->toBe("")
     // })
-    testToExpression("Math.pi", "{:Math.pi}", ~v="3.141592653589793", ())
+    testToExpression("Math.pi", "{(:$_endOfOuterBlock_$ () :Math.pi)}", ~v="3.141592653589793", ())
   })
 })

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

@@ -5,92 +5,92 @@ describe("Peggy Types to Expression", () => {
   describe("type of", () => {
     testToExpression(
       "p: number",
-      "{(:$_typeOf_$ :p #number)}",
-      ~v="@{_typeReferences_: {p: #number}}",
+      "{(:$_typeOf_$ :p #number); (:$_endOfOuterBlock_$ () ())}",
+      // ~v="@{_typeReferences_: {p: #number}}",
       (),
     )
   })
   describe("type alias", () => {
     testToExpression(
       "type index=number",
-      "{(:$_typeAlias_$ #index #number)}",
-      ~v="@{_typeAliases_: {index: #number}}",
+      "{(:$_typeAlias_$ #index #number); (:$_endOfOuterBlock_$ () ())}",
+      // ~v="@{_typeAliases_: {index: #number}}",
       (),
     )
   })
   describe("type or", () => {
     testToExpression(
       "answer: number|string|distribution",
-      "{(:$_typeOf_$ :answer (:$_typeOr_$ (:$_constructArray_$ (#number #string #distribution))))}",
-      ~v="@{_typeReferences_: {answer: {typeOr: [#number,#string,#distribution],typeTag: 'typeOr'}}}",
+      "{(:$_typeOf_$ :answer (:$_typeOr_$ (:$_constructArray_$ (#number #string #distribution)))); (:$_endOfOuterBlock_$ () ())}",
+      // ~v="@{_typeReferences_: {answer: {typeOr: [#number,#string,#distribution],typeTag: 'typeOr'}}}",
       (),
     )
   })
   describe("type function", () => {
     testToExpression(
       "f: number=>number=>number",
-      "{(:$_typeOf_$ :f (:$_typeFunction_$ (:$_constructArray_$ (#number #number #number))))}",
-      ~v="@{_typeReferences_: {f: {inputs: [#number,#number],output: #number,typeTag: 'typeFunction'}}}",
+      "{(:$_typeOf_$ :f (:$_typeFunction_$ (:$_constructArray_$ (#number #number #number)))); (:$_endOfOuterBlock_$ () ())}",
+      // ~v="@{_typeReferences_: {f: {inputs: [#number,#number],output: #number,typeTag: 'typeFunction'}}}",
       (),
     )
     testToExpression(
       "f: number=>number",
-      "{(:$_typeOf_$ :f (:$_typeFunction_$ (:$_constructArray_$ (#number #number))))}",
-      ~v="@{_typeReferences_: {f: {inputs: [#number],output: #number,typeTag: 'typeFunction'}}}",
+      "{(:$_typeOf_$ :f (:$_typeFunction_$ (:$_constructArray_$ (#number #number)))); (:$_endOfOuterBlock_$ () ())}",
+      // ~v="@{_typeReferences_: {f: {inputs: [#number],output: #number,typeTag: 'typeFunction'}}}",
       (),
     )
   })
   describe("high priority contract", () => {
     testToExpression(
       "answer: number<-min(1)<-max(100)|string",
-      "{(:$_typeOf_$ :answer (:$_typeOr_$ (:$_constructArray_$ ((:$_typeModifier_max_$ (:$_typeModifier_min_$ #number 1) 100) #string))))}",
-      ~v="@{_typeReferences_: {answer: {typeOr: [{max: 100,min: 1,typeIdentifier: #number,typeTag: 'typeIdentifier'},#string],typeTag: 'typeOr'}}}",
+      "{(:$_typeOf_$ :answer (:$_typeOr_$ (:$_constructArray_$ ((:$_typeModifier_max_$ (:$_typeModifier_min_$ #number 1) 100) #string)))); (:$_endOfOuterBlock_$ () ())}",
+      // ~v="@{_typeReferences_: {answer: {typeOr: [{max: 100,min: 1,typeIdentifier: #number,typeTag: 'typeIdentifier'},#string],typeTag: 'typeOr'}}}",
       (),
     )
     testToExpression(
       "answer: number<-memberOf([1,3,5])",
-      "{(:$_typeOf_$ :answer (:$_typeModifier_memberOf_$ #number (:$_constructArray_$ (1 3 5))))}",
-      ~v="@{_typeReferences_: {answer: {memberOf: [1,3,5],typeIdentifier: #number,typeTag: 'typeIdentifier'}}}",
+      "{(:$_typeOf_$ :answer (:$_typeModifier_memberOf_$ #number (:$_constructArray_$ (1 3 5)))); (:$_endOfOuterBlock_$ () ())}",
+      // ~v="@{_typeReferences_: {answer: {memberOf: [1,3,5],typeIdentifier: #number,typeTag: 'typeIdentifier'}}}",
       (),
     )
     testToExpression(
       "answer: number<-min(1)",
-      "{(:$_typeOf_$ :answer (:$_typeModifier_min_$ #number 1))}",
-      ~v="@{_typeReferences_: {answer: {min: 1,typeIdentifier: #number,typeTag: 'typeIdentifier'}}}",
+      "{(:$_typeOf_$ :answer (:$_typeModifier_min_$ #number 1)); (:$_endOfOuterBlock_$ () ())}",
+      // ~v="@{_typeReferences_: {answer: {min: 1,typeIdentifier: #number,typeTag: 'typeIdentifier'}}}",
       (),
     )
     testToExpression(
       "answer: number<-max(10)",
-      "{(:$_typeOf_$ :answer (:$_typeModifier_max_$ #number 10))}",
-      ~v="@{_typeReferences_: {answer: {max: 10,typeIdentifier: #number,typeTag: 'typeIdentifier'}}}",
+      "{(:$_typeOf_$ :answer (:$_typeModifier_max_$ #number 10)); (:$_endOfOuterBlock_$ () ())}",
+      // ~v="@{_typeReferences_: {answer: {max: 10,typeIdentifier: #number,typeTag: 'typeIdentifier'}}}",
       (),
     )
     testToExpression(
       "answer: number<-min(1)<-max(10)",
-      "{(:$_typeOf_$ :answer (:$_typeModifier_max_$ (:$_typeModifier_min_$ #number 1) 10))}",
-      ~v="@{_typeReferences_: {answer: {max: 10,min: 1,typeIdentifier: #number,typeTag: 'typeIdentifier'}}}",
+      "{(:$_typeOf_$ :answer (:$_typeModifier_max_$ (:$_typeModifier_min_$ #number 1) 10)); (:$_endOfOuterBlock_$ () ())}",
+      // ~v="@{_typeReferences_: {answer: {max: 10,min: 1,typeIdentifier: #number,typeTag: 'typeIdentifier'}}}",
       (),
     )
     testToExpression(
       "answer: number<-max(10)<-min(1)",
-      "{(:$_typeOf_$ :answer (:$_typeModifier_min_$ (:$_typeModifier_max_$ #number 10) 1))}",
-      ~v="@{_typeReferences_: {answer: {max: 10,min: 1,typeIdentifier: #number,typeTag: 'typeIdentifier'}}}",
+      "{(:$_typeOf_$ :answer (:$_typeModifier_min_$ (:$_typeModifier_max_$ #number 10) 1)); (:$_endOfOuterBlock_$ () ())}",
+      // ~v="@{_typeReferences_: {answer: {max: 10,min: 1,typeIdentifier: #number,typeTag: 'typeIdentifier'}}}",
       (),
     )
   })
   describe("low priority contract", () => {
     testToExpression(
       "answer: number | string $ opaque",
-      "{(:$_typeOf_$ :answer (:$_typeModifier_opaque_$ (:$_typeOr_$ (:$_constructArray_$ (#number #string)))))}",
-      ~v="@{_typeReferences_: {answer: {opaque: true,typeOr: [#number,#string],typeTag: 'typeOr'}}}",
+      "{(:$_typeOf_$ :answer (:$_typeModifier_opaque_$ (:$_typeOr_$ (:$_constructArray_$ (#number #string))))); (:$_endOfOuterBlock_$ () ())}",
+      // ~v="@{_typeReferences_: {answer: {opaque: true,typeOr: [#number,#string],typeTag: 'typeOr'}}}",
       (),
     )
   })
   describe("squiggle expressions in type contracts", () => {
     testToExpression(
       "odds1 = [1,3,5]; odds2 = [7, 9]; type odds = number<-memberOf(concat(odds1, odds2))",
-      "{(:$_let_$ :odds1 {(:$_constructArray_$ (1 3 5))}); (:$_let_$ :odds2 {(:$_constructArray_$ (7 9))}); (:$_typeAlias_$ #odds (:$_typeModifier_memberOf_$ #number (:concat :odds1 :odds2)))}",
-      ~v="@{_typeAliases_: {odds: {memberOf: [1,3,5,7,9],typeIdentifier: #number,typeTag: 'typeIdentifier'}},odds1: [1,3,5],odds2: [7,9]}",
+      "{(:$_let_$ :odds1 {(:$_constructArray_$ (1 3 5))}); (:$_let_$ :odds2 {(:$_constructArray_$ (7 9))}); (:$_typeAlias_$ #odds (:$_typeModifier_memberOf_$ #number (:concat :odds1 :odds2))); (:$_endOfOuterBlock_$ () ())}",
+      // ~v="@{_typeAliases_: {odds: {memberOf: [1,3,5,7,9],typeIdentifier: #number,typeTag: 'typeIdentifier'}},odds1: [1,3,5],odds2: [7,9]}",
       (),
     )
   })

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

@@ -3,18 +3,23 @@ open Reducer_Peggy_TestHelpers
 
 describe("Peggy void", () => {
   //literal
-  testToExpression("()", "{()}", ~v="()", ())
+  testToExpression("()", "{(:$_endOfOuterBlock_$ () ())}", ~v="()", ())
   testToExpression(
     "fn()=1",
-    "{(:$_let_$ :fn (:$$_lambda_$$ [_] {1}))}",
-    ~v="@{fn: lambda(_=>internal code)}",
+    "{(:$_let_$ :fn (:$$_lambda_$$ [_] {1})); (:$_endOfOuterBlock_$ () ())}",
+    // ~v="@{fn: lambda(_=>internal code)}",
+    (),
+  )
+  testToExpression(
+    "fn()=1; fn()",
+    "{(:$_let_$ :fn (:$$_lambda_$$ [_] {1})); (:$_endOfOuterBlock_$ () (:fn ()))}",
+    ~v="1",
     (),
   )
-  testToExpression("fn()=1; fn()", "{(:$_let_$ :fn (:$$_lambda_$$ [_] {1})); (:fn ())}", ~v="1", ())
   testToExpression(
     "fn(a)=(); call fn(1)",
-    "{(:$_let_$ :fn (:$$_lambda_$$ [a] {()})); (:$_let_$ :_ {(:fn 1)})}",
-    ~v="@{_: (),fn: lambda(a=>internal code)}",
+    "{(:$_let_$ :fn (:$$_lambda_$$ [a] {()})); (:$_let_$ :_ {(:fn 1)}); (:$_endOfOuterBlock_$ () ())}",
+    // ~v="@{_: (),fn: lambda(a=>internal code)}",
     (),
   )
 })

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

@@ -1,6 +1,7 @@
+module ErrorValue = Reducer_ErrorValue
+module Expression = Reducer_Expression
 module ExpressionT = Reducer_Expression_T
 module ExternalExpressionValue = ReducerInterface.ExternalExpressionValue
-module ErrorValue = Reducer_ErrorValue
 
 open Jest
 open Expect
@@ -13,25 +14,21 @@ let unwrapRecord = rValue =>
     }
   )
 
-let expectParseToBe = (expr: string, answer: string) =>
-  Reducer.parse(expr)->ExpressionT.toStringResult->expect->toBe(answer)
+let expectParseToBe = (code: string, answer: string) =>
+  Expression.BackCompatible.parse(code)->ExpressionT.toStringResult->expect->toBe(answer)
 
-let expectEvalToBe = (expr: string, answer: string) =>
-  Reducer.evaluate(expr)
+let expectEvalToBe = (code: string, answer: string) =>
+  Expression.BackCompatible.evaluateStringAsExternal(code)
   ->Reducer_Helpers.rRemoveDefaultsExternal
   ->ExternalExpressionValue.toStringResult
   ->expect
   ->toBe(answer)
 
-let expectEvalError = (expr: string) =>
-  Reducer.evaluate(expr)->ExternalExpressionValue.toStringResult->expect->toMatch("Error\(")
-
-let expectEvalBindingsToBe = (expr: string, bindings: Reducer.externalBindings, answer: string) =>
-  Reducer.evaluateUsingOptions(expr, ~externalBindings=Some(bindings), ~environment=None)
-  ->Reducer_Helpers.rRemoveDefaultsExternal
+let expectEvalError = (code: string) =>
+  Expression.BackCompatible.evaluateStringAsExternal(code)
   ->ExternalExpressionValue.toStringResult
   ->expect
-  ->toBe(answer)
+  ->toMatch("Error\(")
 
 let testParseToBe = (expr, answer) => test(expr, () => expectParseToBe(expr, answer))
 let testDescriptionParseToBe = (desc, expr, answer) =>
@@ -40,18 +37,12 @@ let testDescriptionParseToBe = (desc, 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) =>
-  test(expr, () => expectEvalBindingsToBe(expr, bindingsList->Js.Dict.fromList, answer))
 
 module MySkip = {
   let testParseToBe = (expr, answer) => Skip.test(expr, () => expectParseToBe(expr, answer))
   let testEvalToBe = (expr, answer) => Skip.test(expr, () => expectEvalToBe(expr, answer))
-  let testEvalBindingsToBe = (expr, bindingsList, answer) =>
-    Skip.test(expr, () => expectEvalBindingsToBe(expr, bindingsList->Js.Dict.fromList, answer))
 }
 module MyOnly = {
   let testParseToBe = (expr, answer) => Only.test(expr, () => expectParseToBe(expr, answer))
   let testEvalToBe = (expr, answer) => Only.test(expr, () => expectEvalToBe(expr, answer))
-  let testEvalBindingsToBe = (expr, bindingsList, answer) =>
-    Only.test(expr, () => expectEvalBindingsToBe(expr, bindingsList->Js.Dict.fromList, answer))
 }

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

@@ -1,14 +1,14 @@
 open Jest
 open Expect
 
+module Bindings = Reducer_Bindings
 module BindingsReplacer = Reducer_Expression_BindingsReplacer
 module Expression = Reducer_Expression
-// module ExpressionValue = ReducerInterface.ExpressionValue
-module InternalExpressionValue = ReducerInterface.InternalExpressionValue
 module ExpressionWithContext = Reducer_ExpressionWithContext
+module InternalExpressionValue = ReducerInterface.InternalExpressionValue
 module Macro = Reducer_Expression_Macro
+module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
 module T = Reducer_Expression_T
-module Bindings = Reducer_Bindings
 
 let testMacro_ = (
   tester,
@@ -21,8 +21,8 @@ let testMacro_ = (
     expr
     ->Macro.expandMacroCall(
       bindings,
-      InternalExpressionValue.defaultEnvironment,
-      Expression.reduceExpression,
+      ProjectAccessorsT.identityAccessors,
+      Expression.reduceExpressionInProject,
     )
     ->ExpressionWithContext.toStringResult
     ->expect
@@ -41,8 +41,8 @@ let testMacroEval_ = (
     expr
     ->Macro.doMacroCall(
       bindings,
-      InternalExpressionValue.defaultEnvironment,
-      Expression.reduceExpression,
+      ProjectAccessorsT.identityAccessors,
+      Expression.reduceExpressionInProject,
     )
     ->InternalExpressionValue.toStringResult
     ->expect

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

@@ -8,7 +8,7 @@ open Jest
 open Expect
 
 let myIevEval = (aTypeSourceCode: string) =>
-  TypeCompile.ievFromTypeExpression(aTypeSourceCode, Expression.reduceExpression)
+  TypeCompile.ievFromTypeExpression(aTypeSourceCode, Expression.reduceExpressionInProject)
 let myIevEvalToString = (aTypeSourceCode: string) =>
   myIevEval(aTypeSourceCode)->InternalExpressionValue.toStringResult
 
@@ -19,7 +19,7 @@ let myIevTest = (test, aTypeSourceCode, answer) =>
   test(aTypeSourceCode, () => myIevExpectEqual(aTypeSourceCode, answer))
 
 let myTypeEval = (aTypeSourceCode: string) =>
-  TypeCompile.fromTypeExpression(aTypeSourceCode, Expression.reduceExpression)
+  TypeCompile.fromTypeExpression(aTypeSourceCode, Expression.reduceExpressionInProject)
 let myTypeEvalToString = (aTypeSourceCode: string) => myTypeEval(aTypeSourceCode)->T.toStringResult
 
 let myTypeExpectEqual = (aTypeSourceCode, answer) =>

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

@@ -1,8 +1,9 @@
+module Bindings = Reducer_Bindings
+module ErrorValue = Reducer_ErrorValue
 module Expression = Reducer_Expression
 module ExpressionT = Reducer_Expression_T
-module ErrorValue = Reducer_ErrorValue
 module InternalExpressionValue = ReducerInterface_InternalExpressionValue
-module Bindings = Reducer_Bindings
+module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
 module T = Reducer_Type_T
 module TypeChecker = Reducer_Type_TypeChecker
 
@@ -13,10 +14,10 @@ let checkArgumentsSourceCode = (aTypeSourceCode: string, sourceCode: string): re
   'v,
   ErrorValue.t,
 > => {
-  let reducerFn = Expression.reduceExpression
+  let reducerFn = Expression.reduceExpressionInProject
   let rResult =
-    Reducer.parse(sourceCode)->Belt.Result.flatMap(expr =>
-      reducerFn(expr, Bindings.emptyBindings, InternalExpressionValue.defaultEnvironment)
+    Expression.BackCompatible.parse(sourceCode)->Belt.Result.flatMap(expr =>
+      reducerFn(expr, Bindings.emptyBindings, ProjectAccessorsT.identityAccessors)
     )
   rResult->Belt.Result.flatMap(result =>
     switch result {

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

@@ -5,6 +5,7 @@ module InternalExpressionValue = ReducerInterface_InternalExpressionValue
 module Bindings = Reducer_Bindings
 module T = Reducer_Type_T
 module TypeChecker = Reducer_Type_TypeChecker
+module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
 
 open Jest
 open Expect
@@ -16,10 +17,10 @@ let isTypeOfSourceCode = (aTypeSourceCode: string, sourceCode: string): result<
   'v,
   ErrorValue.t,
 > => {
-  let reducerFn = Expression.reduceExpression
+  let reducerFn = Expression.reduceExpressionInProject
   let rResult =
-    Reducer.parse(sourceCode)->Belt.Result.flatMap(expr =>
-      reducerFn(expr, Bindings.emptyBindings, InternalExpressionValue.defaultEnvironment)
+    Expression.BackCompatible.parse(sourceCode)->Belt.Result.flatMap(expr =>
+      reducerFn(expr, Bindings.emptyBindings, ProjectAccessorsT.identityAccessors)
     )
   rResult->Belt.Result.flatMap(result => TypeChecker.isTypeOf(aTypeSourceCode, result, reducerFn))
 }

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

@@ -1,14 +0,0 @@
-open Jest
-open Reducer_TestHelpers
-
-describe("Eval with Bindings", () => {
-  testEvalBindingsToBe("x", list{("x", ExternalExpressionValue.EvNumber(1.))}, "Ok(1)")
-  testEvalBindingsToBe("x+1", list{("x", ExternalExpressionValue.EvNumber(1.))}, "Ok(2)")
-  testParseToBe("y = x+1; y", "Ok({(:$_let_$ :y {(:add :x 1)}); :y})")
-  testEvalBindingsToBe("y = x+1; y", list{("x", ExternalExpressionValue.EvNumber(1.))}, "Ok(2)")
-  testEvalBindingsToBe(
-    "y = x+1",
-    list{("x", ExternalExpressionValue.EvNumber(1.))},
-    "Ok(@{x: 1,y: 2})",
-  )
-})

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

@@ -2,8 +2,14 @@ open Jest
 open Reducer_TestHelpers
 
 describe("Parse function assignment", () => {
-  testParseToBe("f(x)=x", "Ok({(:$_let_$ :f (:$$_lambda_$$ [x] {:x}))})")
-  testParseToBe("f(x)=2*x", "Ok({(:$_let_$ :f (:$$_lambda_$$ [x] {(:multiply 2 :x)}))})")
+  testParseToBe(
+    "f(x)=x",
+    "Ok({(:$_let_$ :f (:$$_lambda_$$ [x] {:x})); (:$_endOfOuterBlock_$ () ())})",
+  )
+  testParseToBe(
+    "f(x)=2*x",
+    "Ok({(:$_let_$ :f (:$$_lambda_$$ [x] {(:multiply 2 :x)})); (:$_endOfOuterBlock_$ () ())})",
+  )
   //MathJs does not allow blocks in function definitions
 })
 

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

@@ -39,33 +39,27 @@ describe("symbol not defined", () => {
 })
 
 describe("call and bindings", () => {
-  testEvalToBe("f(x)=x+1", "Ok(@{f: lambda(x=>internal code)})")
+  testEvalToBe("f(x)=x+1; f(0)", "Ok(1)")
   testEvalToBe("f(x)=x+1; f(1)", "Ok(2)")
-  testEvalToBe("f=1;y=2", "Ok(@{f: 1,y: 2})")
-  testEvalToBe("f(x)=x+1; y=f(1)", "Ok(@{f: lambda(x=>internal code),y: 2})")
+  testEvalToBe("f=1;y=2", "Ok(())")
+  testEvalToBe("f(x)=x+1; y=f(1); y", "Ok(2)")
   testEvalToBe("f(x)=x+1; y=f(1); f(1)", "Ok(2)")
-  testEvalToBe("f(x)=x+1; y=f(1); z=f(1)", "Ok(@{f: lambda(x=>internal code),y: 2,z: 2})")
-  testEvalToBe(
-    "f(x)=x+1; g(x)=f(x)+1",
-    "Ok(@{f: lambda(x=>internal code),g: lambda(x=>internal code)})",
-  )
+  testEvalToBe("f(x)=x+1; y=f(1); z=f(1); z", "Ok(2)")
+  testEvalToBe("f(x)=x+1; g(x)=f(x)+1; g(0)", "Ok(2)")
   testParseToBe(
     "f=99; g(x)=f; g(2)",
-    "Ok({(:$_let_$ :f {99}); (:$_let_$ :g (:$$_lambda_$$ [x] {:f})); (:g 2)})",
+    "Ok({(:$_let_$ :f {99}); (:$_let_$ :g (:$$_lambda_$$ [x] {:f})); (:$_endOfOuterBlock_$ () (:g 2))})",
   )
   testEvalToBe("f=99; g(x)=f; g(2)", "Ok(99)")
   testEvalToBe("f(x)=x; g(x)=f(x); g(2)", "Ok(2)")
-  testEvalToBe(
-    "f(x)=x+1; g(x)=f(x)+1; y=g(2)",
-    "Ok(@{f: lambda(x=>internal code),g: lambda(x=>internal code),y: 4})",
-  )
+  testEvalToBe("f(x)=x+1; g(x)=f(x)+1; y=g(2); y", "Ok(4)")
   testEvalToBe("f(x)=x+1; g(x)=f(x)+1; g(2)", "Ok(4)")
 })
 
 describe("function tricks", () => {
   testEvalError("f(x)=f(y)=2; f(2)") //Error because chain assignment is not allowed
   testEvalToBe("y=2;g(x)=y+1;g(2)", "Ok(3)")
-  testEvalToBe("y=2;g(x)=inspect(y)+1", "Ok(@{g: lambda(x=>internal code),y: 2})")
+  testEvalToBe("y=2;g(x)=inspect(y)+1;y", "Ok(2)")
   MySkip.testEvalToBe("f(x) = x(x); f(f)", "????") // TODO: Infinite loop. Any solution? Catching proper exception or timeout?
   MySkip.testEvalToBe("f(x, x)=x+x; f(1,2)", "????") // TODO: Duplicate parameters
   testEvalToBe("myadd(x,y)=x+y; z=myadd; z", "Ok(lambda(x,y=>internal code))")
@@ -73,10 +67,7 @@ describe("function tricks", () => {
 })
 
 describe("lambda in structures", () => {
-  testEvalToBe(
-    "myadd(x,y)=x+y; z=[myadd]",
-    "Ok(@{myadd: lambda(x,y=>internal code),z: [lambda(x,y=>internal code)]})",
-  )
+  testEvalToBe("myadd(x,y)=x+y; z=[myadd]", "Ok(())")
   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)})")

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

@@ -2,7 +2,10 @@ open Jest
 open Reducer_TestHelpers
 
 describe("Parse ternary operator", () => {
-  testParseToBe("true ? 'YES' : 'NO'", "Ok({(:$$_ternary_$$ true 'YES' 'NO')})")
+  testParseToBe(
+    "true ? 'YES' : 'NO'",
+    "Ok({(:$_endOfOuterBlock_$ () (:$$_ternary_$$ true 'YES' 'NO'))})",
+  )
 })
 
 describe("Evaluate ternary operator", () => {

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

@@ -48,7 +48,7 @@ describe("eval", () => {
     testEvalToBe("x=1; y=x+1; y+1", "Ok(3)")
     testEvalError("1; x=1")
     testEvalError("1; 1")
-    testEvalToBe("x=1; x=1", "Ok(@{x: 1})")
+    testEvalToBe("x=1; x=1; x", "Ok(1)")
   })
 })
 

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

@@ -118,28 +118,40 @@ describe("eval on distribution functions", () => {
 
 describe("parse on distribution functions", () => {
   describe("power", () => {
-    testParse("normal(5,2) ^ normal(5,1)", "Ok({(:pow (:normal 5 2) (:normal 5 1))})")
-    testParse("3 ^ normal(5,1)", "Ok({(:pow 3 (:normal 5 1))})")
-    testParse("normal(5,2) ^ 3", "Ok({(:pow (:normal 5 2) 3)})")
+    testParse(
+      "normal(5,2) ^ normal(5,1)",
+      "Ok({(:$_endOfOuterBlock_$ () (:pow (:normal 5 2) (:normal 5 1)))})",
+    )
+    testParse("3 ^ normal(5,1)", "Ok({(:$_endOfOuterBlock_$ () (:pow 3 (:normal 5 1)))})")
+    testParse("normal(5,2) ^ 3", "Ok({(:$_endOfOuterBlock_$ () (:pow (:normal 5 2) 3))})")
   })
   describe("subtraction", () => {
-    testParse("10 - normal(5,1)", "Ok({(:subtract 10 (:normal 5 1))})")
-    testParse("normal(5,1) - 10", "Ok({(:subtract (:normal 5 1) 10)})")
+    testParse("10 - normal(5,1)", "Ok({(:$_endOfOuterBlock_$ () (:subtract 10 (:normal 5 1)))})")
+    testParse("normal(5,1) - 10", "Ok({(:$_endOfOuterBlock_$ () (: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((:$_endOfOuterBlock_$ () (:$$_block_$$ (:dotSubtract (:normal 5 2) (:normal 5 1)))))",
       // TODO: !!! returns "Ok({(:dotPow (:normal 5 2) (:normal 5 1))})"
     )
-    testParse("normal(5,2) .* normal(5,1)", "Ok({(:dotMultiply (:normal 5 2) (:normal 5 1))})")
-    testParse("normal(5,2) ./ normal(5,1)", "Ok({(:dotDivide (:normal 5 2) (:normal 5 1))})")
-    testParse("normal(5,2) .^ normal(5,1)", "Ok({(:dotPow (:normal 5 2) (:normal 5 1))})")
+    testParse(
+      "normal(5,2) .* normal(5,1)",
+      "Ok({(:$_endOfOuterBlock_$ () (:dotMultiply (:normal 5 2) (:normal 5 1)))})",
+    )
+    testParse(
+      "normal(5,2) ./ normal(5,1)",
+      "Ok({(:$_endOfOuterBlock_$ () (:dotDivide (:normal 5 2) (:normal 5 1)))})",
+    )
+    testParse(
+      "normal(5,2) .^ normal(5,1)",
+      "Ok({(:$_endOfOuterBlock_$ () (:dotPow (:normal 5 2) (:normal 5 1)))})",
+    )
   })
   describe("equality", () => {
-    testParse("5 == normal(5,2)", "Ok({(:equal 5 (:normal 5 2))})")
+    testParse("5 == normal(5,2)", "Ok({(:$_endOfOuterBlock_$ () (: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/__tests__/ReducerProject/ReducerProject_test.res

@@ -0,0 +1,179 @@
+@@warning("-44")
+module ExternalExpressionValue = ReducerInterface_ExternalExpressionValue
+module Project = ReducerProject
+module Bindings = Reducer_Bindings
+module Continuation = ReducerInterface_Value_Continuation
+
+open Jest
+open Expect
+open Expect.Operators
+
+// test("", () => expect(1)->toBe(1))
+
+let runFetchResult = (project, sourceId) => {
+  Project.run(project, sourceId)
+  Project.getExternalResult(project, sourceId)->ExternalExpressionValue.toStringOptionResult
+}
+
+let runFetchBindings = (project, sourceId) => {
+  Project.run(project, sourceId)
+  Project.getExternalBindings(project, sourceId)
+  ->ExternalExpressionValue.EvModule
+  ->ExternalExpressionValue.toString
+}
+
+test("setting continuation", () => {
+  let project = Project.createProject()
+  let privateProject = project->Project.T.Private.castToInternalProject
+  let sampleBindings = Bindings.emptyBindings->Bindings.set("test", IEvVoid)
+  Project.Private.setContinuation(privateProject, "main", sampleBindings)
+  let answer = Project.Private.getContinuation(privateProject, "main")
+  expect(answer)->toBe(sampleBindings)
+})
+
+test("test result true", () => {
+  let project = Project.createProject()
+  Project.setSource(project, "main", "true")
+  runFetchResult(project, "main")->expect->toBe("Ok(true)")
+})
+
+test("test result false", () => {
+  let project = Project.createProject()
+  Project.setSource(project, "main", "false")
+  runFetchResult(project, "main")->expect->toBe("Ok(false)")
+})
+
+test("test library", () => {
+  let project = Project.createProject()
+  Project.setSource(project, "main", "x=Math.pi; x")
+  runFetchResult(project, "main")->expect->toBe("Ok(3.141592653589793)")
+})
+
+test("test bindings", () => {
+  let project = Project.createProject()
+  Project.setSource(project, "variables", "myVariable=666")
+  runFetchBindings(project, "variables")->expect->toBe("@{myVariable: 666}")
+})
+
+describe("project1", () => {
+  let project = Project.createProject()
+  Project.setSource(project, "first", "x=1")
+  Project.setSource(project, "main", "x")
+  Project.setContinues(project, "main", ["first"])
+
+  test("runOrder", () => {
+    expect(Project.getRunOrder(project)) == ["first", "main"]
+  })
+  test("dependents first", () => {
+    expect(Project.getDependents(project, "first")) == ["main"]
+  })
+  test("dependencies first", () => {
+    expect(Project.getDependencies(project, "first")) == []
+  })
+  test("dependents main", () => {
+    expect(Project.getDependents(project, "main")) == []
+  })
+  test("dependencies main", () => {
+    expect(Project.getDependencies(project, "main")) == ["first"]
+  })
+  test("test result", () => {
+    runFetchResult(project, "main")->expect->toBe("Ok(1)")
+  })
+  test("test bindings", () => {
+    runFetchBindings(project, "main")->expect->toBe("@{x: 1}")
+  })
+})
+
+describe("project2", () => {
+  let project = Project.createProject()
+  Project.setContinues(project, "main", ["second"])
+  Project.setContinues(project, "second", ["first"])
+  Project.setSource(project, "first", "x=1")
+  Project.setSource(project, "second", "y=2")
+  Project.setSource(project, "main", "y")
+
+  test("runOrder", () => {
+    expect(Project.getRunOrder(project)) == ["first", "second", "main"]
+  })
+  test("runOrderFor", () => {
+    expect(Project.getRunOrderFor(project, "first")) == ["first"]
+  })
+  test("dependencies first", () => {
+    expect(Project.getDependencies(project, "first")) == []
+  })
+  test("dependents first", () => {
+    expect(Project.getDependents(project, "first")) == ["second", "main"]
+  })
+  test("dependents main", () => {
+    expect(Project.getDependents(project, "main")) == []
+  })
+  test("dependencies main", () => {
+    expect(Project.getDependencies(project, "main")) == ["first", "second"]
+  })
+  test("test result", () => {
+    runFetchResult(project, "main")->expect->toBe("Ok(2)")
+  })
+  test("test bindings", () => {
+    runFetchBindings(project, "main")->expect->toBe("@{x: 1,y: 2}")
+  })
+})
+
+describe("project with include", () => {
+  let project = Project.createProject()
+  Project.setContinues(project, "main", ["second"])
+  Project.setContinues(project, "second", ["first"])
+
+  Project.setSource(
+    project,
+    "first",
+    `
+  #include 'common'
+  x=1`,
+  )
+  Project.parseIncludes(project, "first")
+  Project.parseIncludes(project, "first") //The only way of setting includes
+  //Don't forget to parse includes after changing the source
+
+  Project.setSource(project, "common", "common=0")
+  Project.setSource(
+    project,
+    "second",
+    `
+  #include 'common'
+  y=2`,
+  )
+  Project.parseIncludes(project, "second") //The only way of setting includes
+
+  Project.setSource(project, "main", "y")
+
+  test("runOrder", () => {
+    expect(Project.getRunOrder(project)) == ["common", "first", "second", "main"]
+  })
+
+  test("runOrderFor", () => {
+    expect(Project.getRunOrderFor(project, "first")) == ["common", "first"]
+  })
+
+  test("dependencies first", () => {
+    expect(Project.getDependencies(project, "first")) == ["common"]
+  })
+  test("dependents first", () => {
+    expect(Project.getDependents(project, "first")) == ["second", "main"]
+  })
+  test("dependents main", () => {
+    expect(Project.getDependents(project, "main")) == []
+  })
+  test("dependencies main", () => {
+    expect(Project.getDependencies(project, "main")) == ["common", "first", "second"]
+  })
+  test("test result", () => {
+    runFetchResult(project, "main")->expect->toBe("Ok(2)")
+  })
+  test("test bindings", () => {
+    runFetchBindings(project, "main")->expect->toBe("@{common: 0,x: 1,y: 2}")
+  })
+})
+
+// test bindings
+//TODO: test continues
+//TODO: test include

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

@@ -2,8 +2,12 @@ open Jest
 open Expect
 open Reducer_TestHelpers
 
-let expectEvalToBeOk = (expr: string) =>
-  Reducer.evaluate(expr)->Reducer_Helpers.rRemoveDefaultsExternal->E.R.isOk->expect->toBe(true)
+let expectEvalToBeOk = (code: string) =>
+  Reducer_Expression.BackCompatible.evaluateStringAsExternal(code)
+  ->Reducer_Helpers.rRemoveDefaultsExternal
+  ->E.R.isOk
+  ->expect
+  ->toBe(true)
 
 let registry = FunctionRegistry_Library.registry
 let examples = E.A.to_list(FunctionRegistry_Core.Registry.allExamples(registry))
@@ -88,7 +92,7 @@ describe("FunctionRegistry Library", () => {
       ((fn, example)) => {
         let responseType =
           example
-          ->Reducer.evaluate
+          ->Reducer_Expression.BackCompatible.evaluateStringAsExternal
           ->E.R2.fmap(ReducerInterface_InternalExpressionValue.externalValueToValueType)
         let expectedOutputType = fn.output |> E.O.toExn("")
         expect(responseType)->toEqual(Ok(expectedOutputType))

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

@@ -1,3 +1,5 @@
+module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
+module ProjectReducerFnT = ReducerProject_ReducerFn_T
 type internalExpressionValue = ReducerInterface_InternalExpressionValue.t
 type internalExpressionValueType = ReducerInterface_InternalExpressionValue.internalExpressionValueType
 
@@ -46,8 +48,8 @@ type fnDefinition = {
   run: (
     array<internalExpressionValue>,
     array<frValue>,
-    GenericDist.env,
-    Reducer_Expression_T.reducerFn,
+    ProjectAccessorsT.t,
+    ProjectReducerFnT.t,
   ) => result<internalExpressionValue, string>,
 }
 
@@ -382,12 +384,12 @@ module FnDefinition = {
   let run = (
     t: t,
     args: array<internalExpressionValue>,
-    env: GenericDist.env,
-    reducer: Reducer_Expression_T.reducerFn,
+    accessors: ProjectAccessorsT.t,
+    reducer: ProjectReducerFnT.t,
   ) => {
     let argValues = FRType.matchWithExpressionValueArray(t.inputs, args)
     switch argValues {
-    | Some(values) => t.run(args, values, env, reducer)
+    | Some(values) => t.run(args, values, accessors, reducer)
     | None => Error("Incorrect Types")
     }
   }
@@ -493,8 +495,8 @@ module Registry = {
     ~registry: registry,
     ~fnName: string,
     ~args: array<internalExpressionValue>,
-    ~env: GenericDist.env,
-    ~reducer: Reducer_Expression_T.reducerFn,
+    ~accessors: ProjectAccessorsT.t,
+    ~reducer: ProjectReducerFnT.t,
   ) => {
     let relevantFunctions = Js.Dict.get(registry.fnNameDict, fnName) |> E.O.default([])
     let modified = {functions: relevantFunctions, fnNameDict: registry.fnNameDict}
@@ -512,7 +514,7 @@ module Registry = {
 
     switch Matcher.Registry.findMatches(modified, fnName, args) {
     | Matcher.Match.FullMatch(match) =>
-      match->matchToDef->E.O2.fmap(FnDefinition.run(_, args, env, reducer))
+      match->matchToDef->E.O2.fmap(FnDefinition.run(_, args, accessors, reducer))
     | SameNameDifferentArguments(m) => Some(Error(showNameMatchDefinitions(m)))
     | _ => None
     }
@@ -521,10 +523,10 @@ module Registry = {
   let dispatch = (
     registry,
     (fnName, args): ReducerInterface_InternalExpressionValue.functionCall,
-    env,
-    reducer: Reducer_Expression_T.reducerFn,
+    accessors: ProjectAccessorsT.t,
+    reducer: ProjectReducerFnT.t,
   ) => {
-    _matchAndRun(~registry, ~fnName, ~args, ~env, ~reducer)->E.O2.fmap(
+    _matchAndRun(~registry, ~fnName, ~args, ~accessors, ~reducer)->E.O2.fmap(
       E.R2.errMap(_, s => Reducer_ErrorValue.RETodo(s)),
     )
   }

packages/squiggle-lang/src/rescript/FunctionRegistry/Library/FR_Dist.res

@@ -21,8 +21,8 @@ module DistributionCreation = {
       FnDefinition.make(
         ~name,
         ~inputs=[FRTypeDistOrNumber, FRTypeDistOrNumber],
-        ~run=(_, inputs, env, _) =>
-          inputs->Prepare.ToValueTuple.twoDistOrNumber->process(~fn, ~env),
+        ~run=(_, inputs, accessors, _) =>
+          inputs->Prepare.ToValueTuple.twoDistOrNumber->process(~fn, ~env=accessors.environment),
         (),
       )
     }
@@ -31,8 +31,10 @@ module DistributionCreation = {
       FnDefinition.make(
         ~name,
         ~inputs=[FRTypeRecord([("p5", FRTypeDistOrNumber), ("p95", FRTypeDistOrNumber)])],
-        ~run=(_, inputs, env, _) =>
-          inputs->Prepare.ToValueTuple.Record.twoDistOrNumber->process(~fn, ~env),
+        ~run=(_, inputs, accessors, _) =>
+          inputs
+          ->Prepare.ToValueTuple.Record.twoDistOrNumber
+          ->process(~fn, ~env=accessors.environment),
         (),
       )
     }
@@ -41,8 +43,10 @@ module DistributionCreation = {
       FnDefinition.make(
         ~name,
         ~inputs=[FRTypeRecord([("mean", FRTypeDistOrNumber), ("stdev", FRTypeDistOrNumber)])],
-        ~run=(_, inputs, env, _) =>
-          inputs->Prepare.ToValueTuple.Record.twoDistOrNumber->process(~fn, ~env),
+        ~run=(_, inputs, accessors, _) =>
+          inputs
+          ->Prepare.ToValueTuple.Record.twoDistOrNumber
+          ->process(~fn, ~env=accessors.environment),
         (),
       )
     }
@@ -58,8 +62,8 @@ module DistributionCreation = {
       FnDefinition.make(
         ~name,
         ~inputs=[FRTypeDistOrNumber],
-        ~run=(_, inputs, env, _) =>
-          inputs->Prepare.ToValueTuple.oneDistOrNumber->process(~fn, ~env),
+        ~run=(_, inputs, accessors, _) =>
+          inputs->Prepare.ToValueTuple.oneDistOrNumber->process(~fn, ~env=accessors.environment),
         (),
       )
   }

packages/squiggle-lang/src/rescript/FunctionRegistry/Library/FR_List.res

@@ -1,3 +1,6 @@
+// module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
+// module ProjectReducerFnT = ReducerProject_ReducerFn_T
+
 open FunctionRegistry_Core
 open FunctionRegistry_Helpers
 
@@ -24,17 +27,19 @@ module Internals = {
     Belt.Array.reverse(array),
   )
 
-  let map = (array: array<internalExpressionValue>, environment, eLambdaValue, reducer): result<
-    ReducerInterface_InternalExpressionValue.t,
-    Reducer_ErrorValue.errorValue,
-  > => {
+  let map = (
+    array: array<internalExpressionValue>,
+    accessors: ProjectAccessorsT.t,
+    eLambdaValue,
+    reducer: ProjectReducerFnT.t,
+  ): result<ReducerInterface_InternalExpressionValue.t, Reducer_ErrorValue.errorValue> => {
     let rMappedList = array->E.A.reduceReverse(Ok(list{}), (rAcc, elem) =>
       rAcc->E.R.bind(_, acc => {
         let rNewElem = Reducer_Expression_Lambda.doLambdaCall(
           eLambdaValue,
           list{elem},
-          environment,
-          reducer,
+          (accessors: ProjectAccessorsT.t),
+          (reducer: ProjectReducerFnT.t),
         )
         rNewElem->E.R2.fmap(newElem => list{newElem, ...acc})
       })
@@ -42,29 +47,46 @@ module Internals = {
     rMappedList->E.R2.fmap(mappedList => mappedList->Belt.List.toArray->Wrappers.evArray)
   }
 
-  let reduce = (aValueArray, initialValue, aLambdaValue, environment, reducer) => {
+  let reduce = (
+    aValueArray,
+    initialValue,
+    aLambdaValue,
+    accessors: ProjectAccessorsT.t,
+    reducer: ProjectReducerFnT.t,
+  ) => {
     aValueArray->E.A.reduce(Ok(initialValue), (rAcc, elem) =>
       rAcc->E.R.bind(_, acc =>
-        Reducer_Expression_Lambda.doLambdaCall(aLambdaValue, list{acc, elem}, environment, reducer)
+        Reducer_Expression_Lambda.doLambdaCall(aLambdaValue, list{acc, elem}, accessors, reducer)
       )
     )
   }
 
-  let reduceReverse = (aValueArray, initialValue, aLambdaValue, environment, reducer) => {
+  let reduceReverse = (
+    aValueArray,
+    initialValue,
+    aLambdaValue,
+    accessors: ProjectAccessorsT.t,
+    reducer: ProjectReducerFnT.t,
+  ) => {
     aValueArray->Belt.Array.reduceReverse(Ok(initialValue), (rAcc, elem) =>
       rAcc->Belt.Result.flatMap(acc =>
-        Reducer_Expression_Lambda.doLambdaCall(aLambdaValue, list{acc, elem}, environment, reducer)
+        Reducer_Expression_Lambda.doLambdaCall(aLambdaValue, list{acc, elem}, accessors, reducer)
       )
     )
   }
 
-  let filter = (aValueArray, aLambdaValue, environment, reducer) => {
+  let filter = (
+    aValueArray,
+    aLambdaValue,
+    accessors: ProjectAccessorsT.t,
+    reducer: ProjectReducerFnT.t,
+  ) => {
     let rMappedList = aValueArray->Belt.Array.reduceReverse(Ok(list{}), (rAcc, elem) =>
       rAcc->E.R.bind(_, acc => {
         let rNewElem = Reducer_Expression_Lambda.doLambdaCall(
           aLambdaValue,
           list{elem},
-          environment,
+          accessors,
           reducer,
         )
         rNewElem->E.R2.fmap(newElem => {
@@ -189,10 +211,10 @@ let library = [
       FnDefinition.make(
         ~name="map",
         ~inputs=[FRTypeArray(FRTypeAny), FRTypeLambda],
-        ~run=(inputs, _, env, reducer) =>
+        ~run=(inputs, _, accessors: ProjectAccessorsT.t, reducer) =>
           switch inputs {
           | [IEvArray(array), IEvLambda(lambda)] =>
-            Internals.map(array, env, lambda, reducer)->E.R2.errMap(_ => "Error!")
+            Internals.map(array, accessors, lambda, reducer)->E.R2.errMap(_ => "Error!")
           | _ => Error(impossibleError)
           },
         (),
@@ -209,10 +231,12 @@ let library = [
       FnDefinition.make(
         ~name="reduce",
         ~inputs=[FRTypeArray(FRTypeAny), FRTypeAny, FRTypeLambda],
-        ~run=(inputs, _, env, reducer) =>
+        ~run=(inputs, _, accessors: ProjectAccessorsT.t, reducer) =>
           switch inputs {
           | [IEvArray(array), initialValue, IEvLambda(lambda)] =>
-            Internals.reduce(array, initialValue, lambda, env, reducer)->E.R2.errMap(_ => "Error!")
+            Internals.reduce(array, initialValue, lambda, accessors, reducer)->E.R2.errMap(_ =>
+              "Error!"
+            )
           | _ => Error(impossibleError)
           },
         (),
@@ -229,12 +253,16 @@ let library = [
       FnDefinition.make(
         ~name="reduceReverse",
         ~inputs=[FRTypeArray(FRTypeAny), FRTypeAny, FRTypeLambda],
-        ~run=(inputs, _, env, reducer) =>
+        ~run=(inputs, _, accessors: ProjectAccessorsT.t, reducer: ProjectReducerFnT.t) =>
           switch inputs {
           | [IEvArray(array), initialValue, IEvLambda(lambda)] =>
-            Internals.reduceReverse(array, initialValue, lambda, env, reducer)->E.R2.errMap(_ =>
-              "Error!"
-            )
+            Internals.reduceReverse(
+              array,
+              initialValue,
+              lambda,
+              accessors,
+              reducer,
+            )->E.R2.errMap(_ => "Error!")
           | _ => Error(impossibleError)
           },
         (),
@@ -251,10 +279,10 @@ let library = [
       FnDefinition.make(
         ~name="filter",
         ~inputs=[FRTypeArray(FRTypeAny), FRTypeLambda],
-        ~run=(inputs, _, env, reducer) =>
+        ~run=(inputs, _, accessors: ProjectAccessorsT.t, reducer: ProjectReducerFnT.t) =>
           switch inputs {
           | [IEvArray(array), IEvLambda(lambda)] =>
-            Internals.filter(array, lambda, env, reducer)->E.R2.errMap(_ => "Error!")
+            Internals.filter(array, lambda, accessors, reducer)->E.R2.errMap(_ => "Error!")
           | _ => Error(impossibleError)
           },
         (),

packages/squiggle-lang/src/rescript/FunctionRegistry/Library/FR_Pointset.res

@@ -34,13 +34,13 @@ let library = [
       FnDefinition.make(
         ~name="fromDist",
         ~inputs=[FRTypeDist],
-        ~run=(_, inputs, env, _) =>
+        ~run=(_, inputs, accessors, _) =>
           switch inputs {
           | [FRValueDist(dist)] =>
             GenericDist.toPointSet(
               dist,
-              ~xyPointLength=env.xyPointLength,
-              ~sampleCount=env.sampleCount,
+              ~xyPointLength=accessors.environment.xyPointLength,
+              ~sampleCount=accessors.environment.sampleCount,
               (),
             )
             ->E.R2.fmap(Wrappers.pointSet)

packages/squiggle-lang/src/rescript/FunctionRegistry/Library/FR_Sampleset.res

@@ -1,3 +1,5 @@
+// module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
+// module ProjectReducerFnT = ReducerProject_ReducerFn_T
 open FunctionRegistry_Core
 open FunctionRegistry_Helpers
 
@@ -6,8 +8,14 @@ let requiresNamespace = true
 
 module Internal = {
   type t = SampleSetDist.t
-  let doLambdaCall = (aLambdaValue, list, environment, reducer) =>
-    switch Reducer_Expression_Lambda.doLambdaCall(aLambdaValue, list, environment, reducer) {
+
+  let doLambdaCall = (
+    aLambdaValue,
+    list,
+    accessors: ProjectAccessorsT.t,
+    reducer: ProjectReducerFnT.t,
+  ) =>
+    switch Reducer_Expression_Lambda.doLambdaCall(aLambdaValue, list, accessors, reducer) {
     | Ok(IEvNumber(f)) => Ok(f)
     | _ => Error(Operation.SampleMapNeedsNtoNFunction)
     }
@@ -22,29 +30,26 @@ module Internal = {
     }
 
   //TODO: I don't know why this seems to need at least one input
-  let fromFn = (
-    aLambdaValue,
-    env: ReducerInterface_InternalExpressionValue.environment,
-    reducer,
-  ) => {
-    let sampleCount = env.sampleCount
-    let fn = r => doLambdaCall(aLambdaValue, list{IEvNumber(r)}, env, reducer)
+  let fromFn = (aLambdaValue, accessors: ProjectAccessorsT.t, reducer: ProjectReducerFnT.t) => {
+    let sampleCount = accessors.environment.sampleCount
+    let fn = r => doLambdaCall(aLambdaValue, list{IEvNumber(r)}, accessors, reducer)
     Belt_Array.makeBy(sampleCount, r => fn(r->Js.Int.toFloat))->E.A.R.firstErrorOrOpen
   }
 
-  let map1 = (sampleSetDist: t, aLambdaValue, env, reducer) => {
-    let fn = r => doLambdaCall(aLambdaValue, list{IEvNumber(r)}, env, reducer)
+  let map1 = (sampleSetDist: t, aLambdaValue, accessors: ProjectAccessorsT.t, reducer) => {
+    let fn = r => doLambdaCall(aLambdaValue, list{IEvNumber(r)}, accessors, reducer)
     SampleSetDist.samplesMap(~fn, sampleSetDist)->toType
   }
 
-  let map2 = (t1: t, t2: t, aLambdaValue, env, reducer) => {
-    let fn = (a, b) => doLambdaCall(aLambdaValue, list{IEvNumber(a), IEvNumber(b)}, env, reducer)
+  let map2 = (t1: t, t2: t, aLambdaValue, accessors: ProjectAccessorsT.t, reducer) => {
+    let fn = (a, b) =>
+      doLambdaCall(aLambdaValue, list{IEvNumber(a), IEvNumber(b)}, accessors, reducer)
     SampleSetDist.map2(~fn, ~t1, ~t2)->toType
   }
 
-  let map3 = (t1: t, t2: t, t3: t, aLambdaValue, env, reducer) => {
+  let map3 = (t1: t, t2: t, t3: t, aLambdaValue, accessors: ProjectAccessorsT.t, reducer) => {
     let fn = (a, b, c) =>
-      doLambdaCall(aLambdaValue, list{IEvNumber(a), IEvNumber(b), IEvNumber(c)}, env, reducer)
+      doLambdaCall(aLambdaValue, list{IEvNumber(a), IEvNumber(b), IEvNumber(c)}, accessors, reducer)
     SampleSetDist.map3(~fn, ~t1, ~t2, ~t3)->toType
   }
 
@@ -59,14 +64,19 @@ module Internal = {
     E.A.O.openIfAllSome(E.A.fmap(parseSampleSet, arr))
   }
 
-  let mapN = (aValueArray: array<internalExpressionValue>, aLambdaValue, env, reducer) => {
+  let mapN = (
+    aValueArray: array<internalExpressionValue>,
+    aLambdaValue,
+    accessors: ProjectAccessorsT.t,
+    reducer,
+  ) => {
     switch parseSampleSetArray(aValueArray) {
     | Some(t1) =>
       let fn = a =>
         doLambdaCall(
           aLambdaValue,
           list{IEvArray(E.A.fmap(x => Wrappers.evNumber(x), a))},
-          env,
+          accessors,
           reducer,
         )
       SampleSetDist.mapN(~fn, ~t1)->toType
@@ -86,10 +96,10 @@ let library = [
       FnDefinition.make(
         ~name="fromDist",
         ~inputs=[FRTypeDist],
-        ~run=(_, inputs, env, _) =>
+        ~run=(_, inputs, accessors: ProjectAccessorsT.t, _) =>
           switch inputs {
           | [FRValueDist(dist)] =>
-            GenericDist.toSampleSetDist(dist, env.sampleCount)
+            GenericDist.toSampleSetDist(dist, accessors.environment.sampleCount)
             ->E.R2.fmap(Wrappers.sampleSet)
             ->E.R2.fmap(Wrappers.evDistribution)
             ->E.R2.errMap(_ => "")
@@ -153,10 +163,10 @@ let library = [
       FnDefinition.make(
         ~name="fromFn",
         ~inputs=[FRTypeLambda],
-        ~run=(inputs, _, env, reducer) =>
+        ~run=(inputs, _, accessors: ProjectAccessorsT.t, reducer: ProjectReducerFnT.t) =>
           switch inputs {
           | [IEvLambda(lambda)] =>
-            switch Internal.fromFn(lambda, env, reducer) {
+            switch Internal.fromFn(lambda, accessors, reducer) {
             | Ok(r) => Ok(r->Wrappers.sampleSet->Wrappers.evDistribution)
             | Error(_) => Error("issue")
             }
@@ -177,10 +187,10 @@ let library = [
       FnDefinition.make(
         ~name="map",
         ~inputs=[FRTypeDist, FRTypeLambda],
-        ~run=(inputs, _, env, reducer) =>
+        ~run=(inputs, _, accessors: ProjectAccessorsT.t, reducer) =>
           switch inputs {
           | [IEvDistribution(SampleSet(dist)), IEvLambda(lambda)] =>
-            Internal.map1(dist, lambda, env, reducer)->E.R2.errMap(_ => "")
+            Internal.map1(dist, lambda, accessors, reducer)->E.R2.errMap(_ => "")
           | _ => Error(impossibleError)
           },
         (),
@@ -200,14 +210,14 @@ let library = [
       FnDefinition.make(
         ~name="map2",
         ~inputs=[FRTypeDist, FRTypeDist, FRTypeLambda],
-        ~run=(inputs, _, env, reducer) => {
+        ~run=(inputs, _, accessors: ProjectAccessorsT.t, reducer) => {
           switch inputs {
           | [
               IEvDistribution(SampleSet(dist1)),
               IEvDistribution(SampleSet(dist2)),
               IEvLambda(lambda),
             ] =>
-            Internal.map2(dist1, dist2, lambda, env, reducer)->E.R2.errMap(_ => "")
+            Internal.map2(dist1, dist2, lambda, accessors, reducer)->E.R2.errMap(_ => "")
           | _ => Error(impossibleError)
           }
         },
@@ -228,7 +238,7 @@ let library = [
       FnDefinition.make(
         ~name="map3",
         ~inputs=[FRTypeDist, FRTypeDist, FRTypeDist, FRTypeLambda],
-        ~run=(inputs, _, env, reducer) =>
+        ~run=(inputs, _, accessors: ProjectAccessorsT.t, reducer) =>
           switch inputs {
           | [
               IEvDistribution(SampleSet(dist1)),
@@ -236,7 +246,7 @@ let library = [
               IEvDistribution(SampleSet(dist3)),
               IEvLambda(lambda),
             ] =>
-            Internal.map3(dist1, dist2, dist3, lambda, env, reducer)->E.R2.errMap(_ => "")
+            Internal.map3(dist1, dist2, dist3, lambda, accessors, reducer)->E.R2.errMap(_ => "")
           | _ => Error(impossibleError)
           },
         (),
@@ -256,10 +266,10 @@ let library = [
       FnDefinition.make(
         ~name="mapN",
         ~inputs=[FRTypeArray(FRTypeDist), FRTypeLambda],
-        ~run=(inputs, _, env, reducer) =>
+        ~run=(inputs, _, accessors: ProjectAccessorsT.t, reducer) =>
           switch inputs {
           | [IEvArray(dists), IEvLambda(lambda)] =>
-            Internal.mapN(dists, lambda, env, reducer)->E.R2.errMap(_e => {
+            Internal.mapN(dists, lambda, accessors, reducer)->E.R2.errMap(_e => {
               "AHHH doesn't work"
             })
           | _ => Error(impossibleError)

packages/squiggle-lang/src/rescript/FunctionRegistry/Library/FR_Scoring.res

@@ -30,16 +30,16 @@ let library = [
             ("prior", FRTypeDist),
           ]),
         ],
-        ~run=(_, inputs, env, _) => {
+        ~run=(_, inputs, accessors, _) => {
           switch FunctionRegistry_Helpers.Prepare.ToValueArray.Record.threeArgs(inputs) {
           | Ok([FRValueDist(estimate), FRValueDistOrNumber(FRValueDist(d)), FRValueDist(prior)]) =>
-            runScoring(estimate, Score_Dist(d), Some(prior), env)
+            runScoring(estimate, Score_Dist(d), Some(prior), accessors.environment)
           | Ok([
               FRValueDist(estimate),
               FRValueDistOrNumber(FRValueNumber(d)),
               FRValueDist(prior),
             ]) =>
-            runScoring(estimate, Score_Scalar(d), Some(prior), env)
+            runScoring(estimate, Score_Scalar(d), Some(prior), accessors.environment)
           | Error(e) => Error(e)
           | _ => Error(FunctionRegistry_Helpers.impossibleError)
           }
@@ -49,12 +49,12 @@ let library = [
       FnDefinition.make(
         ~name="logScore",
         ~inputs=[FRTypeRecord([("estimate", FRTypeDist), ("answer", FRTypeDistOrNumber)])],
-        ~run=(_, inputs, env, _) => {
+        ~run=(_, inputs, accessors, _) => {
           switch FunctionRegistry_Helpers.Prepare.ToValueArray.Record.twoArgs(inputs) {
           | Ok([FRValueDist(estimate), FRValueDistOrNumber(FRValueDist(d))]) =>
-            runScoring(estimate, Score_Dist(d), None, env)
+            runScoring(estimate, Score_Dist(d), None, accessors.environment)
           | Ok([FRValueDist(estimate), FRValueDistOrNumber(FRValueNumber(d))]) =>
-            runScoring(estimate, Score_Scalar(d), None, env)
+            runScoring(estimate, Score_Scalar(d), None, accessors.environment)
           | Error(e) => Error(e)
           | _ => Error(FunctionRegistry_Helpers.impossibleError)
           }
@@ -74,10 +74,10 @@ let library = [
       FnDefinition.make(
         ~name="klDivergence",
         ~inputs=[FRTypeDist, FRTypeDist],
-        ~run=(_, inputs, env, _) => {
+        ~run=(_, inputs, accessors, _) => {
           switch inputs {
           | [FRValueDist(estimate), FRValueDist(d)] =>
-            runScoring(estimate, Score_Dist(d), None, env)
+            runScoring(estimate, Score_Dist(d), None, accessors.environment)
           | _ => Error(FunctionRegistry_Helpers.impossibleError)
           }
         },

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

@@ -1,8 +1,6 @@
 module ErrorValue = Reducer_ErrorValue
 module Expression = Reducer_Expression
 module ExternalExpressionValue = ReducerInterface_ExternalExpressionValue
-module InternalExpressionValue = ReducerInterface_InternalExpressionValue
-module Lambda = Reducer_Expression_Lambda
 
 type environment = ReducerInterface_InternalExpressionValue.environment
 type errorValue = Reducer_ErrorValue.errorValue
@@ -10,26 +8,10 @@ type expressionValue = ExternalExpressionValue.t
 type externalBindings = ReducerInterface_ExternalExpressionValue.externalBindings
 type lambdaValue = ExternalExpressionValue.lambdaValue
 
-let evaluate = Expression.evaluate
-let evaluateUsingOptions = Expression.evaluateUsingOptions
-let evaluatePartialUsingExternalBindings = Expression.evaluatePartialUsingExternalBindings
-let parse = Expression.parse
-
-let foreignFunctionInterface = (
-  lambdaValue: ExternalExpressionValue.lambdaValue,
-  argArray: array<expressionValue>,
-  environment: ExternalExpressionValue.environment,
-) => {
-  let internallambdaValue = InternalExpressionValue.lambdaValueToInternal(lambdaValue)
-  let internalArgArray = argArray->Js.Array2.map(InternalExpressionValue.toInternal)
-  Lambda.foreignFunctionInterface(
-    internallambdaValue,
-    internalArgArray,
-    environment,
-    Expression.reduceExpression,
-  )->Belt.Result.map(InternalExpressionValue.toExternal)
-}
+/*
+  Use Reducer_Project instead 
+*/
 
 let defaultEnvironment = ExternalExpressionValue.defaultEnvironment
 
-let defaultExternalBindings = ReducerInterface_StdLib.externalStdLib
+// let defaultExternalBindings = ReducerInterface_StdLib.externalStdLib

packages/squiggle-lang/src/rescript/Reducer/Reducer.resi

@@ -1,7 +1,7 @@
 module ErrorValue = Reducer_ErrorValue
 module Expression = Reducer_Expression
 
-@genType
+@genType0
 type environment = ReducerInterface_ExternalExpressionValue.environment
 @genType
 type errorValue = Reducer_ErrorValue.errorValue
@@ -12,34 +12,34 @@ type externalBindings = ReducerInterface_ExternalExpressionValue.externalBinding
 @genType
 type lambdaValue = ReducerInterface_ExternalExpressionValue.lambdaValue
 
-@genType
-let evaluateUsingOptions: (
-  ~environment: option<QuriSquiggleLang.ReducerInterface_ExternalExpressionValue.environment>,
-  ~externalBindings: option<
-    QuriSquiggleLang.ReducerInterface_ExternalExpressionValue.externalBindings,
-  >,
-  string,
-) => result<expressionValue, errorValue>
-@genType
-let evaluatePartialUsingExternalBindings: (
-  string,
-  QuriSquiggleLang.ReducerInterface_ExternalExpressionValue.externalBindings,
-  QuriSquiggleLang.ReducerInterface_ExternalExpressionValue.environment,
-) => result<externalBindings, errorValue>
-@genType
-let evaluate: string => result<expressionValue, errorValue>
+// @genType
+// let evaluateUsingOptions: (
+//   ~environment: option<QuriSquiggleLang.ReducerInterface_ExternalExpressionValue.environment>,
+//   ~externalBindings: option<
+//     QuriSquiggleLang.ReducerInterface_ExternalExpressionValue.externalBindings,
+//   >,
+//   string,
+// ) => result<expressionValue, errorValue>
+// @genType
+// let evaluatePartialUsingExternalBindings: (
+//   string,
+//   QuriSquiggleLang.ReducerInterface_ExternalExpressionValue.externalBindings,
+//   QuriSquiggleLang.ReducerInterface_ExternalExpressionValue.environment,
+// ) => result<externalBindings, errorValue>
+// @genType
+// let evaluate: string => result<expressionValue, errorValue>
 
-let parse: string => result<Expression.expression, errorValue>
+// let parse: string => result<Expression.t, errorValue>
 
-@genType
-let foreignFunctionInterface: (
-  QuriSquiggleLang.ReducerInterface_ExternalExpressionValue.lambdaValue,
-  array<QuriSquiggleLang.ReducerInterface_ExternalExpressionValue.t>,
-  QuriSquiggleLang.ReducerInterface_ExternalExpressionValue.environment,
-) => result<expressionValue, errorValue>
+// @genType
+// let foreignFunctionInterface: (
+//   QuriSquiggleLang.ReducerInterface_ExternalExpressionValue.lambdaValue,
+//   array<QuriSquiggleLang.ReducerInterface_ExternalExpressionValue.t>,
+//   QuriSquiggleLang.ReducerInterface_ExternalExpressionValue.environment,
+// ) => result<expressionValue, errorValue>
 
 @genType
 let defaultEnvironment: environment
 
-@genType
-let defaultExternalBindings: externalBindings
+// @genType
+// let defaultExternalBindings: externalBindings

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

@@ -74,6 +74,7 @@ let set = (nameSpace: t, id: string, value): t => {
 
 let emptyModule: t = NameSpace(emptyMap)
 let emptyBindings = emptyModule
+let emptyNameSpace = emptyModule
 
 let fromTypeScriptBindings = ReducerInterface_InternalExpressionValue.nameSpaceFromTypeScriptBindings
 let toTypeScriptBindings = ReducerInterface_InternalExpressionValue.nameSpaceToTypeScriptBindings

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

@@ -1,11 +1,15 @@
+module Bindings = Reducer_Bindings
 module BindingsReplacer = Reducer_Expression_BindingsReplacer
+module Continuation = ReducerInterface_Value_Continuation
 module ExpressionT = Reducer_Expression_T
 module ExternalLibrary = ReducerInterface.ExternalLibrary
 module Lambda = Reducer_Expression_Lambda
 module MathJs = Reducer_MathJs
-module Bindings = Reducer_Bindings
+module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
+module ProjectReducerFnT = ReducerProject_ReducerFn_T
 module Result = Belt.Result
 module TypeBuilder = Reducer_Type_TypeBuilder
+
 open ReducerInterface_InternalExpressionValue
 open Reducer_ErrorValue
 
@@ -19,10 +23,11 @@ open Reducer_ErrorValue
 
 exception TestRescriptException
 
-let callInternal = (call: functionCall, environment, reducer: ExpressionT.reducerFn): result<
-  'b,
-  errorValue,
-> => {
+let callInternal = (
+  call: functionCall,
+  accessors: ProjectAccessorsT.t,
+  reducer: ProjectReducerFnT.t,
+): result<'b, errorValue> => {
   let callMathJs = (call: functionCall): result<'b, errorValue> =>
     switch call {
     | ("javascriptraise", [msg]) => Js.Exn.raiseError(toString(msg)) // For Tests
@@ -95,9 +100,17 @@ let callInternal = (call: functionCall, environment, reducer: ExpressionT.reduce
 
   let doExportBindings = (bindings: nameSpace) => bindings->Bindings.toExpressionValue->Ok
 
+  let doIdentity = (value: internalExpressionValue) => value->Ok
+
+  let doDumpBindings = (continuation: nameSpace, value: internalExpressionValue) => {
+    // let _ = Continuation.inspect(continuation, "doDumpBindings")
+    accessors.continuation = continuation
+    value->Ok
+  }
+
   module SampleMap = {
     let doLambdaCall = (aLambdaValue, list) =>
-      switch Lambda.doLambdaCall(aLambdaValue, list, environment, reducer) {
+      switch Lambda.doLambdaCall(aLambdaValue, list, accessors, reducer) {
       | Ok(IEvNumber(f)) => Ok(f)
       | _ => Error(Operation.SampleMapNeedsNtoNFunction)
       }
@@ -137,12 +150,14 @@ let callInternal = (call: functionCall, environment, reducer: ExpressionT.reduce
   | ("$_constructArray_$", [IEvArray(aValueArray)]) => IEvArray(aValueArray)->Ok
   | ("$_constructRecord_$", [IEvArray(arrayOfPairs)]) => constructRecord(arrayOfPairs)
   | ("$_exportBindings_$", [IEvBindings(nameSpace)]) => doExportBindings(nameSpace)
+  | ("$_exportBindings_$", [evValue]) => doIdentity(evValue)
   | ("$_setBindings_$", [IEvBindings(nameSpace), IEvSymbol(symbol), value]) =>
     doSetBindings(nameSpace, symbol, value)
   | ("$_setTypeAliasBindings_$", [IEvBindings(nameSpace), IEvTypeIdentifier(symbol), value]) =>
     doSetTypeAliasBindings(nameSpace, symbol, value)
   | ("$_setTypeOfBindings_$", [IEvBindings(nameSpace), IEvSymbol(symbol), value]) =>
     doSetTypeOfBindings(nameSpace, symbol, value)
+  | ("$_dumpBindings_$", [IEvBindings(nameSpace), _, evValue]) => doDumpBindings(nameSpace, evValue)
   | ("$_typeModifier_memberOf_$", [IEvTypeIdentifier(typeIdentifier), IEvArray(arr)]) =>
     TypeBuilder.typeModifier_memberOf(IEvTypeIdentifier(typeIdentifier), IEvArray(arr))
   | ("$_typeModifier_memberOf_$", [IEvType(typeRecord), IEvArray(arr)]) =>
@@ -182,15 +197,16 @@ let callInternal = (call: functionCall, environment, reducer: ExpressionT.reduce
 /*
   Reducer uses Result monad while reducing expressions
 */
-let dispatch = (call: functionCall, environment, reducer: ExpressionT.reducerFn): result<
-  internalExpressionValue,
-  errorValue,
-> =>
+let dispatch = (
+  call: functionCall,
+  accessors: ProjectAccessorsT.t,
+  reducer: ProjectReducerFnT.t,
+): result<internalExpressionValue, errorValue> =>
   try {
     let (fn, args) = call
     // There is a bug that prevents string match in patterns
     // So we have to recreate a copy of the string
-    ExternalLibrary.dispatch((Js.String.make(fn), args), environment, reducer, callInternal)
+    ExternalLibrary.dispatch((Js.String.make(fn), args), accessors, reducer, callInternal)
   } catch {
   | Js.Exn.Error(obj) => REJavaScriptExn(Js.Exn.message(obj), Js.Exn.name(obj))->Error
   | _ => RETodo("unhandled rescript exception")->Error

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

@@ -3,17 +3,19 @@
   they take expressions as parameters and return a new expression.
   Macros are used to define language building blocks. They are like Lisp macros.
 */
+module Bindings = Reducer_Bindings
 module BindingsReplacer = Reducer_Expression_BindingsReplacer
 module ErrorValue = Reducer_ErrorValue
 module ExpressionBuilder = Reducer_Expression_ExpressionBuilder
 module ExpressionT = Reducer_Expression_T
-module InternalExpressionValue = ReducerInterface_InternalExpressionValue
 module ExpressionWithContext = Reducer_ExpressionWithContext
-module Bindings = Reducer_Bindings
+module InternalExpressionValue = ReducerInterface_InternalExpressionValue
+module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
+module ProjectReducerFnT = ReducerProject_ReducerFn_T
 module Result = Belt.Result
+
 open Reducer_Expression_ExpressionBuilder
 
-type environment = InternalExpressionValue.environment
 type errorValue = ErrorValue.errorValue
 type expression = ExpressionT.expression
 type expressionWithContext = ExpressionWithContext.expressionWithContext
@@ -21,11 +23,11 @@ type expressionWithContext = ExpressionWithContext.expressionWithContext
 let dispatchMacroCall = (
   macroExpression: expression,
   bindings: ExpressionT.bindings,
-  environment,
-  reduceExpression: ExpressionT.reducerFn,
+  accessors: ProjectAccessorsT.t,
+  reduceExpression: ProjectReducerFnT.t,
 ): result<expressionWithContext, errorValue> => {
-  let useExpressionToSetBindings = (bindingExpr: expression, environment, statement, newCode) => {
-    let rExternalBindingsValue = reduceExpression(bindingExpr, bindings, environment)
+  let useExpressionToSetBindings = (bindingExpr: expression, accessors, statement, newCode) => {
+    let rExternalBindingsValue = reduceExpression(bindingExpr, bindings, accessors)
 
     rExternalBindingsValue->Result.flatMap(nameSpaceValue => {
       let newBindings = Bindings.fromExpressionValue(nameSpaceValue)
@@ -45,16 +47,17 @@ let dispatchMacroCall = (
     | "$_let_$" => "$_setBindings_$"
     | "$_typeOf_$" => "$_setTypeOfBindings_$"
     | "$_typeAlias_$" => "$_setTypeAliasBindings_$"
+    | "$_endOfOuterBlock_$" => "$_dumpBindings_$"
     | _ => ""
     }
 
-  let doBindStatement = (bindingExpr: expression, statement: expression, environment) => {
+  let doBindStatement = (bindingExpr: expression, statement: expression, accessors) => {
     let defaultStatement = ErrorValue.REAssignmentExpected->Error
     switch statement {
     | ExpressionT.EList(list{ExpressionT.EValue(IEvCall(callName)), symbolExpr, statement}) => {
         let setBindingsFn = correspondingSetBindingsFn(callName)
         if setBindingsFn !== "" {
-          useExpressionToSetBindings(bindingExpr, environment, statement, (
+          useExpressionToSetBindings(bindingExpr, accessors, statement, (
             newBindingsExpr,
             boundStatement,
           ) => eFunction(setBindingsFn, list{newBindingsExpr, symbolExpr, boundStatement}))
@@ -66,12 +69,12 @@ let dispatchMacroCall = (
     }
   }
 
-  let doBindExpression = (bindingExpr: expression, statement: expression, environment): result<
+  let doBindExpression = (bindingExpr: expression, statement: expression, accessors): result<
     expressionWithContext,
     errorValue,
   > => {
     let defaultStatement = () =>
-      useExpressionToSetBindings(bindingExpr, environment, statement, (
+      useExpressionToSetBindings(bindingExpr, accessors, statement, (
         _newBindingsExpr,
         boundStatement,
       ) => boundStatement)
@@ -80,13 +83,13 @@ let dispatchMacroCall = (
     | ExpressionT.EList(list{ExpressionT.EValue(IEvCall(callName)), symbolExpr, statement}) => {
         let setBindingsFn = correspondingSetBindingsFn(callName)
         if setBindingsFn !== "" {
-          useExpressionToSetBindings(bindingExpr, environment, statement, (
+          useExpressionToSetBindings(bindingExpr, accessors, statement, (
             newBindingsExpr,
             boundStatement,
           ) =>
             eFunction(
               "$_exportBindings_$",
-              list{eFunction(setBindingsFn, list{newBindingsExpr, symbolExpr, boundStatement})},
+              list{eFunction(setBindingsFn, list{newBindingsExpr, symbolExpr, boundStatement})}, // expression returning bindings
             )
           )
         } else {
@@ -97,7 +100,7 @@ let dispatchMacroCall = (
     }
   }
 
-  let doBlock = (exprs: list<expression>, _bindings: ExpressionT.bindings, _environment): result<
+  let doBlock = (exprs: list<expression>, _bindings: ExpressionT.bindings, _accessors): result<
     expressionWithContext,
     errorValue,
   > => {
@@ -130,10 +133,10 @@ let dispatchMacroCall = (
     ifTrue: expression,
     ifFalse: expression,
     bindings: ExpressionT.bindings,
-    environment,
+    accessors,
   ): result<expressionWithContext, errorValue> => {
     let blockCondition = ExpressionBuilder.eBlock(list{condition})
-    let rCondition = reduceExpression(blockCondition, bindings, environment)
+    let rCondition = reduceExpression(blockCondition, bindings, accessors)
     rCondition->Result.flatMap(conditionValue =>
       switch conditionValue {
       | InternalExpressionValue.IEvBool(false) => {
@@ -149,7 +152,7 @@ let dispatchMacroCall = (
     )
   }
 
-  let expandExpressionList = (aList, bindings: ExpressionT.bindings, environment): result<
+  let expandExpressionList = (aList, bindings: ExpressionT.bindings, accessors): result<
     expressionWithContext,
     errorValue,
   > =>
@@ -159,21 +162,21 @@ let dispatchMacroCall = (
         bindingExpr: ExpressionT.expression,
         statement,
       } =>
-      doBindStatement(bindingExpr, statement, environment)
+      doBindStatement(bindingExpr, statement, accessors)
     | list{ExpressionT.EValue(IEvCall("$$_bindStatement_$$")), statement} =>
       // bindings of the context are used when there is no binding expression
-      doBindStatement(eModule(bindings), statement, environment)
+      doBindStatement(eModule(bindings), statement, accessors)
     | list{
         ExpressionT.EValue(IEvCall("$$_bindExpression_$$")),
         bindingExpr: ExpressionT.expression,
         expression,
       } =>
-      doBindExpression(bindingExpr, expression, environment)
+      doBindExpression(bindingExpr, expression, accessors)
     | list{ExpressionT.EValue(IEvCall("$$_bindExpression_$$")), expression} =>
       // bindings of the context are used when there is no binding expression
-      doBindExpression(eModule(bindings), expression, environment)
+      doBindExpression(eModule(bindings), expression, accessors)
     | list{ExpressionT.EValue(IEvCall("$$_block_$$")), ...exprs} =>
-      doBlock(exprs, bindings, environment)
+      doBlock(exprs, bindings, accessors)
     | list{
         ExpressionT.EValue(IEvCall("$$_lambda_$$")),
         ExpressionT.EValue(IEvArrayString(parameters)),
@@ -181,12 +184,12 @@ let dispatchMacroCall = (
       } =>
       doLambdaDefinition(bindings, parameters, lambdaDefinition)
     | list{ExpressionT.EValue(IEvCall("$$_ternary_$$")), condition, ifTrue, ifFalse} =>
-      doTernary(condition, ifTrue, ifFalse, bindings, environment)
+      doTernary(condition, ifTrue, ifFalse, bindings, accessors)
     | _ => ExpressionWithContext.noContext(ExpressionT.EList(aList))->Ok
     }
 
   switch macroExpression {
-  | EList(aList) => expandExpressionList(aList, bindings, environment)
+  | EList(aList) => expandExpressionList(aList, bindings, accessors)
   | _ => ExpressionWithContext.noContext(macroExpression)->Ok
   }
 }

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

@@ -3,7 +3,7 @@ type location
 
 @genType
 type errorValue =
-  | REArityError(option<string>, int, int) //TODO: Binding a lambda to a variable should record the variable name in lambda for error reporting
+  | REArityError(option<string>, int, int)
   | REArrayIndexNotFound(string, int)
   | REAssignmentExpected
   | REDistributionError(DistributionTypes.error)

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

@@ -1,35 +1,29 @@
+module Bindings = Reducer_Bindings
 module BindingsReplacer = Reducer_Expression_BindingsReplacer
 module BuiltIn = Reducer_Dispatch_BuiltIn
 module ExpressionBuilder = Reducer_Expression_ExpressionBuilder
+module ExternalExpressionValue = ReducerInterface_ExternalExpressionValue
 module Extra = Reducer_Extra
 module InternalExpressionValue = ReducerInterface_InternalExpressionValue
 module Lambda = Reducer_Expression_Lambda
 module Macro = Reducer_Expression_Macro
 module MathJs = Reducer_MathJs
-module Bindings = Reducer_Bindings
+module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
 module Result = Belt.Result
 module T = Reducer_Expression_T
 
-type environment = InternalExpressionValue.environment
 type errorValue = Reducer_ErrorValue.errorValue
-type expression = T.expression
-type internalExpressionValue = InternalExpressionValue.t
 type externalExpressionValue = ReducerInterface_ExternalExpressionValue.t
-type t = expression
+type t = T.t
 
 /*
-  Converts a Squigle code to expression
+  Recursively evaluate/reduce the expression (Lisp AST/Lambda calculus)
 */
-let parse = (peggyCode: string): result<t, errorValue> =>
-  peggyCode->Reducer_Peggy_Parse.parse->Result.map(Reducer_Peggy_ToExpression.fromNode)
-
-/*
-  Recursively evaluate/reduce the expression (Lisp AST)
-*/
-let rec reduceExpression = (expression: t, bindings: T.bindings, environment: environment): result<
-  internalExpressionValue,
-  'e,
-> => {
+let rec reduceExpressionInProject = (
+  expression: t,
+  continuation: T.bindings,
+  accessors: ProjectAccessorsT.t,
+): result<InternalExpressionValue.t, 'e> => {
   // Js.log(`reduce: ${T.toString(expression)} bindings: ${bindings->Bindings.toString}`)
   switch expression {
   | T.EValue(value) => value->Ok
@@ -38,41 +32,40 @@ let rec reduceExpression = (expression: t, bindings: T.bindings, environment: en
     | list{EValue(IEvCall(fName)), ..._args} =>
       switch Macro.isMacroName(fName) {
       // A macro expands then reduces itself
-      | true => Macro.doMacroCall(expression, bindings, environment, reduceExpression)
-      | false => reduceExpressionList(list, bindings, environment)
+      | true => Macro.doMacroCall(expression, continuation, accessors, reduceExpressionInProject)
+      | false => reduceExpressionList(list, continuation, accessors)
       }
-    | _ => reduceExpressionList(list, bindings, environment)
+    | _ => reduceExpressionList(list, continuation, accessors)
     }
   }
 }
-
 and reduceExpressionList = (
   expressions: list<t>,
-  bindings: T.bindings,
-  environment: environment,
-): result<internalExpressionValue, 'e> => {
+  continuation: T.bindings,
+  accessors: ProjectAccessorsT.t,
+): result<InternalExpressionValue.t, 'e> => {
   let racc: result<
-    list<internalExpressionValue>,
+    list<InternalExpressionValue.t>,
     'e,
-  > = expressions->Belt.List.reduceReverse(Ok(list{}), (racc, each: expression) =>
+  > = expressions->Belt.List.reduceReverse(Ok(list{}), (racc, each: t) =>
     racc->Result.flatMap(acc => {
       each
-      ->reduceExpression(bindings, environment)
+      ->reduceExpressionInProject(continuation, accessors)
       ->Result.map(newNode => {
         acc->Belt.List.add(newNode)
       })
     })
   )
-  racc->Result.flatMap(acc => acc->reduceValueList(environment))
+  racc->Result.flatMap(acc => acc->reduceValueList(accessors))
 }
 
 /*
     After reducing each level of expression(Lisp AST), we have a value list to evaluate
  */
-and reduceValueList = (valueList: list<internalExpressionValue>, environment): result<
-  internalExpressionValue,
-  'e,
-> =>
+and reduceValueList = (
+  valueList: list<InternalExpressionValue.t>,
+  accessors: ProjectAccessorsT.t,
+): result<InternalExpressionValue.t, 'e> =>
   switch valueList {
   | list{IEvCall(fName), ...args} => {
       let rCheckedArgs = switch fName {
@@ -81,7 +74,10 @@ and reduceValueList = (valueList: list<internalExpressionValue>, environment): r
       }
 
       rCheckedArgs->Result.flatMap(checkedArgs =>
-        (fName, checkedArgs->Belt.List.toArray)->BuiltIn.dispatch(environment, reduceExpression)
+        (fName, checkedArgs->Belt.List.toArray)->BuiltIn.dispatch(
+          accessors,
+          reduceExpressionInProject,
+        )
       )
     }
   | list{IEvLambda(_)} =>
@@ -91,11 +87,11 @@ and reduceValueList = (valueList: list<internalExpressionValue>, environment): r
     ->Result.flatMap(reducedValueList =>
       reducedValueList->Belt.List.toArray->InternalExpressionValue.IEvArray->Ok
     )
-  | list{IEvLambda(lamdaCall), ...args} =>
+  | list{IEvLambda(lambdaCall), ...args} =>
     args
     ->Lambda.checkIfReduced
     ->Result.flatMap(checkedArgs =>
-      Lambda.doLambdaCall(lamdaCall, checkedArgs, environment, reduceExpression)
+      Lambda.doLambdaCall(lambdaCall, checkedArgs, accessors, reduceExpressionInProject)
     )
 
   | _ =>
@@ -106,53 +102,37 @@ and reduceValueList = (valueList: list<internalExpressionValue>, environment): r
     )
   }
 
-let evalUsingBindingsExpression_ = (aExpression, bindings, environment): result<
-  internalExpressionValue,
-  'e,
-> => reduceExpression(aExpression, bindings, environment)
-
-let evaluateUsingOptions = (
-  ~environment: option<ReducerInterface_ExternalExpressionValue.environment>,
-  ~externalBindings: option<ReducerInterface_ExternalExpressionValue.externalBindings>,
-  code: string,
-): result<externalExpressionValue, errorValue> => {
-  let anEnvironment = Belt.Option.getWithDefault(
-    environment,
-    ReducerInterface_ExternalExpressionValue.defaultEnvironment,
-  )
-
-  let mergedBindings: InternalExpressionValue.nameSpace = Bindings.merge(
-    ReducerInterface_StdLib.internalStdLib,
-    Belt.Option.map(externalBindings, Bindings.fromTypeScriptBindings)->Belt.Option.getWithDefault(
-      Bindings.emptyModule,
-    ),
-  )
-
-  parse(code)
-  ->Result.flatMap(expr => evalUsingBindingsExpression_(expr, mergedBindings, anEnvironment))
-  ->Result.map(ReducerInterface_InternalExpressionValue.toExternal)
+let reduceReturningBindings = (
+  expression: t,
+  continuation: T.bindings,
+  accessors: ProjectAccessorsT.t,
+): (result<InternalExpressionValue.t, 'e>, T.bindings) => {
+  let result = reduceExpressionInProject(expression, continuation, accessors)
+  (result, accessors.continuation)
 }
 
-/*
-  IEvaluates Squiggle code and bindings via Reducer and answers the result
-*/
-let evaluate = (code: string): result<externalExpressionValue, errorValue> => {
-  evaluateUsingOptions(~environment=None, ~externalBindings=None, code)
-}
-let evaluatePartialUsingExternalBindings = (
-  code: string,
-  externalBindings: ReducerInterface_ExternalExpressionValue.externalBindings,
-  environment: ReducerInterface_ExternalExpressionValue.environment,
-): result<ReducerInterface_ExternalExpressionValue.externalBindings, errorValue> => {
-  let rAnswer = evaluateUsingOptions(
-    ~environment=Some(environment),
-    ~externalBindings=Some(externalBindings),
-    code,
-  )
-  switch rAnswer {
-  | Ok(EvModule(externalBindings)) => Ok(externalBindings)
-  | Ok(_) =>
-    Error(Reducer_ErrorValue.RESyntaxError(`Partials must end with an assignment or record`, None))
-  | Error(err) => err->Error
+module BackCompatible = {
+  // Those methods are used to support the existing tests
+  // If they are used outside limited testing context, error location reporting will fail
+  let parse = (peggyCode: string): result<t, errorValue> =>
+    peggyCode->Reducer_Peggy_Parse.parse->Result.map(Reducer_Peggy_ToExpression.fromNode)
+
+  let evaluate = (expression: t): result<InternalExpressionValue.t, errorValue> => {
+    let accessors = ProjectAccessorsT.identityAccessors
+    expression->reduceExpressionInProject(accessors.stdLib, accessors)
   }
+
+  let evaluateString = (peggyCode: string): result<InternalExpressionValue.t, errorValue> =>
+    parse(peggyCode)->Result.flatMap(evaluate)
+
+  let evaluateAsExternal = (expression: t): result<ExternalExpressionValue.t, errorValue> =>
+    {
+      let accessors = ProjectAccessorsT.identityAccessors
+      expression->reduceExpressionInProject(accessors.stdLib, accessors)
+    }->Result.map(InternalExpressionValue.toExternal)
+
+  let evaluateStringAsExternal = (peggyCode: string): result<
+    ExternalExpressionValue.t,
+    errorValue,
+  > => parse(peggyCode)->Result.flatMap(evaluateAsExternal)
 }

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

@@ -1,9 +1,11 @@
+module Bindings = Reducer_Bindings
 module BindingsReplacer = Reducer_Expression_BindingsReplacer
 module ErrorValue = Reducer_ErrorValue
 module ExpressionT = Reducer_Expression_T
 module InternalExpressionValue = ReducerInterface_InternalExpressionValue
+module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
+module ProjectReducerFnT = ReducerProject_ReducerFn_T
 module Result = Belt.Result
-module Bindings = Reducer_Bindings
 
 type bindings = ExpressionT.bindings
 type context = bindings
@@ -11,7 +13,6 @@ type environment = InternalExpressionValue.environment
 type errorValue = Reducer_ErrorValue.errorValue
 type expression = ExpressionT.expression
 type internalExpressionValue = InternalExpressionValue.t
-type reducerFn = ExpressionT.reducerFn
 
 type expressionWithContext =
   | ExpressionWithContext(expression, context)
@@ -20,16 +21,16 @@ type expressionWithContext =
 let callReducer = (
   expressionWithContext: expressionWithContext,
   bindings: bindings,
-  environment: environment,
-  reducer: reducerFn,
+  accessors: ProjectAccessorsT.t,
+  reducer: ProjectReducerFnT.t,
 ): result<internalExpressionValue, errorValue> => {
   switch expressionWithContext {
   | ExpressionNoContext(expr) =>
     // Js.log(`callReducer: bindings ${Bindings.toString(bindings)} expr ${ExpressionT.toString(expr)}`)
-    reducer(expr, bindings, environment)
+    reducer(expr, bindings, accessors)
   | ExpressionWithContext(expr, context) =>
     // Js.log(`callReducer: context ${Bindings.toString(context)} expr ${ExpressionT.toString(expr)}`)
-    reducer(expr, context, environment)
+    reducer(expr, context, accessors)
   }
 }
 

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

@@ -1,12 +1,13 @@
+module Bindings = Reducer_Bindings
 module BindingsReplacer = Reducer_Expression_BindingsReplacer
 module ErrorValue = Reducer_ErrorValue
 module ExpressionBuilder = Reducer_Expression_ExpressionBuilder
 module ExpressionT = Reducer_Expression_T
 module ExpressionValue = ReducerInterface_InternalExpressionValue
-module Bindings = Reducer_Bindings
+module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
+module ProjectReducerFnT = ReducerProject_ReducerFn_T
 module Result = Belt.Result
 
-type environment = ReducerInterface_InternalExpressionValue.environment
 type expression = ExpressionT.expression
 type expressionOrFFI = ExpressionT.expressionOrFFI
 type internalExpressionValue = ReducerInterface_InternalExpressionValue.t
@@ -44,7 +45,13 @@ let checkIfReduced = (args: list<internalExpressionValue>) =>
     )
   )
 
-let caseNotFFI = (lambdaValue: ExpressionValue.lambdaValue, expr, args, environment, reducer) => {
+let caseNotFFI = (
+  lambdaValue: ExpressionValue.lambdaValue,
+  expr,
+  args,
+  accessors: ProjectAccessorsT.t,
+  reducer: ProjectReducerFnT.t,
+) => {
   let parameterList = lambdaValue.parameters->Belt.List.fromArray
   let zippedParameterList = parameterList->Belt.List.zip(args)
   let bindings = Belt.List.reduce(zippedParameterList, lambdaValue.context, (
@@ -52,39 +59,43 @@ let caseNotFFI = (lambdaValue: ExpressionValue.lambdaValue, expr, args, environm
     (variable, variableValue),
   ) => acc->Bindings.set(variable, variableValue))
   let newExpression = ExpressionBuilder.eBlock(list{expr})
-  reducer(newExpression, bindings, environment)
+  reducer(newExpression, bindings, accessors)
 }
 
-let caseFFI = (ffiFn: ExpressionT.ffiFn, args, environment) => {
-  ffiFn(args->Belt.List.toArray, environment)
+let caseFFI = (ffiFn: ExpressionT.ffiFn, args, accessors: ProjectAccessorsT.t) => {
+  ffiFn(args->Belt.List.toArray, accessors.environment)
 }
 
 let applyParametersToLambda = (
   lambdaValue: ExpressionValue.lambdaValue,
   args,
-  environment,
-  reducer: ExpressionT.reducerFn,
+  accessors: ProjectAccessorsT.t,
+  reducer: ProjectReducerFnT.t,
 ): result<internalExpressionValue, 'e> => {
   checkArity(lambdaValue, args)->Result.flatMap(args =>
     checkIfReduced(args)->Result.flatMap(args => {
       let exprOrFFI = castInternalCodeToExpression(lambdaValue.body)
       switch exprOrFFI {
-      | NotFFI(expr) => caseNotFFI(lambdaValue, expr, args, environment, reducer)
-      | FFI(ffiFn) => caseFFI(ffiFn, args, environment)
+      | NotFFI(expr) => caseNotFFI(lambdaValue, expr, args, accessors, reducer)
+      | FFI(ffiFn) => caseFFI(ffiFn, args, accessors)
       }
     })
   )
 }
 
-let doLambdaCall = (lambdaValue: ExpressionValue.lambdaValue, args, environment, reducer) =>
-  applyParametersToLambda(lambdaValue, args, environment, reducer)
+let doLambdaCall = (
+  lambdaValue: ExpressionValue.lambdaValue,
+  args,
+  accessors: ProjectAccessorsT.t,
+  reducer: ProjectReducerFnT.t,
+) => applyParametersToLambda(lambdaValue, args, accessors, reducer)
 
 let foreignFunctionInterface = (
   lambdaValue: ExpressionValue.lambdaValue,
   argArray: array<internalExpressionValue>,
-  environment: ExpressionValue.environment,
-  reducer: ExpressionT.reducerFn,
+  accessors: ProjectAccessorsT.t,
+  reducer: ProjectReducerFnT.t,
 ): result<internalExpressionValue, 'e> => {
   let args = argArray->Belt.List.fromArray
-  applyParametersToLambda(lambdaValue, args, environment, reducer)
+  applyParametersToLambda(lambdaValue, args, accessors, reducer)
 }

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

@@ -2,6 +2,8 @@ module ExpressionT = Reducer_Expression_T
 module InternalExpressionValue = ReducerInterface_InternalExpressionValue
 module ExpressionWithContext = Reducer_ExpressionWithContext
 module Result = Belt.Result
+module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
+module ProjectReducerFnT = ReducerProject_ReducerFn_T
 
 type environment = InternalExpressionValue.environment
 type expression = ExpressionT.expression
@@ -11,34 +13,29 @@ type expressionWithContext = ExpressionWithContext.expressionWithContext
 let expandMacroCall = (
   macroExpression: expression,
   bindings: ExpressionT.bindings,
-  environment: environment,
-  reduceExpression: ExpressionT.reducerFn,
+  accessors: ProjectAccessorsT.t,
+  reduceExpression: ProjectReducerFnT.t,
 ): result<expressionWithContext, 'e> =>
   Reducer_Dispatch_BuiltInMacros.dispatchMacroCall(
     macroExpression,
     bindings,
-    environment,
+    accessors,
     reduceExpression,
   )
 
 let doMacroCall = (
   macroExpression: expression,
   bindings: ExpressionT.bindings,
-  environment: environment,
-  reduceExpression: ExpressionT.reducerFn,
+  accessors: ProjectAccessorsT.t,
+  reduceExpression: ProjectReducerFnT.t,
 ): result<internalExpressionValue, 'e> =>
   expandMacroCall(
     macroExpression,
     bindings,
-    environment,
-    reduceExpression,
+    (accessors: ProjectAccessorsT.t),
+    (reduceExpression: ProjectReducerFnT.t),
   )->Result.flatMap(expressionWithContext =>
-    ExpressionWithContext.callReducer(
-      expressionWithContext,
-      bindings,
-      environment,
-      reduceExpression,
-    )
+    ExpressionWithContext.callReducer(expressionWithContext, bindings, accessors, reduceExpression)
   )
 
 let isMacroName = (fName: string): bool => fName->Js.String2.startsWith("$$")

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

@@ -17,6 +17,8 @@ type rec expression =
   | EValue(internalExpressionValue) // Irreducible built-in value. Reducer should not know the internals. External libraries are responsible
 and bindings = InternalExpressionValue.nameSpace
 
+type t = expression
+
 type reducerFn = (
   expression,
   bindings,

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

@@ -9,12 +9,25 @@ start
 
 zeroOMoreArgumentsBlockOrExpression = innerBlockOrExpression / lambda
 
+//   { return h.makeFunctionCall('$_typeOf_$', [identifier, typeExpression])}
+// {return [h.nodeVoid()];}
 outerBlock 
   = statements:array_statements  finalExpression: (statementSeparator @expression)?
-    { if (finalExpression != null) { statements.push(finalExpression) }
+    { if (finalExpression != null) 
+        { 
+          var newFinalExpression = h.makeFunctionCall('$_endOfOuterBlock_$', [h.nodeVoid(), finalExpression]);
+          statements.push(newFinalExpression);
+        }
+      else 
+        {
+          var newFinalStatement = h.makeFunctionCall('$_endOfOuterBlock_$', [h.nodeVoid(), h.nodeVoid()]);
+          statements.push(newFinalStatement);
+        }
       return h.nodeBlock(statements) }
   / finalExpression: expression
-    { return h.nodeBlock([finalExpression])}
+    { 
+      var newFinalExpression = h.makeFunctionCall('$_endOfOuterBlock_$', [h.nodeVoid(), finalExpression]);
+      return h.nodeBlock([newFinalExpression])}
     
 innerBlockOrExpression  
   = quotedInnerBlock

packages/squiggle-lang/src/rescript/Reducer/Reducer_Type/Reducer_Type_Compile.res

@@ -1,40 +1,37 @@
+module Bindings = Reducer_Bindings
 module ErrorValue = Reducer_ErrorValue
+module Expression = Reducer_Expression
 module ExpressionT = Reducer_Expression_T
 module InternalExpressionValue = ReducerInterface_InternalExpressionValue
-module Bindings = Reducer_Bindings
+module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
+module ProjectReducerFnT = ReducerProject_ReducerFn_T
 module T = Reducer_Type_T
 
 let ievFromTypeExpression = (
   typeExpressionSourceCode: string,
-  reducerFn: ExpressionT.reducerFn,
+  reducerFn: ProjectReducerFnT.t,
 ): result<InternalExpressionValue.t, ErrorValue.t> => {
   let sIndex = "compiled"
   let sourceCode = `type ${sIndex}=${typeExpressionSourceCode}`
-  Reducer_Expression.parse(sourceCode)->Belt.Result.flatMap(expr => {
-    let rContext = reducerFn(
-      expr,
-      Bindings.emptyBindings,
-      InternalExpressionValue.defaultEnvironment,
-    )
-    Belt.Result.map(rContext, context =>
-      switch context {
-      | IEvBindings(nameSpace) =>
+  Reducer_Expression.BackCompatible.parse(sourceCode)->Belt.Result.flatMap(expr => {
+    let accessors = ProjectAccessorsT.identityAccessors
+    let result = reducerFn(expr, Bindings.emptyBindings, accessors)
+    let nameSpace = accessors.continuation
+
+    switch result {
+    | Ok(_) =>
       switch Bindings.getType(nameSpace, sIndex) {
-        | Some(value) => value
+      | Some(value) => value->Ok
       | None => raise(Reducer_Exception.ImpossibleException("Reducer_Type_Compile-none"))
       }
-      | _ => raise(Reducer_Exception.ImpossibleException("Reducer_Type_Compile-raise"))
+    | err => err
     }
-    )
   })
 }
 
-let fromTypeExpression = (
-  typeExpressionSourceCode: string,
-  reducerFn: ExpressionT.reducerFn,
-): result<T.t, ErrorValue.t> => {
-  ievFromTypeExpression(
-    (typeExpressionSourceCode: string),
-    (reducerFn: ExpressionT.reducerFn),
-  )->Belt.Result.map(T.fromIEvValue)
+let fromTypeExpression = (typeExpressionSourceCode: string, reducerFn: ProjectReducerFnT.t): result<
+  T.t,
+  ErrorValue.t,
+> => {
+  ievFromTypeExpression(typeExpressionSourceCode, reducerFn)->Belt.Result.map(T.fromIEvValue)
 }

packages/squiggle-lang/src/rescript/Reducer/Reducer_Type/Reducer_Type_TypeChecker.res

@@ -1,5 +1,7 @@
 module ExpressionT = Reducer_Expression_T
 module InternalExpressionValue = ReducerInterface_InternalExpressionValue
+module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
+module ProjectReducerFnT = ReducerProject_ReducerFn_T
 module T = Reducer_Type_T
 module TypeContracts = Reducer_Type_Contracts
 open InternalExpressionValue
@@ -124,7 +126,7 @@ let rec isITypeOf = (anIType: T.iType, aValue): result<bool, T.typeErrorValue> =
 let isTypeOf = (
   typeExpressionSourceCode: string,
   aValue: InternalExpressionValue.t,
-  reducerFn: ExpressionT.reducerFn,
+  reducerFn: ProjectReducerFnT.t,
 ): result<InternalExpressionValue.t, ErrorValue.t> => {
   switch typeExpressionSourceCode->Reducer_Type_Compile.fromTypeExpression(reducerFn) {
   | Ok(anIType) =>
@@ -152,7 +154,7 @@ let checkITypeArguments = (anIType: T.iType, args: array<InternalExpressionValue
 let checkArguments = (
   typeExpressionSourceCode: string,
   args: array<InternalExpressionValue.t>,
-  reducerFn: ExpressionT.reducerFn,
+  reducerFn: ProjectReducerFnT.t,
 ): result<InternalExpressionValue.t, ErrorValue.t> => {
   switch typeExpressionSourceCode->Reducer_Type_Compile.fromTypeExpression(reducerFn) {
   | Ok(anIType) =>

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

@@ -92,6 +92,18 @@ let toStringResult = x =>
   | Error(m) => `Error(${ErrorValue.errorToString(m)})`
   }
 
+let toStringOptionResult = x =>
+  switch x {
+  | Some(a) => toStringResult(a)
+  | None => `None`
+  }
+
+let toStringOption = x =>
+  switch x {
+  | Some(a) => toString(a)
+  | None => `None`
+  }
+
 @genType
 type environment = GenericDist.env
 

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

@@ -1,4 +1,6 @@
 module InternalExpressionValue = ReducerInterface_InternalExpressionValue
+module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
+module ProjectReducerFnT = ReducerProject_ReducerFn_T
 type internalExpressionValue = InternalExpressionValue.t
 
 /*
@@ -6,17 +8,17 @@ type internalExpressionValue = InternalExpressionValue.t
 */
 let dispatch = (
   call: InternalExpressionValue.functionCall,
-  environment,
-  reducer: Reducer_Expression_T.reducerFn,
+  accessors: ProjectAccessorsT.t,
+  reducer: ProjectReducerFnT.t,
   chain,
 ): result<internalExpressionValue, 'e> => {
   E.A.O.firstSomeFn([
-    () => ReducerInterface_GenericDistribution.dispatch(call, environment),
-    () => ReducerInterface_Date.dispatch(call, environment),
-    () => ReducerInterface_Duration.dispatch(call, environment),
-    () => ReducerInterface_Number.dispatch(call, environment),
-    () => FunctionRegistry_Library.dispatch(call, environment, reducer),
-  ])->E.O2.defaultFn(() => chain(call, environment, reducer))
+    () => ReducerInterface_GenericDistribution.dispatch(call, accessors.environment),
+    () => ReducerInterface_Date.dispatch(call, accessors.environment),
+    () => ReducerInterface_Duration.dispatch(call, accessors.environment),
+    () => ReducerInterface_Number.dispatch(call, accessors.environment),
+    () => FunctionRegistry_Library.dispatch(call, accessors, reducer),
+  ])->E.O2.defaultFn(() => chain(call, accessors, reducer))
 }
 
 /*

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

@@ -132,6 +132,12 @@ let toStringResult = x =>
   | Error(m) => `Error(${ErrorValue.errorToString(m)})`
   }
 
+let toStringOptionResult = x =>
+  switch x {
+  | Some(a) => `${toStringResult(a)})`
+  | None => "None"
+  }
+
 let toStringResultOkless = (codeResult: result<t, ErrorValue.errorValue>): string =>
   switch codeResult {
   | Ok(a) => toString(a)

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

@@ -1,7 +1,6 @@
 module Bindings = Reducer_Bindings
 
-let internalStdLib =
+let internalStdLib: Bindings.t =
   Bindings.emptyBindings->SquiggleLibrary_Math.makeBindings->SquiggleLibrary_Versions.makeBindings
 
-@genType
 let externalStdLib = internalStdLib->Bindings.toTypeScriptBindings

packages/squiggle-lang/src/rescript/ReducerInterface/ReducerInterface_Value/ReducerInterface_Value_Continuation.res

@@ -0,0 +1,28 @@
+module InternalExpressionValue = ReducerInterface_InternalExpressionValue
+
+type t = InternalExpressionValue.nameSpace
+
+let toValue = nameSpace => InternalExpressionValue.IEvBindings(nameSpace)
+let toString = nameSpace => InternalExpressionValue.toString(toValue(nameSpace))
+let toStringResult = rNameSpace =>
+  Belt.Result.map(rNameSpace, toValue(_))->InternalExpressionValue.toStringResult
+let toStringOptionResult = orNameSpace =>
+  Belt.Option.map(
+    orNameSpace,
+    Belt.Result.map(_, toValue(_)),
+  )->InternalExpressionValue.toStringOptionResult
+
+let inspect = (nameSpace, label: string) => Js.log(`${label}: ${toString(nameSpace)}`)
+
+let inspectOption = (oNameSpace, label: string) =>
+  switch oNameSpace {
+  | Some(nameSpace) => inspect(nameSpace, label)
+  | None => Js.log(`${label}: None`)
+  }
+
+let minus = (NameSpace(thisContainer): t, NameSpace(thatContainer): t) => {
+  Belt.Map.String.removeMany(
+    thisContainer,
+    Belt.Map.String.keysToArray(thatContainer),
+  )->InternalExpressionValue.NameSpace
+}

packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject.res

@@ -0,0 +1,396 @@
+// TODO: Restore run FFI?
+// TODO: Auto clean project based on topology
+
+module Bindings = Reducer_Bindings
+module Continuation = ReducerInterface_Value_Continuation
+module ErrorValue = Reducer_ErrorValue
+module ExternalExpressionValue = ReducerInterface_ExternalExpressionValue
+module InternalExpressionValue = ReducerInterface_InternalExpressionValue
+module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
+module ProjectItem = ReducerProject_ProjectItem
+module T = ReducerProject_T
+
+@genType.opaque
+type project = T.t
+type t = T.t
+
+module Private = {
+  type internalProject = T.Private.t
+  type t = T.Private.t
+
+  let getSourceIds = (this: t): array<string> => Belt.Map.String.keysToArray(this["items"])
+
+  let getItem = (this: t, sourceId: string) =>
+    Belt.Map.String.getWithDefault(this["items"], sourceId, ProjectItem.emptyItem)
+
+  let getImmediateDependencies = (this: t, sourceId: string): ProjectItem.T.includesType =>
+    getItem(this, sourceId)->ProjectItem.getImmediateDependencies
+
+  type topologicalSortState = (Belt.Map.String.t<bool>, list<string>)
+  let rec topologicalSortUtil = (
+    this: t,
+    sourceId: string,
+    state: topologicalSortState,
+  ): topologicalSortState => {
+    let dependencies = getImmediateDependencies(this, sourceId)->Belt.Result.getWithDefault([])
+    let (visited, stack) = state
+    let myVisited = Belt.Map.String.set(visited, sourceId, true)
+    let (newVisited, newStack) = dependencies->Belt.Array.reduce((myVisited, stack), (
+      (currVisited, currStack),
+      dependency,
+    ) => {
+      if !Belt.Map.String.getWithDefault(currVisited, dependency, false) {
+        topologicalSortUtil(this, dependency, (currVisited, currStack))
+      } else {
+        (currVisited, currStack)
+      }
+    })
+    (newVisited, list{sourceId, ...newStack})
+  }
+
+  let getTopologicalSort = (this: t): array<string> => {
+    let (_visited, stack) = getSourceIds(this)->Belt.Array.reduce((Belt.Map.String.empty, list{}), (
+      (currVisited, currStack),
+      currId,
+    ) =>
+      if !Belt.Map.String.getWithDefault(currVisited, currId, false) {
+        topologicalSortUtil(this, currId, (currVisited, currStack))
+      } else {
+        (currVisited, currStack)
+      }
+    )
+    Belt.List.reverse(stack)->Belt.List.toArray
+  }
+
+  let getTopologicalSortFor = (this: t, sourceId) => {
+    let runOrder = getTopologicalSort(this)
+    let index = runOrder->Js.Array2.indexOf(sourceId)
+    let after = Belt.Array.sliceToEnd(runOrder, index + 1)
+    let before = Js.Array2.slice(runOrder, ~start=0, ~end_=index + 1)
+    (before, after)
+  }
+
+  let getRunOrder = getTopologicalSort
+
+  let createProject = () => {
+    let this: t = {
+      "items": Belt.Map.String.empty,
+      "stdLib": ReducerInterface_StdLib.internalStdLib,
+      "environment": InternalExpressionValue.defaultEnvironment,
+    }
+    this
+  }
+
+  let getRunOrderFor = (this: t, sourceId: string) => {
+    let (runOrder, _) = getTopologicalSortFor(this, sourceId)
+    runOrder
+  }
+
+  let getDependencies = (this: t, sourceId: string): array<string> => {
+    let runOrder = getRunOrderFor(this, sourceId)
+
+    let _ = Js.Array2.pop(runOrder)
+    runOrder
+  }
+
+  let getDependents = (this: t, sourceId: string): array<string> => {
+    let (_, dependents) = getTopologicalSortFor(this, sourceId)
+    dependents
+  }
+
+  let rec touchSource = (this: t, sourceId: string): unit => {
+    let item = this->getItem(sourceId)
+    let newItem = ProjectItem.touchSource(item)
+    Belt.Map.String.set(this["items"], sourceId, newItem)->T.Private.setFieldItems(this, _)
+    touchDependents(this, sourceId)
+  }
+  and touchDependents = (this: t, sourceId: string): unit => {
+    let _ = getDependents(this, sourceId)->Belt.Array.forEach(_, touchSource(this, _))
+  }
+
+  let getSource = (this: t, sourceId: string): option<string> =>
+    Belt.Map.String.get(this["items"], sourceId)->Belt.Option.map(ProjectItem.getSource)
+
+  let setSource = (this: t, sourceId: string, value: string): unit => {
+    let newItem = this->getItem(sourceId)->ProjectItem.setSource(value)
+    Belt.Map.String.set(this["items"], sourceId, newItem)->T.Private.setFieldItems(this, _)
+    touchDependents(this, sourceId)
+  }
+
+  let clean = (this: t, sourceId: string): unit => {
+    let newItem = this->getItem(sourceId)->ProjectItem.clean
+    Belt.Map.String.set(this["items"], sourceId, newItem)->T.Private.setFieldItems(this, _)
+  }
+
+  let cleanAll = (this: t): unit =>
+    getSourceIds(this)->Belt.Array.forEach(sourceId => clean(this, sourceId))
+
+  let cleanResults = (this: t, sourceId: string): unit => {
+    let newItem = this->getItem(sourceId)->ProjectItem.cleanResults
+    Belt.Map.String.set(this["items"], sourceId, newItem)->T.Private.setFieldItems(this, _)
+  }
+
+  let cleanAllResults = (this: t): unit =>
+    getSourceIds(this)->Belt.Array.forEach(sourceId => cleanResults(this, sourceId))
+
+  let getIncludes = (this: t, sourceId: string): ProjectItem.T.includesType =>
+    this->getItem(sourceId)->ProjectItem.getIncludes
+
+  let setContinues = (this: t, sourceId: string, continues: array<string>): unit => {
+    let newItem = this->getItem(sourceId)->ProjectItem.setContinues(continues)
+    Belt.Map.String.set(this["items"], sourceId, newItem)->T.Private.setFieldItems(this, _)
+    touchSource(this, sourceId)
+  }
+  let getContinues = (this: t, sourceId: string): array<string> =>
+    ProjectItem.getContinues(this->getItem(sourceId))
+
+  let removeContinues = (this: t, sourceId: string): unit => {
+    let newItem = this->getItem(sourceId)->ProjectItem.removeContinues
+    Belt.Map.String.set(this["items"], sourceId, newItem)->T.Private.setFieldItems(this, _)
+    touchSource(this, sourceId)
+  }
+
+  let getContinuation = (this: t, sourceId: string): ProjectItem.T.continuationArgumentType =>
+    this->getItem(sourceId)->ProjectItem.getContinuation
+
+  let setContinuation = (
+    this: t,
+    sourceId: string,
+    continuation: ProjectItem.T.continuationArgumentType,
+  ): unit => {
+    let newItem = this->getItem(sourceId)->ProjectItem.setContinuation(continuation)
+    Belt.Map.String.set(this["items"], sourceId, newItem)->T.Private.setFieldItems(this, _)
+  }
+
+  let getResult = (this: t, sourceId: string): ProjectItem.T.resultType =>
+    this->getItem(sourceId)->ProjectItem.getResult
+
+  let setResult = (this: t, sourceId: string, value: ProjectItem.T.resultArgumentType): unit => {
+    let newItem = this->getItem(sourceId)->ProjectItem.setResult(value)
+    Belt.Map.String.set(this["items"], sourceId, newItem)->T.Private.setFieldItems(this, _)
+  }
+
+  let getExternalResult = (this: t, sourceId: string): ProjectItem.T.externalResultType =>
+    this->getItem(sourceId)->ProjectItem.getExternalResult
+
+  let parseIncludes = (this: t, sourceId: string): unit => {
+    let newItem = this->getItem(sourceId)->ProjectItem.parseIncludes
+    Belt.Map.String.set(this["items"], sourceId, newItem)->T.Private.setFieldItems(this, _)
+  }
+
+  let rawParse = (this: t, sourceId): unit => {
+    let newItem = this->getItem(sourceId)->ProjectItem.rawParse
+    Belt.Map.String.set(this["items"], sourceId, newItem)->T.Private.setFieldItems(this, _)
+  }
+
+  let getStdLib = (this: t): Reducer_Bindings.t => this["stdLib"]
+  let setStdLib = (this: t, value: Reducer_Bindings.t): unit =>
+    T.Private.setFieldStdLib(this, value)
+
+  let getEnvironment = (this: t): InternalExpressionValue.environment => this["environment"]
+  let setEnvironment = (this: t, value: InternalExpressionValue.environment): unit =>
+    T.Private.setFieldEnvironment(this, value)
+
+  let getExternalBindings = (
+    this: t,
+    sourceId: string,
+  ): ProjectItem.T.externalBindingsArgumentType => {
+    let those = this->getContinuation(sourceId)
+    let these = this->getStdLib
+    let ofUser = Continuation.minus(those, these)
+    ofUser->InternalExpressionValue.nameSpaceToTypeScriptBindings
+  }
+
+  let buildProjectAccessors = (this: t): ProjectAccessorsT.t => {
+    continuation: Bindings.emptyBindings,
+    stdLib: getStdLib(this),
+    environment: getEnvironment(this),
+  }
+
+  let doRunWithContinuation = (
+    this: t,
+    sourceId: string,
+    continuation: ProjectItem.T.continuation,
+  ): unit => {
+    let accessors = buildProjectAccessors(this)
+    let newItem = this->getItem(sourceId)->ProjectItem.run(continuation, accessors)
+    Belt.Map.String.set(this["items"], sourceId, newItem)->T.Private.setFieldItems(this, _)
+    setContinuation(this, sourceId, accessors.continuation)
+  }
+
+  type runState = (ProjectItem.T.resultArgumentType, ProjectItem.T.continuation)
+
+  let tryRunWithContinuation = (
+    this: t,
+    sourceId: string,
+    (rPrevResult: ProjectItem.T.resultArgumentType, continuation: ProjectItem.T.continuation),
+  ): (ProjectItem.T.resultArgumentType, ProjectItem.T.continuation) => {
+    switch getResult(this, sourceId) {
+    | Some(result) => (result, getContinuation(this, sourceId)) // already ran
+    | None =>
+      switch rPrevResult {
+      | Error(error) => {
+          setResult(this, sourceId, Error(error))
+          (Error(error), continuation)
+        }
+      | Ok(_prevResult) => {
+          doRunWithContinuation(this, sourceId, continuation)
+          (
+            getResult(this, sourceId)->Belt.Option.getWithDefault(rPrevResult),
+            getContinuation(this, sourceId),
+          )
+        }
+      }
+    }
+  }
+
+  let runAll = (this: t): unit => {
+    let runOrder = getTopologicalSort(this)
+    let initialState = (Ok(InternalExpressionValue.IEvVoid), getStdLib(this))
+    let _finalState = Belt.Array.reduce(runOrder, initialState, (currState, currId) =>
+      tryRunWithContinuation(this, currId, currState)
+    )
+  }
+
+  let run = (this: t, sourceId: string): unit => {
+    let runOrder = getRunOrderFor(this, sourceId)
+    let initialState = (Ok(InternalExpressionValue.IEvVoid), getStdLib(this))
+    let _finalState = Belt.Array.reduce(runOrder, initialState, (currState, currId) =>
+      tryRunWithContinuation(this, currId, currState)
+    )
+  }
+
+  let evaluate = (sourceCode: string) => {
+    let project = createProject()
+    setSource(project, "main", sourceCode)
+    runAll(project)
+    (
+      getResult(project, "main")->Belt.Option.getWithDefault(IEvVoid->Ok),
+      getContinuation(project, "main"),
+    )
+  }
+}
+
+/*
+  PUBLIC FUNCTIONS
+*/
+
+// Create a new this to hold the sources, executables, bindings and other data.
+// The this is a mutable object for use in TypeScript.
+let createProject = (): t => Private.createProject()->T.Private.castFromInternalProject
+
+// Answers the array of existing source ids to enumerate over.
+let getSourceIds = (this: t): array<string> =>
+  this->T.Private.castToInternalProject->Private.getSourceIds
+
+// Sets the source for a given source id.
+let setSource = (this: t, sourceId: string, value: string): unit =>
+  this->T.Private.castToInternalProject->Private.setSource(sourceId, value)
+
+// Gets the source for a given source id.
+let getSource = (this: t, sourceId: string): option<string> =>
+  this->T.Private.castToInternalProject->Private.getSource(sourceId)
+
+// Touches the source for a given source id. This forces the dependency graph to be re-evaluated.
+// Touching source code clears the includes so that they can be reevaluated.
+let touchSource = (this: t, sourceId: string): unit =>
+  this->T.Private.castToInternalProject->Private.touchSource(sourceId)
+
+// Cleans the compilation artifacts for a given source id. The results stay untouched.
+let clean = (this: t, sourceId: string): unit =>
+  this->T.Private.castToInternalProject->Private.clean(sourceId)
+
+// Cleans all compilation artifacts for all the this. The results stay untouched.
+let cleanAll = (this: t): unit => this->T.Private.castToInternalProject->Private.cleanAll
+
+// Cleans results. Compilation stays untouched to rerun the source.
+let cleanResults = (this: t, sourceId: string): unit =>
+  this->T.Private.castToInternalProject->Private.cleanResults(sourceId)
+
+// Cleans all results. Compilations stays untouched to rerun the source.
+let cleanAllResults = (this: t): unit =>
+  this->T.Private.castToInternalProject->Private.cleanAllResults
+
+let getIncludes = (this: t, sourceId: string): ProjectItem.T.includesType =>
+  this->T.Private.castToInternalProject->Private.getIncludes(sourceId)
+
+let getContinues = (this: t, sourceId: string): array<string> =>
+  this->T.Private.castToInternalProject->Private.getContinues(sourceId)
+
+// setContinues acts like an include hidden in the source. It is used to define a continuation.
+let setContinues = (this: t, sourceId: string, continues: array<string>): unit =>
+  this->T.Private.castToInternalProject->Private.setContinues(sourceId, continues)
+
+// This source is not continuing any other source. It is a standalone source.
+// Touches this source also.
+let removeContinues = (this: t, sourceId: string): unit =>
+  this->T.Private.castToInternalProject->Private.removeContinues(sourceId)
+
+// Gets includes and continues for a given source id. SourceId is depending on them
+let getDependencies = (this: t, sourceId: string): array<string> =>
+  this->T.Private.castToInternalProject->Private.getDependencies(sourceId)
+
+// Get source ids depending on a given source id.
+let getDependents = (this: t, sourceId: string): array<string> =>
+  this->T.Private.castToInternalProject->Private.getDependents(sourceId)
+
+// Get run order for all sources. It is a topological sort of the dependency graph.
+let getRunOrder = (this: t) => this->T.Private.castToInternalProject->Private.getRunOrder
+
+// Get run order for a given source id. It is a topological sort of the dependency graph.
+let getRunOrderFor = (this: t, sourceId: string) =>
+  this->T.Private.castToInternalProject->Private.getRunOrderFor(sourceId)
+
+// Parse includes so that you can load them before running. Use getIncludes to get the includes.
+// It is your responsibility to load the includes before running.
+let parseIncludes = (this: t, sourceId: string): unit =>
+  this->T.Private.castToInternalProject->Private.parseIncludes(sourceId)
+
+// Parse the source code if it is not done already. Use getRawParse to get the parse tree
+let rawParse = (this: t, sourceId: string): unit =>
+  this->T.Private.castToInternalProject->Private.rawParse(sourceId)
+
+// Runs the source code.
+// The code is parsed if it is not already done.
+// If it continues/includes another source then it will run that source also if is not already done.
+let run = (this: t, sourceId: string): unit =>
+  this->T.Private.castToInternalProject->Private.run(sourceId)
+
+// Runs all the sources.
+let runAll = (this: t): unit => this->T.Private.castToInternalProject->Private.runAll
+
+// WARNING" getExternalBindings will be deprecated. Cyclic directed graph problems
+// Get the bindings after running the source code.
+let getExternalBindings = (this: t, sourceId: string): ExternalExpressionValue.record =>
+  this->T.Private.castToInternalProject->Private.getExternalBindings(sourceId)
+
+//WARNING: externalResult will be deprecated. Cyclic directed graph problems
+let getExternalResult = (this: t, sourceId: string): option<
+  result<ExternalExpressionValue.t, Reducer_ErrorValue.errorValue>,
+> => this->T.Private.castToInternalProject->Private.getExternalResult(sourceId)
+
+// This is a convenience function to get the result of a single source.
+// You cannot use includes
+let evaluate = (sourceCode: string): ('r, 'b) => {
+  let (result, continuation) = Private.evaluate(sourceCode)
+  (
+    result->Belt.Result.map(InternalExpressionValue.toExternal),
+    continuation->InternalExpressionValue.nameSpaceToTypeScriptBindings,
+  )
+}
+
+let foreignFunctionInterface = (
+  lambdaValue: ExternalExpressionValue.lambdaValue,
+  argArray: array<ExternalExpressionValue.t>,
+  environment: ExternalExpressionValue.environment,
+) => {
+  let internallambdaValue = InternalExpressionValue.lambdaValueToInternal(lambdaValue)
+  let internalArgArray = argArray->Js.Array2.map(InternalExpressionValue.toInternal)
+  let accessors = ProjectAccessorsT.identityAccessorsWithEnvironment(environment)
+  Reducer_Expression_Lambda.foreignFunctionInterface(
+    internallambdaValue,
+    internalArgArray,
+    accessors,
+    Reducer_Expression.reduceExpressionInProject,
+  )->Belt.Result.map(InternalExpressionValue.toExternal)
+}

packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject_IncludeParser.js

@@ -0,0 +1,915 @@
+// Generated by Peggy 2.0.1.
+//
+// https://peggyjs.org/
+
+"use strict";
+
+function peg$subclass(child, parent) {
+  function C() { this.constructor = child; }
+  C.prototype = parent.prototype;
+  child.prototype = new C();
+}
+
+function peg$SyntaxError(message, expected, found, location) {
+  var self = Error.call(this, message);
+  // istanbul ignore next Check is a necessary evil to support older environments
+  if (Object.setPrototypeOf) {
+    Object.setPrototypeOf(self, peg$SyntaxError.prototype);
+  }
+  self.expected = expected;
+  self.found = found;
+  self.location = location;
+  self.name = "SyntaxError";
+  return self;
+}
+
+peg$subclass(peg$SyntaxError, Error);
+
+function peg$padEnd(str, targetLength, padString) {
+  padString = padString || " ";
+  if (str.length > targetLength) { return str; }
+  targetLength -= str.length;
+  padString += padString.repeat(targetLength);
+  return str + padString.slice(0, targetLength);
+}
+
+peg$SyntaxError.prototype.format = function(sources) {
+  var str = "Error: " + this.message;
+  if (this.location) {
+    var src = null;
+    var k;
+    for (k = 0; k < sources.length; k++) {
+      if (sources[k].source === this.location.source) {
+        src = sources[k].text.split(/\r\n|\n|\r/g);
+        break;
+      }
+    }
+    var s = this.location.start;
+    var loc = this.location.source + ":" + s.line + ":" + s.column;
+    if (src) {
+      var e = this.location.end;
+      var filler = peg$padEnd("", s.line.toString().length, ' ');
+      var line = src[s.line - 1];
+      var last = s.line === e.line ? e.column : line.length + 1;
+      var hatLen = (last - s.column) || 1;
+      str += "\n --> " + loc + "\n"
+          + filler + " |\n"
+          + s.line + " | " + line + "\n"
+          + filler + " | " + peg$padEnd("", s.column - 1, ' ')
+          + peg$padEnd("", hatLen, "^");
+    } else {
+      str += "\n at " + loc;
+    }
+  }
+  return str;
+};
+
+peg$SyntaxError.buildMessage = function(expected, found) {
+  var DESCRIBE_EXPECTATION_FNS = {
+    literal: function(expectation) {
+      return "\"" + literalEscape(expectation.text) + "\"";
+    },
+
+    class: function(expectation) {
+      var escapedParts = expectation.parts.map(function(part) {
+        return Array.isArray(part)
+          ? classEscape(part[0]) + "-" + classEscape(part[1])
+          : classEscape(part);
+      });
+
+      return "[" + (expectation.inverted ? "^" : "") + escapedParts.join("") + "]";
+    },
+
+    any: function() {
+      return "any character";
+    },
+
+    end: function() {
+      return "end of input";
+    },
+
+    other: function(expectation) {
+      return expectation.description;
+    }
+  };
+
+  function hex(ch) {
+    return ch.charCodeAt(0).toString(16).toUpperCase();
+  }
+
+  function literalEscape(s) {
+    return s
+      .replace(/\\/g, "\\\\")
+      .replace(/"/g,  "\\\"")
+      .replace(/\0/g, "\\0")
+      .replace(/\t/g, "\\t")
+      .replace(/\n/g, "\\n")
+      .replace(/\r/g, "\\r")
+      .replace(/[\x00-\x0F]/g,          function(ch) { return "\\x0" + hex(ch); })
+      .replace(/[\x10-\x1F\x7F-\x9F]/g, function(ch) { return "\\x"  + hex(ch); });
+  }
+
+  function classEscape(s) {
+    return s
+      .replace(/\\/g, "\\\\")
+      .replace(/\]/g, "\\]")
+      .replace(/\^/g, "\\^")
+      .replace(/-/g,  "\\-")
+      .replace(/\0/g, "\\0")
+      .replace(/\t/g, "\\t")
+      .replace(/\n/g, "\\n")
+      .replace(/\r/g, "\\r")
+      .replace(/[\x00-\x0F]/g,          function(ch) { return "\\x0" + hex(ch); })
+      .replace(/[\x10-\x1F\x7F-\x9F]/g, function(ch) { return "\\x"  + hex(ch); });
+  }
+
+  function describeExpectation(expectation) {
+    return DESCRIBE_EXPECTATION_FNS[expectation.type](expectation);
+  }
+
+  function describeExpected(expected) {
+    var descriptions = expected.map(describeExpectation);
+    var i, j;
+
+    descriptions.sort();
+
+    if (descriptions.length > 0) {
+      for (i = 1, j = 1; i < descriptions.length; i++) {
+        if (descriptions[i - 1] !== descriptions[i]) {
+          descriptions[j] = descriptions[i];
+          j++;
+        }
+      }
+      descriptions.length = j;
+    }
+
+    switch (descriptions.length) {
+      case 1:
+        return descriptions[0];
+
+      case 2:
+        return descriptions[0] + " or " + descriptions[1];
+
+      default:
+        return descriptions.slice(0, -1).join(", ")
+          + ", or "
+          + descriptions[descriptions.length - 1];
+    }
+  }
+
+  function describeFound(found) {
+    return found ? "\"" + literalEscape(found) + "\"" : "end of input";
+  }
+
+  return "Expected " + describeExpected(expected) + " but " + describeFound(found) + " found.";
+};
+
+function peg$parse(input, options) {
+  options = options !== undefined ? options : {};
+
+  var peg$FAILED = {};
+  var peg$source = options.grammarSource;
+
+  var peg$startRuleFunctions = { start: peg$parsestart };
+  var peg$startRuleFunction = peg$parsestart;
+
+  var peg$c0 = "#include";
+  var peg$c1 = "'";
+  var peg$c2 = "\"";
+  var peg$c3 = "//";
+  var peg$c4 = "/*";
+  var peg$c5 = "*/";
+
+  var peg$r0 = /^[^']/;
+  var peg$r1 = /^[^"]/;
+  var peg$r2 = /^[^*]/;
+  var peg$r3 = /^[ \t]/;
+  var peg$r4 = /^[\n\r]/;
+  var peg$r5 = /^[^\r\n]/;
+
+  var peg$e0 = peg$literalExpectation("#include", false);
+  var peg$e1 = peg$otherExpectation("string");
+  var peg$e2 = peg$literalExpectation("'", false);
+  var peg$e3 = peg$classExpectation(["'"], true, false);
+  var peg$e4 = peg$literalExpectation("\"", false);
+  var peg$e5 = peg$classExpectation(["\""], true, false);
+  var peg$e6 = peg$literalExpectation("//", false);
+  var peg$e7 = peg$literalExpectation("/*", false);
+  var peg$e8 = peg$classExpectation(["*"], true, false);
+  var peg$e9 = peg$literalExpectation("*/", false);
+  var peg$e10 = peg$otherExpectation("white space");
+  var peg$e11 = peg$classExpectation([" ", "\t"], false, false);
+  var peg$e12 = peg$otherExpectation("newline");
+  var peg$e13 = peg$classExpectation(["\n", "\r"], false, false);
+  var peg$e14 = peg$classExpectation(["\r", "\n"], true, false);
+
+  var peg$f0 = function(head, tail) {return [head, ...tail].filter( e => e != '');};
+  var peg$f1 = function() {return [];};
+  var peg$f2 = function(characters) {return characters.join('');};
+  var peg$f3 = function(characters) {return characters.join('');};
+  var peg$f4 = function() { return '';};
+  var peg$f5 = function() { return '';};
+  var peg$currPos = 0;
+  var peg$savedPos = 0;
+  var peg$posDetailsCache = [{ line: 1, column: 1 }];
+  var peg$maxFailPos = 0;
+  var peg$maxFailExpected = [];
+  var peg$silentFails = 0;
+
+  var peg$resultsCache = {};
+
+  var peg$result;
+
+  if ("startRule" in options) {
+    if (!(options.startRule in peg$startRuleFunctions)) {
+      throw new Error("Can't start parsing from rule \"" + options.startRule + "\".");
+    }
+
+    peg$startRuleFunction = peg$startRuleFunctions[options.startRule];
+  }
+
+  function text() {
+    return input.substring(peg$savedPos, peg$currPos);
+  }
+
+  function offset() {
+    return peg$savedPos;
+  }
+
+  function range() {
+    return {
+      source: peg$source,
+      start: peg$savedPos,
+      end: peg$currPos
+    };
+  }
+
+  function location() {
+    return peg$computeLocation(peg$savedPos, peg$currPos);
+  }
+
+  function expected(description, location) {
+    location = location !== undefined
+      ? location
+      : peg$computeLocation(peg$savedPos, peg$currPos);
+
+    throw peg$buildStructuredError(
+      [peg$otherExpectation(description)],
+      input.substring(peg$savedPos, peg$currPos),
+      location
+    );
+  }
+
+  function error(message, location) {
+    location = location !== undefined
+      ? location
+      : peg$computeLocation(peg$savedPos, peg$currPos);
+
+    throw peg$buildSimpleError(message, location);
+  }
+
+  function peg$literalExpectation(text, ignoreCase) {
+    return { type: "literal", text: text, ignoreCase: ignoreCase };
+  }
+
+  function peg$classExpectation(parts, inverted, ignoreCase) {
+    return { type: "class", parts: parts, inverted: inverted, ignoreCase: ignoreCase };
+  }
+
+  function peg$anyExpectation() {
+    return { type: "any" };
+  }
+
+  function peg$endExpectation() {
+    return { type: "end" };
+  }
+
+  function peg$otherExpectation(description) {
+    return { type: "other", description: description };
+  }
+
+  function peg$computePosDetails(pos) {
+    var details = peg$posDetailsCache[pos];
+    var p;
+
+    if (details) {
+      return details;
+    } else {
+      p = pos - 1;
+      while (!peg$posDetailsCache[p]) {
+        p--;
+      }
+
+      details = peg$posDetailsCache[p];
+      details = {
+        line: details.line,
+        column: details.column
+      };
+
+      while (p < pos) {
+        if (input.charCodeAt(p) === 10) {
+          details.line++;
+          details.column = 1;
+        } else {
+          details.column++;
+        }
+
+        p++;
+      }
+
+      peg$posDetailsCache[pos] = details;
+
+      return details;
+    }
+  }
+
+  function peg$computeLocation(startPos, endPos) {
+    var startPosDetails = peg$computePosDetails(startPos);
+    var endPosDetails = peg$computePosDetails(endPos);
+
+    return {
+      source: peg$source,
+      start: {
+        offset: startPos,
+        line: startPosDetails.line,
+        column: startPosDetails.column
+      },
+      end: {
+        offset: endPos,
+        line: endPosDetails.line,
+        column: endPosDetails.column
+      }
+    };
+  }
+
+  function peg$fail(expected) {
+    if (peg$currPos < peg$maxFailPos) { return; }
+
+    if (peg$currPos > peg$maxFailPos) {
+      peg$maxFailPos = peg$currPos;
+      peg$maxFailExpected = [];
+    }
+
+    peg$maxFailExpected.push(expected);
+  }
+
+  function peg$buildSimpleError(message, location) {
+    return new peg$SyntaxError(message, null, null, location);
+  }
+
+  function peg$buildStructuredError(expected, found, location) {
+    return new peg$SyntaxError(
+      peg$SyntaxError.buildMessage(expected, found),
+      expected,
+      found,
+      location
+    );
+  }
+
+  function peg$parsestart() {
+    var s0, s1, s2, s3;
+
+    var key = peg$currPos * 10 + 0;
+    var cached = peg$resultsCache[key];
+
+    if (cached) {
+      peg$currPos = cached.nextPos;
+
+      return cached.result;
+    }
+
+    s0 = peg$currPos;
+    s1 = peg$parseincludes();
+    if (s1 !== peg$FAILED) {
+      s2 = [];
+      s3 = peg$parsenewLine();
+      while (s3 !== peg$FAILED) {
+        s2.push(s3);
+        s3 = peg$parsenewLine();
+      }
+      s3 = peg$parseignore();
+      s0 = s1;
+    } else {
+      peg$currPos = s0;
+      s0 = peg$FAILED;
+    }
+
+    peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };
+
+    return s0;
+  }
+
+  function peg$parseincludes() {
+    var s0, s1, s2, s3, s4, s5;
+
+    var key = peg$currPos * 10 + 1;
+    var cached = peg$resultsCache[key];
+
+    if (cached) {
+      peg$currPos = cached.nextPos;
+
+      return cached.result;
+    }
+
+    s0 = peg$currPos;
+    s1 = peg$parseincludeStatement();
+    if (s1 !== peg$FAILED) {
+      s2 = [];
+      s3 = peg$currPos;
+      s4 = [];
+      s5 = peg$parsenewLine();
+      if (s5 !== peg$FAILED) {
+        while (s5 !== peg$FAILED) {
+          s4.push(s5);
+          s5 = peg$parsenewLine();
+        }
+      } else {
+        s4 = peg$FAILED;
+      }
+      if (s4 !== peg$FAILED) {
+        s5 = peg$parseincludeStatement();
+        if (s5 !== peg$FAILED) {
+          s3 = s5;
+        } else {
+          peg$currPos = s3;
+          s3 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s3;
+        s3 = peg$FAILED;
+      }
+      while (s3 !== peg$FAILED) {
+        s2.push(s3);
+        s3 = peg$currPos;
+        s4 = [];
+        s5 = peg$parsenewLine();
+        if (s5 !== peg$FAILED) {
+          while (s5 !== peg$FAILED) {
+            s4.push(s5);
+            s5 = peg$parsenewLine();
+          }
+        } else {
+          s4 = peg$FAILED;
+        }
+        if (s4 !== peg$FAILED) {
+          s5 = peg$parseincludeStatement();
+          if (s5 !== peg$FAILED) {
+            s3 = s5;
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s3;
+          s3 = peg$FAILED;
+        }
+      }
+      peg$savedPos = s0;
+      s0 = peg$f0(s1, s2);
+    } else {
+      peg$currPos = s0;
+      s0 = peg$FAILED;
+    }
+    if (s0 === peg$FAILED) {
+      s0 = peg$currPos;
+      s1 = peg$parseignore();
+      peg$savedPos = s0;
+      s1 = peg$f1();
+      s0 = s1;
+    }
+
+    peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };
+
+    return s0;
+  }
+
+  function peg$parseincludeStatement() {
+    var s0, s1, s2, s3, s4, s5;
+
+    var key = peg$currPos * 10 + 2;
+    var cached = peg$resultsCache[key];
+
+    if (cached) {
+      peg$currPos = cached.nextPos;
+
+      return cached.result;
+    }
+
+    s0 = peg$currPos;
+    if (input.substr(peg$currPos, 8) === peg$c0) {
+      s1 = peg$c0;
+      peg$currPos += 8;
+    } else {
+      s1 = peg$FAILED;
+      if (peg$silentFails === 0) { peg$fail(peg$e0); }
+    }
+    if (s1 !== peg$FAILED) {
+      s2 = [];
+      s3 = peg$parse_();
+      while (s3 !== peg$FAILED) {
+        s2.push(s3);
+        s3 = peg$parse_();
+      }
+      s3 = peg$parsestring();
+      if (s3 !== peg$FAILED) {
+        s4 = [];
+        s5 = peg$parse_();
+        while (s5 !== peg$FAILED) {
+          s4.push(s5);
+          s5 = peg$parse_();
+        }
+        s0 = s3;
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+    } else {
+      peg$currPos = s0;
+      s0 = peg$FAILED;
+    }
+    if (s0 === peg$FAILED) {
+      s0 = peg$parsecomment();
+      if (s0 === peg$FAILED) {
+        s0 = peg$parsedelimitedComment();
+      }
+    }
+
+    peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };
+
+    return s0;
+  }
+
+  function peg$parsestring() {
+    var s0, s1, s2, s3, s4;
+
+    var key = peg$currPos * 10 + 3;
+    var cached = peg$resultsCache[key];
+
+    if (cached) {
+      peg$currPos = cached.nextPos;
+
+      return cached.result;
+    }
+
+    peg$silentFails++;
+    s0 = peg$currPos;
+    s1 = peg$currPos;
+    if (input.charCodeAt(peg$currPos) === 39) {
+      s2 = peg$c1;
+      peg$currPos++;
+    } else {
+      s2 = peg$FAILED;
+      if (peg$silentFails === 0) { peg$fail(peg$e2); }
+    }
+    if (s2 !== peg$FAILED) {
+      s3 = [];
+      if (peg$r0.test(input.charAt(peg$currPos))) {
+        s4 = input.charAt(peg$currPos);
+        peg$currPos++;
+      } else {
+        s4 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$e3); }
+      }
+      while (s4 !== peg$FAILED) {
+        s3.push(s4);
+        if (peg$r0.test(input.charAt(peg$currPos))) {
+          s4 = input.charAt(peg$currPos);
+          peg$currPos++;
+        } else {
+          s4 = peg$FAILED;
+          if (peg$silentFails === 0) { peg$fail(peg$e3); }
+        }
+      }
+      if (input.charCodeAt(peg$currPos) === 39) {
+        s4 = peg$c1;
+        peg$currPos++;
+      } else {
+        s4 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$e2); }
+      }
+      if (s4 !== peg$FAILED) {
+        s1 = s3;
+      } else {
+        peg$currPos = s1;
+        s1 = peg$FAILED;
+      }
+    } else {
+      peg$currPos = s1;
+      s1 = peg$FAILED;
+    }
+    if (s1 !== peg$FAILED) {
+      peg$savedPos = s0;
+      s1 = peg$f2(s1);
+    }
+    s0 = s1;
+    if (s0 === peg$FAILED) {
+      s0 = peg$currPos;
+      s1 = peg$currPos;
+      if (input.charCodeAt(peg$currPos) === 34) {
+        s2 = peg$c2;
+        peg$currPos++;
+      } else {
+        s2 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$e4); }
+      }
+      if (s2 !== peg$FAILED) {
+        s3 = [];
+        if (peg$r1.test(input.charAt(peg$currPos))) {
+          s4 = input.charAt(peg$currPos);
+          peg$currPos++;
+        } else {
+          s4 = peg$FAILED;
+          if (peg$silentFails === 0) { peg$fail(peg$e5); }
+        }
+        while (s4 !== peg$FAILED) {
+          s3.push(s4);
+          if (peg$r1.test(input.charAt(peg$currPos))) {
+            s4 = input.charAt(peg$currPos);
+            peg$currPos++;
+          } else {
+            s4 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$e5); }
+          }
+        }
+        if (input.charCodeAt(peg$currPos) === 34) {
+          s4 = peg$c2;
+          peg$currPos++;
+        } else {
+          s4 = peg$FAILED;
+          if (peg$silentFails === 0) { peg$fail(peg$e4); }
+        }
+        if (s4 !== peg$FAILED) {
+          s1 = s3;
+        } else {
+          peg$currPos = s1;
+          s1 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s1;
+        s1 = peg$FAILED;
+      }
+      if (s1 !== peg$FAILED) {
+        peg$savedPos = s0;
+        s1 = peg$f3(s1);
+      }
+      s0 = s1;
+    }
+    peg$silentFails--;
+    if (s0 === peg$FAILED) {
+      s1 = peg$FAILED;
+      if (peg$silentFails === 0) { peg$fail(peg$e1); }
+    }
+
+    peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };
+
+    return s0;
+  }
+
+  function peg$parseignore() {
+    var s0, s1;
+
+    var key = peg$currPos * 10 + 4;
+    var cached = peg$resultsCache[key];
+
+    if (cached) {
+      peg$currPos = cached.nextPos;
+
+      return cached.result;
+    }
+
+    s0 = [];
+    s1 = peg$parseany();
+    if (s1 === peg$FAILED) {
+      s1 = peg$parsenewLine();
+      if (s1 === peg$FAILED) {
+        s1 = peg$parse_();
+      }
+    }
+    while (s1 !== peg$FAILED) {
+      s0.push(s1);
+      s1 = peg$parseany();
+      if (s1 === peg$FAILED) {
+        s1 = peg$parsenewLine();
+        if (s1 === peg$FAILED) {
+          s1 = peg$parse_();
+        }
+      }
+    }
+
+    peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };
+
+    return s0;
+  }
+
+  function peg$parsecomment() {
+    var s0, s1, s2, s3;
+
+    var key = peg$currPos * 10 + 5;
+    var cached = peg$resultsCache[key];
+
+    if (cached) {
+      peg$currPos = cached.nextPos;
+
+      return cached.result;
+    }
+
+    s0 = peg$currPos;
+    if (input.substr(peg$currPos, 2) === peg$c3) {
+      s1 = peg$c3;
+      peg$currPos += 2;
+    } else {
+      s1 = peg$FAILED;
+      if (peg$silentFails === 0) { peg$fail(peg$e6); }
+    }
+    if (s1 !== peg$FAILED) {
+      s2 = [];
+      s3 = peg$parseany();
+      while (s3 !== peg$FAILED) {
+        s2.push(s3);
+        s3 = peg$parseany();
+      }
+      peg$savedPos = s0;
+      s0 = peg$f4();
+    } else {
+      peg$currPos = s0;
+      s0 = peg$FAILED;
+    }
+
+    peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };
+
+    return s0;
+  }
+
+  function peg$parsedelimitedComment() {
+    var s0, s1, s2, s3;
+
+    var key = peg$currPos * 10 + 6;
+    var cached = peg$resultsCache[key];
+
+    if (cached) {
+      peg$currPos = cached.nextPos;
+
+      return cached.result;
+    }
+
+    s0 = peg$currPos;
+    if (input.substr(peg$currPos, 2) === peg$c4) {
+      s1 = peg$c4;
+      peg$currPos += 2;
+    } else {
+      s1 = peg$FAILED;
+      if (peg$silentFails === 0) { peg$fail(peg$e7); }
+    }
+    if (s1 !== peg$FAILED) {
+      s2 = [];
+      if (peg$r2.test(input.charAt(peg$currPos))) {
+        s3 = input.charAt(peg$currPos);
+        peg$currPos++;
+      } else {
+        s3 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$e8); }
+      }
+      while (s3 !== peg$FAILED) {
+        s2.push(s3);
+        if (peg$r2.test(input.charAt(peg$currPos))) {
+          s3 = input.charAt(peg$currPos);
+          peg$currPos++;
+        } else {
+          s3 = peg$FAILED;
+          if (peg$silentFails === 0) { peg$fail(peg$e8); }
+        }
+      }
+      if (input.substr(peg$currPos, 2) === peg$c5) {
+        s3 = peg$c5;
+        peg$currPos += 2;
+      } else {
+        s3 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$e9); }
+      }
+      if (s3 !== peg$FAILED) {
+        peg$savedPos = s0;
+        s0 = peg$f5();
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+    } else {
+      peg$currPos = s0;
+      s0 = peg$FAILED;
+    }
+
+    peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };
+
+    return s0;
+  }
+
+  function peg$parse_() {
+    var s0, s1;
+
+    var key = peg$currPos * 10 + 7;
+    var cached = peg$resultsCache[key];
+
+    if (cached) {
+      peg$currPos = cached.nextPos;
+
+      return cached.result;
+    }
+
+    peg$silentFails++;
+    if (peg$r3.test(input.charAt(peg$currPos))) {
+      s0 = input.charAt(peg$currPos);
+      peg$currPos++;
+    } else {
+      s0 = peg$FAILED;
+      if (peg$silentFails === 0) { peg$fail(peg$e11); }
+    }
+    peg$silentFails--;
+    if (s0 === peg$FAILED) {
+      s1 = peg$FAILED;
+      if (peg$silentFails === 0) { peg$fail(peg$e10); }
+    }
+
+    peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };
+
+    return s0;
+  }
+
+  function peg$parsenewLine() {
+    var s0, s1;
+
+    var key = peg$currPos * 10 + 8;
+    var cached = peg$resultsCache[key];
+
+    if (cached) {
+      peg$currPos = cached.nextPos;
+
+      return cached.result;
+    }
+
+    peg$silentFails++;
+    if (peg$r4.test(input.charAt(peg$currPos))) {
+      s0 = input.charAt(peg$currPos);
+      peg$currPos++;
+    } else {
+      s0 = peg$FAILED;
+      if (peg$silentFails === 0) { peg$fail(peg$e13); }
+    }
+    peg$silentFails--;
+    if (s0 === peg$FAILED) {
+      s1 = peg$FAILED;
+      if (peg$silentFails === 0) { peg$fail(peg$e12); }
+    }
+
+    peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };
+
+    return s0;
+  }
+
+  function peg$parseany() {
+    var s0;
+
+    var key = peg$currPos * 10 + 9;
+    var cached = peg$resultsCache[key];
+
+    if (cached) {
+      peg$currPos = cached.nextPos;
+
+      return cached.result;
+    }
+
+    if (peg$r5.test(input.charAt(peg$currPos))) {
+      s0 = input.charAt(peg$currPos);
+      peg$currPos++;
+    } else {
+      s0 = peg$FAILED;
+      if (peg$silentFails === 0) { peg$fail(peg$e14); }
+    }
+
+    peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };
+
+    return s0;
+  }
+
+  peg$result = peg$startRuleFunction();
+
+  if (peg$result !== peg$FAILED && peg$currPos === input.length) {
+    return peg$result;
+  } else {
+    if (peg$result !== peg$FAILED && peg$currPos < input.length) {
+      peg$fail(peg$endExpectation());
+    }
+
+    throw peg$buildStructuredError(
+      peg$maxFailExpected,
+      peg$maxFailPos < input.length ? input.charAt(peg$maxFailPos) : null,
+      peg$maxFailPos < input.length
+        ? peg$computeLocation(peg$maxFailPos, peg$maxFailPos + 1)
+        : peg$computeLocation(peg$maxFailPos, peg$maxFailPos)
+    );
+  }
+}
+
+module.exports = {
+  SyntaxError: peg$SyntaxError,
+  parse: peg$parse
+};

packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject_IncludeParser.peggy

@@ -0,0 +1,41 @@
+// Includes are at the start of the file, before any other code. 
+// There might be some comments before or between the includes.
+// #include "string"
+// #include "string2"
+
+
+start
+  = @includes newLine* ignore
+
+includes
+ = head:includeStatement tail:(newLine+ @includeStatement)* 
+ {return [head, ...tail].filter( e => e != '');}
+ / ignore 
+ {return [];}
+
+includeStatement
+  = '#include' _* @string _* 
+  / comment
+  / delimitedComment
+
+string 'string'
+  = characters:("'" @([^'])* "'") {return characters.join('');} 
+  / characters:('"' @([^"])* '"') {return characters.join('');}
+
+ignore = (any / newLine / _)*
+
+comment
+= '//'any*
+{ return '';}
+
+delimitedComment  
+= '/*' ([^*]*) '*/'
+{ return '';}
+
+_ "white space"
+  = [ \t]
+
+newLine "newline"
+  = [\n\r]
+  
+any = [^\r\n]

packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject_ParseIncludes.res

@@ -0,0 +1,8 @@
+@module("./ReducerProject_IncludeParser.js") external parse__: string => array<string> = "parse"
+
+let parseIncludes = (expr: string): array<string> =>
+  try {
+    parse__(expr)
+  } catch {
+  | Js.Exn.Error(_obj) => []
+  }

packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject_ProjectAccessors_T.res

@@ -0,0 +1,24 @@
+module ProjectItemT = ReducerProject_ProjectItem_T
+module Bindings = Reducer_Bindings
+module ExpressionT = Reducer_Expression_T
+module InternalExpressionValue = ReducerInterface_InternalExpressionValue
+
+type projectAccessors = {
+  stdLib: Reducer_Bindings.t,
+  environment: ExpressionT.environment,
+  mutable continuation: ProjectItemT.continuationArgumentType,
+}
+
+type t = projectAccessors
+
+let identityAccessors: t = {
+  continuation: Bindings.emptyBindings,
+  stdLib: ReducerInterface_StdLib.internalStdLib,
+  environment: InternalExpressionValue.defaultEnvironment,
+}
+
+let identityAccessorsWithEnvironment = (environment): t => {
+  continuation: Bindings.emptyBindings,
+  stdLib: ReducerInterface_StdLib.internalStdLib,
+  environment: environment,
+}

packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject_ProjectItem.res

@@ -0,0 +1,176 @@
+// TODO: Use actual types instead of aliases in public functions
+// TODO: Use topological sorting to prevent unnecessary runs
+module Bindings = Reducer_Bindings
+module Continuation = ReducerInterface_Value_Continuation
+module ExpressionT = Reducer_Expression_T
+module InternalExpressionValue = ReducerInterface_InternalExpressionValue
+module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
+module ReducerFnT = ReducerProject_ReducerFn_T
+module T = ReducerProject_ProjectItem_T
+
+type projectItem = T.projectItem
+type t = T.t
+
+let emptyItem = T.ProjectItem({
+  source: "",
+  rawParse: None,
+  expression: None,
+  continuation: Bindings.emptyBindings,
+  result: None,
+  continues: [],
+  includes: []->Ok,
+})
+// source -> rawParse -> includes -> expression -> continuation -> externalBindings -> result -> externalResult
+
+let getSource = (T.ProjectItem(r)): T.sourceType => r.source
+let getRawParse = (T.ProjectItem(r)): T.rawParseType => r.rawParse
+let getExpression = (T.ProjectItem(r)): T.expressionType => r.expression
+let getContinuation = (T.ProjectItem(r)): T.continuationArgumentType => r.continuation
+let toExternalBindings = continuation =>
+  continuation->InternalExpressionValue.nameSpaceToTypeScriptBindings
+let getResult = (T.ProjectItem(r)): T.resultType => r.result
+let getExternalResult = (T.ProjectItem(r)): T.externalResultType =>
+  r.result->Belt.Option.map(opt =>
+    opt->Belt.Result.map(value => value->InternalExpressionValue.toExternal)
+  )
+
+let getContinues = (T.ProjectItem(r)): T.continuesType => r.continues
+let getIncludes = (T.ProjectItem(r)): T.includesType => r.includes
+
+let touchSource = (this: t): t => {
+  let T.ProjectItem(r) = emptyItem
+  T.ProjectItem({
+    ...r,
+    includes: getIncludes(this),
+    continues: getContinues(this),
+    source: getSource(this),
+  })
+}
+let touchRawParse = (this: t): t => {
+  let T.ProjectItem(r) = emptyItem
+  T.ProjectItem({
+    ...r,
+    continues: getContinues(this),
+    source: getSource(this),
+    rawParse: getRawParse(this),
+    includes: getIncludes(this),
+  })
+}
+let touchExpression = (this: t): t => {
+  let T.ProjectItem(r) = emptyItem
+  T.ProjectItem({
+    ...r,
+    continues: getContinues(this),
+    source: getSource(this),
+    rawParse: getRawParse(this),
+    includes: getIncludes(this),
+    expression: getExpression(this),
+  })
+}
+
+let setSource = (T.ProjectItem(r): t, source: T.sourceArgumentType): t =>
+  T.ProjectItem({...r, source: source})->touchSource
+
+let setRawParse = (T.ProjectItem(r): t, rawParse: T.rawParseArgumentType): t =>
+  T.ProjectItem({...r, rawParse: Some(rawParse)})->touchRawParse
+
+let setExpression = (T.ProjectItem(r): t, expression: T.expressionArgumentType): t =>
+  T.ProjectItem({...r, expression: Some(expression)})->touchExpression
+
+let setContinuation = (T.ProjectItem(r): t, continuation: T.continuationArgumentType): t => {
+  T.ProjectItem({...r, continuation: continuation})
+}
+
+let setResult = (T.ProjectItem(r): t, result: T.resultArgumentType): t => T.ProjectItem({
+  ...r,
+  result: Some(result),
+})
+
+let cleanResults = touchExpression
+
+let clean = (this: t): t => {
+  let T.ProjectItem(r) = emptyItem
+  T.ProjectItem({
+    ...r,
+    source: getSource(this),
+    continuation: getContinuation(this),
+    result: getResult(this),
+  })
+}
+
+let getImmediateDependencies = (this: t): T.includesType =>
+  getIncludes(this)->Belt.Result.map(Js.Array2.concat(_, getContinues(this)))
+
+let setContinues = (T.ProjectItem(r): t, continues: array<string>): t =>
+  T.ProjectItem({...r, continues: continues})->touchSource
+let removeContinues = (T.ProjectItem(r): t): t => T.ProjectItem({...r, continues: []})->touchSource
+
+let setIncludes = (T.ProjectItem(r): t, includes: T.includesType): t => T.ProjectItem({
+  ...r,
+  includes: includes,
+})
+
+//TODO: forward parse errors to the user
+let parseIncludes = (this: t): t =>
+  setIncludes(this, getSource(this)->ReducerProject_ParseIncludes.parseIncludes->Ok)
+
+let doRawParse = (this: t): T.rawParseArgumentType => this->getSource->Reducer_Peggy_Parse.parse
+
+let rawParse = (this: t): t =>
+  this->getRawParse->E.O2.defaultFn(() => doRawParse(this))->setRawParse(this, _)
+
+let doBuildExpression = (this: t): T.expressionType =>
+  this
+  ->getRawParse
+  ->Belt.Option.map(o => o->Belt.Result.map(r => r->Reducer_Peggy_ToExpression.fromNode))
+
+let buildExpression = (this: t): t => {
+  let withRawParse: t = this->rawParse
+  switch withRawParse->getExpression {
+  | Some(_) => withRawParse
+  | None =>
+    withRawParse
+    ->doBuildExpression
+    ->Belt.Option.map(setExpression(withRawParse, _))
+    ->E.O2.defaultFn(() => withRawParse)
+  }
+}
+
+let wrappedReducer = (
+  rExpression: T.expressionArgumentType,
+  aContinuation: T.continuation,
+  accessors: ProjectAccessorsT.t,
+): T.resultArgumentType => {
+  Belt.Result.flatMap(
+    rExpression,
+    Reducer_Expression.reduceExpressionInProject(_, aContinuation, accessors),
+  )
+}
+
+let doBuildResult = (
+  this: t,
+  aContinuation: T.continuation,
+  accessors: ProjectAccessorsT.t,
+): T.resultType =>
+  this
+  ->getExpression
+  ->Belt.Option.map(
+    Belt.Result.flatMap(
+      _,
+      Reducer_Expression.reduceExpressionInProject(_, aContinuation, accessors),
+    ),
+  )
+
+let buildResult = (this: t, aContinuation: T.continuation, accessors: ProjectAccessorsT.t): t => {
+  let withExpression: t = this->buildExpression
+  switch withExpression->getResult {
+  | Some(_) => withExpression
+  | None =>
+    withExpression
+    ->doBuildResult(aContinuation, accessors)
+    ->Belt.Option.map(setResult(withExpression, _))
+    ->E.O2.defaultFn(() => withExpression)
+  }
+}
+
+let run = buildResult

packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject_ProjectItem_T.res

@@ -0,0 +1,39 @@
+module Parse = Reducer_Peggy_Parse
+module ExpressionT = Reducer_Expression_T
+module InternalExpressionValue = ReducerInterface_InternalExpressionValue
+module ExternalExpressionValue = ReducerInterface_ExternalExpressionValue
+open Reducer_ErrorValue
+
+type sourceArgumentType = string
+type sourceType = string
+type rawParseArgumentType = result<Parse.node, errorValue>
+type rawParseType = option<rawParseArgumentType>
+type expressionArgumentType = result<ExpressionT.t, errorValue>
+type expressionType = option<expressionArgumentType>
+type continuation = InternalExpressionValue.nameSpace
+type continuationArgumentType = InternalExpressionValue.nameSpace
+type continuationType = option<continuationArgumentType>
+type continuationResultType = option<result<continuationArgumentType, errorValue>>
+type externalBindingsArgumentType = ExternalExpressionValue.record
+type externalBindingsType = option<externalBindingsArgumentType>
+type resultArgumentType = result<InternalExpressionValue.t, errorValue>
+type resultType = option<resultArgumentType>
+type externalResultArgumentType = result<ExternalExpressionValue.t, errorValue>
+type externalResultType = option<externalResultArgumentType>
+type continuesArgumentType = array<string>
+type continuesType = array<string>
+type includesArgumentType = string
+type includesType = result<array<string>, errorValue>
+
+type projectItem =
+  | ProjectItem({
+      source: sourceType,
+      rawParse: rawParseType,
+      expression: expressionType,
+      continuation: continuationArgumentType,
+      result: resultType,
+      continues: continuesType,
+      includes: includesType,
+    })
+
+type t = projectItem

packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject_ReducerFn_T.res

@@ -0,0 +1,9 @@
+module ExpressionT = Reducer_Expression_T
+module InternalExpressionValue = ReducerInterface_InternalExpressionValue
+module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
+
+type t = (
+  ExpressionT.t,
+  ExpressionT.bindings,
+  ProjectAccessorsT.t,
+) => result<InternalExpressionValue.t, Reducer_ErrorValue.errorValue>

packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject_T.res

@@ -0,0 +1,25 @@
+module ProjectItem = ReducerProject_ProjectItem
+module ExpressionT = Reducer_Expression_T
+module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
+
+type project = Object
+type t = project
+
+module Private = {
+  type internalProject = {
+    "items": Belt.Map.String.t<ProjectItem.t>,
+    "stdLib": Reducer_Bindings.t,
+    "environment": ExpressionT.environment,
+  }
+  type t = internalProject
+
+  @set
+  external setFieldItems: (t, Belt.Map.String.t<ProjectItem.t>) => unit = "items"
+  @set
+  external setFieldStdLib: (t, Reducer_Bindings.t) => unit = "stdLib"
+  @set
+  external setFieldEnvironment: (t, ExpressionT.environment) => unit = "stdLib"
+
+  external castFromInternalProject: t => project = "%identity"
+  external castToInternalProject: project => t = "%identity"
+}

packages/squiggle-lang/src/rescript/TypescriptInterface.res

@@ -34,17 +34,17 @@ type resultString = result<string, distributionError>
 @genType
 let makeSampleSetDist = SampleSetDist.make
 
-@genType
-let evaluate = Reducer.evaluate
+// @genType
+// let evaluate = Reducer.evaluate
 
-@genType
-let evaluateUsingOptions = Reducer.evaluateUsingOptions
+// @genType
+// let evaluateUsingOptions = Reducer.evaluateUsingOptions
 
 @genType
 let parse = Reducer_Peggy_Parse.parse
 
-@genType
-let evaluatePartialUsingExternalBindings = Reducer.evaluatePartialUsingExternalBindings
+// @genType
+// let evaluatePartialUsingExternalBindings = Reducer.evaluatePartialUsingExternalBindings
 
 @genType
 type externalBindings = Reducer.externalBindings
@@ -91,8 +91,8 @@ type environment = ReducerInterface_ExternalExpressionValue.environment
 @genType
 let defaultEnvironment = ReducerInterface_ExternalExpressionValue.defaultEnvironment
 
-@genType
-let foreignFunctionInterface = Reducer.foreignFunctionInterface
+// @genType
+// let foreignFunctionInterface = Reducer.foreignFunctionInterface
 
 @genType
 type declarationArg = Declaration.arg