Function definition evaluated

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

@@ -7,6 +7,6 @@ describe("Parse function assignment", () => {
   //MathJs does not allow blocks in function definitions
 })
 
-Skip.describe("Evaluate function assignment", () => {
-  testParseToBe("f(x)=x; f(1)", "Ok(1)")
+describe("Evaluate function assignment", () => {
+  testEvalToBe("f(x)=x; f(1)", "Ok(1)")
 })

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

@@ -20,28 +20,29 @@ let rec replaceSymbols = (expression: expression, bindings: ExpressionT.bindings
   expression,
   errorValue,
 > => {
-  let getParameters = (bindings: ExpressionT.bindings): list<string> => {
-    let eParameters = Belt.Map.String.getWithDefault(bindings, "$parameters", EParameters(list{}))
+  let getParameters = (bindings: ExpressionT.bindings): array<string> => {
+    let eParameters = Belt.Map.String.getWithDefault(bindings, "$parameters", EParameters([]))
     switch eParameters {
     | EParameters(parameters) => parameters
-    | _ => list{}
+    | _ => []
     }
   }
 
   let putParameters = (
     bindings: ExpressionT.bindings,
-    parameters: list<string>,
+    parameters: array<string>,
   ): ExpressionT.bindings =>
     Belt.Map.String.set(bindings, "$parameters", ExpressionT.EParameters(parameters))
+
   switch expression {
   | ExpressionT.EValue(EvSymbol(aSymbol)) => {
       let parameters = getParameters(bindings)
-      switch Belt.List.has(parameters, aSymbol, (a, b) => a == b) {
+      switch Js.Array2.some(parameters, a => a == aSymbol) {
       | true => expression->Ok // We cannot bind the parameters with global values
       | false =>
-    switch bindings->Belt.Map.String.get(aSymbol) {
-    | Some(boundExpression) => boundExpression->Ok
-    | None => RESymbolNotFound(aSymbol)->Error
+        switch bindings->Belt.Map.String.get(aSymbol) {
+        | Some(boundExpression) => boundExpression->Ok
+        | None => RESymbolNotFound(aSymbol)->Error
         }
       }
     }
@@ -54,14 +55,16 @@ let rec replaceSymbols = (expression: expression, bindings: ExpressionT.bindings
       expr,
     }) => {
       let oldParameters = getParameters(bindings)
-      let newParameters = oldParameters->Belt.List.concat(parameters)
+      let newParameters = oldParameters->Js.Array2.concat(parameters)
       let newBindings = putParameters(bindings, newParameters)
       let rNewExpr = replaceSymbols(expr, newBindings)
-      rNewExpr -> Result.flatMap(newExpr => ExpressionT.EList(list{
-        ExpressionT.EValue(EvCall("$lambda")),
-        ExpressionT.EParameters(parameters),
-        newExpr
-      })->Ok)
+      rNewExpr->Result.flatMap(newExpr =>
+        ExpressionT.EList(list{
+          ExpressionT.EValue(EvCall("$lambda")),
+          ExpressionT.EParameters(parameters),
+          newExpr,
+        })->Ok
+      )
     }
   | ExpressionT.EList(list) => {
       let racc = list->Belt.List.reduceReverse(Ok(list{}), (racc, each: expression) =>
@@ -83,7 +86,6 @@ let dispatchMacroCall = (
   bindings: ExpressionT.bindings,
   reduceExpression: reducerFn,
 ): result<expression, 'e> => {
-
   let doBindStatement = (statement: expression, bindings: ExpressionT.bindings) => {
     switch statement {
     | ExpressionT.EList(list{

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

@@ -8,15 +8,19 @@ open Reducer_ErrorValue
 
 type expression = T.expression
 type expressionValue = ExpressionValue.expressionValue
+type internalCode = ExpressionValue.internalCode
 type t = expression
 
+external castExpressionToInternalCode: expression => internalCode = "%identity"
+external castInternalCodeToInternalCode: internalCode => expression = "%identity"
+
 /*
   Shows the expression as text of expression
 */
 let rec toString = expression =>
   switch expression {
   | T.EBindings(_) => "$$bound"
-  | T.EParameters(params) => `(${Js.Array2.toString(params->Belt.List.toArray)})`
+  | T.EParameters(params) => `(${Js.Array2.toString(params)})`
   | T.EList(aList) =>
     `(${Belt.List.map(aList, aValue => toString(aValue))
       ->Extra.List.interperse(" ")
@@ -93,9 +97,11 @@ let rec reduceExpression = (expression: t, bindings: T.bindings): result<express
 
   let rec reduceExpandedExpression = (expression: t): result<expressionValue, 'e> =>
     switch expression {
-    // | T.EList(list{T.EValue(EvCall("$lambda")), T.EParameters(parameters), functionDefinition}) => {
-    //     let lambda = T.ELambda(parameters, functionDefinition)
-    //     lambda->Ok}
+    | T.EList(list{
+        T.EValue(EvCall("$lambda")),
+        T.EParameters(parameters),
+        functionDefinition,
+      }) => EvLambda(parameters, functionDefinition->castExpressionToInternalCode)->Ok
     | T.EValue(value) => value->Ok
     | T.EList(list) => {
         let racc: result<list<expressionValue>, 'e> = list->Belt.List.reduceReverse(Ok(list{}), (
@@ -113,7 +119,8 @@ let rec reduceExpression = (expression: t, bindings: T.bindings): result<express
         racc->Result.flatMap(acc => acc->reduceValueList)
       }
     | EBindings(_bindings) => RETodo("Error: Bindings cannot be reduced to values")->Error
-    | EParameters(_parameters) => RETodo("Error: Lambda Parameters cannot be reduced to values")->Error
+    | EParameters(_parameters) =>
+      RETodo("Error: Lambda Parameters cannot be reduced to values")->Error
     }
 
   let rExpandedExpression: result<t, 'e> = expression->seekMacros(bindings)
@@ -142,7 +149,9 @@ let evalPartialUsingExternalBindings_ = (codeText: string, bindings: T.bindings)
   Therefore all statments are assignments.
 */
 let evalOuterWBindings_ = (codeText: string, bindings: T.bindings) => {
-  parseOuter(codeText)->Result.flatMap(expression => expression->evalUsingExternalBindingsExpression_(bindings))
+  parseOuter(codeText)->Result.flatMap(expression =>
+    expression->evalUsingExternalBindingsExpression_(bindings)
+  )
 }
 
 /*

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

@@ -12,5 +12,5 @@ type rec expression =
   | EList(list<expression>) // A list to map-reduce
   | EValue(expressionValue) // Irreducible built-in value. Reducer should not know the internals. External libraries are responsible
   | EBindings(bindings) // $let kind of statements return bindings; for internal use only
-  | EParameters(list<string>) // for $defun; for internal use only
+  | EParameters(array<string>) // for $defun; for internal use only
 and bindings = Belt.Map.String.t<expression>

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

@@ -104,7 +104,7 @@ let rec fromNode = (mathJsNode: Parse.node): result<expression, errorValue> =>
       let rValueExpression = fromNode(faNode["expr"])
 
       rValueExpression->Result.flatMap(valueExpression => {
-        let lispParams = faNode["params"]->Belt.List.fromArray->ExpressionT.EParameters
+        let lispParams = faNode["params"]->ExpressionT.EParameters
         let rLambda = passToFunction("$lambda", list{lispParams, valueExpression}->Ok)
         rLambda->Result.flatMap(lambda => {
           passToFunction("$let", list{symbol, lambda}->Ok)

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

@@ -56,14 +56,15 @@ and toStringRecord = aRecord => {
 
 let toStringWithType = aValue =>
   switch aValue {
+  | EvArray(_) => `Array::${toString(aValue)}`
   | EvBool(_) => `Bool::${toString(aValue)}`
   | EvCall(_) => `Call::${toString(aValue)}`
+  | EvDistribution(_) => `Distribution::${toString(aValue)}`
+  | EvLambda(_parameters, _internalCode) => `Lambda::${toString(aValue)}`
   | EvNumber(_) => `Number::${toString(aValue)}`
+  | EvRecord(_) => `Record::${toString(aValue)}`
   | EvString(_) => `String::${toString(aValue)}`
   | EvSymbol(_) => `Symbol::${toString(aValue)}`
-  | EvArray(_) => `Array::${toString(aValue)}`
-  | EvRecord(_) => `Record::${toString(aValue)}`
-  | EvDistribution(_) => `Distribution::${toString(aValue)}`
   }
 
 let argsToString = (args: array<expressionValue>): string => {