Added symbolic functions and tests for reducer interface distribution code

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

@@ -0,0 +1,26 @@
+open Jest
+open Reducer_TestHelpers
+
+let makeTest = (str, result) => test(str, () => expectEvalToBe(str, result))
+
+describe("eval", () => {
+  Only.describe("expressions", () => {
+    makeTest("normal(5,2)", "Ok(Normal(5,2))")
+    makeTest("lognormal(5,2)", "Ok(Lognormal(5,2))")
+    makeTest("mean(normal(5,2))", "Ok(5)")
+    makeTest("mean(lognormal(1,2))", "Ok(20.085536923187668)")
+    makeTest("normalize(normal(5,2))", "Ok(Normal(5,2))")
+    makeTest("toPointSet(normal(5,2))", "Ok(Point Set Distribution)")
+    makeTest("toSampleSet(normal(5,2), 100)", "Ok(Sample Set Distribution)")
+    makeTest("add(normal(5,2), normal(10,2))", "Ok(Normal(15,2.8284271247461903))")
+    makeTest("add(normal(5,2), lognormal(10,2))", "Ok(Sample Set Distribution)")
+    makeTest("dotAdd(normal(5,2), lognormal(10,2))", "Ok(Point Set Distribution)")
+    makeTest("dotAdd(normal(5,2), 3)", "Ok(Point Set Distribution)")
+    makeTest("add(normal(5,2), 3)", "Ok(Point Set Distribution)")
+    makeTest("add(3, normal(5,2))", "Ok(Point Set Distribution)")
+    makeTest("3+normal(5,2)", "Ok(Point Set Distribution)")
+    makeTest("add(3, 3)", "Ok(6)")
+    makeTest("truncateLeft(normal(5,2), 3)", "Ok(Point Set Distribution)")
+    makeTest("mean(add(3, normal(5,2)))", "Ok(8.004619792609384)")
+  })
+})

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

@@ -74,11 +74,54 @@ let genericOutputToReducerValue = (o: GenericDist_GenericOperation.outputType):
   | GenDistError(Other(s)) => Error(RETodo(s))
   }
 
+module SymbolicConstructor = {
+  let oneFloat = name =>
+    switch name {
+    | "exponential" => Ok(SymbolicDist.Exponential.make)
+    | _ => Error("impossible path")
+    }
+
+  let twoFloat = name =>
+    switch name {
+    | "normal" => Ok(SymbolicDist.Normal.make)
+    | "uniform" => Ok(SymbolicDist.Uniform.make)
+    | "beta" => Ok(SymbolicDist.Beta.make)
+    | "lognormal" => Ok(SymbolicDist.Lognormal.make)
+    | _ => Error("impossible path")
+    }
+
+  let threeFloat = name =>
+    switch name {
+    | "triangular" => Ok(SymbolicDist.Triangular.make)
+    | _ => Error("impossible path")
+    }
+
+  let symbolicResultToOutput = (
+    symbolicResult: result<SymbolicDistTypes.symbolicDist, string>,
+  ): option<GenericDist_GenericOperation.outputType> =>
+    switch symbolicResult {
+    | Ok(r) => Some(Dist(Symbolic(r)))
+    | Error(r) => Some(GenDistError(Other(r)))
+    }
+}
+
 let dispatchToGenericOutput = (call: ExpressionValue.functionCall): option<
   GenericDist_GenericOperation.outputType,
 > => {
   let (fnName, args) = call
   switch (fnName, args) {
+  | ("exponential" as fnName, [EvNumber(f1)]) =>
+    SymbolicConstructor.oneFloat(fnName)
+    ->E.R.bind(r => r(f1))
+    ->SymbolicConstructor.symbolicResultToOutput
+  | (("normal" | "uniform" | "beta" | "lognormal") as fnName, [EvNumber(f1), EvNumber(f2)]) =>
+    SymbolicConstructor.twoFloat(fnName)
+    ->E.R.bind(r => r(f1, f2))
+    ->SymbolicConstructor.symbolicResultToOutput
+  | ("triangular" as fnName, [EvNumber(f1), EvNumber(f2), EvNumber(f3)]) =>
+    SymbolicConstructor.threeFloat(fnName)
+    ->E.R.bind(r => r(f1, f2, f3))
+    ->SymbolicConstructor.symbolicResultToOutput
   | ("sample", [EvDistribution(dist)]) => toFloatFn(#Sample, dist)
   | ("mean", [EvDistribution(dist)]) => toFloatFn(#Mean, dist)
   | ("normalize", [EvDistribution(dist)]) => toDistFn(Normalize, dist)
@@ -88,7 +131,8 @@ let dispatchToGenericOutput = (call: ExpressionValue.functionCall): option<
   | ("inv", [EvDistribution(dist), EvNumber(float)]) => toFloatFn(#Inv(float), dist)
   | ("toSampleSet", [EvDistribution(dist), EvNumber(float)]) =>
     toDistFn(ToSampleSet(Belt.Int.fromFloat(float)), dist)
-  | ("truncateLeft", [EvDistribution(dist), EvNumber(float)]) => toDistFn(Truncate(Some(float), None), dist)
+  | ("truncateLeft", [EvDistribution(dist), EvNumber(float)]) =>
+    toDistFn(Truncate(Some(float), None), dist)
   | ("truncateRight", [EvDistribution(dist), EvNumber(float)]) =>
     toDistFn(Truncate(None, Some(float)), dist)
   | ("truncate", [EvDistribution(dist), EvNumber(float1), EvNumber(float2)]) =>