Cleanup of SampleSet map

packages/squiggle-lang/src/rescript/Distributions/GenericDist.res

@@ -281,7 +281,7 @@ module AlgebraicCombination = {
       let fn = Operation.Algebraic.toFn(arithmeticOperation)
       E.R.merge(toSampleSet(t1), toSampleSet(t2))
       ->E.R.bind(((t1, t2)) => {
-        SampleSetDist.map2(~fn, ~t1, ~t2)->E.R2.errMap(x => DistributionTypes.OperationError(x))
+        SampleSetDist.map2(~fn, ~t1, ~t2)->E.R2.errMap(x => DistributionTypes.SampleSetError(x))
       })
       ->E.R2.fmap(r => DistributionTypes.SampleSet(r))
     }

packages/squiggle-lang/src/rescript/Distributions/SampleSetDist/SampleSetDist.res

@@ -20,6 +20,14 @@ module Error = {
     }
 
   let fromOperationError = e => OperationError(e)
+
+  let toString = (err: sampleSetError) => {
+    switch(err){
+      | TooFewSamples => "Too few samples when constructing sample set"
+      | NonNumericInput(err) => `Found a non-number in input: ${err}`
+      | OperationError(err) => Operation.Error.toString(err)
+    }
+  }
 }
 
 include Error
@@ -87,48 +95,27 @@ let sampleN = (t: t, n) => {
   }
 }
 
+let _fromSampleResultArray = (samples: array<result<float, QuriSquiggleLang.Operation.Error.t>>) =>
+  E.A.R.firstErrorOrOpen(samples)->E.R2.errMap(Error.fromOperationError) |> E.R2.bind(make)
+
 let samplesMap = (~fn: float => result<float, Operation.Error.t>, t: t): result<
   t,
   sampleSetError,
-> => {
-  let samples = T.get(t)->E.A2.fmap(fn)
-  E.A.R.firstErrorOrOpen(samples)->E.R2.errMap(Error.fromOperationError) |> E.R2.bind(make)
-}
+> => T.get(t)->E.A2.fmap(fn)->_fromSampleResultArray
 
 //TODO: Figure out what to do if distributions are different lengths. ``zip`` is kind of inelegant for this.
 let map2 = (~fn: (float, float) => result<float, Operation.Error.t>, ~t1: t, ~t2: t): result<
   t,
-  Operation.Error.t,
-> => {
-  let samples = E.A.zip(get(t1), get(t2))->E.A2.fmap(((a, b)) => fn(a, b))
-
-  // This assertion should never be reached. In order for it to be reached, one
-  // of the input parameters would need to be a sample set distribution with less
-  // than 6 samples. Which should be impossible due to the smart constructor.
-  // I could prove this to the type system (say, creating a {first: float, second: float, ..., fifth: float, rest: array<float>}
-  // But doing so would take too much time, so I'll leave it as an assertion
-  E.A.R.firstErrorOrOpen(samples)->E.R2.fmap(x =>
-    E.R.toExnFnString(Error.sampleSetErrorToString, make(x))
-  )
-}
+  sampleSetError,
+> => E.A.zip(get(t1), get(t2))->E.A2.fmap(E.Tuple2.toFnCall(fn))->_fromSampleResultArray
 
 let map3 = (
   ~fn: (float, float, float) => result<float, Operation.Error.t>,
   ~t1: t,
   ~t2: t,
   ~t3: t,
-): result<t, Operation.Error.t> => {
-  let samples = E.A.zip3(get(t1), get(t2), get(t3))->E.A2.fmap(((a, b, c)) => fn(a, b, c))
-
-  // This assertion should never be reached. In order for it to be reached, one
-  // of the input parameters would need to be a sample set distribution with less
-  // than 6 samples. Which should be impossible due to the smart constructor.
-  // I could prove this to the type system (say, creating a {first: float, second: float, ..., fifth: float, rest: array<float>}
-  // But doing so would take too much time, so I'll leave it as an assertion
-  E.A.R.firstErrorOrOpen(samples)->E.R2.fmap(x =>
-    E.R.toExnFnString(Error.sampleSetErrorToString, make(x))
-  )
-}
+): result<t, sampleSetError> =>
+  E.A.zip3(get(t1), get(t2), get(t3))->E.A2.fmap(E.Tuple3.toFnCall(fn))->_fromSampleResultArray
 
 let mean = t => T.get(t)->E.A.Floats.mean
 let geomean = t => T.get(t)->E.A.Floats.geomean

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

@@ -75,7 +75,7 @@ module Process = {
         | Ok((t1, t2)) =>
           switch SampleSetDist.map2(~fn=altFn, ~t1, ~t2) {
           | Ok(r) => Ok(DistributionTypes.SampleSet(r))
-          | Error(r) => Error(Operation.Error.toString(r))
+          | Error(r) => Error(SampleSetDist.Error.toString(r))
           }
         | Error(r) => Error(DistributionTypes.Error.toString(r))
         }

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

@@ -122,12 +122,12 @@ let callInternal = (call: functionCall, environment, reducer: ExpressionT.reduce
 
     let map2 = (t1: t, t2: t, aLambdaValue) => {
       let fn = (a, b) => doLambdaCall(aLambdaValue, list{EvNumber(a), EvNumber(b)})
-      SampleSetDist.map2(~fn, ~t1, ~t2)->E.R2.errMap(SampleSetDist.Error.fromOperationError)->toType
+      SampleSetDist.map2(~fn, ~t1, ~t2)->toType
     }
 
     let map3 = (t1: t, t2: t, t3: t, aLambdaValue) => {
       let fn = (a, b, c) => doLambdaCall(aLambdaValue, list{EvNumber(a), EvNumber(b), EvNumber(c)})
-      SampleSetDist.map3(~fn, ~t1, ~t2, ~t3)->E.R2.errMap(SampleSetDist.Error.fromOperationError)->toType
+      SampleSetDist.map3(~fn, ~t1, ~t2, ~t3)->toType
     }
   }
 

packages/squiggle-lang/src/rescript/Utility/E.res

@@ -55,6 +55,10 @@ module Tuple2 = {
   let toFnCall = (fn, (a1, a2)) => fn(a1, a2)
 }
 
+module Tuple3 = {
+  let toFnCall = (fn, (a1, a2, a3)) => fn(a1, a2, a3)
+}
+
 module O = {
   let dimap = (sFn, rFn, e) =>
     switch e {