Simple experiment of it working

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

@@ -95,9 +95,13 @@ module FnDefinition = {
     if E.A.length(f.inputs) !== E.A.length(args) {
       None
     } else {
-      E.A.zip(inputTypes, args)
+      let foo = E.A.zip(inputTypes, args)
+      ->(e => {Js.log2("Here", e); e})
       ->E.A2.fmap(((input, arg)) => matchInput(input, arg))
-      ->E.A.O.arrSomeToSomeArr
+      ->(e => {Js.log2("Here2", e); e})
+      ->E.A.O.openIfAllSome
+      ->(e => {Js.log2("Here3", e); e});
+      foo
     }
   }
 
@@ -117,7 +121,9 @@ module FnDefinition = {
   }
 
   let run = (f: fnDefinition, args: array<expressionValue>) => {
+      Js.log3("Run", f, args)
     let argValues = getArgValues(f, args)
+      Js.log2("RunArgValues", argValues)
     switch argValues {
     | Some(values) => f.run(values)
     | None => Error("Impossible")
@@ -227,17 +233,21 @@ module Registry = {
 
   let matchAndRun = (r: registry, fnName: string, args: array<expressionValue>) => {
     switch findMatches(r, fnName, args) {
-    | Match.FullMatch(m) => fullMatchToDef(r, m)->E.O2.fmap(FnDefinition.run(_, args))
+    | Match.FullMatch(m) => fullMatchToDef(r, m)->E.O2.fmap(r => {
+        FnDefinition.run(r, args)
+    })
     | _ => None
     }
   }
 }
 
-let twoNumberInputs = (inputs: array<value>) =>
+let twoNumberInputs = (inputs: array<value>) =>{
+    Js.log2("HII",inputs);
   switch inputs {
   | [Number(n1), Number(n2)] => Ok(n1, n2)
   | _ => Error("Wrong inputs / Logically impossible")
   }
+}
 
 let twoNumberInputsRecord = (v1, v2, inputs: array<value>) =>
   switch inputs {
@@ -270,7 +280,7 @@ let normal = Function.make(
     ),
     Function.makeDefinition("normal", [I_Record([("p5", I_Numeric), ("p95", I_Numeric)])], inputs =>
       twoNumberInputsRecord("p5", "p95", inputs)->E.R.bind(((mean, stdev)) =>
-        meanStdev(mean, stdev)
+        Ok(p5and95(mean, stdev))
       )
     ),
   ],

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

@@ -227,8 +227,8 @@ let dispatchToGenericOutput = (
   | ("delta", [EvNumber(f)]) =>
     SymbolicDist.Float.makeSafe(f)->SymbolicConstructors.symbolicResultToOutput
   | (
-      ("normal"
-      | "uniform"
+      (
+       "uniform"
       | "beta"
       | "lognormal"
       | "cauchy"
@@ -386,6 +386,19 @@ let genericOutputToReducerValue = (o: DistributionOperation.outputType): result<
   | GenDistError(err) => Error(REDistributionError(err))
   }
 
-let dispatch = (call, environment) => {
-  dispatchToGenericOutput(call, environment)->E.O2.fmap(genericOutputToReducerValue)
+let registered = [FunctionRegistry.normal]
+
+let tryRegistry = (call:ExpressionValue.functionCall) => {
+  let (fnName, args) = call;
+  let response = FunctionRegistry.Registry.matchAndRun(registered, fnName, args)
+  let foo = response -> E.O2.fmap(r => r->E.R2.errMap(s => Reducer_ErrorValue.RETodo(s)))
+  foo
+}
+
+let dispatch = (call:ExpressionValue.functionCall, environment) => {
+  let regularDispatch = dispatchToGenericOutput(call, environment)->E.O2.fmap(genericOutputToReducerValue)
+  switch(regularDispatch){
+    | Some(x) => Some(x)
+    | None => tryRegistry(call)
+  }
 }

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

@@ -646,6 +646,14 @@ module A = {
       O.flatten(getByOpen(r, l => l(), O.isSome))
 
     let firstSomeFnWithDefault = (r, default) => firstSomeFn(r)->O2.default(default)
+
+    let openIfAllSome = (optionals: array<option<'a>>): option<array<'a>> => {
+      if all(O.isSome, optionals) {
+        Some(optionals |> fmap(O.toExn("Warning: This should not have happened")))
+      } else {
+        None
+      }
+    }
   }
 
   module R = {