From 5d6de7b4878371d0d07d8a0395d2885499844e49 Mon Sep 17 00:00:00 2001
From: Quinn Dougherty <quinnd@riseup.net>
Date: Tue, 3 May 2022 10:15:48 -0400
Subject: [PATCH] Response to CR

Value: [1e-4 to 4e-3]
---
 .../squiggle-lang/__tests__/TestHelpers.res   | 21 +++++++------------
 .../Distributions/PointSetDist/Discrete.res   |  1 -
 .../PointSetDist/PointSetDist_Scoring.res     | 12 ++++++++---
 .../src/rescript/Utility/Operation.res        |  6 ++++--
 4 files changed, 21 insertions(+), 19 deletions(-)

diff --git a/packages/squiggle-lang/__tests__/TestHelpers.res b/packages/squiggle-lang/__tests__/TestHelpers.res
index 4502c68a..c9ed718e 100644
--- a/packages/squiggle-lang/__tests__/TestHelpers.res
+++ b/packages/squiggle-lang/__tests__/TestHelpers.res
@@ -61,18 +61,13 @@ let lognormalMake = SymbolicDist.Lognormal.make
 let triangularMake = SymbolicDist.Triangular.make
 let floatMake = SymbolicDist.Float.make
 
-let normalMakeR = (mean, stdev) =>
-  E.R.fmap(s => DistributionTypes.Symbolic(s), SymbolicDist.Normal.make(mean, stdev))
-let betaMakeR = (alpha, beta) =>
-  E.R.fmap(s => DistributionTypes.Symbolic(s), SymbolicDist.Beta.make(alpha, beta))
-let exponentialMakeR = rate =>
-  E.R.fmap(s => DistributionTypes.Symbolic(s), SymbolicDist.Exponential.make(rate))
-let uniformMakeR = (low, high) =>
-  E.R.fmap(s => DistributionTypes.Symbolic(s), SymbolicDist.Uniform.make(low, high))
-let cauchyMakeR = (local, rate) =>
-  E.R.fmap(s => DistributionTypes.Symbolic(s), SymbolicDist.Cauchy.make(local, rate))
-let lognormalMakeR = (mu, sigma) =>
-  E.R.fmap(s => DistributionTypes.Symbolic(s), SymbolicDist.Lognormal.make(mu, sigma))
+let fmapGenDist = symbdistres => E.R.fmap(s => DistributionTypes.Symbolic(s), symbdistres)
+let normalMakeR = (mean, stdev) => fmapGenDist(SymbolicDist.Normal.make(mean, stdev))
+let betaMakeR = (alpha, beta) => fmapGenDist(SymbolicDist.Beta.make(alpha, beta))
+let exponentialMakeR = rate => fmapGenDist(SymbolicDist.Exponential.make(rate))
+let uniformMakeR = (low, high) => fmapGenDist(SymbolicDist.Uniform.make(low, high))
+let cauchyMakeR = (local, rate) => fmapGenDist(SymbolicDist.Cauchy.make(local, rate))
+let lognormalMakeR = (mu, sigma) => fmapGenDist(SymbolicDist.Lognormal.make(mu, sigma))
 let triangularMakeR = (low, mode, high) =>
-  E.R.fmap(s => DistributionTypes.Symbolic(s), SymbolicDist.Triangular.make(low, mode, high))
+  fmapGenDist(SymbolicDist.Triangular.make(low, mode, high))
 // let floatMakeR = x =>E.R.fmap(s => DistributionTypes.Symbolic(s), SymbolicDist.Float.make(x))
diff --git a/packages/squiggle-lang/src/rescript/Distributions/PointSetDist/Discrete.res b/packages/squiggle-lang/src/rescript/Distributions/PointSetDist/Discrete.res
index 4eef1f91..a6c04e6b 100644
--- a/packages/squiggle-lang/src/rescript/Distributions/PointSetDist/Discrete.res
+++ b/packages/squiggle-lang/src/rescript/Distributions/PointSetDist/Discrete.res
@@ -233,6 +233,5 @@ module T = Dist({
     combinePointwise(~fn=PointSetDist_Scoring.LogScoring.logScore, base, reference) |> E.R2.bind(
       integralEndYResult,
     )
-    // |> (r => Ok(r))
   }
 })
diff --git a/packages/squiggle-lang/src/rescript/Distributions/PointSetDist/PointSetDist_Scoring.res b/packages/squiggle-lang/src/rescript/Distributions/PointSetDist/PointSetDist_Scoring.res
index d025d835..1524243d 100644
--- a/packages/squiggle-lang/src/rescript/Distributions/PointSetDist/PointSetDist_Scoring.res
+++ b/packages/squiggle-lang/src/rescript/Distributions/PointSetDist/PointSetDist_Scoring.res
@@ -1,8 +1,14 @@
 module LogScoring = {
   let logFn = Js.Math.log
   let subtraction = (a, b) => Ok(a -. b)
-  let logScore = (a: float, b: float): result<float, Operation.Error.t> => Ok(
-    logFn(Js.Math.abs_float(a /. b)),
-  )
+  let logScore = (a: float, b: float): result<float, Operation.Error.t> =>
+    if a == 0.0 {
+      Error(Operation.Error.NegativeInfinityError)
+    } else if b == 0.0 {
+      Error(Operation.Error.DivideByZeroError)
+    } else {
+      let quot = a /. b
+      quot < 0.0 ? Error(OperationError.ComplexNumberError) : Ok(logFn(quot))
+    }
   let multiply = (a: float, b: float): result<float, Operation.Error.t> => Ok(a *. b)
 }
diff --git a/packages/squiggle-lang/src/rescript/Utility/Operation.res b/packages/squiggle-lang/src/rescript/Utility/Operation.res
index 8f67c340..a14fdcdc 100644
--- a/packages/squiggle-lang/src/rescript/Utility/Operation.res
+++ b/packages/squiggle-lang/src/rescript/Utility/Operation.res
@@ -53,6 +53,7 @@ type operationError =
   | DivisionByZeroError
   | ComplexNumberError
   | InfinityError
+  | NegativeInfinityError
 
 @genType
 module Error = {
@@ -63,7 +64,8 @@ module Error = {
     switch err {
     | DivisionByZeroError => "Cannot divide by zero"
     | ComplexNumberError => "Operation returned complex result"
-    | InfinityError => "Operation returned + or - infinity"
+    | InfinityError => "Operation returned positive infinity"
+    | NegativeInfinityError => "Operation returned negative infinity"
     }
 }
 
@@ -89,7 +91,7 @@ let logarithm = (a: float, b: float): result<float, Error.t> =>
   } else if a > 0.0 && b > 0.0 {
     Ok(log(a) /. log(b))
   } else if a == 0.0 {
-    Error(InfinityError)
+    Error(NegativeInfinityError)
   } else {
     Error(ComplexNumberError)
   }