fix(math): correct type signatures for copysign, fmod and curried bindings (#253)

* fix(math): correct type signatures for copysign, fmod and curried bindings

- math.copysign: fix y parameter type from int to float (Python always
  takes two floats)
- math.fmod: fix parameter and return types from int to float (computes
  floating-point remainder, not integer modulo)
- math.comb, math.pow, math.atan2, math.dist: convert curried parameter
  syntax to tupled for consistency with all other multi-parameter
  bindings in the codebase

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fix: update tests for tupled params, restore CHANGELOG entries

Update tests for comb, copysign, fmod, pow, atan2, dist to use tupled
calling convention matching the corrected type signatures. Restore
PR #251 entries that were dropped from the Unreleased CHANGELOG section.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: Dag Brattli <dag@brattli.net>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 4 people

CHANGELOG.md

@@ -12,6 +12,9 @@ All notable changes to this project will be documented in this file.
 ### 🐞 Bug Fixes
 
 * Fix `math.factorial` binding: changed signature from `float -> float` to `int -> int` to match Python 3.12+ where float arguments raise `TypeError`. Fixes test to use integer literals.
+* Fix `math.copysign` binding: `y` parameter was incorrectly typed as `int`, now correctly `float`
+* Fix `math.fmod` binding: parameters were incorrectly typed as `int -> int -> int`, now correctly `float * float -> float`
+* Fix `math.comb`, `math.pow`, `math.atan2`, `math.dist` bindings: converted curried parameter syntax to tupled for consistency
 
 ### ✨ Enhancements
 

src/stdlib/Math.fs

@@ -40,10 +40,10 @@ type IExports =
     abstract ceil: x: float -> int
     /// Return the number of ways to choose k items from n items (n choose k)
     /// See https://docs.python.org/3/library/math.html#math.comb
-    abstract comb: n: int -> k: int -> int
+    abstract comb: n: int * k: int -> int
     /// Return a float with the magnitude of x and the sign of y
     /// See https://docs.python.org/3/library/math.html#math.copysign
-    abstract copysign: x: float -> y: int -> float
+    abstract copysign: x: float * y: float -> float
     /// Return the absolute value of x
     /// See https://docs.python.org/3/library/math.html#math.fabs
     abstract fabs: x: float -> float
@@ -59,7 +59,7 @@ type IExports =
     abstract floor: x: float -> int
     /// Return the floating-point remainder of x / y
     /// See https://docs.python.org/3/library/math.html#math.fmod
-    abstract fmod: x: int -> y: int -> int
+    abstract fmod: x: float * y: float -> float
     /// Return an accurate floating-point sum of values in the iterable
     /// See https://docs.python.org/3/library/math.html#math.fsum
     abstract fsum: iterable: float seq -> float
@@ -132,7 +132,7 @@ type IExports =
     abstract log10: x: float -> float
     /// Return x raised to the power y
     /// See https://docs.python.org/3/library/math.html#math.pow
-    abstract pow: x: float -> y: float -> float
+    abstract pow: x: float * y: float -> float
     /// Return the square root of x
     /// See https://docs.python.org/3/library/math.html#math.sqrt
     abstract sqrt: x: float -> float
@@ -152,7 +152,7 @@ type IExports =
     abstract atan: x: float -> float
     /// Return the arc tangent of y/x in radians
     /// See https://docs.python.org/3/library/math.html#math.atan2
-    abstract atan2: y: float -> x: float -> float
+    abstract atan2: y: float * x: float -> float
     /// Return the cosine of x radians
     /// See https://docs.python.org/3/library/math.html#math.cos
     abstract cos: x: float -> float
@@ -218,7 +218,7 @@ type IExports =
 
     /// Return the Euclidean distance between two points p and q
     /// See https://docs.python.org/3/library/math.html#math.dist
-    abstract dist: p: float[] -> q: float[] -> float
+    abstract dist: p: float[] * q: float[] -> float
 
 /// Mathematical functions
 [<ImportAll("math")>]

test/TestMath.fs

@@ -17,13 +17,13 @@ let ``test floor works`` () =
 
 [<Fact>]
 let ``test comb works`` () =
-    math.comb 5 2 |> equal 10
-    math.comb 10 3 |> equal 120
+    math.comb (5, 2) |> equal 10
+    math.comb (10, 3) |> equal 120
 
 [<Fact>]
 let ``test copysign works`` () =
-    math.copysign 1.0 -1 |> equal -1.0
-    math.copysign -1.0 1 |> equal 1.0
+    math.copysign (1.0, -1.0) |> equal -1.0
+    math.copysign (-1.0, 1.0) |> equal 1.0
 
 [<Fact>]
 let ``test fabs works`` () =
@@ -37,8 +37,8 @@ let ``test factorial works`` () =
 
 [<Fact>]
 let ``test fmod works`` () =
-    math.fmod 10 3 |> equal 1
-    math.fmod 7 2 |> equal 1
+    math.fmod (10.0, 3.0) |> equal 1.0
+    math.fmod (7.0, 2.0) |> equal 1.0
 
 [<Fact>]
 let ``test gcd works`` () =
@@ -89,8 +89,8 @@ let ``test log10 works`` () =
 
 [<Fact>]
 let ``test pow works`` () =
-    math.pow 2.0 3.0 |> equal 8.0
-    math.pow 10.0 2.0 |> equal 100.0
+    math.pow (2.0, 3.0) |> equal 8.0
+    math.pow (10.0, 2.0) |> equal 100.0
 
 [<Fact>]
 let ``test sin works`` () =
@@ -118,7 +118,7 @@ let ``test atan works`` () =
 
 [<Fact>]
 let ``test atan2 works`` () =
-    math.atan2 0.0 1.0 |> equal 0.0
+    math.atan2 (0.0, 1.0) |> equal 0.0
 
 [<Fact>]
 let ``test pi constant works`` () =
@@ -182,7 +182,7 @@ let ``test perm works`` () =
 
 [<Fact>]
 let ``test dist works`` () =
-    math.dist [| 0.0; 0.0 |] [| 3.0; 4.0 |] |> equal 5.0
+    math.dist ([| 0.0; 0.0 |], [| 3.0; 4.0 |]) |> equal 5.0
 
 [<Fact>]
 let ``test cosh works`` () =