fix(math): fix factorial signature and add missing constants/functions

CHANGELOG.md

@@ -7,6 +7,18 @@ name: Fable.Python
 
 All notable changes to this project will be documented in this file.
 
+## Unreleased
+
+### 🐞 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.
+
+### ✨ Enhancements
+
+* Add missing `math` module constants: `pi`, `e`, `tau`, `inf`, `nan`
+* Add missing `math` module functions: `sqrt`, `degrees`, `radians`, `trunc`, `hypot`, `fsum`, `isqrt`, `prod`, `perm`, `acosh`, `asinh`, `atanh`, `cosh`, `sinh`, `tanh`, `erf`, `erfc`, `gamma`, `lgamma`
+* Fix `math.dist` signature to accept float arrays (for multi-dimensional distance)
+
 ## 5.0.0-rc.3 - 2026-04-16
 
 ### 🐞 Bug Fixes

src/stdlib/Math.fs

@@ -8,6 +8,30 @@ open Fable.Core
 
 [<Erase>]
 type IExports =
+    // ========================================================================
+    // Constants
+    // ========================================================================
+
+    /// The mathematical constant π = 3.141592…
+    /// See https://docs.python.org/3/library/math.html#math.pi
+    abstract pi: float
+    /// The mathematical constant e = 2.718281…
+    /// See https://docs.python.org/3/library/math.html#math.e
+    abstract e: float
+    /// The mathematical constant τ = 6.283185… (2π)
+    /// See https://docs.python.org/3/library/math.html#math.tau
+    abstract tau: float
+    /// Floating-point positive infinity
+    /// See https://docs.python.org/3/library/math.html#math.inf
+    abstract inf: float
+    /// A floating-point "not a number" (NaN) value
+    /// See https://docs.python.org/3/library/math.html#math.nan
+    abstract nan: float
+
+    // ========================================================================
+    // Number-theoretic and representation functions
+    // ========================================================================
+
     /// Return the ceiling of x as an integer
     /// See https://docs.python.org/3/library/math.html#math.ceil
     abstract ceil: x: int -> int
@@ -23,22 +47,48 @@ type IExports =
     /// Return the absolute value of x
     /// See https://docs.python.org/3/library/math.html#math.fabs
     abstract fabs: x: float -> float
-    /// Return the factorial of x
+    /// Return the factorial of n as an integer. Raises ValueError if n is negative.
+    /// Note: float arguments were deprecated in Python 3.9 and removed in Python 3.12.
     /// See https://docs.python.org/3/library/math.html#math.factorial
-    abstract factorial: x: float -> float
+    abstract factorial: n: int -> int
     /// Return the floor of x as an integer
     /// See https://docs.python.org/3/library/math.html#math.floor
     abstract floor: x: int -> int
     /// Return the floor of x as an integer
     /// See https://docs.python.org/3/library/math.html#math.floor
     abstract floor: x: float -> int
-    /// Return the remainder of x / y
+    /// 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
-
+    /// 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
     /// Return the greatest common divisor of the integers
     /// See https://docs.python.org/3/library/math.html#math.gcd
     abstract gcd: [<ParamArray>] ints: int[] -> int
+    /// Return the integer square root of the non-negative integer n
+    /// See https://docs.python.org/3/library/math.html#math.isqrt
+    abstract isqrt: n: int -> int
+    /// Return the least common multiple of the integers
+    /// See https://docs.python.org/3/library/math.html#math.lcm
+    abstract lcm: [<ParamArray>] ints: int[] -> int
+    /// Return the number of ways to choose k items from n items without repetition and with order
+    /// See https://docs.python.org/3/library/math.html#math.perm
+    abstract perm: n: int -> int
+    /// Return the number of ways to choose k items from n items without repetition and with order
+    /// See https://docs.python.org/3/library/math.html#math.perm
+    abstract perm: n: int * k: int -> int
+    /// Return the product of all elements in the iterable
+    /// See https://docs.python.org/3/library/math.html#math.prod
+    abstract prod: iterable: 'T seq -> 'T
+    /// Truncate x to an integer (towards zero)
+    /// See https://docs.python.org/3/library/math.html#math.trunc
+    abstract trunc: x: float -> int
+
+    // ========================================================================
+    // Floating-point predicates
+    // ========================================================================
+
     /// Check if x is neither an infinity nor a NaN
     /// See https://docs.python.org/3/library/math.html#math.isfinite
     abstract isfinite: x: float -> bool
@@ -57,9 +107,10 @@ type IExports =
     /// Check if x is a NaN (not a number)
     /// See https://docs.python.org/3/library/math.html#math.isnan
     abstract isnan: x: int -> bool
-    /// Return the least common multiple of the integers
-    /// See https://docs.python.org/3/library/math.html#math.lcm
-    abstract lcm: [<ParamArray>] ints: int[] -> int
+
+    // ========================================================================
+    // Power and logarithmic functions
+    // ========================================================================
 
     /// Return e raised to the power of x
     /// See https://docs.python.org/3/library/math.html#math.exp
@@ -82,6 +133,13 @@ type IExports =
     /// 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
+    /// Return the square root of x
+    /// See https://docs.python.org/3/library/math.html#math.sqrt
+    abstract sqrt: x: float -> float
+
+    // ========================================================================
+    // Trigonometric functions
+    // ========================================================================
 
     /// Return the arc cosine of x in radians
     /// See https://docs.python.org/3/library/math.html#math.acos
@@ -98,15 +156,69 @@ type IExports =
     /// Return the cosine of x radians
     /// See https://docs.python.org/3/library/math.html#math.cos
     abstract cos: x: float -> float
-    /// Return the Euclidean distance between two points
-    /// See https://docs.python.org/3/library/math.html#math.dist
-    abstract dist: p: float -> q: float -> float
     /// Return the sine of x radians
     /// See https://docs.python.org/3/library/math.html#math.sin
     abstract sin: x: float -> float
     /// Return the tangent of x radians
     /// See https://docs.python.org/3/library/math.html#math.tan
     abstract tan: x: float -> float
+    /// Return the Euclidean norm of a sequence of coordinates
+    /// See https://docs.python.org/3/library/math.html#math.hypot
+    abstract hypot: [<ParamArray>] coordinates: float[] -> float
+    /// Convert angle x from radians to degrees
+    /// See https://docs.python.org/3/library/math.html#math.degrees
+    abstract degrees: x: float -> float
+    /// Convert angle x from degrees to radians
+    /// See https://docs.python.org/3/library/math.html#math.radians
+    abstract radians: x: float -> float
+
+    // ========================================================================
+    // Hyperbolic functions
+    // ========================================================================
+
+    /// Return the inverse hyperbolic cosine of x
+    /// See https://docs.python.org/3/library/math.html#math.acosh
+    abstract acosh: x: float -> float
+    /// Return the inverse hyperbolic sine of x
+    /// See https://docs.python.org/3/library/math.html#math.asinh
+    abstract asinh: x: float -> float
+    /// Return the inverse hyperbolic tangent of x
+    /// See https://docs.python.org/3/library/math.html#math.atanh
+    abstract atanh: x: float -> float
+    /// Return the hyperbolic cosine of x
+    /// See https://docs.python.org/3/library/math.html#math.cosh
+    abstract cosh: x: float -> float
+    /// Return the hyperbolic sine of x
+    /// See https://docs.python.org/3/library/math.html#math.sinh
+    abstract sinh: x: float -> float
+    /// Return the hyperbolic tangent of x
+    /// See https://docs.python.org/3/library/math.html#math.tanh
+    abstract tanh: x: float -> float
+
+    // ========================================================================
+    // Special functions
+    // ========================================================================
+
+    /// Return the error function at x
+    /// See https://docs.python.org/3/library/math.html#math.erf
+    abstract erf: x: float -> float
+    /// Return the complementary error function at x
+    /// See https://docs.python.org/3/library/math.html#math.erfc
+    abstract erfc: x: float -> float
+    /// Return the Gamma function at x
+    /// See https://docs.python.org/3/library/math.html#math.gamma
+    abstract gamma: x: float -> float
+    /// Return the natural logarithm of the absolute value of the Gamma function at x
+    /// See https://docs.python.org/3/library/math.html#math.lgamma
+    abstract lgamma: x: float -> float
+
+    // ========================================================================
+    // Distance and geometry
+    // ========================================================================
+
+    /// 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
 
 /// Mathematical functions
 [<ImportAll("math")>]

test/TestMath.fs

@@ -32,8 +32,8 @@ let ``test fabs works`` () =
 
 [<Fact>]
 let ``test factorial works`` () =
-    math.factorial 5.0 |> equal 120.0
-    math.factorial 0.0 |> equal 1.0
+    math.factorial 5 |> equal 120
+    math.factorial 0 |> equal 1
 
 [<Fact>]
 let ``test fmod works`` () =
@@ -119,3 +119,108 @@ let ``test atan works`` () =
 [<Fact>]
 let ``test atan2 works`` () =
     math.atan2 0.0 1.0 |> equal 0.0
+
+[<Fact>]
+let ``test pi constant works`` () =
+    math.pi |> fun x -> (x > 3.14159 && x < 3.14160) |> equal true
+
+[<Fact>]
+let ``test e constant works`` () =
+    math.e |> fun x -> (x > 2.71828 && x < 2.71829) |> equal true
+
+[<Fact>]
+let ``test tau constant works`` () =
+    math.tau |> fun x -> (x > 6.28318 && x < 6.28319) |> equal true
+
+[<Fact>]
+let ``test inf constant works`` () =
+    math.isinf math.inf |> equal true
+
+[<Fact>]
+let ``test sqrt works`` () =
+    math.sqrt 4.0 |> equal 2.0
+    math.sqrt 9.0 |> equal 3.0
+
+[<Fact>]
+let ``test degrees works`` () =
+    math.degrees math.pi |> fun x -> (x > 179.999 && x < 180.001) |> equal true
+
+[<Fact>]
+let ``test radians works`` () =
+    math.radians 180.0 |> fun x -> (x > 3.14158 && x < 3.14160) |> equal true
+
+[<Fact>]
+let ``test trunc works`` () =
+    math.trunc 2.7 |> equal 2
+    math.trunc -2.7 |> equal -2
+
+[<Fact>]
+let ``test hypot works`` () =
+    math.hypot (3.0, 4.0) |> equal 5.0
+
+[<Fact>]
+let ``test isqrt works`` () =
+    math.isqrt 16 |> equal 4
+    math.isqrt 17 |> equal 4
+
+[<Fact>]
+let ``test fsum works`` () =
+    math.fsum [ 1.0; 2.0; 3.0 ] |> equal 6.0
+
+[<Fact>]
+let ``test nan constant works`` () =
+    math.isnan math.nan |> equal true
+
+[<Fact>]
+let ``test prod works`` () =
+    math.prod [ 1; 2; 3; 4 ] |> equal 24
+
+[<Fact>]
+let ``test perm works`` () =
+    math.perm 5 |> equal 120
+    math.perm (5, 2) |> equal 20
+
+[<Fact>]
+let ``test dist works`` () =
+    math.dist [| 0.0; 0.0 |] [| 3.0; 4.0 |] |> equal 5.0
+
+[<Fact>]
+let ``test cosh works`` () =
+    math.cosh 0.0 |> equal 1.0
+
+[<Fact>]
+let ``test sinh works`` () =
+    math.sinh 0.0 |> equal 0.0
+
+[<Fact>]
+let ``test tanh works`` () =
+    math.tanh 0.0 |> equal 0.0
+
+[<Fact>]
+let ``test acosh works`` () =
+    math.acosh 1.0 |> equal 0.0
+
+[<Fact>]
+let ``test asinh works`` () =
+    math.asinh 0.0 |> equal 0.0
+
+[<Fact>]
+let ``test atanh works`` () =
+    math.atanh 0.0 |> equal 0.0
+
+[<Fact>]
+let ``test erf works`` () =
+    math.erf 0.0 |> equal 0.0
+
+[<Fact>]
+let ``test erfc works`` () =
+    math.erfc 0.0 |> equal 1.0
+
+[<Fact>]
+let ``test gamma works`` () =
+    math.gamma 1.0 |> equal 1.0
+    math.gamma 5.0 |> equal 24.0
+
+[<Fact>]
+let ``test lgamma works`` () =
+    math.lgamma 1.0 |> equal 0.0