Module: math.floats

Source: ./math/floats.reef

Overview

math/floats - Extended floating-point mathematical functions

Provides additional floating-point operations including:

Mathematical constants (pi, e)
Inverse trigonometric functions
Additional utility functions
Special value checking (NaN, infinity)

Note: Basic float functions (sqrt, sin, cos, etc.) are in math/basic

FREESTANDING (2026-09-06). This module no longer depends on libc/libm.

It used to wrap libc for eleven functions -- trunc_f, cbrt_f, log2_f, asin_f, acos_f, atan_f, atan2_f, sinh_f, cosh_f, tanh_f, hypot_f -- and those eleven were its ONLY use of libc. They were also exactly the eleven names it duplicated from math.basic, which implements all of them in pure Reef (IEEE-754 bit manipulation, ported from A2 Oberon MathL.Mod). So the module carried two bodies per name, with no caller able to tell which it would get, and the whole libm dependency existed to serve the duplicates.

They now forward to math.basic: one implementation per function, no libm, and the same public API. Divergence was MEASURED against libc across [-10, 10] before this change was made, and every one of the eleven agrees to <= 2.8e-14, with nine of them at <= 1e-15:

That was NOT true before reef-lang#56: atan_f/atan2_f were 5.0e-4 off and asin_f/acos_f 1.4e-7, so forwarding would have silently degraded accuracy in graphics (the one package that imports both modules). Fix the pure implementation first, measure, then converge -- in that order.

Functions

`fn pi(): float`

Returns the mathematical constant pi (3.14159...)

`fn e(): float`

Returns Euler's number e (2.71828...)

`fn tau(): float`

Returns tau (2 * pi = 6.28318...)

`fn trunc_f(x: float): float`

Returns x truncated toward zero (removes fractional part)

`fn cbrt_f(x: float): float`

Returns the cube root of x

`fn log2_f(x: float): float`

Returns the base-2 logarithm of x

`fn asin_f(x: float): float`

Returns the arc sine of x (result in radians) Input must be in range [-1, 1]

`fn acos_f(x: float): float`

Returns the arc cosine of x (result in radians) Input must be in range [-1, 1]

`fn atan_f(x: float): float`

Returns the arc tangent of x (result in radians)

`fn atan2_f(y: float, x: float): float`

Returns the arc tangent of y/x using signs to determine quadrant Result in radians, range [-pi, pi]

`fn sinh_f(x: float): float`

Returns the hyperbolic sine of x

`fn cosh_f(x: float): float`

Returns the hyperbolic cosine of x

`fn tanh_f(x: float): float`

Returns the hyperbolic tangent of x

`fn hypot_f(x: float, y: float): float`

Returns the hypotenuse: sqrt(xx + yy) More accurate than computing directly for large values

`fn degrees(rad: float): float`

Converts radians to degrees

`fn radians(deg: float): float`

Converts degrees to radians

`fn clamp_f(x: float, lo: float, hi: float): float`

Clamps x to the range [lo, hi]

`fn sign_f(x: float): int`

Returns -1 if x < 0, 0 if x == 0, 1 if x > 0

`fn lerp_f(a: float, b: float, t: float): float`

Linear interpolation between a and b Returns a when t=0, b when t=1

`fn is_nan(x: float): bool`

Returns true if x is NaN (Not a Number)

`fn is_infinite(x: float): bool`

Returns true if x is positive or negative infinity

`fn is_finite(x: float): bool`

Returns true if x is a normal finite number (not NaN or infinity)

`fn to_int(x: float): int`

Converts float to int by truncating toward zero

`fn to_int_floor(x: float): int`

Converts float to int by rounding toward negative infinity

`fn to_int_ceil(x: float): int`

Converts float to int by rounding toward positive infinity

`fn to_int_round(x: float): int`

Converts float to int by rounding to nearest integer

Generated by reefc doc