mirror of
https://github.com/luxfi/math.git
synced 2026-07-27 03:38:49 +00:00
Zach Kelling
fd27f2ecb0
- Create math/big for big.Int utilities (HexOrDecimal256, U256, parsing) - Create math/safe for overflow-safe arithmetic (SafeAdd, SafeMul, etc.) - Move averager files to root package level - Add re-exports in root package for backwards compatibility - Update README with new package structure documentation - Remove old math/meter directory (consolidated elsewhere) - Remove redundant math/ subdirectory structure
82 lines
1.7 KiB
Go
82 lines
1.7 KiB
Go
// Copyright (C) 2019-2025, Lux Industries, Inc. All rights reserved.
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// See the file LICENSE for licensing terms.
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package math
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import (
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"errors"
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"golang.org/x/exp/constraints"
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)
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var (
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ErrOverflow = errors.New("overflow")
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ErrUnderflow = errors.New("underflow")
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// Deprecated: Add64 is deprecated. Use Add[uint64] instead.
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Add64 = Add[uint64]
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// Deprecated: Mul64 is deprecated. Use Mul[uint64] instead.
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Mul64 = Mul[uint64]
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)
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// MaxUint returns the maximum value of an unsigned integer of type T.
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func MaxUint[T constraints.Unsigned]() T {
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return ^T(0)
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}
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// Add returns:
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// 1) a + b
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// 2) If there is overflow, an error
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func Add[T constraints.Unsigned](a, b T) (T, error) {
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if a > MaxUint[T]()-b {
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return 0, ErrOverflow
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}
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return a + b, nil
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}
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// Sub returns:
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// 1) a - b
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// 2) If there is underflow, an error
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func Sub[T constraints.Unsigned](a, b T) (T, error) {
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if a < b {
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return 0, ErrUnderflow
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}
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return a - b, nil
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}
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// Mul returns:
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// 1) a * b
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// 2) If there is overflow, an error
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func Mul[T constraints.Unsigned](a, b T) (T, error) {
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if b != 0 && a > MaxUint[T]()/b {
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return 0, ErrOverflow
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}
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return a * b, nil
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}
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// AbsDiff returns the absolute difference between a and b.
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func AbsDiff[T constraints.Unsigned](a, b T) T {
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return max(a, b) - min(a, b)
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}
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// SafeAdd returns x+y and whether overflow occurred.
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func SafeAdd(x, y uint64) (uint64, bool) {
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sum := x + y
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return sum, sum < x
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}
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// SafeSub returns x-y and whether underflow occurred.
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func SafeSub(x, y uint64) (uint64, bool) {
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return x - y, x < y
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}
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// SafeMul returns x*y and whether overflow occurred.
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func SafeMul(x, y uint64) (uint64, bool) {
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if x == 0 || y == 0 {
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return 0, false
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}
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result := x * y
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return result, result/y != x
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}
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