added math functions

Simplex/Math/math.php

@@ -0,0 +1,125 @@
+<?php
+
+declare(strict_types = 1);
+
+/**
+ * This file is part of the Simplex-Calculator library
+ *
+ * Copyright (c) 2014 Petr Kessler (https://kesspess.cz)
+ *
+ * @license  MIT
+ * @link     https://github.com/uestla/Simplex-Calculator
+ */
+
+namespace Simplex\Math;
+
+use Simplex\ZeroGcdArgumentsException;
+
+
+function add(string $a, string $b): string {
+	return bcadd($a, $b, 0);
+}
+
+
+function sub(string $a, string $b): string {
+	return bcsub($a, $b, 0);
+}
+
+
+function mul(string $a, string $b): string {
+	if ($b === '-1') { // micro-optimization for multiplying by -1
+		if ($a === '0') {
+			return '0';
+		}
+
+		if (isNegative($a)) {
+			return substr($a, 1);
+		}
+
+		return '-' . $a;
+	}
+
+	return bcmul($a, $b, 0);
+}
+
+
+function div(string $a, string $b, int $precision = 0): string {
+	return bcdiv($a, $b, $precision);
+}
+
+
+function pow(string $a, string $b): string {
+	return bcpow($a, $b, 0);
+}
+
+
+function mod(string $a, string $b): string {
+	return bcmod($a, $b, 0);
+}
+
+
+function abs(string $n): string {
+	if (isNegative($n)) {
+		return substr($n, 1);
+	}
+
+	return $n;
+}
+
+
+function isNegative(string $n): bool {
+	return strncmp($n, '-', 1) === 0;
+}
+
+
+function comp(string $a, string $b): int {
+	return bccomp($a, $b, 0);
+}
+
+
+function round(string $n, int $precision): string {
+	if (isNegative($n)) {
+		$result = bcsub($n, '0.' . str_repeat('0', $precision) . '5', $precision);
+
+	} else {
+		$result = bcadd($n, '0.' . str_repeat('0', $precision) . '5', $precision);
+	}
+
+	if (!str_contains($result, '.')) {
+		return $result;
+	}
+
+	return rtrim(rtrim($result, '0'), '.');
+}
+
+
+function gcd(string $a, string $b): string {
+	$aZero = $a === '0';
+	$bZero = $b === '0';
+
+	if ($aZero && $bZero) {
+		throw new ZeroGcdArgumentsException;
+	}
+
+	if ($aZero) {
+		return $b;
+	}
+
+	if ($bZero) {
+		return $a;
+	}
+
+	while (true) {
+		$mod = mod($a, $b);
+
+		if ($mod === '0') {
+			$gcd = $b;
+			break;
+		}
+
+		$a = $b;
+		$b = $mod;
+	}
+
+	return abs($gcd ?? $b);
+}

Simplex/exceptions.php

@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types = 1);
+
+/**
+ * This file is part of the Simplex-Calculator library
+ *
+ * Copyright (c) 2014 Petr Kessler (https://kesspess.cz)
+ *
+ * @license  MIT
+ * @link     https://github.com/uestla/Simplex-Calculator
+ */
+
+namespace Simplex;
+
+
+final class ZeroGcdArgumentsException extends SimplexException
+{
+	public function __construct()
+	{
+		parent::__construct('At least one number must not be a zero.');
+	}
+}
+
+
+abstract class SimplexException extends \Exception
+{}

Simplex/simplex.php

@@ -14,3 +14,5 @@
 namespace Simplex;
 
 
+require_once __DIR__ . '/exceptions.php';
+require_once __DIR__ . '/Math/math.php';