Added Nette\Utils\Floats class for comparing floats (#221)

src/Utils/Floats.php

@@ -0,0 +1,109 @@
+<?php
+
+/**
+ * This file is part of the Nette Framework (https://nette.org)
+ * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
+ */
+
+declare(strict_types=1);
+
+namespace Nette\Utils;
+
+use Nette;
+
+
+/**
+ * Floats compare tools library.
+ */
+class Floats
+{
+	use Nette\StaticClass;
+
+	/** @var float */
+	private const EPSILON = 1e-10;
+
+
+	public static function isZero(float $value): bool
+	{
+		return abs($value) < self::EPSILON;
+	}
+
+
+	public static function isInteger(float $value): bool
+	{
+		return abs(round($value) - $value) < self::EPSILON;
+	}
+
+
+	/**
+	 * Compare two floats. If $a < $b it returns -1, if they are equal it returns 0 and if $a > $b it returns 1
+	 * @throws \LogicException if one of parameters is NAN
+	 */
+	public static function compare(float $a, float $b): int
+	{
+		if (is_nan($a) || is_nan($b)) {
+			throw new \LogicException('Trying to compare NAN');
+
+		} elseif (!is_finite($a) && !is_finite($b) && $a === $b) {
+			return 0;
+
+		} else {
+			$diff = abs($a - $b);
+			if (($diff < self::EPSILON || ($diff / max(abs($a), abs($b)) < self::EPSILON))) {
+				return 0;
+			}
+		}
+
+		return $a < $b ? -1 : 1;
+	}
+
+
+	/**
+	 * Returns true if $a = $b
+	 * @throws \LogicException if one or both parameters are NAN
+	 */
+	public static function areEqual(float $a, float $b): bool
+	{
+		return self::compare($a, $b) === 0;
+	}
+
+
+	/**
+	 * Returns true if $a < $b
+	 * @throws \LogicException if one or both parameters are NAN
+	 */
+	public static function isLessThan(float $a, float $b): bool
+	{
+		return self::compare($a, $b) < 0;
+	}
+
+
+	/**
+	 * Returns true if $a <= $b
+	 * @throws \LogicException if one or both parameters are NAN
+	 */
+	public static function isLessThanOrEqualTo(float $a, float $b): bool
+	{
+		return self::compare($a, $b) <= 0;
+	}
+
+
+	/**
+	 * Returns true if $a > $b
+	 * @throws \LogicException if one or both parameters are NAN
+	 */
+	public static function isGreaterThan(float $a, float $b): bool
+	{
+		return self::compare($a, $b) > 0;
+	}
+
+
+	/**
+	 * Returns true if $a >= $b
+	 * @throws \LogicException if one or both parameters are NAN
+	 */
+	public static function isGreaterThanOrEqualTo(float $a, float $b): bool
+	{
+		return self::compare($a, $b) >= 0;
+	}
+}

tests/Utils/Floats.areEqual().phpt

@@ -0,0 +1,41 @@
+<?php
+
+/**
+ * Test: Nette\Utils\Floats::areEqual()
+ */
+
+declare(strict_types=1);
+
+use Nette\Utils\Floats;
+use Tester\Assert;
+
+
+require __DIR__ . '/../bootstrap.php';
+
+
+Assert::true(Floats::areEqual(9, 9));
+Assert::true(Floats::areEqual(9, 9.0));
+Assert::true(Floats::areEqual(3.0, 3));
+Assert::true(Floats::areEqual(0.0, 0));
+Assert::true(Floats::areEqual(0.0, 0.0));
+Assert::true(Floats::areEqual(0.1 + 0.2, 0.3));
+Assert::true(Floats::areEqual(0.1 - 0.5, -0.4));
+Assert::false(Floats::areEqual(0.0, 5));
+Assert::false(Floats::areEqual(-5, 5));
+Assert::false(Floats::areEqual(0.001, 0.01));
+
+$float1 = 1 / 3;
+$float2 = 1 - 2 / 3;
+Assert::true(Floats::areEqual($float1, $float2));
+Assert::true(Floats::areEqual($float1 * 1e9, $float2 * 1e9));
+Assert::true(Floats::areEqual($float1 - $float2, 0.0));
+Assert::true(Floats::areEqual($float1 - $float2 + 123, $float2 - $float1 + 123));
+Assert::true(Floats::areEqual($float1 - $float2, $float2 - $float1));
+
+Assert::true(Floats::areEqual(INF, INF));
+Assert::false(Floats::areEqual(INF, -INF));
+Assert::false(Floats::areEqual(-INF, INF));
+
+Assert::exception(function () {
+	Floats::areEqual(NAN, NAN);
+}, \LogicException::class);

tests/Utils/Floats.compare().phpt

@@ -0,0 +1,37 @@
+<?php
+
+/**
+ * Test: Nette\Utils\Floats::compare()
+ */
+
+declare(strict_types=1);
+
+use Nette\Utils\Floats;
+use Tester\Assert;
+
+
+require __DIR__ . '/../bootstrap.php';
+
+
+Assert::same(0, Floats::compare(0, 0));
+Assert::same(0, Floats::compare(0.0, 0));
+Assert::same(0, Floats::compare(0, 0x0));
+Assert::same(1, Floats::compare(0, -25.7));
+Assert::same(-1, Floats::compare(-2, 30.7));
+Assert::same(1, Floats::compare(0.0, -5));
+Assert::same(1, Floats::compare(20, 10));
+Assert::same(-1, Floats::compare(20, 30));
+Assert::same(1, Floats::compare(-20, -30));
+Assert::same(-1, Floats::compare(-50, -30));
+
+Assert::exception(function () {
+	Floats::compare(NAN, -30);
+}, \LogicException::class);
+
+Assert::exception(function () {
+	Floats::compare(6, NAN);
+}, \LogicException::class);
+
+Assert::exception(function () {
+	Floats::compare(NAN, NAN);
+}, \LogicException::class);

tests/Utils/Floats.isGreaterThan().phpt

@@ -0,0 +1,32 @@
+<?php
+
+/**
+ * Test: Nette\Utils\Floats::isGreaterThan()
+ */
+
+declare(strict_types=1);
+
+use Nette\Utils\Floats;
+use Tester\Assert;
+
+
+require __DIR__ . '/../bootstrap.php';
+
+
+Assert::false(Floats::isGreaterThan(-9, 9));
+Assert::false(Floats::isGreaterThan(-9.7, 0.0));
+Assert::false(Floats::isGreaterThan(10, 150));
+Assert::false(Floats::isGreaterThan(0, 0.0));
+Assert::false(Floats::isGreaterThan(10, 10));
+Assert::false(Floats::isGreaterThan(-50, -50));
+Assert::true(Floats::isGreaterThan(170, 150));
+Assert::true(Floats::isGreaterThan(170.879, -20));
+Assert::true(Floats::isGreaterThan(11.879, 0.0));
+
+Assert::true(Floats::isGreaterThan(INF, -INF));
+Assert::false(Floats::isGreaterThan(INF, INF));
+Assert::false(Floats::isGreaterThan(-INF, INF));
+
+Assert::exception(function () {
+	Floats::isGreaterThan(NAN, NAN);
+}, \LogicException::class);

tests/Utils/Floats.isGreaterThanOrEqualTo().phpt

@@ -0,0 +1,32 @@
+<?php
+
+/**
+ * Test: Nette\Utils\Floats::isGreaterOrEqualThan()
+ */
+
+declare(strict_types=1);
+
+use Nette\Utils\Floats;
+use Tester\Assert;
+
+
+require __DIR__ . '/../bootstrap.php';
+
+
+Assert::false(Floats::isGreaterThanOrEqualTo(-9, 9));
+Assert::false(Floats::isGreaterThanOrEqualTo(-9.7, 0.0));
+Assert::false(Floats::isGreaterThanOrEqualTo(10, 150));
+Assert::true(Floats::isGreaterThanOrEqualTo(0, 0.0));
+Assert::true(Floats::isGreaterThanOrEqualTo(10, 10));
+Assert::true(Floats::isGreaterThanOrEqualTo(-50, -50));
+Assert::true(Floats::isGreaterThanOrEqualTo(170, 150));
+Assert::true(Floats::isGreaterThanOrEqualTo(170.879, -20));
+Assert::true(Floats::isGreaterThanOrEqualTo(11.879, 0.0));
+
+Assert::true(Floats::isGreaterThanOrEqualTo(INF, INF));
+Assert::true(Floats::isGreaterThanOrEqualTo(INF, -INF));
+Assert::false(Floats::isGreaterThanOrEqualTo(-INF, INF));
+
+Assert::exception(function () {
+	Floats::isGreaterThanOrEqualTo(NAN, NAN);
+}, \LogicException::class);

tests/Utils/Floats.isInteger().phpt

@@ -0,0 +1,25 @@
+<?php
+
+/**
+ * Test: Nette\Utils\Floats::isInteger()
+ */
+
+declare(strict_types=1);
+
+use Nette\Utils\Floats;
+use Tester\Assert;
+
+
+require __DIR__ . '/../bootstrap.php';
+
+
+Assert::true(Floats::isInteger(0));
+Assert::true(Floats::isInteger(0.0));
+Assert::true(Floats::isInteger(5.0));
+Assert::true(Floats::isInteger(-5.0));
+Assert::true(Floats::isInteger(-5));
+Assert::true(Floats::isInteger((1 - (0.1 + 0.2)) * 10));
+Assert::false(Floats::isInteger(-5.1));
+Assert::false(Floats::isInteger(0.000001));
+Assert::false(Floats::isInteger(NAN));
+Assert::false(Floats::isInteger(INF));

tests/Utils/Floats.isLessThan().phpt

@@ -0,0 +1,32 @@
+<?php
+
+/**
+ * Test: Nette\Utils\Floats::isLowerThan()
+ */
+
+declare(strict_types=1);
+
+use Nette\Utils\Floats;
+use Tester\Assert;
+
+
+require __DIR__ . '/../bootstrap.php';
+
+
+Assert::true(Floats::isLessThan(-9, 9));
+Assert::true(Floats::isLessThan(-9.7, 0.0));
+Assert::true(Floats::isLessThan(10, 150));
+Assert::false(Floats::isLessThan(0, 0.0));
+Assert::false(Floats::isLessThan(10, 10));
+Assert::false(Floats::isLessThan(-50, -50));
+Assert::false(Floats::isLessThan(170, 150));
+Assert::false(Floats::isLessThan(170.879, -20));
+Assert::false(Floats::isLessThan(11.879, 0.0));
+
+Assert::true(Floats::isLessThan(-INF, INF));
+Assert::false(Floats::isLessThan(INF, INF));
+Assert::false(Floats::isLessThan(INF, -INF));
+
+Assert::exception(function () {
+	Floats::isLessThan(NAN, NAN);
+}, \LogicException::class);

tests/Utils/Floats.isLessThanOrEqualTo().phpt

@@ -0,0 +1,32 @@
+<?php
+
+/**
+ * Test: Nette\Utils\Floats::isLowerOrEqualThan()
+ */
+
+declare(strict_types=1);
+
+use Nette\Utils\Floats;
+use Tester\Assert;
+
+
+require __DIR__ . '/../bootstrap.php';
+
+
+Assert::true(Floats::isLessThanOrEqualTo(-9, 9));
+Assert::true(Floats::isLessThanOrEqualTo(-9.7, 0.0));
+Assert::true(Floats::isLessThanOrEqualTo(10, 150));
+Assert::true(Floats::isLessThanOrEqualTo(0, 0.0));
+Assert::true(Floats::isLessThanOrEqualTo(10, 10));
+Assert::true(Floats::isLessThanOrEqualTo(-50, -50));
+Assert::false(Floats::isLessThanOrEqualTo(170, 150));
+Assert::false(Floats::isLessThanOrEqualTo(170.879, -20));
+Assert::false(Floats::isLessThanOrEqualTo(11.879, 0.0));
+
+Assert::true(Floats::isLessThanOrEqualTo(-INF, INF));
+Assert::true(Floats::isLessThanOrEqualTo(INF, INF));
+Assert::false(Floats::isLessThanOrEqualTo(INF, -INF));
+
+Assert::exception(function () {
+	Floats::isLessThanOrEqualTo(NAN, NAN);
+}, \LogicException::class);

tests/Utils/Floats.isZero().phpt

@@ -0,0 +1,25 @@
+<?php
+
+/**
+ * Test: Nette\Utils\Floats::isZero()
+ */
+
+declare(strict_types=1);
+
+use Nette\Utils\Floats;
+use Tester\Assert;
+
+
+require __DIR__ . '/../bootstrap.php';
+
+
+Assert::true(Floats::isZero(0));
+Assert::true(Floats::isZero(0.0));
+Assert::true(Floats::isZero(0x0));
+Assert::false(Floats::isZero(-12.5));
+Assert::false(Floats::isZero(0.2));
+Assert::false(Floats::isZero(20));
+Assert::false(Floats::isZero(-2));
+Assert::false(Floats::isZero(0x5));
+Assert::false(Floats::isZero(INF));
+Assert::false(Floats::isZero(NAN));