<?php /* * This file is part of the Symfony package. * * (c) Fabien Potencier <fabien@symfony.com> * * For the full copyright and license information, please view the LICENSE * file that was distributed with this source code. */ namespace Symfony\Component\Translation; /** * Tests if a given number belongs to a given math interval. * * An interval can represent a finite set of numbers: * * {1,2,3,4} * * An interval can represent numbers between two numbers: * * [1, +Inf] * ]-1,2[ * * The left delimiter can be [ (inclusive) or ] (exclusive). * The right delimiter can be [ (exclusive) or ] (inclusive). * Beside numbers, you can use -Inf and +Inf for the infinite. * * @author Fabien Potencier <fabien@symfony.com> * * @see http://en.wikipedia.org/wiki/Interval_%28mathematics%29#The_ISO_notation */ class Interval { /** * Tests if the given number is in the math interval. * * @param integer $number A number * @param string $interval An interval * * @return Boolean * * @throws \InvalidArgumentException */ public static function test($number, $interval) { $interval = trim($interval); if (!preg_match('/^'.self::getIntervalRegexp().'$/x', $interval, $matches)) { throw new \InvalidArgumentException(sprintf('"%s" is not a valid interval.', $interval)); } if ($matches[1]) { foreach (explode(',', $matches[2]) as $n) { if ($number == $n) { return true; } } } else { $leftNumber = self::convertNumber($matches['left']); $rightNumber = self::convertNumber($matches['right']); return ('[' === $matches['left_delimiter'] ? $number >= $leftNumber : $number > $leftNumber) && (']' === $matches['right_delimiter'] ? $number <= $rightNumber : $number < $rightNumber) ; } return false; } /** * Returns a Regexp that matches valid intervals. * * @return string A Regexp (without the delimiters) */ public static function getIntervalRegexp() { return <<<EOF ({\s* (\-?\d+(\.\d+)?[\s*,\s*\-?\d+(\.\d+)?]*) \s*}) | (?P<left_delimiter>[\[\]]) \s* (?P<left>-Inf|\-?\d+(\.\d+)?) \s*,\s* (?P<right>\+?Inf|\-?\d+(\.\d+)?) \s* (?P<right_delimiter>[\[\]]) EOF; } private static function convertNumber($number) { if ('-Inf' === $number) { return log(0); } elseif ('+Inf' === $number || 'Inf' === $number) { return -log(0); } return (float) $number; } }