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