1 <?php

     2 

     3 /*

     4  * This file is part of the Symfony package.

     5  *

     6  * (c) Fabien Potencier <fabien@symfony.com>

     7  *

     8  * For the full copyright and license information, please view the LICENSE

     9  * file that was distributed with this source code.

    10  */

    11 

    12 namespace Symfony\Component\Translation;

    13 

    14 /**

    15  * Tests if a given number belongs to a given math interval.

    16  *

    17  * An interval can represent a finite set of numbers:

    18  *

    19  *  {1,2,3,4}

    20  *

    21  * An interval can represent numbers between two numbers:

    22  *

    23  *  [1, +Inf]

    24  *  ]-1,2[

    25  *

    26  * The left delimiter can be [ (inclusive) or ] (exclusive).

    27  * The right delimiter can be [ (exclusive) or ] (inclusive).

    28  * Beside numbers, you can use -Inf and +Inf for the infinite.

    29  *

    30  * @see http://en.wikipedia.org/wiki/Interval_%28mathematics%29#The_ISO_notation

    31  *

    32  * @author Fabien Potencier <fabien@symfony.com>

    33  */

    34 class Interval

    35 {

    36     /**

    37      * Tests if the given number is in the math interval.

    38      *

    39      * @param integer $number   A number

    40      * @param string  $interval An interval

    41      */

    42     static public function test($number, $interval)

    43     {

    44         $interval = trim($interval);

    45 

    46         if (!preg_match('/^'.self::getIntervalRegexp().'$/x', $interval, $matches)) {

    47             throw new \InvalidArgumentException(sprintf('"%s" is not a valid interval.', $interval));

    48         }

    49 

    50         if ($matches[1]) {

    51             foreach (explode(',', $matches[2]) as $n) {

    52                 if ($number == $n) {

    53                     return true;

    54                 }

    55             }

    56         } else {

    57             $leftNumber = self::convertNumber($matches['left']);

    58             $rightNumber = self::convertNumber($matches['right']);

    59 

    60             return

    61                 ('[' === $matches['left_delimiter'] ? $number >= $leftNumber : $number > $leftNumber)

    62                 && (']' === $matches['right_delimiter'] ? $number <= $rightNumber : $number < $rightNumber)

    63             ;

    64         }

    65 

    66         return false;

    67     }

    68 

    69     /**

    70      * Returns a Regexp that matches valid intervals.

    71      *

    72      * @return string A Regexp (without the delimiters)

    73      */

    74     static public function getIntervalRegexp()

    75     {

    76         return <<<EOF

    77         ({\s*

    78             (\-?\d+[\s*,\s*\-?\d+]*)

    79         \s*})

    80 

    81             |

    82 

    83         (?<left_delimiter>[\[\]])

    84             \s*

    85             (?<left>-Inf|\-?\d+)

    86             \s*,\s*

    87             (?<right>\+?Inf|\-?\d+)

    88             \s*

    89         (?<right_delimiter>[\[\]])

    90 EOF;

    91     }

    92 

    93     static private function convertNumber($number)

    94     {

    95         if ('-Inf' === $number) {

    96             return log(0);

    97         } elseif ('+Inf' === $number || 'Inf' === $number) {

    98             return -log(0);

    99         }

   100 

   101         return (int) $number;

   102     }

   103 }