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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 | * @author Fabien Potencier <fabien@symfony.com> | |
31 | * | |
32 | * @see http://en.wikipedia.org/wiki/Interval_%28mathematics%29#The_ISO_notation | |
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 $interval An interval | |
41 | * | |
42 | * @return Boolean | |
43 | * | |
44 | * @throws \InvalidArgumentException | |
45 | */ | |
46 | public static function test($number, $interval) | |
47 | { | |
48 | $interval = trim($interval); | |
49 | ||
50 | if (!preg_match('/^'.self::getIntervalRegexp().'$/x', $interval, $matches)) { | |
51 | throw new \InvalidArgumentException(sprintf('"%s" is not a valid interval.', $interval)); | |
52 | } | |
53 | ||
54 | if ($matches[1]) { | |
55 | foreach (explode(',', $matches[2]) as $n) { | |
56 | if ($number == $n) { | |
57 | return true; | |
58 | } | |
59 | } | |
60 | } else { | |
61 | $leftNumber = self::convertNumber($matches['left']); | |
62 | $rightNumber = self::convertNumber($matches['right']); | |
63 | ||
64 | return | |
65 | ('[' === $matches['left_delimiter'] ? $number >= $leftNumber : $number > $leftNumber) | |
66 | && (']' === $matches['right_delimiter'] ? $number <= $rightNumber : $number < $rightNumber) | |
67 | ; | |
68 | } | |
69 | ||
70 | return false; | |
71 | } | |
72 | ||
73 | /** | |
74 | * Returns a Regexp that matches valid intervals. | |
75 | * | |
76 | * @return string A Regexp (without the delimiters) | |
77 | */ | |
78 | public static function getIntervalRegexp() | |
79 | { | |
80 | return <<<EOF | |
81 | ({\s* | |
82 | (\-?\d+(\.\d+)?[\s*,\s*\-?\d+(\.\d+)?]*) | |
83 | \s*}) | |
84 | ||
85 | | | |
86 | ||
87 | (?P<left_delimiter>[\[\]]) | |
88 | \s* | |
89 | (?P<left>-Inf|\-?\d+(\.\d+)?) | |
90 | \s*,\s* | |
91 | (?P<right>\+?Inf|\-?\d+(\.\d+)?) | |
92 | \s* | |
93 | (?P<right_delimiter>[\[\]]) | |
94 | EOF; | |
95 | } | |
96 | ||
97 | private static function convertNumber($number) | |
98 | { | |
99 | if ('-Inf' === $number) { | |
100 | return log(0); | |
101 | } elseif ('+Inf' === $number || 'Inf' === $number) { | |
102 | return -log(0); | |
103 | } | |
104 | ||
105 | return (float) $number; | |
106 | } | |
107 | } |