Copybara bot | be50d49 | 2023-11-30 00:16:42 +0100 | [diff] [blame] | 1 | <?php |
| 2 | class intervals { |
| 3 | public static function wellFormed($i) { |
| 4 | return (isset($i[0]) && isset($i[1]) && $i[0] <= $i[1]); |
| 5 | } |
| 6 | |
| 7 | public static function measure($i) { |
| 8 | return ($i[1] - $i[0]); |
| 9 | } |
| 10 | |
| 11 | // Does A overlap B? (with "$open = true" meaning [0, 100] does not overlap [100, 200]) |
| 12 | public static function overlaps($a, $b, $open = true) { |
| 13 | return ($open ? ($a[0] < $b[1] && $a[1] > $b[0]) : ($a[0] <= $b[1] && $a[1] >= $b[0])); |
| 14 | } |
| 15 | |
| 16 | // Is A inside of B? |
| 17 | public static function isSubset($a, $b) { |
| 18 | return ($a[0] >= $b[0] && $a[1] <= $b[1]); |
| 19 | } |
| 20 | |
| 21 | // Intersect A and B and return the corresponding interval |
| 22 | public static function intersect($a, $b) { |
| 23 | $int = [max($a[0], $b[0]), min($a[1], $b[1])]; |
| 24 | |
| 25 | return (self::wellFormed($int) ? $int : false); |
| 26 | } |
| 27 | |
| 28 | // Return measure of the intersection |
| 29 | public static function measureIntersection($a, $b) { |
| 30 | return self::measure(self::intersect($a, $b)); |
| 31 | } |
| 32 | } |