| <?php |
| /** |
| * Database row sorting. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License along |
| * with this program; if not, write to the Free Software Foundation, Inc., |
| * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
| * http://www.gnu.org/copyleft/gpl.html |
| * |
| * @file |
| */ |
| |
| /** |
| * @since 1.16.3 |
| * @author Tim Starling |
| * @stable to extend |
| */ |
| abstract class Collation { |
| |
| /** |
| * Given a string, convert it to a (hopefully short) key that can be used |
| * for efficient sorting. A binary sort according to the sortkeys |
| * corresponds to a logical sort of the corresponding strings. Current |
| * code expects that a line feed character should sort before all others, but |
| * has no other particular expectations (and that one can be changed if |
| * necessary). |
| * |
| * @since 1.16.3 |
| * |
| * @param string $string UTF-8 string |
| * @return string Binary sortkey |
| */ |
| abstract public function getSortKey( $string ); |
| |
| /** |
| * Get multiple sort keys |
| * |
| * @param string[] $strings |
| * @return string[] |
| */ |
| public function getSortKeys( $strings ) { |
| $ret = []; |
| foreach ( $strings as $key => $s ) { |
| $ret[$key] = $this->getSortKey( $s ); |
| } |
| return $ret; |
| } |
| |
| /** |
| * Given a string, return the logical "first letter" to be used for |
| * grouping on category pages and so on. This has to be coordinated |
| * carefully with convertToSortkey(), or else the sorted list might jump |
| * back and forth between the same "initial letters" or other pathological |
| * behavior. For instance, if you just return the first character, but "a" |
| * sorts the same as "A" based on getSortKey(), then you might get a |
| * list like |
| * |
| * == A == |
| * * [[Aardvark]] |
| * |
| * == a == |
| * * [[antelope]] |
| * |
| * == A == |
| * * [[Ape]] |
| * |
| * etc., assuming for the sake of argument that $wgCapitalLinks is false. |
| * |
| * @since 1.16.3 |
| * |
| * @param string $string UTF-8 string |
| * @return string UTF-8 string corresponding to the first letter of input |
| */ |
| abstract public function getFirstLetter( $string ); |
| |
| } |