Req #51335 [Opn->Sus]: Search first substring from list

Edit report at https://bugs.php.net/bug.php?id=51335&edit=1 ID: 51335 Updated by: cmb@php.net Reported by: vovan-ve at yandex dot ru Summary: Search first substring from list -Status: Open +Status: Suspended Type: Feature/Change Request Package: Strings related PHP Version: Irrelevant Block user comment: N Private report: N New Comment: This appears to be a controversial feature addition, and as such deserves to be discussed on the PHP internals mailing list[1]. Feel free to post there; for the time being I'm suspending this ticket. [1] <https://www.php.net/mailing-lists.php#internals> Previous Comments: ------------------------------------------------------------------------ [2010-06-11 17:48:17] vovan-ve at yandex dot ru Yes, such functionality can be done by strpos() foreach needle in the array. But I see at least two ways to make such search more optimal: 1. Make limit for maximal possible position after which we should not search a needles. The strpos() has no such limit, so we need to make substr() after we find next nearest needle. 2. Check length of a next needle and remaining substring to search in. Of course I can write the function, which do what I need, but I think, that it won't more optimal in PHP code, then build-in PCRE or build-in function I request. ------------------------------------------------------------------------ [2010-06-11 14:21:18] kalle@php.net I dont think we should add such functionality that already can be done with a few lines of php code already, combining strpos/stripos with a foreach and you should get your result: <?php function strpos_array_impl($case_sensitive, $haystack, Array $needle, &$found = NULL, $position = 0) { if(!sizeof($needle) || empty($haystack)) { return(false); } $strpos_function = ($case_sensitive ? 'strpos' : 'stripos'); foreach($needle as $temp) { if(($pos = $strpos_function($haystack, $temp, $found, $position) !== false) { return($pos); } } return(false); } function strpos_array($haystack, Array $needle, &$found = NULL, $position = 0) { return(strpos_array_impl(false, $haystack, $needle, $found, $position)); } function stripos_array($haystack, Array $needle, &$found = NULL, $position = 0) { return(strpos_array_impl(true, $haystack, $needle, $found, $position)); } ?> Dont take that code for granted, as i wrote it on my cell so it might be buggy, but should show what I mean ------------------------------------------------------------------------ [2010-03-20 11:45:58] vovan-ve at yandex dot ru Description: ------------ If we want to search first substrings from list, we should make multiple calls to strpos() for each substring. Using PCRE will slowdown performance. So, we need some new function like: int strpos_array(string $haystack, array $needles, string &$found [, int $offset = 0 ]) which will accept array of substrings in $needle, search first position of them. If nothing found then returns FALSE. If found any substring then assign it to $found and return its position. The function name is not important. Other functions for case-insensitive search and/or for reverse search (stripos_array, strrpos_array, strripos_array) also useful. Extending function strpos() to accept array in $needle is not good due to &$found parameter. Good example of using such function is writing parser of some data like SQL dump. Performance of the function should be higher then PCRE. Test script: --------------- $string = 'foo;bar::baz-qwe'; $search = array('-', ';', '::'); $pos = strpos_array($string, $search, $found, 5); if ($pos === false) { echo "Nothing found"; } else { echo "Found '$found' at $pos"; } Expected result: ---------------- Found '::' at 7 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=51335&edit=1