From: philip at cornado dot com
Operating system: Irrelevant
PHP version: Irrelevant
PHP Bug Type: Feature/Change Request
Bug description: callback function for levenshtein
Description:
------------
The levenshtein() documentation goes into great detail on a third yet to
be implemented parameter for a levenshtein callback function. Below are
those docs which will soon be removed from the php manual until this
feature is actually implemented:
The third variant (which is not implemented yet) will be the most general
and adaptive, but also the slowest alternative. It will call a
user-supplied function that will determine the cost for every possible
operation.
The user-supplied function will be called with the following arguments:
* operation to apply: 'I', 'R' or 'D'
* actual character in string 1
* actual character in string 2
* position in string 1
* position in string 2
* remaining characters in string 1
* remaining characters in string 2
The user-supplied function has to return a positive integer describing the
cost for this particular operation, but it may decide to use only some of
the supplied arguments.
The user-supplied function approach offers the possibility to take into
account the relevance of and/or difference between certain symbols
(characters) or even the context those symbols appear in to determine the
cost of insert, replace and delete operations, but at the cost of losing
all optimizations done regarding cpu register utilization and cache misses
that have been worked into the other two variants.
Attempting to use it gives us:
php_error_docref(NULL TSRMLS_CC, E_WARNING, "The general Levenshtein
support is not there yet");
And a return value of -1.
--
Edit bug report at http://bugs.php.net/?id=29552&edit=1
--
Try a CVS snapshot (php4): http://bugs.php.net/fix.php?id=29552&r=trysnapshot4
Try a CVS snapshot (php5): http://bugs.php.net/fix.php?id=29552&r=trysnapshot5
Fixed in CVS: http://bugs.php.net/fix.php?id=29552&r=fixedcvs
Fixed in release: http://bugs.php.net/fix.php?id=29552&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=29552&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=29552&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=29552&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=29552&r=support
Expected behavior: http://bugs.php.net/fix.php?id=29552&r=notwrong
Not enough info: http://bugs.php.net/fix.php?id=29552&r=notenoughinfo
Submitted twice: http://bugs.php.net/fix.php?id=29552&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=29552&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=29552&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=29552&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=29552&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=29552&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=29552&r=float
