I'm wondering if there would be a way to do such a thing as
overloading the () operator of a class in order to use that class as a
callback function. I presently would love to do this with the usort
function in order to easily pass runtime information to the custom
sort callback function. It has been my habit in the past(and with
other languages) to do this by using a class for my callback, setting
the information in the constructor(or any time before the cal really),
and then overloading () to give the class the facade of a function.
If this is posible in PHP please tell me. or, if there is a way to do
a similar thing that's more in keeping with the PHP idiom I'll listen
to that to. It would be useful to know this without all that mucking
about in documentation. If the no is resounding enough I'll write the
sort myself, but with a perfectly good sorting function just sitting
there it seems like a shame to have to do so. 2 1634
"justin allen" <ju************ @gmail.com> wrote in message
news:d3******** *************** **@posting.goog le.com... I'm wondering if there would be a way to do such a thing as overloading the () operator of a class in order to use that class as a callback function. I presently would love to do this with the usort function in order to easily pass runtime information to the custom sort callback function. It has been my habit in the past(and with other languages) to do this by using a class for my callback, setting the information in the constructor(or any time before the cal really), and then overloading () to give the class the facade of a function. If this is posible in PHP please tell me. or, if there is a way to do a similar thing that's more in keeping with the PHP idiom I'll listen to that to. It would be useful to know this without all that mucking about in documentation. If the no is resounding enough I'll write the sort myself, but with a perfectly good sorting function just sitting there it seems like a shame to have to do so.
Use the array($obj, <name-of-callback>) convention. The following example
uses the Levenstein function to sort an array according to how similiar it
is to a specific text string.
<?
class LevenshteinSort er {
var $text;
function LevenshteinSort er($text) {
$this->text = $text;
}
function Compare($s1, $s2) {
$d1 = levenshtein($s1 , $this->text);
$d2 = levenshtein($s2 , $this->text);
return $d1 - $d2;
}
}
$names = array(
"I am not a crook",
"I don't like crooks",
"I have a dream",
"Chicken came first, damn it!",
"PHP is easy",
);
$L1 = new LevenshteinSort er("I am dreaming");
usort($names, array($L1, 'Compare'));
print_r($names) ;
$L2 = new LevenshteinSort er("I am a crook");
usort($names, array($L2, 'Compare'));
print_r($names) ;
?>
"Chung Leong" <ch***********@ hotmail.com> wrote in message news:<XJ******* *************@c omcast.com>... "justin allen" <ju************ @gmail.com> wrote in message news:d3******** *************** **@posting.goog le.com... I'm wondering if there would be a way to do such a thing as overloading the () operator of a class in order to use that class as a callback function. I presently would love to do this with the usort function in order to easily pass runtime information to the custom sort callback function. It has been my habit in the past(and with other languages) to do this by using a class for my callback, setting the information in the constructor(or any time before the cal really), and then overloading () to give the class the facade of a function. If this is posible in PHP please tell me. or, if there is a way to do a similar thing that's more in keeping with the PHP idiom I'll listen to that to. It would be useful to know this without all that mucking about in documentation. If the no is resounding enough I'll write the sort myself, but with a perfectly good sorting function just sitting there it seems like a shame to have to do so.
Use the array($obj, <name-of-callback>) convention. The following example uses the Levenstein function to sort an array according to how similiar it is to a specific text string.
<?
class LevenshteinSort er { var $text;
function LevenshteinSort er($text) { $this->text = $text; }
function Compare($s1, $s2) { $d1 = levenshtein($s1 , $this->text); $d2 = levenshtein($s2 , $this->text); return $d1 - $d2; } }
$names = array( "I am not a crook", "I don't like crooks", "I have a dream", "Chicken came first, damn it!", "PHP is easy", );
$L1 = new LevenshteinSort er("I am dreaming"); usort($names, array($L1, 'Compare'));
print_r($names) ;
$L2 = new LevenshteinSort er("I am a crook"); usort($names, array($L2, 'Compare'));
print_r($names) ;
?>
sweet. That's exactly what I needed. Thanks. This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
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The PHP manual mentions "overloading"
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att = 1
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