Re: [PHP-DEV] Multi-Method Dispatch in PHP 5.1?

[George Schlossnagle]

On Apr 20, 2004, at 2:51 PM, Andrey Hristov wrote:

Quoting Sebastian Bergmann <[EMAIL PROTECTED]>:

  Since we introduce class type hints in PHP 5.0 I think it would be a
  good thing [tm] to add multi-method dispatch in PHP 5.1.
  What I mean by this would be to allow for the following:

    class Foo {
        public function doSomething(Foo $foo) {}
        public function doSomething(Bar $bar) {}
    }
  How complicated would this be to implement?

Hi,
yesterday while waiting at the UBahn (Metro) station I came to the 
idea such
thing can me made in userland. func_get_args() can help combined with
get_type()  for simple types. if it's class than => use also the class 
name if
you want.

<?php
class fubar {
        protected function 
doSomething_integer_integer_double($i1,$i2,$f) {
                $a = func_get_args();var_dump(__METHOD__, $a);
        }
        protected function doSomething_integer_double($i,$f) {
                $a = func_get_args();var_dump(__METHOD__, $a);
        }

        public function doSomething() {
                $args = func_get_args();
                $method_name = __FUNCTION__;
                foreach ($args as $v) {
                        $method_name .= "_".gettype($v);
                }
                if (method_exists($this, $method_name)) {
                        return call_user_func_array(array($this, 
$method_name),
$args);
        }
}
}//class fubar

$a = new fubar();
$a->doSomething(1, 2.0);
$a->doSomething(3,4, 5.0);
?>
The problem with this is that that integer may well be a string when 
you look at it.  There's no good way to do this past discriminating 
between scalar, array and object (by type, of course).   I personally 
think that that is fine (adding an array typehint would be nice).

George

--
PHP Internals - PHP Runtime Development Mailing List
To unsubscribe, visit: http://www.php.net/unsub.php