Re: PEAR_Callback proposal

Lukas Feiler wrote:

Hi, Alexey Borzov wrote:

Hi, Lukas Feiler wrote:

    
A couple of days ago I proposed the package PEAR_Callback;

see http://pear.php.net/pepr/pepr-proposal-show.php?id=468 It addresses three major limitations of the callback pseudo-type: - By looking at a callback pseudo-type variable you cannot tell if it really is a callback. - The callback pseudo-type does not allow you to specify arguments at the time you create the callback. - There is no way to force a user to pass only callback functions to your API, that meet certain requirements (i.e. accept certain arguments and have a certain return type)

All of these major limitations can be overcome by using the Command design pattern: http://en.wikipedia.org/wiki/Command_pattern I don't honestly see the benefit for PEAR in adding a wrapper around functions when all these checks are already available for classes / objects in PHP5.

PEAR_Callback effectively is a general command pattern implementation - it eliminates the need to write a command class for every callback function a programmer wants to use. But I do get your point. After all, OO languages like Java don't even have something like call_user_func(). Cheers, Lukas I'm still a fan of the code. I think callbacks are underused in PHP, just because the java approach is what you find in books doesn't mean its the best approach for php. -josh