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Subject: Re: [PHP-DEV] closures questions
From: chris_se@gmx.net (Christian Seiler)

Hi!

>> so do we even want the toString() method?
> 
> IMHO we should drop toString from Closure.

There is one case which *may* cause problems:

function doSomething ($callback) {
   if (!is_callable ($callback)) {
     throw new Exception (...);
   }

   // special treatment
   if ($callback == 'default') {
     ...
   } else {
     ...
   }
}

Here, the comparison of $callback with 'default' will yield a notice
that $callback couldn't be converted. The comparison will fail
correctly, of course, but it could cause some confusion. The correct
way of comparing would obviously be using ===, that won't cause these
hickups.

Personally, I don't care whether a object-to-string cast is present or
not.

> I don't think Closure can be meaningfully exported. Can we prohibit it? 

Unfortunately, currently not, see the var_export code.

> I think we can make working clone there - just copy all data, etc. 

Perhaps. But I'd recommend this should be postponed, as there are quite
a few subtleties regarding semantics of bound variables involved. Should
there seem to be a strong need for cloning closures by the community,
this can always be implemented in a future PHP version. IMHO.

Regards,
Christian