[PHPTAL] Support for PHP 5.3 closures

[Iván Montes]

I fail to see why checking for closures makes variable access much 
slower. As far as I remember, interpolated variable paths are "compiled" 
to use the $ctx->path() method, and it already does quite a few type 
checking logic already.

Checking for a closure basically would mean adding "instanceof" 
conditions, being instanceof an operator and as such extremely fast, I 
don't see why it should hurt overall performance.

best regards,
/imv

On 12/23/09 6:42 PM, Kornel Lesiński wrote:
> In PHP 5.3 you can create function "on the fly":
>
> $phptal->variable = function() {
>     return "Hello World";
> }
>
>
> This looks like a great solution for lazy loading of data - instead of 
> loading data up front, you just wrap it in a function that will be 
> called in template when needed.
>
>
> I've hoped to create "no-syntax" syntax for it, i.e. the code above 
> would automatically execute function:
>
> ${variable} == "Hello World"
>
>
> Although this is doable, it would make some optimisations impossible, 
> and in turn make PHPTAL's variable access much slower (basically every 
> time any variable is accessed, I'd have to check if it's a closure).
>
> So I'm thinking about alternative syntax for it that would make 
> execution of closures explicit.
>
> ${variable/invoke} or ${variable/()}? ${variable()} is an option too, 
> but harder to implement efficiently.
>
>
> Zope's TAL has nocall: modifier that makes functions returned as 
> objects. Perhaps PHPTAL could have the opposite that makes all 
> closures automatically executed?
>
> ${call:variable}
>
>
>
> I've used simple variable in the examples, but I expect more complex 
> cases to work as well:
>
> $phptal->array = array('closure'=>function(){
>     return new Object();
> });
>
> ${call:array/closure/objects_property}
>
> etc.
>