Re: Code References

On Mon, 2003-05-19 at 11:09, Zeev Suraski wrote: > At 16:34 19/05/2003, Sterling Hughes wrote: > >On Mon, 2003-05-19 at 10:55, Wez Furlong wrote: > > > use perl; > > > >Python, Ruby, LISP, Java, C, whatever, all support this in some form or > >another (whether it be function pointers or code references.) > > And so does PHP, through create_function, using PHPish > syntax. create_function is not related in any way to call_user_func(), > it's fairly fast, and will be faster. I don't see any additional things > that are supported by this syntax, other than a tiny performance gain, that > comes at the price of significantly reduced functionality (the code cannot > contain anything dynamic, whereas with create_function, it can). > That's why one has eval. Create_function() is a really hacky way of having closures/callbacks. Its not only inefficient, its ugly. create_function() is hardly ever used because its such an inelegant (and inefficient) way of doing things. From a syntax perspective anonymous functions are much clearer (the problem with single quotes is you need to then escape all single quotes). (responding to a previous message re conditional compilation) What about when a compiler cache is introduced? Every high performance application most likely uses a compiler cache. Introducing a code reference, would remove that overhead, and would seriously simplify and improve callback code (I have a patch which optimizes nearly all of the callback code in php5, which I'll send shortly, but its cleaner if we had the concept of code references.) -Sterling -- "Reductionists like to take things apart. The rest of us are just trying to get it together." - Larry Wall, Programming Perl, 3rd Edition