PATCH: anonymous functions in PHP

Your nitpicking happens to be wrong ;-) sizeof("string constant") is the "same" as strlen("string constant") +1, but is resolved at compile time, so we use sizeof("string constant")-1 to get a compile time evaluated strlen(). This trick is used throughout the PHP internals. --Wez. On Mar 18, 2007, at 9:27 PM, Gwynne wrote:

This argument is false in any case, since create_function exists and this implementation is other way to write create_function :)

Stanislav Malyshev wrote:

Wez' proposal sounds very intriguing. At the same time I wouldn't try to add closures to PHP as while they might be a mighty concept they are also complicated and have a high WTF factor IMHO. When I first started doing more complex things in Javascript I was bitten more than once by closures: Sometimes they did what I expected and sometimes they didn't (e.g. when using 'this'). But I agree that it would be great to being able to pass context to the generated function, preferably not via a global variable. One possible solution would be to generate the function as a method of the current object and expose this so something like usort($data, function($a, $b) { return $this->cmp($a, $b); }); could be used. - Chris

I think this is the key to this whole discussion. I doubt PHP will ever be able to fully support JavaScript- and Lisp-style closures. To take Stas' example to another level: function foo() { $bar = function () { echo "bar"; } return $bar; } $bar = foo(); $bar(); // does this work? According to our current current syntax: function foo() { $bar = create_function('', 'echo "bar";'); return $bar; } $bar = foo(); $bar(); // this does work I don't know Lisp very well at all, but in JavaScript, functions are general containers, and this sort of thing works fine, albeit VERY differently. PHP's scoping rules are already completely different from JavaScript's (there's no way to access the parent scope unless it happens to be the global scope). I strongly prefer Wez's syntax for anonymous function declaration. It would help on many levels, from readability to syntax-highlighting, to optimization (maybe...). On optimization, the question becomes "how does Wez's proposal tokenize?" --------Old: T_OPEN_TAG : <?php T_VARIABLE : $bar T_WHITESPACE : = T_WHITESPACE : T_STRING : create_function ( T_CONSTANT_ENCAPSED_STRING : '' , T_WHITESPACE : T_CONSTANT_ENCAPSED_STRING : 'echo "bar";' ) ; --------New: T_OPEN_TAG : <?php T_VARIABLE : $bar T_WHITESPACE : = T_WHITESPACE : T_FUNCTION : function ( ) T_WHITESPACE : { T_WHITESPACE : T_ECHO : echo T_WHITESPACE : T_CONSTANT_ENCAPSED_STRING : "bar" ; T_WHITESPACE : } ; If the answer is "New", then this could be compiled at.. well, compile-time, not at execute time. That could be even more interesting. (sorry for the long post.. most of it's code (-; ) S

Richard Lynch wrote:

I don't have anything against 'function', I think JS uses the same syntax - function without a name. If you change it to something different, e.g 'callback', then you loose the information that it is actually a function $error_func = callback($msg) { file_put_contents('php://stderr',"Error: $msg\n"); } vs. $error_func = function($msg) { file_put_contents('php://stderr',"Error: $msg\n"); } The second one looks better for me.