> $apos = curry strpos(..., 'a'));
> $apos(); // runtime error wrong param count?
> $apos("bar"); // fine
> $apos("bar", "foo"); // 'a' casted to long, used as offset?
> $apos("bar", "foo", 0); // run-time error wrong param count?
I understand where this can be useful sometimes, but I disagree that this
should be added as a language feature. It is still possible to implement this
(parameter positioning in your curried function) using a function that returns
a closure similar to the curry_left example in the RFC. One possible method
(inspired by the C++ system for doing the same thing) would be:
$apos = curry( 'strpos', _1(), 'a' ); // _1() returns a placeholder positioning
object
This isn't quite as nice as the proposed T_FILL, but on the other hand, it is
more powerful (parameters could change order) and isn't nearly as confusing as
the RFC syntax (which looks like perhaps strpos is being called in some strange
way).
Of course, there is also always the regular old closure, which is far more
explicit and leaves no confusion about exactly what is being returned.
No offense to anyone who loves currying, but I don't see why this should be
implemented. There are plenty of good options available for achieving identical
or better results without modifying the language.
John Crenshaw
Priacta, Inc.
