Just thought I'd chime in here with an example that seemed relevant: cout << "foo" << "bar" << endl;
cin >> input; Here, << and >> have nothing to do with bit-shifting and have different meanings. So, maybe one can't assume that '<' and '>' always have to apply to the typical mathematical operations (e.g. $pacman < $ghost). Benj Carson PS: Is it a coincidence that goto support & operator overloading have the same author? ;) On Thursday 16 February 2006 15:55, Zeev Suraski wrote: > I understand. Aren't you slightly worried about the implications of > making it possible for x>y to have a different meaning than y<x? > > In languages where operator overloading is supported, it comes hand > in hand with strict typing, which wouldn't allow for different values > for x>y and y<x... > > Zeev > > At 19:55 16/02/2006, Sara Golemon wrote: > > > >Enter PECL/operator, which tries to implement operator overloading > > > >for objects (and does a decent job at that). In the interrest of > > > >ease of use and consistency, every overloaded binary operator is > > > >[meant to be] left associative. This is, in the expression expr1 > > > >op expr2 expr1 gets to decide how it will combine-with/compare-to > > > >expr2. > > > > > What does it mean that it gets to decide? If it's left associative, > > > then it's evaluated from left to right, no? > > > >Yes, and that's the problem. $a > $b *isn't* read by the current > > parser as $a > $b, it's read as $b < $a. > > > >For all normal PHP comparisons, the distinction is unimportant... 4 < > > 2 and 2 > 4 will both evaluate to false after all. > > > >However, the way object operator overloading is being done is: If the > > first operand is an object implementing an overload method for this op, > > dispatch to that method rather than using the tranditional comparison > > function. e.g. $a < $b turns into $a->__is_smaller($b). > > > >Now say you've got that expression the other way around: $a > $b. > > What you'd expect is that if $a is an object, it'll try to call > >$a->__is_greater($b). What you get is an automatic reversal of the > >expression by the engine: $b < $a, which turns into: "If $b is an > > object, dispatch to $b->__is_smaller($a);" which is not the same > > thing. > > > >-Sara -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
