Derick Rethans wrote: > On Mon, 6 Jun 2016, Dominic Grostate wrote: > >> As I understand it, using Java-like function overloading in PHP is >> undesirable due to hindrance in readability. > > Besides it impacting, readability, it will also create a large impact on > performance. > > Right now, functions (and methods) are looked up by their name only. In > order to support function overloading, the argument's types also need to > be taken into account. In C++, it works by mangling function names by > adding markers for types, such as: > > _ZN4HPHP34c_MongoDBDriverCursor_ni_getServerEPNS_10ObjectDataE > > which means: > > HPHP::c_MongoDBDriverCursor_ni_getServer(HPHP::ObjectData*) > > But unlike in C++, this needs to be done at runtime, and every time a > function is called because PHP is dynamically typed, and not statically. > > For example: > > myOverLoadedFunction(string $s, long $l, Weather $w) > > could be: > > myOverLoadedFunction_s_l_cWeather > > or something like that. > > Doing these conversions would mean (in the most simple way), that for > each function call, a string needs to be manipulated to create the > mangled function name to lookup for in a hash, where right now, they > only have to be strtolower()'ed (because of case insensivity). > > And then you need to do something sensible when *no* types have been > defined.
And we would run into similar issues as with the union types with regard to weak typing. -- Christoph M. Becker -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
