Lately I've been playing with the idea that the only language feature you need to support the functional style is partial application.
I've even been playing with the more extreme idea that the even if you have other language features associated with the functional style, perhaps it is a good idea to limit yourself to partial application. The language features I'm thinking of avoiding are anonymous, nestable, and lexically-scoped functions.
I'll leave it to another post to explain these ideas. All I really want to do here is share my implementations of partial application in Perl and PHP.
Of course these implementations rely on all those features mentioned above: anonymous, nestable, and lexically-scoped functions. So the style I'm experimenting with uses all those features, but only here, in the implementation of the partial application function!