Re^5: Near-free function currying in Perl

[dragonchild]

I like

sub foo : required($$$) {
    ...
}

That allows more than just currying to use the attribute. Also, you can then do something like:

sub foo : required( address, city, state, zip ) {
    ...
}

That way, you can do both parameter validation and named-parameter currying (as per Limbic~Region's comment below). Plus, you're specifying the API, which would allow for something like doxygen to document your API.

An even nicer thing would be to combine this idea of a required() attribute to methods, meaning that you could do something like:

package Foo;

sub new
  : required( attr1, attr2 )
  : optional( attr3 )
{
    ...
}

This would behave like Class::MethodMaker and create the attr1(), attr2(), and attr3() mutators, plus require that the first two be passed in to the constructor.

It wouldn't be too hard to come up with a list of useful function/method attributes. Off the top of my head, I can see multiple uses for:

• required
• optional
• deprecated