I actually had this very discussion with stvn this morning, but with respect to Ruby's signatures. To learn Ruby, I've been porting a Tree module that I just wrote in Perl to Ruby. One of the things I would like to be able to do is: 
def add_child( Hash options is optional, Tree *children )
    # Subroutine body here
end

[download]
Since I cannot do that, I have to do something like: 
def add_child( *children )
    options = children[0].is_a( 'Hash' ) ? children.shift : Hash.new;
    if children.any? { |node| !node.is_a( 'Tree' ) }:
        raise ArgumentError "Non-Tree argument found in add_child()"
    end

    # Resume regular processing here
end

[download]
I'd much rather have the subroutine signature do that for me. Perl6 will have this and I hope Ruby2.0 will, but we'll have to see.
My criteria for good software:
  1. Does it work?
  2. Can someone else come in, make a change, and be reasonably certain no bugs were introduced?

In reply to Re^3: Your named arguments by dragonchild
in thread Your named arguments by Juerd

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