I'm not sure we've reached consensus here, so I will try to summarize what everyone said so far in order to clear my own head a bit. :) Sorry in advance if i horribly misrepresent anyone's opinions.
Luke: Thinks the "_" syntax is no joke, since every language with pattern matching abilities has it. Further, using "undef" won't work because it means "this has to be undef" in signature unification. Dks: Replies to Luke. Thinks that "undef" is more perl5ish, and that "_" can disappear too easily, and is too Huffmanized. Doesn't think "_" is obvious, but is sure we will end up using it if this feature is added. TSa: Prefers to rely on lazy evaluation, and says both tounge-in-cheek and philosophically that if I don't want to care about some elements, I should do so, and let Perl6 optimize. Proposes several ways of not giving a name to a variable. Yuval Kogman: Replies to David. Seems to repeat Luke's point about value binding in signatures. Shows an example of value binding in action. Argues for the "_" or "__" syntax. Thinks that making this feature easy encourages reuse of calling code, not only callee code. So, in summary, it's not obvious that this feature is needed at all because things can be optimized away. Also, neither the "undef" nor the "_" syntax have 100% support, and "undef" seems to have problems related to signature unification. Hm. For the time being I will assume that this functionality is not sufficiently wanted to deserve its own syntax. But I must admit I'm actually starting to like "_" in subroutine signatures... not sure if it works well with positionals and the like, however. // Carl
