On Mon, Oct 19, 2009 at 11:47 PM, Jon Lang <datawea...@gmail.com> wrote: > Because a method is part of a role, and ought to abide by the same > terms by which the role abides. If Logging doesn't do Numeric, it > shouldn't have any methods in it that won't work unless it does.
100% agreed. So what the OP wants to do is declare a method that is available on all those invocants - and only those invocatnts - which do all of roles X, Y, and Z. Granted, you can declare a new role XandYandZ that does X, Y, and Z, and define the method there, but that won't work on $foo unless you declare explicitly '$foo does XandYandZ' . The goal is to have the method show up no matter how $foo comes to do all three roles. This is an interesting idea. Currently, it doesn't work because there's no place for such a method to live, so perhaps there could be a way to declare a "method space" for arbitrary combinations of roles, a sort of meta-role. It's an odd duck, but it does sort of fall out of the multiple-dispatch semantics, which already let you base implementation chioce on arbitrary combinations of roles... -- Mark J. Reed <markjr...@gmail.com>
