From: chromatic (via RT) <[EMAIL PROTECTED]> Date: Sat, 25 Oct 2008 18:21:26 -0700
# New Ticket Created by chromatic # Please include the string: [perl #60124] # in the subject line of all future correspondence about this issue. # <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=60124 > I expect this code to dispatch properly; autoboxing works and :optional parameters work, at least separately. When combined, they appear not to work. I think this is purely an autoboxing+MMD issue: The following simplified version fails in the same way, even without the :optional param: .sub 'main' :main foo('Hello') .end .sub foo :multi(String) .param pmc s say s .end but supplying a PMC as the first arg make it work again: .sub 'main' :main $P0 = new 'String' $P0 = 'Hello' foo($P0) foo($P0, 1) $P1 = new 'String' $P1 = 'Goodbye' foo($P1, 2) $P2 = new 'Integer' $P2 = 1 foo($P2) $P3 = new 'Integer' $P3 = 100 foo($P3, 200) .end This gives your expected output, using the same multis with :optional params from your version. Which brings us to an interesting question: How can you decide what type to use for autoboxing before you've determined the actual sub you're going to call? And how can you find the sub without having the correct dispatch types up front? I suppose the Alexandrian solution would be to determine what types the HLL of the multi would use to autobox everything that needed it, and dispatch on those. That might be kinda weird if the actual autobox operation during parameter passing picked a different type, especially if it was incompatible with the dispatch type . . . HTH (but have no time to take it further), -- Bob Rogers http://rgrjr.dyndns.org/
