Re: Argument Patterns

[Rod Adams]

Luke Palmer wrote:
All this Haskell programming has opened my eyes to what our multimethod
dispatch could be.  As we have seen with C<sort>, the dispatch system is
a pattern matcher.  But it's a pretty terrible one. 

I think we should replace our multimethod system with a more general
pattern matcher, a "variadic multimethod" system of sorts.  Multimethods
need to be variadic anyway, because we want pugs's quicksort example to
work.
Here's my proposal:
Inside an argument list, the first mention of a variable introduces its
binding.  Later arguments require a match.  We can now define 'equal':
   sub equal ($x, $x) { 1 }
   sub equal ($x, $y) { "" }
That's one of the MTOWs at least.  The evaluation order of the patterns
still needs to be thought out.
 

I thought Larry already declared that we are not making Perl act like ML 
(yet).

-- Rod Adams