Re: RFC 97 (v1) prototype-based method overloading

On Mon, Aug 14, 2000 at 04:17:51PM -0000, Perl6 RFC Librarian wrote:
> =head1 SUMMARY
> 
> 	$frog_t = qs(frog);
> 	sub listargs($){ print "One arg, $_[0]"}
> 	sub listargs($$){ print "Two args, $_[0] and $[1]"}
> 	sub listargs($$frog_t){ print "$_[0] and a frog $[1]"}
> 	sub listargs { throw argsyntax, "odd arguments to listargs" }
> 
> 	my frog $k = new frog(type=>tree);
> 	listargs("franz","tree");	# prints "Two args..."
> 	listargs("franz",$k);		# prints "franz and ..."
> 	listargs($k,"franz");		# throws an argsyntax error

Perl can't distinguish that last one as an error since it matches the
prototype for 

	sub listargs($$) { ... }

unless you somehow include strong typing in your RFC.  Right now, $
means "I need a scalar, any scalar".

-Scott
-- 
Jonathan Scott Duff
[email protected]