On 4/20/04 10:42 AM, Dan Sugalski wrote:
> At 9:50 AM -0400 4/20/04, John Siracusa wrote:
>> On 4/19/04 7:16 PM, Larry Wall wrote:
>>> Well, no, we're still stuck at run-time validation of that. In the case
>>> of methods you can't really do anything else anyway, generally speaking.
>>
>> Why is that?
>
> Because at compile time all you have is a generic thing, a (possibly
> indirectly accessed) method name, and a list of parameters. There's
> no good way to tell which method will ultimately be called, and
> validating against all declared methods of that name won't get you
> anything useful there since the result's likely going to be pretty
> contradictory.
Hm, so how would the "is required" trait that Damian posted work? Would it
simply be shorthand for a run-time check that I don't have to write myself?
I was under the impression that it would work the way I described earlier:
sub foo(+$a is required, +$b is required) { ... }
foo(); # compile-time error!
foo(1, 2); # compile-time error!
foo(a => 1, 2); # compile-time error!
foo(a => 1); # compile-time error!
foo(a => 5, b => 7); # ok
foo(b => 1, a => 2); # ok
It really is a shame about the inability to do it at compile-time with
methods, but shorthand for a run-time check in that case would be welcome
too :)
-John
