Damian Conway writes:
> Micholas Clarke asked:
>
> > If a subroutine explicitly needs access to its invocant's topic, what is so
> > wrong with having an explicit read-write parameter in the argument list that
> > the caller of the subroutine is expected to put $_ in?
>
> Absolutely nothing. And perfectly legal. You can even call that rw parameter $_
> if you like:
>
> sub get($id_obj, $_ is rw) {
> when "who" { return $id_obj.name }
> when "choose" { return any($id_obj.features).pick }
> when "all" { return $id_obj.features }
> }
>
> for «name choose all» {
> print get($obj, $_);
> }
>
Just ( my ) terminology clean-up : in this example sub{ } is implicit
topicalizer ( it does not set $_ explicitly ) , and you are setting $_
for perl . that's why you can use "when" .
???
is this valid ?
(morning() is function that analyse stringifyed time )
#!/usr/bin/perl -w
when ~time ~~ &morning { print "good morning" }
__END__
and also
#!/usr/bin/perl -w
$_ = ~time
when &morning() { print "good morning" }
__END__
arcadi .
