On Thu, Aug 28, 2008 at 08:32:41AM -0700, Carl Mäsak wrote:
> r30590:
> $ ./perl6 -e 'regex a { b }; "b" ~~ a'
> too few arguments passed (0) - 2 params expected
> [...]
>
> I've also added tests for this in t/spec/S05-metasyntax/regex.t.
>
> (S05 is not entirely clear as to whether this should actually work.
> IMHO, there's noreason for it not to. Storing anonymous regexes in
> scalar variables already works.)
>
> $ ./perl6 -e 'my $a = regex { b }; say "b" ~~ $a'
> b
For now I'm going to claim that Rakudo has this one correct. The
difference between the first and second examples above is that in
the scalar variable example, the $a variable passed to infix:<~~>
contains the regex sub itself, whereas in the first example the
a regex is being invoked as a 0-argument listop prior to calling
the smart match.
In other words, the correct syntax is to use &a, as in:
$ ./parrot perl6.pbc -e 'regex a { b }; say "b" ~~ &a;'
b
By way of analogy:
sub foo($x) { $x eq 'b' }
say "b" ~~ foo; # wrong, sub foo called as 0-arg listop
say "b" ~~ &foo; # right, sub foo passed to infix:<~~>
Pm
