Lexical $_ in given/when vs. BLOCK arguments

[mbethke]

Hi guys,

I just noticed that the given/when construct's way of introducing a lexical $_ plays badly with functions that take BLOCKs such as List::MoreUtils::any. The following does not print anything:

use 5.010;
use strict;
use warnings;
use List::MoreUtils qw/ any /;

my $s = "foo";
my @list = ( 1, undef, 2 );
given($s) {
    when('foo') {
        say "found undef" if any { ! defined($_) } @list;
    }
}

Within the block, $_ is always 'foo' as it was bound during the block's definition.

Now this must be a known problem, right? For my inner peace, could someone explain me the rationale for making "given" so subtly different from say "for"? And for my productivity, is there a way around it short of "don't use 'given'"?

Thanks very much!