The only time I used : lvalue was in writing the following subroutine:

sub set : lvalue {
  @_ == 1 ? $_[0] : set($_[0]{$_[1]},@_[2..$#_]);
}

[download]

..which is used to set values at any depth in a recursive hash structure, like so:

use Data::Dumper;
sub set : lvalue {
  @_ == 1 ? $_[0] : set($_[0]{$_[1]},@_[2..$#_]);
}

my $h = {foo => 1,
         bar => 2,
         baz => {
                 troz => 3,
                 zort => 4,
                 poit => {
                          qux  => 5,
                          quux => 6,
                         },
                },
        };

print Dumper($h);
set($h, qw/baz troz/) = 42;
set($h, qw/baz poit qux/) = 17;
print Dumper($h);

[download]

In this particular case, doing data verification wasn't overly useful, but I can definately see when it might be. While I'm not convinced that using $_ "won't break any existing code," it seems to be the most perlish choice to use.

perl -pe '"I lo*`+$^X$\"$]!$/"=~m%(.*)%s;$_=$1;y^`+*^e v^#$&V"+@( NO CARRIER'

In reply to Re: What the [sub]in 'L value do they have? by Chmrr
in thread What the [sub]in 'L value do they have? by BrowserUk

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