Looking for equivalent to LHS eval

[elbie]

I'm parsing a hash, and while I should be keeping them in the hash, there are reasons not to. I dunno. Maybe I should rewrite the program, but in the meantime, I actually want to assign a few of those pairs to variables named after the keys of the hash.

I was hoping I could do something like the following:

for my $key ( qw/key1 key2 key3/ ) {
    eval( "${$key}" ) = $hash{$key};
}

or something similar. Is there a way to do this?

elbieelbieelbie

[merlyn]

Yes, but you shouldn't. For the reasons why not, do a super search here for "symbolic references". Bad idea. Bad idea.

-- Randal L. Schwartz, Perl hacker
Be sure to read my standard disclaimer if this is a reply.

[Zaxo]

If you really want symbolic references,

{
    no strict qw/refs vars/;
    for my $key ( qw/list of keys/ ) {
        next if $key =~ /\W/ or $key =~ /^\d/;
        ${$key} = $hash{$key};
    }
}

I'm curious to know why you want this.

After Compline,
Zaxo

[simonm]

Yup, it's just a matter of figuring out what gets quoted; this should do it:

%hash = ( key1 => 'A', key2 => 'B', key3 => 'C' );
for my $key ( qw/key1 key2 key3/ ) {
    eval( '$' . "$key = \$hash{\$key}";
}
print $key1 . $key2 . $key3;

[merlyn]

Uh, no. You really really don't want to do this. This would be the greater of two evils, the lesser of which would be using symbolic references. And if that's discouraged, using eval to do the same thing is discouraged-squared. {grin}

-- Randal L. Schwartz, Perl hacker
Be sure to read my standard disclaimer if this is a reply.

[Aristotle]

The only sane method is using a second hash.

my %copy_to = (
    key1 => \$key1,
    key2 => \$key2,
    key3 => \$key3,
);

while(my ($key, $var) = each %copy_to) {
    $$var = $hash{$key};
}

Makeshifts last the longest.