I suspect I read more than I write too. I think I’ve come across the Hash::Util functions before but for some reason I’ve never used them in production code. Thanks for pointing them out.

Cheers

#!/usr/bin/perl

use strict;
use warnings;

use Hash::Util qw/unlock_keys lock_keys_plus/;

my %h;
my $i = 0;
for my $k (qw/a b c d e f/) {
unlock_keys %h;
lock_keys_plus %h, $k;
$h{$k} = $i++;
}

print “$h{a}\n”;
print “$h{z}\n”;

But with a less enlightened language than perl, if you have this problem then as long as you also have subroutines, you can fix it.

@hdp – you have summarized my intention neatly. Thanks!

Not so many hashes or number or e.t.c. needs this functional. I can suggest to use “tied variables” for such tasks.

For example:

use 5.012;

package Strict_hash;
use Tie::Hash;
use base qw(Tie::StdHash);

sub FETCH {
	exists $_[0]{$_[1]} or die "KeyNotExists: $_[1]\n";
	$_[0]{$_[1]};
}

1;

package main;

tie( my %h,'Strict_hash' );

%h = ( a => 1,c => 3);

say $h{b};

prints:
KeyNotExists: b

And i want to advise you not to try to find bottlenecks by yourself manually them almost impossible to predict, there is special programs for this (Devel::NYTProf for Perl for example).

Perl has a lot of features to make writing quick programs easy. Those same features are often a pain when you have to look through 50k lines of code and figure out why your data is silently being converted from one thing to another somewhere in the middle. In that context, finding a way to avoid accidental nonexistent hash key lookups is perfectly reasonable.

Second example (about numbers) i never used in my life in any language =). I can not even imagine where this might come in handy, so you worry about this.

Your problems with Perl programs is in not so good understanding of the language. Try to understand it principles or write your programs in python if deems more appropriate.

P.S. sorry for my bad English, i’m working on it.