in reply to Creating constants modules

I've coded a slightly simpler variant of that: 
package MY::Constants;

my %constants = (
  FRED => 2,
  DINO => 4,
  WILMA => "bb-b-b-b-uck!",
  LARGE => 1e38,
);

sub import {
  for (@_) {
    unless (exists $constants{$_}) {
      require Carp;
      Carp::croak("Constant $_ invalid");
    }
    {
      no strict 'refs';
      my $full_name = caller()."::$_";
      my $value = $constants{$_}; # for closure
      *$full_name = sub () { $value };
    }
  }
}

'0 but true';

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Unfortunately, you lose the default import list and the other nice things with Exporter, but for quick stuff, it's nice to say: 
use MY::Constants qw(FRED WILMA);

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-- Randal L. Schwartz, Perl hacker

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Re: •Re: Creating constants modules
by nite_man (Deacon) on Mar 11, 2004 at 14:05 UTC

    I've been implementing the same thing - module which consists all project contstants. Your code is good but I'd like to make small addition. I guess we should shift package name from @_ because it's passed as first parameter: 

    package MY::Constants;

my %constants = (
  FRED => 2,
  DINO => 4,
  WILMA => "bb-b-b-b-uck!",
  LARGE => 1e38,
);

sub import {
  my $package = shift; 
  for (@_) {
    unless (exists $constants{$_}) {
      require Carp;
      Carp::croak("Constant $_ invalid");
    }
    {
      no strict 'refs';
      my $full_name = caller()."::$_";
      my $value = $constants{$_}; # for closure
      *$full_name = sub () { $value };
    }
  }
}

'0 but true';

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    ~ Schiller

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