This idea came from my (mis?)understanding of something in the CB, and is probably a bad idea (seeing as how this ought to be done through the Exporter module or whatever export mechanism is built into a module), but I figured as long as its doable, and as long as there's an Exporter module, there ought to be an Importer module which will import variables and subroutines from other modules.

Update: A possible valid use for this is in the case of a module which overuses the @EXPORT array, and you don't want to import everything it exports, so you require the module, and use this Importer module to import only the things you want. Another update: No, then you'd just include the symbols you want in the import list of the 'use' statement when you use a module. So I'm still looking for a valid use for this :-)

package Importer;                              
                                               
sub import {
  shift;                                   
  for (@_) {       
    if (/^([\$@&%]?)(?:\w+::)*(\w+)$/) {
      ($sigil, $name) = ($1, $2);
      $var = $sigil ? "\\$_" : "*$_";
      eval "*" . caller() . "::$name = $var";
      die $@ if $@;
    } else { die "Can't import $_" }
  }
}                                              
1;

# Example

use strict;
use warnings;
use Importer qw($MyPackage::var);

# Pretend you have a module/package "MyPackage" that
# contains a package variable "var"
$MyPackage::var = 5;

print "$var\n";

# Update: Alternate version which avoids string eval
package Importer;

my %sig = (
  '$' => sub { *{"$_[0]::$_[1]"} = \${$_[2]} },
  '@' => sub { *{"$_[0]::$_[1]"} = \@{$_[2]} },
  '%' => sub { *{"$_[0]::$_[1]"} = \%{$_[2]} },
  '&' => sub { *{"$_[0]::$_[1]"} = \&{$_[2]} },
  '*' => sub { *{"$_[0]::$_[1]"} = *{$_[2]} },
);
# Yet another update: Or maybe you like this better:
my %sig = map {     
  $_ => eval sprintf
    'sub { *{"$_[0]::$_[1]"} = %s{$_[2]} }', ($_ eq "*") ? $_ : "\\$_"
} qw($ @ % & *);


sub import {
  shift;
  for (@_) {
    if (/^([\$@&%*]?)((?:\w+::)*(\w+))$/) {
      ($sigil, $name, $base) = ($1 || "*", $2, $3);
      $sig{$sigil}->(scalar(caller), $base, $name);
    } else { die "Can't import $_\n" }
  }
}
1;

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In reply to Importer by runrig

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