Edit: /usr/share/perl5/Exporter.pm (18595B)
package Exporter;
require 5.006;
# Be lean.
#use strict;
#no strict 'refs';
our $Debug = 0;
our $ExportLevel = 0;
our $Verbose ||= 0;
our $VERSION = '5.63';
our (%Cache);
# Carp 1.05+ does this now for us, but we may be running with an old Carp
$Carp::Internal{Exporter}++;
sub as_heavy {
require Exporter::Heavy;
# Unfortunately, this does not work if the caller is aliased as *name = \&foo
# Thus the need to create a lot of identical subroutines
my $c = (caller(1))[3];
$c =~ s/.*:://;
\&{"Exporter::Heavy::heavy_$c"};
}
sub export {
goto &{as_heavy()};
}
sub import {
my $pkg = shift;
my $callpkg = caller($ExportLevel);
if ($pkg eq "Exporter" and @_ and $_[0] eq "import") {
*{$callpkg."::import"} = \&import;
return;
}
# We *need* to treat @{"$pkg\::EXPORT_FAIL"} since Carp uses it :-(
my($exports, $fail) = (\@{"$pkg\::EXPORT"}, \@{"$pkg\::EXPORT_FAIL"});
return export $pkg, $callpkg, @_
if $Verbose or $Debug or @$fail > 1;
my $export_cache = ($Cache{$pkg} ||= {});
my $args = @_ or @_ = @$exports;
local $_;
if ($args and not %$export_cache) {
s/^&//, $export_cache->{$_} = 1
foreach (@$exports, @{"$pkg\::EXPORT_OK"});
}
my $heavy;
# Try very hard not to use {} and hence have to enter scope on the foreach
# We bomb out of the loop with last as soon as heavy is set.
if ($args or $fail) {
($heavy = (/\W/ or $args and not exists $export_cache->{$_}
or @$fail and $_ eq $fail->[0])) and last
foreach (@_);
} else {
($heavy = /\W/) and last
foreach (@_);
}
return export $pkg, $callpkg, ($args ? @_ : ()) if $heavy;
local $SIG{__WARN__} =
sub {require Carp; &Carp::carp};
# shortcut for the common case of no type character
*{"$callpkg\::$_"} = \&{"$pkg\::$_"} foreach @_;
}
# Default methods
sub export_fail {
my $self = shift;
@_;
}
# Unfortunately, caller(1)[3] "does not work" if the caller is aliased as
# *name = \&foo. Thus the need to create a lot of identical subroutines
# Otherwise we could have aliased them to export().
sub export_to_level {
goto &{as_heavy()};
}
sub export_tags {
goto &{as_heavy()};
}
sub export_ok_tags {
goto &{as_heavy()};
}
sub require_version {
goto &{as_heavy()};
}
1;
__END__
=head1 NAME
Exporter - Implements default import method for modules
=head1 SYNOPSIS
In module F
:
package YourModule;
require Exporter;
@ISA = qw(Exporter);
@EXPORT_OK = qw(munge frobnicate); # symbols to export on request
or
package YourModule;
use Exporter 'import'; # gives you Exporter's import() method directly
@EXPORT_OK = qw(munge frobnicate); # symbols to export on request
In other files which wish to use C:
use YourModule qw(frobnicate); # import listed symbols
frobnicate ($left, $right) # calls YourModule::frobnicate
Take a look at L for some variants
you will like to use in modern Perl code.
=head1 DESCRIPTION
The Exporter module implements an C method which allows a module
to export functions and variables to its users' namespaces. Many modules
use Exporter rather than implementing their own C method because
Exporter provides a highly flexible interface, with an implementation optimised
for the common case.
Perl automatically calls the C method when processing a
C