package Sub::Exporter::Progressive;
$Sub::Exporter::Progressive::VERSION = '0.001013';
use strict;
use warnings;
# ABSTRACT: Only use Sub::Exporter if you need it
sub _croak {
require Carp;
&Carp::croak;
}
sub import {
my ($self, @args) = @_;
my $inner_target = caller;
my $export_data = sub_export_options($inner_target, @args);
my $full_exporter;
no strict 'refs';
no warnings 'once';
@{"${inner_target}::EXPORT_OK"} = @{$export_data->{exports}};
@{"${inner_target}::EXPORT"} = @{$export_data->{defaults}};
%{"${inner_target}::EXPORT_TAGS"} = %{$export_data->{tags}};
*{"${inner_target}::import"} = sub {
use strict;
my ($self, @args) = @_;
if ( grep {
length ref $_
or
$_ !~ / \A [:-]? \w+ \z /xm
} @args ) {
_croak 'your usage of Sub::Exporter::Progressive requires Sub::Exporter to be installed'
unless eval { require Sub::Exporter };
$full_exporter ||= Sub::Exporter::build_exporter($export_data->{original});
goto $full_exporter;
} elsif ( defined( (my ($num) = grep { m/^\d/ } @args)[0] ) ) {
_croak "cannot export symbols with a leading digit: '$num'";
} else {
require Exporter;
s/ \A - /:/xm for @args;
@_ = ($self, @args);
goto \&Exporter::import;
}
};
return;
}
my $too_complicated = <<'DEATH';
You are using Sub::Exporter::Progressive, but the features your program uses from
Sub::Exporter cannot be implemented without Sub::Exporter, so you might as well
just use vanilla Sub::Exporter
DEATH
sub sub_export_options {
my ($inner_target, $setup, $options) = @_;
my @exports;
my @defaults;
my %tags;
if ( ($setup||'') eq '-setup') {
my %options = %$options;
OPTIONS:
for my $opt (keys %options) {
if ($opt eq 'exports') {
_croak $too_complicated if ref $options{exports} ne 'ARRAY';
@exports = @{$options{exports}};
_croak $too_complicated if grep { length ref $_ } @exports;
} elsif ($opt eq 'groups') {
%tags = %{$options{groups}};
for my $tagset (values %tags) {
_croak $too_complicated if grep {
length ref $_
or
$_ =~ / \A - (?! all \b ) /x
} @{$tagset};
}
@defaults = @{$tags{default} || [] };
} else {
_croak $too_complicated;
}
}
@{$_} = map { / \A [:-] all \z /x ? @exports : $_ } @{$_} for \@defaults, values %tags;
$tags{all} ||= [ @exports ];
my %exports = map { $_ => 1 } @exports;
my @errors = grep { not $exports{$_} } @defaults;
_croak join(', ', @errors) . " is not exported by the $inner_target module\n" if @errors;
}
return {
exports => \@exports,
defaults => \@defaults,
original => $options,
tags => \%tags,
};
}
1;
__END__
=pod
=encoding UTF-8
=head1 NAME
Sub::Exporter::Progressive - Only use Sub::Exporter if you need it
=head1 VERSION
version 0.001013
=head1 SYNOPSIS
package Syntax::Keyword::Gather;
use Sub::Exporter::Progressive -setup => {
exports => [qw( break gather gathered take )],
groups => {
default => [qw( break gather gathered take )],
},
};
# elsewhere
# uses Exporter for speed
use Syntax::Keyword::Gather;
# somewhere else
# uses Sub::Exporter for features
use Syntax::Keyword::Gather 'gather', take => { -as => 'grab' };
=head1 DESCRIPTION
L<Sub::Exporter> is an incredibly powerful module, but with that power comes
great responsibility, er- as well as some runtime penalties. This module
is a C<Sub::Exporter> wrapper that will let your users just use L<Exporter>
if all they are doing is picking exports, but use C<Sub::Exporter> if your
users try to use C<Sub::Exporter>'s more advanced features, like
renaming exports, if they try to use them.
Note that this module will export C<@EXPORT>, C<@EXPORT_OK> and
C<%EXPORT_TAGS> package variables for C<Exporter> to work. Additionally, if
your package uses advanced C<Sub::Exporter> features like currying, this module
will only ever use C<Sub::Exporter>, so you might as well use it directly.
=head1 CONTRIBUTORS
ilmari - Dagfinn Ilmari Mannsåker (cpan:ILMARI) <ilmari@ilmari.org>
mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
leont - Leon Timmermans (cpan:LEONT) <leont@cpan.org>
=head1 AUTHOR
Arthur Axel "fREW" Schmidt <Sub-Exporter-Progressive@afoolishmanifesto.com>
=head1 COPYRIGHT AND LICENSE
This software is copyright (c) 2016 by Arthur Axel "fREW" Schmidt.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
=cut