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package Exporter::Heavy;
use strict;
no strict 'refs';
# On one line so MakeMaker will see it.
require Exporter; our $VERSION = $Exporter::VERSION;
$Carp::Internal{"Exporter::Heavy"} = 1;
our $Verbose;
=head1 NAME
Exporter::Heavy - Exporter guts
=head1 SYNOPIS
(internal use only)
=head1 DESCRIPTION
No user-serviceable parts inside.
=cut
#
# We go to a lot of trouble not to 'require Carp' at file scope,
# because Carp requires Exporter, and something has to give.
#
sub heavy_export {
# First make import warnings look like they're coming from the "use".
local $SIG{__WARN__} = sub {
my $text = shift;
if ($text =~ s/ at \S*Exporter\S*.pm line \d+.*\n//) {
require Carp;
local $Carp::CarpLevel = 1; # ignore package calling us too.
Carp::carp($text);
}
else {
warn $text;
}
};
local $SIG{__DIE__} = sub {
require Carp;
local $Carp::CarpLevel = 1; # ignore package calling us too.
Carp::croak("$_[0]Illegal null symbol in \@${1}::EXPORT")
if $_[0] =~ /^Unable to create sub named "(.*?)::"/;
};
my($pkg, $callpkg, @imports) = @_;
my($type, $sym, $oops);
my($exports, $export_cache) = (\@{"${pkg}::EXPORT"},
\%{"${pkg}::EXPORT"});
if (@imports) {
if (!%$export_cache) {
s/^&// foreach @$exports;
@{$export_cache}{@$exports} = (1) x @$exports;
my $ok = \@{"${pkg}::EXPORT_OK"};
if (@$ok) {
s/^&// foreach @$ok;
@{$export_cache}{@$ok} = (1) x @$ok;
}
}
if ($imports[0] =~ m#^[/!:]#){
my $tagsref = \%{"${pkg}::EXPORT_TAGS"};
my $tagdata;
my %imports;
my($remove, $spec, @names, @allexports);
# negated first item implies starting with default set:
unshift @imports, ':DEFAULT' if $imports[0] =~ m/^!/;
foreach $spec (@imports){
$remove = $spec =~ s/^!//;
if ($spec =~ s/^://){
if ($spec eq 'DEFAULT'){
@names = @$exports;
}
elsif ($tagdata = $tagsref->{$spec}) {
@names = @$tagdata;
}
else {
warn qq["$spec" is not defined in %${pkg}::EXPORT_TAGS];
++$oops;
next;
}
}
elsif ($spec =~ m:^/(.*)/$:){
my $patn = $1;
@allexports = keys %$export_cache unless @allexports; # only do keys once
@names = grep(/$patn/, @allexports); # not anchored by default
}
else {
@names = ($spec); # is a normal symbol name
}
warn "Import ".($remove ? "del":"add").": @names "
if $Verbose;
if ($remove) {
foreach $sym (@names) { delete $imports{$sym} }
}
else {
@imports{@names} = (1) x @names;
}
}
@imports = keys %imports;
}
foreach $sym (@imports) {
if (!$export_cache->{$sym}) {
if ($sym =~ m/^\d/) {
$pkg->VERSION($sym); # inherit from UNIVERSAL
# If the version number was the only thing specified
# then we should act as if nothing was specified:
if (@imports == 1) {
@imports = @$exports;
last;
}
# We need a way to emulate 'use Foo ()' but still
# allow an easy version check: "use Foo 1.23, ''";
if (@imports == 2 and !$imports[1]) {
@imports = ();
last;
}
} elsif ($sym !~ s/^&// || !$export_cache->{$sym}) {
unless ($^S) {
# If we are trying to trap import of non-existent
# symbols using eval, let's be silent for now and
# just croak in the end.
require Carp;
Carp::carp(qq["$sym" is not exported by the $pkg module]);
}
$oops++;
}
}
}
if ($oops) {
require Carp;
Carp::croak("Can't continue after import errors");
}
}
else {
@imports = @$exports;
}
my($fail, $fail_cache) = (\@{"${pkg}::EXPORT_FAIL"},
\%{"${pkg}::EXPORT_FAIL"});
if (@$fail) {
if (!%$fail_cache) {
# Build cache of symbols. Optimise the lookup by adding
# barewords twice... both with and without a leading &.
# (Technique could be applied to $export_cache at cost of memory)
my @expanded = map { /^\w/ ? ($_, '&'.$_) : $_ } @$fail;
warn "${pkg}::EXPORT_FAIL cached: @expanded" if $Verbose;
@{$fail_cache}{@expanded} = (1) x @expanded;
}
my @failed;
foreach $sym (@imports) { push(@failed, $sym) if $fail_cache->{$sym} }
if (@failed) {
@failed = $pkg->export_fail(@failed);
foreach $sym (@failed) {
require Carp;
Carp::carp(qq["$sym" is not implemented by the $pkg module ],
"on this architecture");
}
if (@failed) {
require Carp;
Carp::croak("Can't continue after import errors");
}
}
}
warn "Importing into $callpkg from $pkg: ",
join(", ",sort @imports) if $Verbose;
foreach $sym (@imports) {
# shortcut for the common case of no type character
(*{"${callpkg}::$sym"} = \&{"${pkg}::$sym"}, next)
unless $sym =~ s/^(\W)//;
$type = $1;
*{"${callpkg}::$sym"} =
$type eq '&' ? \&{"${pkg}::$sym"} :
$type eq '$' ? \${"${pkg}::$sym"} :
$type eq '@' ? \@{"${pkg}::$sym"} :
$type eq '%' ? \%{"${pkg}::$sym"} :
$type eq '*' ? *{"${pkg}::$sym"} :
do { require Carp; Carp::croak("Can't export symbol: $type$sym") };
}
}
sub heavy_export_to_level
{
my $pkg = shift;
my $level = shift;
(undef) = shift; # XXX redundant arg
my $callpkg = caller($level);
$pkg->export($callpkg, @_);
}
# Utility functions
sub _push_tags {
my($pkg, $var, $syms) = @_;
my @nontag = ();
my $export_tags = \%{"${pkg}::EXPORT_TAGS"};
push(@{"${pkg}::$var"},
map { $export_tags->{$_} ? @{$export_tags->{$_}}
: scalar(push(@nontag,$_),$_) }
(@$syms) ? @$syms : keys %$export_tags);
if (@nontag and $^W) {
# This may change to a die one day
require Carp;
Carp::carp(join(", ", @nontag)." are not tags of $pkg");
}
}
sub require_version {
my($self, $wanted) = @_;
my $pkg = ref $self || $self;
return ${pkg}->VERSION($wanted);
}
1;
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