lib/Exporter/Heavy.pm

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;

=head1 NAME

Exporter::Heavy - Exporter guts

=head1 SYNOPSIS

(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 _rebuild_cache {
    my ($pkg, $exports, $cache) = @_;
    s/^&// foreach @$exports;
    @{$cache}{@$exports} = (1) x @$exports;
    my $ok = \@{"${pkg}::EXPORT_OK"};
    if (@$ok) {
        s/^&// foreach @$ok;
        @{$cache}{@$ok} = (1) x @$ok;
    }
}

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, $cache_is_current, $oops);
    my($exports, $export_cache) = (\@{"${pkg}::EXPORT"},
                                   $Exporter::Cache{$pkg} ||= {});

    if (@imports) {
        if (!%$export_cache) {
            _rebuild_cache ($pkg, $exports, $export_cache);
            $cache_is_current = 1;
        }

        if (grep m{^[/!:]}, @imports) {
            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 $Exporter::Verbose;

                if ($remove) {
                   foreach $sym (@names) { delete $imports{$sym} } 
                }
                else {
                    @imports{@names} = (1) x @names;
                }
            }
            @imports = keys %imports;
        }

        my @carp;
        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}) {
                    # Last chance - see if they've updated EXPORT_OK since we
                    # cached it.

                    unless ($cache_is_current) {
                        %$export_cache = ();
                        _rebuild_cache ($pkg, $exports, $export_cache);
                        $cache_is_current = 1;
                    }

                    if (!$export_cache->{$sym}) {
                        # accumulate the non-exports
                        push @carp,
                          qq["$sym" is not exported by the $pkg module\n];
                        $oops++;
                    }
                }
            }
        }
        if ($oops) {
            require Carp;
            Carp::croak("@{carp}Can't continue after import errors");
        }
    }
    else {
        @imports = @$exports;
    }

    my($fail, $fail_cache) = (\@{"${pkg}::EXPORT_FAIL"},
                              $Exporter::FailCache{$pkg} ||= {});

    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 $Exporter::Verbose;
            @{$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 $Exporter::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 heavy_require_version {
    my($self, $wanted) = @_;
    my $pkg = ref $self || $self;
    return ${pkg}->VERSION($wanted);
}

sub heavy_export_tags {
  _push_tags((caller)[0], "EXPORT",    \@_);
}

sub heavy_export_ok_tags {
  _push_tags((caller)[0], "EXPORT_OK", \@_);
}

1;
Revision:	1.1
Committed:	Thu Jun 30 14:27:10 2005 UTC (21 years, 3 months ago) by root
Branch:	MAIN
CVS Tags:	PERL-5-8-7, HEAD
Branch point for:	PERL
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	package Exporter::Heavy;
2
3			use strict;
4			no strict 'refs';
5
6			# On one line so MakeMaker will see it.
7			require Exporter; our $VERSION = $Exporter::VERSION;
8			$Carp::Internal{"Exporter::Heavy"} = 1;
9
10			=head1 NAME
11
12			Exporter::Heavy - Exporter guts
13
14			=head1 SYNOPSIS
15
16			(internal use only)
17
18			=head1 DESCRIPTION
19
20			No user-serviceable parts inside.
21
22			=cut
23
24			#
25			# We go to a lot of trouble not to 'require Carp' at file scope,
26			# because Carp requires Exporter, and something has to give.
27			#
28
29			sub _rebuild_cache {
30			my ($pkg, $exports, $cache) = @_;
31			s/^&// foreach @$exports;
32			@{$cache}{@$exports} = (1) x @$exports;
33			my $ok = \@{"${pkg}::EXPORT_OK"};
34			if (@$ok) {
35			s/^&// foreach @$ok;
36			@{$cache}{@$ok} = (1) x @$ok;
37			}
38			}
39
40			sub heavy_export {
41
42			# First make import warnings look like they're coming from the "use".
43			local $SIG{__WARN__} = sub {
44			my $text = shift;
45			if ($text =~ s/ at \SExporter\S.pm line \d+.*\n//) {
46			require Carp;
47			local $Carp::CarpLevel = 1; # ignore package calling us too.
48			Carp::carp($text);
49			}
50			else {
51			warn $text;
52			}
53			};
54			local $SIG{__DIE__} = sub {
55			require Carp;
56			local $Carp::CarpLevel = 1; # ignore package calling us too.
57			Carp::croak("$_[0]Illegal null symbol in \@${1}::EXPORT")
58			if $_[0] =~ /^Unable to create sub named "(.*?)::"/;
59			};
60
61			my($pkg, $callpkg, @imports) = @_;
62			my($type, $sym, $cache_is_current, $oops);
63			my($exports, $export_cache) = (\@{"${pkg}::EXPORT"},
64			$Exporter::Cache{$pkg} \|\|= {});
65
66			if (@imports) {
67			if (!%$export_cache) {
68			_rebuild_cache ($pkg, $exports, $export_cache);
69			$cache_is_current = 1;
70			}
71
72			if (grep m{^[/!:]}, @imports) {
73			my $tagsref = \%{"${pkg}::EXPORT_TAGS"};
74			my $tagdata;
75			my %imports;
76			my($remove, $spec, @names, @allexports);
77			# negated first item implies starting with default set:
78			unshift @imports, ':DEFAULT' if $imports[0] =~ m/^!/;
79			foreach $spec (@imports){
80			$remove = $spec =~ s/^!//;
81
82			if ($spec =~ s/^://){
83			if ($spec eq 'DEFAULT'){
84			@names = @$exports;
85			}
86			elsif ($tagdata = $tagsref->{$spec}) {
87			@names = @$tagdata;
88			}
89			else {
90			warn qq["$spec" is not defined in %${pkg}::EXPORT_TAGS];
91			++$oops;
92			next;
93			}
94			}
95			elsif ($spec =~ m:^/(.*)/$:){
96			my $patn = $1;
97			@allexports = keys %$export_cache unless @allexports; # only do keys once
98			@names = grep(/$patn/, @allexports); # not anchored by default
99			}
100			else {
101			@names = ($spec); # is a normal symbol name
102			}
103
104			warn "Import ".($remove ? "del":"add").": @names "
105			if $Exporter::Verbose;
106
107			if ($remove) {
108			foreach $sym (@names) { delete $imports{$sym} }
109			}
110			else {
111			@imports{@names} = (1) x @names;
112			}
113			}
114			@imports = keys %imports;
115			}
116
117			my @carp;
118			foreach $sym (@imports) {
119			if (!$export_cache->{$sym}) {
120			if ($sym =~ m/^\d/) {
121			$pkg->VERSION($sym); # inherit from UNIVERSAL
122			# If the version number was the only thing specified
123			# then we should act as if nothing was specified:
124			if (@imports == 1) {
125			@imports = @$exports;
126			last;
127			}
128			# We need a way to emulate 'use Foo ()' but still
129			# allow an easy version check: "use Foo 1.23, ''";
130			if (@imports == 2 and !$imports[1]) {
131			@imports = ();
132			last;
133			}
134			} elsif ($sym !~ s/^&// \|\| !$export_cache->{$sym}) {
135			# Last chance - see if they've updated EXPORT_OK since we
136			# cached it.
137
138			unless ($cache_is_current) {
139			%$export_cache = ();
140			_rebuild_cache ($pkg, $exports, $export_cache);
141			$cache_is_current = 1;
142			}
143
144			if (!$export_cache->{$sym}) {
145			# accumulate the non-exports
146			push @carp,
147			qq["$sym" is not exported by the $pkg module\n];
148			$oops++;
149			}
150			}
151			}
152			}
153			if ($oops) {
154			require Carp;
155			Carp::croak("@{carp}Can't continue after import errors");
156			}
157			}
158			else {
159			@imports = @$exports;
160			}
161
162			my($fail, $fail_cache) = (\@{"${pkg}::EXPORT_FAIL"},
163			$Exporter::FailCache{$pkg} \|\|= {});
164
165			if (@$fail) {
166			if (!%$fail_cache) {
167			# Build cache of symbols. Optimise the lookup by adding
168			# barewords twice... both with and without a leading &.
169			# (Technique could be applied to $export_cache at cost of memory)
170			my @expanded = map { /^\w/ ? ($_, '&'.$_) : $_ } @$fail;
171			warn "${pkg}::EXPORT_FAIL cached: @expanded" if $Exporter::Verbose;
172			@{$fail_cache}{@expanded} = (1) x @expanded;
173			}
174			my @failed;
175			foreach $sym (@imports) { push(@failed, $sym) if $fail_cache->{$sym} }
176			if (@failed) {
177			@failed = $pkg->export_fail(@failed);
178			foreach $sym (@failed) {
179			require Carp;
180			Carp::carp(qq["$sym" is not implemented by the $pkg module ],
181			"on this architecture");
182			}
183			if (@failed) {
184			require Carp;
185			Carp::croak("Can't continue after import errors");
186			}
187			}
188			}
189
190			warn "Importing into $callpkg from $pkg: ",
191			join(", ",sort @imports) if $Exporter::Verbose;
192
193			foreach $sym (@imports) {
194			# shortcut for the common case of no type character
195			(*{"${callpkg}::$sym"} = \&{"${pkg}::$sym"}, next)
196			unless $sym =~ s/^(\W)//;
197			$type = $1;
198			*{"${callpkg}::$sym"} =
199			$type eq '&' ? \&{"${pkg}::$sym"} :
200			$type eq '$' ? \${"${pkg}::$sym"} :
201			$type eq '@' ? \@{"${pkg}::$sym"} :
202			$type eq '%' ? \%{"${pkg}::$sym"} :
203			$type eq '' ? {"${pkg}::$sym"} :
204			do { require Carp; Carp::croak("Can't export symbol: $type$sym") };
205			}
206			}
207
208			sub heavy_export_to_level
209			{
210			my $pkg = shift;
211			my $level = shift;
212			(undef) = shift; # XXX redundant arg
213			my $callpkg = caller($level);
214			$pkg->export($callpkg, @_);
215			}
216
217			# Utility functions
218
219			sub _push_tags {
220			my($pkg, $var, $syms) = @_;
221			my @nontag = ();
222			my $export_tags = \%{"${pkg}::EXPORT_TAGS"};
223			push(@{"${pkg}::$var"},
224			map { $export_tags->{$_} ? @{$export_tags->{$_}}
225			: scalar(push(@nontag,$_),$_) }
226			(@$syms) ? @$syms : keys %$export_tags);
227			if (@nontag and $^W) {
228			# This may change to a die one day
229			require Carp;
230			Carp::carp(join(", ", @nontag)." are not tags of $pkg");
231			}
232			}
233
234			sub heavy_require_version {
235			my($self, $wanted) = @_;
236			my $pkg = ref $self \|\| $self;
237			return ${pkg}->VERSION($wanted);
238			}
239
240			sub heavy_export_tags {
241			_push_tags((caller)[0], "EXPORT", \@_);
242			}
243
244			sub heavy_export_ok_tags {
245			_push_tags((caller)[0], "EXPORT_OK", \@_);
246			}
247
248			1;