package Exporter;
-require 5.000;
+require 5.001;
+
+use strict;
+no strict 'refs';
+
+our $Debug = 0;
+our $ExportLevel = 0;
+our $Verbose ||= 0;
+our $VERSION = '5.563';
+
+sub export_to_level {
+ require Exporter::Heavy;
+ goto &Exporter::Heavy::heavy_export_to_level;
+}
+
+sub export {
+ require Exporter::Heavy;
+ goto &Exporter::Heavy::heavy_export;
+}
+
+sub export_tags {
+ require Exporter::Heavy;
+ Exporter::Heavy::_push_tags((caller)[0], "EXPORT", \@_);
+}
+
+sub export_ok_tags {
+ require Exporter::Heavy;
+ Exporter::Heavy::_push_tags((caller)[0], "EXPORT_OK", \@_);
+}
sub import {
- my ($callpack, $callfile, $callline) = caller($ExportLevel);
- my $pack = shift;
- my @imports = @_;
- *exports = \@{"${pack}::EXPORT"};
- if (@imports) {
- my $oops;
- my $type;
- *exports = \%{"${pack}::EXPORT"};
- if (!%exports) {
- grep(s/^&//, @exports);
- @exports{@exports} = (1) x @exports;
- }
- foreach $sym (@imports) {
- if (!$exports{$sym}) {
- if ($sym !~ s/^&// || !$exports{$sym}) {
- warn "$sym is not exported by the $pack module ",
- "at $callfile line $callline\n";
- $oops++;
- next;
- }
- }
- }
- die "Can't continue with import errors.\n" if $oops;
- }
- else {
- @imports = @exports;
- }
- foreach $sym (@imports) {
- $type = '&';
- $type = $1 if $sym =~ s/^(\W)//;
- *{"${callpack}::$sym"} =
- $type eq '&' ? \&{"${pack}::$sym"} :
- $type eq '$' ? \${"${pack}::$sym"} :
- $type eq '@' ? \@{"${pack}::$sym"} :
- $type eq '%' ? \%{"${pack}::$sym"} :
- $type eq '*' ? *{"${pack}::$sym"} :
- warn "Can't export symbol: $type$sym\n";
+ my $pkg = shift;
+ my $callpkg = caller($ExportLevel);
+
+ my($exports, $export_cache) = (\@{"$pkg\::EXPORT"},
+ \%{"$pkg\::EXPORT"});
+ # We *need* to treat @{"$pkg\::EXPORT_FAIL"} since Carp uses it :-(
+ my($fail) = \@{"$pkg\::EXPORT_FAIL"};
+ return export $pkg, $callpkg, @_
+ if $Verbose or $Debug or @$fail > 1;
+ my $args = @_ or @_ = @$exports;
+
+ if ($args and not %$export_cache) {
+ foreach my $sym (@$exports, @{"$pkg\::EXPORT_OK"}) {
+ $sym =~ s/^&//;
+ $export_cache->{$sym} = 1;
}
-};
+ }
+ if ($Verbose or $Debug
+ or grep {/\W/ or $args and not exists $export_cache->{$_}
+ or @$fail and $_ eq $fail->[0]
+ or (@{"$pkg\::EXPORT_OK"}
+ and $_ eq ${"$pkg\::EXPORT_OK"}[0])} @_) {
+ return export $pkg, $callpkg, ($args ? @_ : ());
+ }
+ local $SIG{__WARN__} =
+ sub {require Carp; local $Carp::CarpLevel = 1; &Carp::carp};
+ foreach my $sym (@_) {
+ # shortcut for the common case of no type character
+ *{"$callpkg\::$sym"} = \&{"$pkg\::$sym"};
+ }
+}
+
+
+# Default methods
+
+sub export_fail {
+ my $self = shift;
+ @_;
+}
+
+
+sub require_version {
+ require Exporter::Heavy;
+ goto &Exporter::Heavy::require_version;
+}
+
1;
+
+
+=head1 NAME
+
+Exporter - Implements default import method for modules
+
+=head1 SYNOPSIS
+
+In module ModuleName.pm:
+
+ package ModuleName;
+ require Exporter;
+ @ISA = qw(Exporter);
+
+ @EXPORT = qw(...); # symbols to export by default
+ @EXPORT_OK = qw(...); # symbols to export on request
+ %EXPORT_TAGS = tag => [...]; # define names for sets of symbols
+
+In other files which wish to use ModuleName:
+
+ use ModuleName; # import default symbols into my package
+
+ use ModuleName qw(...); # import listed symbols into my package
+
+ use ModuleName (); # do not import any symbols
+
+=head1 DESCRIPTION
+
+The Exporter module implements a default C<import> method which
+many modules choose to inherit rather than implement their own.
+
+Perl automatically calls the C<import> method when processing a
+C<use> statement for a module. Modules and C<use> are documented
+in L<perlfunc> and L<perlmod>. Understanding the concept of
+modules and how the C<use> statement operates is important to
+understanding the Exporter.
+
+=head2 How to Export
+
+The arrays C<@EXPORT> and C<@EXPORT_OK> in a module hold lists of
+symbols that are going to be exported into the users name space by
+default, or which they can request to be exported, respectively. The
+symbols can represent functions, scalars, arrays, hashes, or typeglobs.
+The symbols must be given by full name with the exception that the
+ampersand in front of a function is optional, e.g.
+
+ @EXPORT = qw(afunc $scalar @array); # afunc is a function
+ @EXPORT_OK = qw(&bfunc %hash *typeglob); # explicit prefix on &bfunc
+
+=head2 Selecting What To Export
+
+Do B<not> export method names!
+
+Do B<not> export anything else by default without a good reason!
+
+Exports pollute the namespace of the module user. If you must export
+try to use @EXPORT_OK in preference to @EXPORT and avoid short or
+common symbol names to reduce the risk of name clashes.
+
+Generally anything not exported is still accessible from outside the
+module using the ModuleName::item_name (or $blessed_ref-E<gt>method)
+syntax. By convention you can use a leading underscore on names to
+informally indicate that they are 'internal' and not for public use.
+
+(It is actually possible to get private functions by saying:
+
+ my $subref = sub { ... };
+ &$subref;
+
+But there's no way to call that directly as a method, since a method
+must have a name in the symbol table.)
+
+As a general rule, if the module is trying to be object oriented
+then export nothing. If it's just a collection of functions then
+@EXPORT_OK anything but use @EXPORT with caution.
+
+Other module design guidelines can be found in L<perlmod>.
+
+=head2 Specialised Import Lists
+
+If the first entry in an import list begins with !, : or / then the
+list is treated as a series of specifications which either add to or
+delete from the list of names to import. They are processed left to
+right. Specifications are in the form:
+
+ [!]name This name only
+ [!]:DEFAULT All names in @EXPORT
+ [!]:tag All names in $EXPORT_TAGS{tag} anonymous list
+ [!]/pattern/ All names in @EXPORT and @EXPORT_OK which match
+
+A leading ! indicates that matching names should be deleted from the
+list of names to import. If the first specification is a deletion it
+is treated as though preceded by :DEFAULT. If you just want to import
+extra names in addition to the default set you will still need to
+include :DEFAULT explicitly.
+
+e.g., Module.pm defines:
+
+ @EXPORT = qw(A1 A2 A3 A4 A5);
+ @EXPORT_OK = qw(B1 B2 B3 B4 B5);
+ %EXPORT_TAGS = (T1 => [qw(A1 A2 B1 B2)], T2 => [qw(A1 A2 B3 B4)]);
+
+ Note that you cannot use tags in @EXPORT or @EXPORT_OK.
+ Names in EXPORT_TAGS must also appear in @EXPORT or @EXPORT_OK.
+
+An application using Module can say something like:
+
+ use Module qw(:DEFAULT :T2 !B3 A3);
+
+Other examples include:
+
+ use Socket qw(!/^[AP]F_/ !SOMAXCONN !SOL_SOCKET);
+ use POSIX qw(:errno_h :termios_h !TCSADRAIN !/^EXIT/);
+
+Remember that most patterns (using //) will need to be anchored
+with a leading ^, e.g., C</^EXIT/> rather than C</EXIT/>.
+
+You can say C<BEGIN { $Exporter::Verbose=1 }> to see how the
+specifications are being processed and what is actually being imported
+into modules.
+
+=head2 Exporting without using Export's import method
+
+Exporter has a special method, 'export_to_level' which is used in situations
+where you can't directly call Export's import method. The export_to_level
+method looks like:
+
+MyPackage->export_to_level($where_to_export, $package, @what_to_export);
+
+where $where_to_export is an integer telling how far up the calling stack
+to export your symbols, and @what_to_export is an array telling what
+symbols *to* export (usually this is @_). The $package argument is
+currently unused.
+
+For example, suppose that you have a module, A, which already has an
+import function:
+
+package A;
+
+@ISA = qw(Exporter);
+@EXPORT_OK = qw ($b);
+
+sub import
+{
+ $A::b = 1; # not a very useful import method
+}
+
+and you want to Export symbol $A::b back to the module that called
+package A. Since Exporter relies on the import method to work, via
+inheritance, as it stands Exporter::import() will never get called.
+Instead, say the following:
+
+package A;
+@ISA = qw(Exporter);
+@EXPORT_OK = qw ($b);
+
+sub import
+{
+ $A::b = 1;
+ A->export_to_level(1, @_);
+}
+
+This will export the symbols one level 'above' the current package - ie: to
+the program or module that used package A.
+
+Note: Be careful not to modify '@_' at all before you call export_to_level
+- or people using your package will get very unexplained results!
+
+
+=head2 Module Version Checking
+
+The Exporter module will convert an attempt to import a number from a
+module into a call to $module_name-E<gt>require_version($value). This can
+be used to validate that the version of the module being used is
+greater than or equal to the required version.
+
+The Exporter module supplies a default require_version method which
+checks the value of $VERSION in the exporting module.
+
+Since the default require_version method treats the $VERSION number as
+a simple numeric value it will regard version 1.10 as lower than
+1.9. For this reason it is strongly recommended that you use numbers
+with at least two decimal places, e.g., 1.09.
+
+=head2 Managing Unknown Symbols
+
+In some situations you may want to prevent certain symbols from being
+exported. Typically this applies to extensions which have functions
+or constants that may not exist on some systems.
+
+The names of any symbols that cannot be exported should be listed
+in the C<@EXPORT_FAIL> array.
+
+If a module attempts to import any of these symbols the Exporter
+will give the module an opportunity to handle the situation before
+generating an error. The Exporter will call an export_fail method
+with a list of the failed symbols:
+
+ @failed_symbols = $module_name->export_fail(@failed_symbols);
+
+If the export_fail method returns an empty list then no error is
+recorded and all the requested symbols are exported. If the returned
+list is not empty then an error is generated for each symbol and the
+export fails. The Exporter provides a default export_fail method which
+simply returns the list unchanged.
+
+Uses for the export_fail method include giving better error messages
+for some symbols and performing lazy architectural checks (put more
+symbols into @EXPORT_FAIL by default and then take them out if someone
+actually tries to use them and an expensive check shows that they are
+usable on that platform).
+
+=head2 Tag Handling Utility Functions
+
+Since the symbols listed within %EXPORT_TAGS must also appear in either
+@EXPORT or @EXPORT_OK, two utility functions are provided which allow
+you to easily add tagged sets of symbols to @EXPORT or @EXPORT_OK:
+
+ %EXPORT_TAGS = (foo => [qw(aa bb cc)], bar => [qw(aa cc dd)]);
+
+ Exporter::export_tags('foo'); # add aa, bb and cc to @EXPORT
+ Exporter::export_ok_tags('bar'); # add aa, cc and dd to @EXPORT_OK
+
+Any names which are not tags are added to @EXPORT or @EXPORT_OK
+unchanged but will trigger a warning (with C<-w>) to avoid misspelt tags
+names being silently added to @EXPORT or @EXPORT_OK. Future versions
+may make this a fatal error.
+
+=cut
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