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Diffstat (limited to 'contrib/perl5/lib/Exporter.pm')
| -rw-r--r-- | contrib/perl5/lib/Exporter.pm | 313 |
1 files changed, 0 insertions, 313 deletions
diff --git a/contrib/perl5/lib/Exporter.pm b/contrib/perl5/lib/Exporter.pm deleted file mode 100644 index 585109e..0000000 --- a/contrib/perl5/lib/Exporter.pm +++ /dev/null @@ -1,313 +0,0 @@ -package Exporter; - -require 5.001; - -$ExportLevel = 0; -$Verbose ||= 0; -$VERSION = '5.562'; - -sub export_to_level { - require Exporter::Heavy; - goto &heavy_export_to_level; -} - -sub export { - require Exporter::Heavy; - goto &heavy_export; -} - -sub export_tags { - require Exporter::Heavy; - _push_tags((caller)[0], "EXPORT", \@_); -} - -sub export_ok_tags { - require Exporter::Heavy; - _push_tags((caller)[0], "EXPORT_OK", \@_); -} - -sub import { - my $pkg = shift; - my $callpkg = caller($ExportLevel); - *exports = *{"$pkg\::EXPORT"}; - # We *need* to treat @{"$pkg\::EXPORT_FAIL"} since Carp uses it :-( - *fail = *{"$pkg\::EXPORT_FAIL"}; - return export $pkg, $callpkg, @_ - if $Verbose or $Debug or @fail > 1; - my $args = @_ or @_ = @exports; - - if ($args and not %exports) { - foreach my $sym (@exports, @{"$pkg\::EXPORT_OK"}) { - $sym =~ s/^&//; - $exports{$sym} = 1; - } - } - if ($Verbose or $Debug - or grep {/\W/ or $args and not exists $exports{$_} - 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; goto &Carp::carp}; - local $SIG{__WARN__} = - sub {require Carp; local $Carp::CarpLevel = 1; &Carp::carp}; - foreach $sym (@_) { - # shortcut for the common case of no type character - *{"$callpkg\::$sym"} = \&{"$pkg\::$sym"}; - } -} - -1; - -# A simple self test harness. Change 'require Carp' to 'use Carp ()' for testing. -# package main; eval(join('',<DATA>)) or die $@ unless caller; -__END__ -package Test; -$INC{'Exporter.pm'} = 1; -@ISA = qw(Exporter); -@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)], T3=>[qw(X3)]); -@EXPORT_FAIL = qw(B4); -Exporter::export_ok_tags('T3', 'unknown_tag'); -sub export_fail { - map { "Test::$_" } @_ # edit symbols just as an example -} - -package main; -$Exporter::Verbose = 1; -#import Test; -#import Test qw(X3); # export ok via export_ok_tags() -#import Test qw(:T1 !A2 /5/ !/3/ B5); -import Test qw(:T2 !B4); -import Test qw(:T2); # should fail -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 |
