| File | /usr/local/lib/perl5/5.10.1/Exporter.pm |
| Statements Executed | 2514 |
| Statement Execution Time | 8.10ms |
| Calls | P | F | Exclusive Time |
Inclusive Time |
Subroutine |
|---|---|---|---|---|---|
| 142 | 142 | 77 | 7.30ms | 8.68ms | Exporter::import |
| 18 | 3 | 1 | 2.52ms | 2.64ms | Exporter::as_heavy |
| 752 | 1 | 2 | 252µs | 252µs | Exporter::CORE:match (opcode) |
| 374 | 2 | 2 | 118µs | 118µs | Exporter::CORE:subst (opcode) |
| 14 | 5 | 4 | 65µs | 222µs | Exporter::export |
| 2 | 2 | 2 | 15µs | 2.47ms | Exporter::export_to_level |
| 2 | 2 | 2 | 11µs | 42µs | Exporter::export_ok_tags |
| 0 | 0 | 0 | 0s | 0s | Exporter::__ANON__[:65] |
| 0 | 0 | 0 | 0s | 0s | Exporter::export_fail |
| 0 | 0 | 0 | 0s | 0s | Exporter::export_tags |
| 0 | 0 | 0 | 0s | 0s | Exporter::require_version |
| Line | State ments |
Time on line |
Calls | Time in subs |
Code |
|---|---|---|---|---|---|
| 1 | package Exporter; | ||||
| 2 | |||||
| 3 | 1 | 34µs | require 5.006; | ||
| 4 | |||||
| 5 | # Be lean. | ||||
| 6 | #use strict; | ||||
| 7 | #no strict 'refs'; | ||||
| 8 | |||||
| 9 | 1 | 500ns | our $Debug = 0; | ||
| 10 | 1 | 200ns | our $ExportLevel = 0; | ||
| 11 | 1 | 500ns | our $Verbose ||= 0; | ||
| 12 | 1 | 7µs | our $VERSION = '5.63'; | ||
| 13 | 1 | 500ns | our (%Cache); | ||
| 14 | |||||
| 15 | # Carp 1.05+ does this now for us, but we may be running with an old Carp | ||||
| 16 | 1 | 2µs | $Carp::Internal{Exporter}++; | ||
| 17 | |||||
| 18 | # spent 2.64ms (2.52+127µs) within Exporter::as_heavy which was called 18 times, avg 147µs/call:
# 14 times (123µs+34µs) by Exporter::export at line 28, avg 11µs/call
# 2 times (2.37ms+85µs) by Exporter::export_to_level at line 82, avg 1.23ms/call
# 2 times (23µs+8µs) by Exporter::export_ok_tags at line 90, avg 15µs/call | ||||
| 19 | 18 | 105µs | require Exporter::Heavy; | ||
| 20 | # Unfortunately, this does not work if the caller is aliased as *name = \&foo | ||||
| 21 | # Thus the need to create a lot of identical subroutines | ||||
| 22 | 18 | 78µs | my $c = (caller(1))[3]; | ||
| 23 | 18 | 109µs | 18 | 56µs | $c =~ s/.*:://; # spent 56µs making 18 calls to Exporter::CORE:subst, avg 3µs/call |
| 24 | 18 | 80µs | \&{"Exporter::Heavy::heavy_$c"}; | ||
| 25 | } | ||||
| 26 | |||||
| 27 | # spent 222µs (65+157) within Exporter::export which was called 14 times, avg 16µs/call:
# 8 times (34µs+86µs) by Exporter::import at line 63, avg 15µs/call
# 2 times (11µs+27µs) by IO::Socket::import at line 36 of IO/Socket.pm, avg 19µs/call
# 2 times (10µs+20µs) by Exporter::Heavy::heavy_export_to_level at line 217 of Exporter/Heavy.pm, avg 15µs/call
# once (7µs+16µs) by FileHandle::import at line 73 of FileHandle.pm
# once (3µs+7µs) by FileHandle::import at line 81 of FileHandle.pm | ||||
| 28 | 14 | 75µs | 28 | 3.14ms | goto &{as_heavy()}; # spent 2.99ms making 14 calls to Exporter::Heavy::heavy_export, avg 213µs/call
# spent 157µs making 14 calls to Exporter::as_heavy, avg 11µs/call |
| 29 | } | ||||
| 30 | |||||
| 31 | # spent 8.68ms (7.30+1.37) within Exporter::import which was called 142 times, avg 61µs/call:
# once (744µs+34µs) by IO::Socket::BEGIN@12 at line 12 of IO/Socket.pm
# once (720µs+19µs) by IO::Socket::INET::BEGIN@12 at line 12 of IO/Socket/INET.pm
# once (77µs+235µs) by File::GlobMapper::BEGIN@10 at line 77 of File/Glob.pm
# once (304µs+6µs) by IO::Uncompress::RawInflate::BEGIN@8 at line 8 of IO/Uncompress/RawInflate.pm
# once (253µs+22µs) by IO::Seekable::BEGIN@104 at line 104 of IO/Seekable.pm
# once (55µs+171µs) by IO::Uncompress::Gunzip::BEGIN@16 at line 16 of IO/Uncompress/Gunzip.pm
# once (53µs+166µs) by IO::Compress::Zlib::Extra::BEGIN@13 at line 13 of IO/Compress/Zlib/Extra.pm
# once (70µs+114µs) by IO::Uncompress::RawInflate::BEGIN@9 at line 9 of IO/Uncompress/RawInflate.pm
# once (152µs+4µs) by IO::Uncompress::Base::BEGIN@20 at line 20 of IO/Uncompress/Base.pm
# once (125µs+11µs) by IO::Uncompress::Adapter::Inflate::BEGIN@8 at line 8 of IO/Uncompress/Adapter/Inflate.pm
# once (125µs+7µs) by Storable::BEGIN@23 at line 39 of FileHandle.pm
# once (126µs+5µs) by IO::Uncompress::Base::BEGIN@17 at line 17 of IO/Uncompress/Base.pm
# once (124µs+4µs) by Storable::BEGIN@23 at line 148 of IO/File.pm
# once (20µs+104µs) by IO::Uncompress::Adapter::Inflate::BEGIN@7 at line 7 of IO/Uncompress/Adapter/Inflate.pm
# once (17µs+106µs) by IO::Uncompress::Gunzip::BEGIN@50 at line 50 of IO/Uncompress/Gunzip.pm
# once (16µs+99µs) by IO::Uncompress::Gunzip::BEGIN@15 at line 15 of IO/Uncompress/Gunzip.pm
# once (19µs+95µs) by Storable::BEGIN@44 at line 45 of Storable.pm
# once (99µs+6µs) by Moose::Exporter::BEGIN@12 at line 12 of Moose/Exporter.pm
# once (91µs+6µs) by Class::MOP::BEGIN@13 at line 13 of Class/MOP.pm
# once (91µs+5µs) by SimpleDB::Client::BEGIN@47 at line 47 of ../lib/SimpleDB/Client.pm
# once (75µs+3µs) by Class::MOP::Method::BEGIN@7 at line 7 of Class/MOP/Method.pm
# once (68µs+3µs) by Sub::Install::BEGIN@6 at line 6 of Sub/Install.pm
# once (64µs+3µs) by Class::MOP::Mixin::AttributeCore::BEGIN@10 at line 10 of Class/MOP/Mixin/AttributeCore.pm
# once (63µs+3µs) by Class::MOP::Method::BEGIN@8 at line 8 of Class/MOP/Method.pm
# once (59µs+4µs) by Class::MOP::Class::BEGIN@16 at line 16 of Class/MOP/Class.pm
# once (60µs+3µs) by Moose::BEGIN@11 at line 11 of Moose.pm
# once (57µs+4µs) by Class::MOP::BEGIN@11 at line 11 of Class/MOP.pm
# once (55µs+2µs) by Moose::Meta::Role::BEGIN@8 at line 8 of Moose/Meta/Role.pm
# once (52µs+1µs) by Time::Local::BEGIN@4 at line 4 of Time/Local.pm
# once (52µs+2µs) by Try::Tiny::BEGIN@46 at line 46 of Try/Tiny.pm
# once (51µs+2µs) by IO::File::BEGIN@130 at line 130 of IO/File.pm
# once (49µs+2µs) by Devel::StackTrace::BEGIN@9 at line 9 of Devel/StackTrace.pm
# once (49µs+2µs) by Class::MOP::BEGIN@12 at line 12 of Class/MOP.pm
# once (48µs+3µs) by SimpleDB::Client::BEGIN@52 at line 52 of ../lib/SimpleDB/Client.pm
# once (49µs+1µs) by Compress::Raw::Zlib::BEGIN@7 at line 7 of Compress/Raw/Zlib.pm
# once (47µs+2µs) by Class::MOP::Mixin::HasMethods::BEGIN@12 at line 12 of Class/MOP/Mixin/HasMethods.pm
# once (48µs+2µs) by Class::MOP::Method::Accessor::BEGIN@8 at line 8 of Class/MOP/Method/Accessor.pm
# once (46µs+2µs) by Class::MOP::Method::Constructor::BEGIN@7 at line 7 of Class/MOP/Method/Constructor.pm
# once (46µs+2µs) by Class::MOP::Method::Inlined::BEGIN@7 at line 7 of Class/MOP/Method/Inlined.pm
# once (43µs+1µs) by IO::Compress::Base::Common::BEGIN@8 at line 8 of IO/Compress/Base/Common.pm
# once (43µs+2µs) by Class::MOP::Method::Accessor::BEGIN@7 at line 7 of Class/MOP/Method/Accessor.pm
# once (43µs+2µs) by Socket::BEGIN@178 at line 178 of Socket.pm
# once (42µs+2µs) by Moose::Meta::Role::Composite::BEGIN@7 at line 7 of Moose/Meta/Role/Composite.pm
# once (42µs+2µs) by Moose::Meta::Method::Constructor::BEGIN@7 at line 7 of Moose/Meta/Method/Constructor.pm
# once (42µs+2µs) by Class::MOP::Method::Constructor::BEGIN@8 at line 8 of Class/MOP/Method/Constructor.pm
# once (41µs+1µs) by Exception::Class::BEGIN@8 at line 8 of Exception/Class.pm
# once (40µs+2µs) by URI::_idna::BEGIN@7 at line 7 of URI/_idna.pm
# once (39µs+3µs) by Moose::Util::MetaRole::BEGIN@12 at line 12 of Moose/Util/MetaRole.pm
# once (39µs+1µs) by URI::_server::BEGIN@6 at line 6 of URI/_server.pm
# once (39µs+1µs) by Class::MOP::Class::BEGIN@13 at line 13 of Class/MOP/Class.pm
# once (38µs+2µs) by IO::File::BEGIN@131 at line 131 of IO/File.pm
# once (37µs+2µs) by Moose::BEGIN@12 at line 12 of Moose.pm
# once (37µs+2µs) by Class::MOP::Deprecated::BEGIN@6 at line 6 of Class/MOP/Deprecated.pm
# once (37µs+2µs) by Class::MOP::Package::BEGIN@7 at line 7 of Class/MOP/Package.pm
# once (38µs+0s) by SimpleDB::Client::BEGIN@48 at line 48 of ../lib/SimpleDB/Client.pm
# once (36µs+1µs) by Class::MOP::Method::Generated::BEGIN@7 at line 7 of Class/MOP/Method/Generated.pm
# once (35µs+1µs) by File::GlobMapper::BEGIN@5 at line 5 of File/GlobMapper.pm
# once (35µs+1µs) by IO::Compress::Base::Common::BEGIN@503 at line 503 of IO/Compress/Base/Common.pm
# once (35µs+900ns) by Moose::Meta::TypeConstraint::Class::BEGIN@7 at line 7 of Moose/Meta/TypeConstraint/Class.pm
# once (35µs+1µs) by IO::Uncompress::Base::BEGIN@21 at line 21 of IO/Uncompress/Base.pm
# once (31µs+4µs) by Class::MOP::Instance::BEGIN@7 at line 7 of Class/MOP/Instance.pm
# once (34µs+2µs) by Moose::Meta::TypeConstraint::BEGIN@11 at line 11 of Moose/Meta/TypeConstraint.pm
# once (34µs+1µs) by XML::Bare::BEGIN@3 at line 3 of XML/Bare.pm
# once (33µs+1µs) by Class::MOP::Class::BEGIN@12 at line 12 of Class/MOP/Class.pm
# once (33µs+1µs) by IO::Seekable::BEGIN@98 at line 98 of IO/Seekable.pm
# once (33µs+1µs) by Class::MOP::Module::BEGIN@7 at line 7 of Class/MOP/Module.pm
# once (33µs+900ns) by Moose::Meta::Role::Attribute::BEGIN@6 at line 6 of Moose/Meta/Role/Attribute.pm
# once (33µs+1µs) by Class::MOP::Attribute::BEGIN@9 at line 9 of Class/MOP/Attribute.pm
# once (33µs+1µs) by IO::File::BEGIN@133 at line 133 of IO/File.pm
# once (33µs+800ns) by IO::Uncompress::Base::BEGIN@24 at line 24 of IO/Uncompress/Base.pm
# once (32µs+1µs) by Moose::Meta::Class::BEGIN@11 at line 11 of Moose/Meta/Class.pm
# once (32µs+1µs) by SelectSaver::BEGIN@38 at line 38 of SelectSaver.pm
# once (31µs+1µs) by Carp::BEGIN@11 at line 11 of Carp/Heavy.pm
# once (31µs+1µs) by SelectSaver::BEGIN@39 at line 39 of SelectSaver.pm
# once (31µs+1µs) by Class::MOP::Method::Inlined::BEGIN@6 at line 6 of Class/MOP/Method/Inlined.pm
# once (31µs+800ns) by Class::MOP::Module::BEGIN@8 at line 8 of Class/MOP/Module.pm
# once (30µs+1µs) by Moose::Util::TypeConstraints::OptimizedConstraints::BEGIN@7 at line 7 of Moose/Util/TypeConstraints/OptimizedConstraints.pm
# once (30µs+1µs) by IO::Compress::Base::Common::BEGIN@7 at line 7 of IO/Compress/Base/Common.pm
# once (30µs+1µs) by IO::Socket::UNIX::BEGIN@12 at line 12 of IO/Socket/UNIX.pm
# once (30µs+1µs) by Class::MOP::Mixin::HasAttributes::BEGIN@10 at line 10 of Class/MOP/Mixin/HasAttributes.pm
# once (29µs+2µs) by Moose::Meta::Role::Application::ToClass::BEGIN@8 at line 8 of Moose/Meta/Role/Application/ToClass.pm
# once (30µs+1µs) by Class::MOP::Class::Immutable::Trait::BEGIN@8 at line 8 of Class/MOP/Class/Immutable/Trait.pm
# once (29µs+1µs) by IO::Handle::BEGIN@263 at line 263 of IO/Handle.pm
# once (29µs+1µs) by Moose::Util::TypeConstraints::BEGIN@5 at line 5 of Moose/Util/TypeConstraints.pm
# once (29µs+1µs) by IO::Handle::BEGIN@264 at line 264 of IO/Handle.pm
# once (29µs+1µs) by Class::MOP::Method::Wrapped::BEGIN@7 at line 7 of Class/MOP/Method/Wrapped.pm
# once (29µs+700ns) by Class::MOP::Mixin::HasMethods::BEGIN@11 at line 11 of Class/MOP/Mixin/HasMethods.pm
# once (29µs+1µs) by IO::Socket::BEGIN@13 at line 13 of IO/Socket.pm
# once (28µs+1µs) by IO::BEGIN@6 at line 6 of IO.pm
# once (29µs+800ns) by Moose::Meta::Role::Attribute::BEGIN@8 at line 8 of Moose/Meta/Role/Attribute.pm
# once (29µs+800ns) by Moose::Meta::Attribute::BEGIN@9 at line 9 of Moose/Meta/Attribute.pm
# once (28µs+1µs) by metaclass::BEGIN@7 at line 7 of metaclass.pm
# once (28µs+1µs) by URI::_query::BEGIN@5 at line 5 of URI/_query.pm
# once (28µs+1µs) by IO::Socket::INET::BEGIN@13 at line 13 of IO/Socket/INET.pm
# once (29µs+0s) by IO::Socket::BEGIN@11 at line 11 of IO/Socket.pm
# once (28µs+700ns) by Class::MOP::Class::BEGIN@14 at line 14 of Class/MOP/Class.pm
# once (28µs+1µs) by Moose::Meta::Method::Delegation::BEGIN@8 at line 8 of Moose/Meta/Method/Delegation.pm
# once (28µs+900ns) by Class::MOP::Attribute::BEGIN@11 at line 11 of Class/MOP/Attribute.pm
# once (27µs+1µs) by Class::MOP::Mixin::BEGIN@10 at line 10 of Class/MOP/Mixin.pm
# once (27µs+1µs) by Moose::Meta::Attribute::BEGIN@7 at line 7 of Moose/Meta/Attribute.pm
# once (27µs+1µs) by Moose::Meta::Method::Destructor::BEGIN@8 at line 8 of Moose/Meta/Method/Destructor.pm
# once (28µs+700ns) by Class::MOP::Package::BEGIN@8 at line 8 of Class/MOP/Package.pm
# once (26µs+900ns) by Moose::Meta::TypeConstraint::Role::BEGIN@7 at line 7 of Moose/Meta/TypeConstraint/Role.pm
# once (26µs+1000ns) by Moose::Meta::Method::Delegation::BEGIN@7 at line 7 of Moose/Meta/Method/Delegation.pm
# once (26µs+1µs) by Class::MOP::Mixin::HasMethods::BEGIN@10 at line 10 of Class/MOP/Mixin/HasMethods.pm
# once (25µs+1µs) by Moose::Util::MetaRole::BEGIN@5 at line 5 of Moose/Util/MetaRole.pm
# once (26µs+900ns) by Class::MOP::Class::Immutable::Trait::BEGIN@9 at line 9 of Class/MOP/Class/Immutable/Trait.pm
# once (25µs+1µs) by Moose::Meta::Class::BEGIN@10 at line 10 of Moose/Meta/Class.pm
# once (25µs+800ns) by Moose::Meta::Role::BEGIN@9 at line 9 of Moose/Meta/Role.pm
# once (25µs+800ns) by Moose::Util::TypeConstraints::BEGIN@6 at line 6 of Moose/Util/TypeConstraints.pm
# once (25µs+900ns) by Moose::Meta::TypeConstraint::Registry::BEGIN@8 at line 8 of Moose/Meta/TypeConstraint/Registry.pm
# once (25µs+1µs) by IO::Uncompress::Gunzip::BEGIN@14 at line 14 of IO/Uncompress/Gunzip.pm
# once (24µs+900ns) by Moose::Exporter::BEGIN@15 at line 15 of Moose/Exporter.pm
# once (24µs+800ns) by Moose::Meta::Class::BEGIN@12 at line 12 of Moose/Meta/Class.pm
# once (24µs+900ns) by Moose::Meta::Role::Application::ToRole::BEGIN@7 at line 7 of Moose/Meta/Role/Application/ToRole.pm
# once (24µs+900ns) by Class::MOP::Attribute::BEGIN@10 at line 10 of Class/MOP/Attribute.pm
# once (24µs+800ns) by Moose::Meta::Role::Application::RoleSummation::BEGIN@7 at line 7 of Moose/Meta/Role/Application/RoleSummation.pm
# once (24µs+700ns) by Class::MOP::Deprecated::BEGIN@7 at line 7 of Class/MOP/Deprecated.pm
# once (24µs+700ns) by Moose::Meta::Role::Attribute::BEGIN@7 at line 7 of Moose/Meta/Role/Attribute.pm
# once (24µs+700ns) by Moose::Meta::TypeConstraint::BEGIN@12 at line 12 of Moose/Meta/TypeConstraint.pm
# once (23µs+900ns) by Moose::Meta::Role::Application::ToInstance::BEGIN@7 at line 7 of Moose/Meta/Role/Application/ToInstance.pm
# once (24µs+800ns) by Moose::Meta::TypeCoercion::Union::BEGIN@8 at line 8 of Moose/Meta/TypeCoercion/Union.pm
# once (23µs+1000ns) by Moose::Util::BEGIN@8 at line 8 of Moose/Util.pm
# once (23µs+900ns) by Class::MOP::Object::BEGIN@7 at line 7 of Class/MOP/Object.pm
# once (23µs+800ns) by Moose::Meta::TypeConstraint::DuckType::BEGIN@7 at line 7 of Moose/Meta/TypeConstraint/DuckType.pm
# once (23µs+1µs) by URI::_generic::BEGIN@7 at line 7 of URI/_generic.pm
# once (23µs+800ns) by Moose::Meta::TypeConstraint::Parameterized::BEGIN@7 at line 7 of Moose/Meta/TypeConstraint/Parameterized.pm
# once (23µs+600ns) by Moose::Meta::Attribute::BEGIN@8 at line 8 of Moose/Meta/Attribute.pm
# once (23µs+600ns) by IO::Uncompress::Base::BEGIN@22 at line 22 of IO/Uncompress/Base.pm
# once (22µs+700ns) by metaclass::BEGIN@8 at line 8 of metaclass.pm
# once (22µs+700ns) by Class::MOP::Mixin::HasAttributes::BEGIN@11 at line 11 of Class/MOP/Mixin/HasAttributes.pm
# once (22µs+700ns) by Moose::Util::MetaRole::BEGIN@11 at line 11 of Moose/Util/MetaRole.pm
# once (22µs+600ns) by URI::_idna::BEGIN@8 at line 8 of URI/_idna.pm
# once (22µs+0s) by IO::Uncompress::Gunzip::BEGIN@12 at line 12 of IO/Uncompress/Gunzip.pm
# once (21µs+700ns) by Moose::Meta::TypeConstraint::DuckType::BEGIN@8 at line 8 of Moose/Meta/TypeConstraint/DuckType.pm
# once (21µs+600ns) by IO::Uncompress::Base::BEGIN@23 at line 23 of IO/Uncompress/Base.pm
# once (22µs+0s) by IO::Uncompress::RawInflate::BEGIN@11 at line 11 of IO/Uncompress/RawInflate.pm
# once (20µs+600ns) by Class::MOP::Method::Wrapped::BEGIN@8 at line 8 of Class/MOP/Method/Wrapped.pm
# once (16µs+0s) by IO::Socket::BEGIN@16 at line 16 of IO/Socket.pm
# once (13µs+0s) by IO::Socket::BEGIN@17 at line 17 of IO/Socket.pm
# once (12µs+0s) by IO::Socket::INET::BEGIN@14 at line 14 of IO/Socket/INET.pm
# once (11µs+0s) by IO::Socket::INET::BEGIN@15 at line 15 of IO/Socket/INET.pm | ||||
| 32 | 142 | 85µs | my $pkg = shift; | ||
| 33 | 142 | 93µs | my $callpkg = caller($ExportLevel); | ||
| 34 | |||||
| 35 | 142 | 60µs | if ($pkg eq "Exporter" and @_ and $_[0] eq "import") { | ||
| 36 | *{$callpkg."::import"} = \&import; | ||||
| 37 | return; | ||||
| 38 | } | ||||
| 39 | |||||
| 40 | # We *need* to treat @{"$pkg\::EXPORT_FAIL"} since Carp uses it :-( | ||||
| 41 | 142 | 449µs | my($exports, $fail) = (\@{"$pkg\::EXPORT"}, \@{"$pkg\::EXPORT_FAIL"}); | ||
| 42 | 142 | 105µs | return export $pkg, $callpkg, @_ | ||
| 43 | if $Verbose or $Debug or @$fail > 1; | ||||
| 44 | 142 | 112µs | my $export_cache = ($Cache{$pkg} ||= {}); | ||
| 45 | 142 | 321µs | my $args = @_ or @_ = @$exports; | ||
| 46 | |||||
| 47 | 142 | 27µs | local $_; | ||
| 48 | 142 | 138µs | if ($args and not %$export_cache) { | ||
| 49 | s/^&//, $export_cache->{$_} = 1 | ||||
| 50 | 26 | 655µs | 356 | 62µs | foreach (@$exports, @{"$pkg\::EXPORT_OK"}); # spent 62µs making 356 calls to Exporter::CORE:subst, avg 174ns/call |
| 51 | } | ||||
| 52 | 142 | 17µs | my $heavy; | ||
| 53 | # Try very hard not to use {} and hence have to enter scope on the foreach | ||||
| 54 | # We bomb out of the loop with last as soon as heavy is set. | ||||
| 55 | 142 | 67µs | if ($args or $fail) { | ||
| 56 | ($heavy = (/\W/ or $args and not exists $export_cache->{$_} | ||||
| 57 | or @$fail and $_ eq $fail->[0])) and last | ||||
| 58 | 284 | 1.79ms | 752 | 252µs | foreach (@_); # spent 252µs making 752 calls to Exporter::CORE:match, avg 335ns/call |
| 59 | } else { | ||||
| 60 | ($heavy = /\W/) and last | ||||
| 61 | foreach (@_); | ||||
| 62 | } | ||||
| 63 | 142 | 65µs | 8 | 121µs | return export $pkg, $callpkg, ($args ? @_ : ()) if $heavy; # spent 121µs making 8 calls to Exporter::export, avg 15µs/call |
| 64 | local $SIG{__WARN__} = | ||||
| 65 | 134 | 619µs | sub {require Carp; &Carp::carp}; | ||
| 66 | # shortcut for the common case of no type character | ||||
| 67 | 268 | 2.96ms | *{"$callpkg\::$_"} = \&{"$pkg\::$_"} foreach @_; | ||
| 68 | } | ||||
| 69 | |||||
| 70 | # Default methods | ||||
| 71 | |||||
| 72 | sub export_fail { | ||||
| 73 | my $self = shift; | ||||
| 74 | @_; | ||||
| 75 | } | ||||
| 76 | |||||
| 77 | # Unfortunately, caller(1)[3] "does not work" if the caller is aliased as | ||||
| 78 | # *name = \&foo. Thus the need to create a lot of identical subroutines | ||||
| 79 | # Otherwise we could have aliased them to export(). | ||||
| 80 | |||||
| 81 | # spent 2.47ms (15µs+2.45) within Exporter::export_to_level which was called 2 times, avg 1.24ms/call:
# once (9µs+2.44ms) by Test::Builder::Module::import at line 93 of Test/Builder/Module.pm
# once (6µs+16µs) by Time::HiRes::import at line 62 of Time/HiRes.pm | ||||
| 82 | 2 | 23µs | 4 | 2.91ms | goto &{as_heavy()}; # spent 2.45ms making 2 calls to Exporter::as_heavy, avg 1.23ms/call
# spent 456µs making 2 calls to Exporter::Heavy::heavy_export_to_level, avg 228µs/call |
| 83 | } | ||||
| 84 | |||||
| 85 | sub export_tags { | ||||
| 86 | goto &{as_heavy()}; | ||||
| 87 | } | ||||
| 88 | |||||
| 89 | # spent 42µs (11+30) within Exporter::export_ok_tags which was called 2 times, avg 21µs/call:
# once (7µs+18µs) by IO::Uncompress::Gunzip::BEGIN@12 at line 25 of IO/Uncompress/RawInflate.pm
# once (4µs+12µs) by Net::HTTP::Methods::gunzip_ok at line 27 of IO/Uncompress/Gunzip.pm | ||||
| 90 | 2 | 12µs | 4 | 62µs | goto &{as_heavy()}; # spent 32µs making 2 calls to Exporter::Heavy::heavy_export_ok_tags, avg 16µs/call
# spent 30µs making 2 calls to Exporter::as_heavy, avg 15µs/call |
| 91 | } | ||||
| 92 | |||||
| 93 | sub require_version { | ||||
| 94 | goto &{as_heavy()}; | ||||
| 95 | } | ||||
| 96 | |||||
| 97 | 1 | 15µs | 1; | ||
| 98 | __END__ | ||||
| 99 | |||||
| 100 | =head1 NAME | ||||
| 101 | |||||
| 102 | Exporter - Implements default import method for modules | ||||
| 103 | |||||
| 104 | =head1 SYNOPSIS | ||||
| 105 | |||||
| 106 | In module F<YourModule.pm>: | ||||
| 107 | |||||
| 108 | package YourModule; | ||||
| 109 | require Exporter; | ||||
| 110 | @ISA = qw(Exporter); | ||||
| 111 | @EXPORT_OK = qw(munge frobnicate); # symbols to export on request | ||||
| 112 | |||||
| 113 | or | ||||
| 114 | |||||
| 115 | package YourModule; | ||||
| 116 | use Exporter 'import'; # gives you Exporter's import() method directly | ||||
| 117 | @EXPORT_OK = qw(munge frobnicate); # symbols to export on request | ||||
| 118 | |||||
| 119 | In other files which wish to use C<YourModule>: | ||||
| 120 | |||||
| 121 | use YourModule qw(frobnicate); # import listed symbols | ||||
| 122 | frobnicate ($left, $right) # calls YourModule::frobnicate | ||||
| 123 | |||||
| 124 | Take a look at L</Good Practices> for some variants | ||||
| 125 | you will like to use in modern Perl code. | ||||
| 126 | |||||
| 127 | =head1 DESCRIPTION | ||||
| 128 | |||||
| 129 | The Exporter module implements an C<import> method which allows a module | ||||
| 130 | to export functions and variables to its users' namespaces. Many modules | ||||
| 131 | use Exporter rather than implementing their own C<import> method because | ||||
| 132 | Exporter provides a highly flexible interface, with an implementation optimised | ||||
| 133 | for the common case. | ||||
| 134 | |||||
| 135 | Perl automatically calls the C<import> method when processing a | ||||
| 136 | C<use> statement for a module. Modules and C<use> are documented | ||||
| 137 | in L<perlfunc> and L<perlmod>. Understanding the concept of | ||||
| 138 | modules and how the C<use> statement operates is important to | ||||
| 139 | understanding the Exporter. | ||||
| 140 | |||||
| 141 | =head2 How to Export | ||||
| 142 | |||||
| 143 | The arrays C<@EXPORT> and C<@EXPORT_OK> in a module hold lists of | ||||
| 144 | symbols that are going to be exported into the users name space by | ||||
| 145 | default, or which they can request to be exported, respectively. The | ||||
| 146 | symbols can represent functions, scalars, arrays, hashes, or typeglobs. | ||||
| 147 | The symbols must be given by full name with the exception that the | ||||
| 148 | ampersand in front of a function is optional, e.g. | ||||
| 149 | |||||
| 150 | @EXPORT = qw(afunc $scalar @array); # afunc is a function | ||||
| 151 | @EXPORT_OK = qw(&bfunc %hash *typeglob); # explicit prefix on &bfunc | ||||
| 152 | |||||
| 153 | If you are only exporting function names it is recommended to omit the | ||||
| 154 | ampersand, as the implementation is faster this way. | ||||
| 155 | |||||
| 156 | =head2 Selecting What To Export | ||||
| 157 | |||||
| 158 | Do B<not> export method names! | ||||
| 159 | |||||
| 160 | Do B<not> export anything else by default without a good reason! | ||||
| 161 | |||||
| 162 | Exports pollute the namespace of the module user. If you must export | ||||
| 163 | try to use C<@EXPORT_OK> in preference to C<@EXPORT> and avoid short or | ||||
| 164 | common symbol names to reduce the risk of name clashes. | ||||
| 165 | |||||
| 166 | Generally anything not exported is still accessible from outside the | ||||
| 167 | module using the C<YourModule::item_name> (or C<< $blessed_ref->method >>) | ||||
| 168 | syntax. By convention you can use a leading underscore on names to | ||||
| 169 | informally indicate that they are 'internal' and not for public use. | ||||
| 170 | |||||
| 171 | (It is actually possible to get private functions by saying: | ||||
| 172 | |||||
| 173 | my $subref = sub { ... }; | ||||
| 174 | $subref->(@args); # Call it as a function | ||||
| 175 | $obj->$subref(@args); # Use it as a method | ||||
| 176 | |||||
| 177 | However if you use them for methods it is up to you to figure out | ||||
| 178 | how to make inheritance work.) | ||||
| 179 | |||||
| 180 | As a general rule, if the module is trying to be object oriented | ||||
| 181 | then export nothing. If it's just a collection of functions then | ||||
| 182 | C<@EXPORT_OK> anything but use C<@EXPORT> with caution. For function and | ||||
| 183 | method names use barewords in preference to names prefixed with | ||||
| 184 | ampersands for the export lists. | ||||
| 185 | |||||
| 186 | Other module design guidelines can be found in L<perlmod>. | ||||
| 187 | |||||
| 188 | =head2 How to Import | ||||
| 189 | |||||
| 190 | In other files which wish to use your module there are three basic ways for | ||||
| 191 | them to load your module and import its symbols: | ||||
| 192 | |||||
| 193 | =over 4 | ||||
| 194 | |||||
| 195 | =item C<use YourModule;> | ||||
| 196 | |||||
| 197 | This imports all the symbols from YourModule's C<@EXPORT> into the namespace | ||||
| 198 | of the C<use> statement. | ||||
| 199 | |||||
| 200 | =item C<use YourModule ();> | ||||
| 201 | |||||
| 202 | This causes perl to load your module but does not import any symbols. | ||||
| 203 | |||||
| 204 | =item C<use YourModule qw(...);> | ||||
| 205 | |||||
| 206 | This imports only the symbols listed by the caller into their namespace. | ||||
| 207 | All listed symbols must be in your C<@EXPORT> or C<@EXPORT_OK>, else an error | ||||
| 208 | occurs. The advanced export features of Exporter are accessed like this, | ||||
| 209 | but with list entries that are syntactically distinct from symbol names. | ||||
| 210 | |||||
| 211 | =back | ||||
| 212 | |||||
| 213 | Unless you want to use its advanced features, this is probably all you | ||||
| 214 | need to know to use Exporter. | ||||
| 215 | |||||
| 216 | =head1 Advanced features | ||||
| 217 | |||||
| 218 | =head2 Specialised Import Lists | ||||
| 219 | |||||
| 220 | If any of the entries in an import list begins with !, : or / then | ||||
| 221 | the list is treated as a series of specifications which either add to | ||||
| 222 | or delete from the list of names to import. They are processed left to | ||||
| 223 | right. Specifications are in the form: | ||||
| 224 | |||||
| 225 | [!]name This name only | ||||
| 226 | [!]:DEFAULT All names in @EXPORT | ||||
| 227 | [!]:tag All names in $EXPORT_TAGS{tag} anonymous list | ||||
| 228 | [!]/pattern/ All names in @EXPORT and @EXPORT_OK which match | ||||
| 229 | |||||
| 230 | A leading ! indicates that matching names should be deleted from the | ||||
| 231 | list of names to import. If the first specification is a deletion it | ||||
| 232 | is treated as though preceded by :DEFAULT. If you just want to import | ||||
| 233 | extra names in addition to the default set you will still need to | ||||
| 234 | include :DEFAULT explicitly. | ||||
| 235 | |||||
| 236 | e.g., F<Module.pm> defines: | ||||
| 237 | |||||
| 238 | @EXPORT = qw(A1 A2 A3 A4 A5); | ||||
| 239 | @EXPORT_OK = qw(B1 B2 B3 B4 B5); | ||||
| 240 | %EXPORT_TAGS = (T1 => [qw(A1 A2 B1 B2)], T2 => [qw(A1 A2 B3 B4)]); | ||||
| 241 | |||||
| 242 | Note that you cannot use tags in @EXPORT or @EXPORT_OK. | ||||
| 243 | Names in EXPORT_TAGS must also appear in @EXPORT or @EXPORT_OK. | ||||
| 244 | |||||
| 245 | An application using Module can say something like: | ||||
| 246 | |||||
| 247 | use Module qw(:DEFAULT :T2 !B3 A3); | ||||
| 248 | |||||
| 249 | Other examples include: | ||||
| 250 | |||||
| 251 | use Socket qw(!/^[AP]F_/ !SOMAXCONN !SOL_SOCKET); | ||||
| 252 | use POSIX qw(:errno_h :termios_h !TCSADRAIN !/^EXIT/); | ||||
| 253 | |||||
| 254 | Remember that most patterns (using //) will need to be anchored | ||||
| 255 | with a leading ^, e.g., C</^EXIT/> rather than C</EXIT/>. | ||||
| 256 | |||||
| 257 | You can say C<BEGIN { $Exporter::Verbose=1 }> to see how the | ||||
| 258 | specifications are being processed and what is actually being imported | ||||
| 259 | into modules. | ||||
| 260 | |||||
| 261 | =head2 Exporting without using Exporter's import method | ||||
| 262 | |||||
| 263 | Exporter has a special method, 'export_to_level' which is used in situations | ||||
| 264 | where you can't directly call Exporter's import method. The export_to_level | ||||
| 265 | method looks like: | ||||
| 266 | |||||
| 267 | MyPackage->export_to_level($where_to_export, $package, @what_to_export); | ||||
| 268 | |||||
| 269 | where C<$where_to_export> is an integer telling how far up the calling stack | ||||
| 270 | to export your symbols, and C<@what_to_export> is an array telling what | ||||
| 271 | symbols *to* export (usually this is C<@_>). The C<$package> argument is | ||||
| 272 | currently unused. | ||||
| 273 | |||||
| 274 | For example, suppose that you have a module, A, which already has an | ||||
| 275 | import function: | ||||
| 276 | |||||
| 277 | package A; | ||||
| 278 | |||||
| 279 | @ISA = qw(Exporter); | ||||
| 280 | @EXPORT_OK = qw ($b); | ||||
| 281 | |||||
| 282 | sub import | ||||
| 283 | { | ||||
| 284 | $A::b = 1; # not a very useful import method | ||||
| 285 | } | ||||
| 286 | |||||
| 287 | and you want to Export symbol C<$A::b> back to the module that called | ||||
| 288 | package A. Since Exporter relies on the import method to work, via | ||||
| 289 | inheritance, as it stands Exporter::import() will never get called. | ||||
| 290 | Instead, say the following: | ||||
| 291 | |||||
| 292 | package A; | ||||
| 293 | @ISA = qw(Exporter); | ||||
| 294 | @EXPORT_OK = qw ($b); | ||||
| 295 | |||||
| 296 | sub import | ||||
| 297 | { | ||||
| 298 | $A::b = 1; | ||||
| 299 | A->export_to_level(1, @_); | ||||
| 300 | } | ||||
| 301 | |||||
| 302 | This will export the symbols one level 'above' the current package - ie: to | ||||
| 303 | the program or module that used package A. | ||||
| 304 | |||||
| 305 | Note: Be careful not to modify C<@_> at all before you call export_to_level | ||||
| 306 | - or people using your package will get very unexplained results! | ||||
| 307 | |||||
| 308 | =head2 Exporting without inheriting from Exporter | ||||
| 309 | |||||
| 310 | By including Exporter in your C<@ISA> you inherit an Exporter's import() method | ||||
| 311 | but you also inherit several other helper methods which you probably don't | ||||
| 312 | want. To avoid this you can do | ||||
| 313 | |||||
| 314 | package YourModule; | ||||
| 315 | use Exporter qw( import ); | ||||
| 316 | |||||
| 317 | which will export Exporter's own import() method into YourModule. | ||||
| 318 | Everything will work as before but you won't need to include Exporter in | ||||
| 319 | C<@YourModule::ISA>. | ||||
| 320 | |||||
| 321 | Note: This feature was introduced in version 5.57 | ||||
| 322 | of Exporter, released with perl 5.8.3. | ||||
| 323 | |||||
| 324 | =head2 Module Version Checking | ||||
| 325 | |||||
| 326 | The Exporter module will convert an attempt to import a number from a | ||||
| 327 | module into a call to C<< $module_name->require_version($value) >>. This can | ||||
| 328 | be used to validate that the version of the module being used is | ||||
| 329 | greater than or equal to the required version. | ||||
| 330 | |||||
| 331 | The Exporter module supplies a default C<require_version> method which | ||||
| 332 | checks the value of C<$VERSION> in the exporting module. | ||||
| 333 | |||||
| 334 | Since the default C<require_version> method treats the C<$VERSION> number as | ||||
| 335 | a simple numeric value it will regard version 1.10 as lower than | ||||
| 336 | 1.9. For this reason it is strongly recommended that you use numbers | ||||
| 337 | with at least two decimal places, e.g., 1.09. | ||||
| 338 | |||||
| 339 | =head2 Managing Unknown Symbols | ||||
| 340 | |||||
| 341 | In some situations you may want to prevent certain symbols from being | ||||
| 342 | exported. Typically this applies to extensions which have functions | ||||
| 343 | or constants that may not exist on some systems. | ||||
| 344 | |||||
| 345 | The names of any symbols that cannot be exported should be listed | ||||
| 346 | in the C<@EXPORT_FAIL> array. | ||||
| 347 | |||||
| 348 | If a module attempts to import any of these symbols the Exporter | ||||
| 349 | will give the module an opportunity to handle the situation before | ||||
| 350 | generating an error. The Exporter will call an export_fail method | ||||
| 351 | with a list of the failed symbols: | ||||
| 352 | |||||
| 353 | @failed_symbols = $module_name->export_fail(@failed_symbols); | ||||
| 354 | |||||
| 355 | If the C<export_fail> method returns an empty list then no error is | ||||
| 356 | recorded and all the requested symbols are exported. If the returned | ||||
| 357 | list is not empty then an error is generated for each symbol and the | ||||
| 358 | export fails. The Exporter provides a default C<export_fail> method which | ||||
| 359 | simply returns the list unchanged. | ||||
| 360 | |||||
| 361 | Uses for the C<export_fail> method include giving better error messages | ||||
| 362 | for some symbols and performing lazy architectural checks (put more | ||||
| 363 | symbols into C<@EXPORT_FAIL> by default and then take them out if someone | ||||
| 364 | actually tries to use them and an expensive check shows that they are | ||||
| 365 | usable on that platform). | ||||
| 366 | |||||
| 367 | =head2 Tag Handling Utility Functions | ||||
| 368 | |||||
| 369 | Since the symbols listed within C<%EXPORT_TAGS> must also appear in either | ||||
| 370 | C<@EXPORT> or C<@EXPORT_OK>, two utility functions are provided which allow | ||||
| 371 | you to easily add tagged sets of symbols to C<@EXPORT> or C<@EXPORT_OK>: | ||||
| 372 | |||||
| 373 | %EXPORT_TAGS = (foo => [qw(aa bb cc)], bar => [qw(aa cc dd)]); | ||||
| 374 | |||||
| 375 | Exporter::export_tags('foo'); # add aa, bb and cc to @EXPORT | ||||
| 376 | Exporter::export_ok_tags('bar'); # add aa, cc and dd to @EXPORT_OK | ||||
| 377 | |||||
| 378 | Any names which are not tags are added to C<@EXPORT> or C<@EXPORT_OK> | ||||
| 379 | unchanged but will trigger a warning (with C<-w>) to avoid misspelt tags | ||||
| 380 | names being silently added to C<@EXPORT> or C<@EXPORT_OK>. Future versions | ||||
| 381 | may make this a fatal error. | ||||
| 382 | |||||
| 383 | =head2 Generating combined tags | ||||
| 384 | |||||
| 385 | If several symbol categories exist in C<%EXPORT_TAGS>, it's usually | ||||
| 386 | useful to create the utility ":all" to simplify "use" statements. | ||||
| 387 | |||||
| 388 | The simplest way to do this is: | ||||
| 389 | |||||
| 390 | %EXPORT_TAGS = (foo => [qw(aa bb cc)], bar => [qw(aa cc dd)]); | ||||
| 391 | |||||
| 392 | # add all the other ":class" tags to the ":all" class, | ||||
| 393 | # deleting duplicates | ||||
| 394 | { | ||||
| 395 | my %seen; | ||||
| 396 | |||||
| 397 | push @{$EXPORT_TAGS{all}}, | ||||
| 398 | grep {!$seen{$_}++} @{$EXPORT_TAGS{$_}} foreach keys %EXPORT_TAGS; | ||||
| 399 | } | ||||
| 400 | |||||
| 401 | F<CGI.pm> creates an ":all" tag which contains some (but not really | ||||
| 402 | all) of its categories. That could be done with one small | ||||
| 403 | change: | ||||
| 404 | |||||
| 405 | # add some of the other ":class" tags to the ":all" class, | ||||
| 406 | # deleting duplicates | ||||
| 407 | { | ||||
| 408 | my %seen; | ||||
| 409 | |||||
| 410 | push @{$EXPORT_TAGS{all}}, | ||||
| 411 | grep {!$seen{$_}++} @{$EXPORT_TAGS{$_}} | ||||
| 412 | foreach qw/html2 html3 netscape form cgi internal/; | ||||
| 413 | } | ||||
| 414 | |||||
| 415 | Note that the tag names in C<%EXPORT_TAGS> don't have the leading ':'. | ||||
| 416 | |||||
| 417 | =head2 C<AUTOLOAD>ed Constants | ||||
| 418 | |||||
| 419 | Many modules make use of C<AUTOLOAD>ing for constant subroutines to | ||||
| 420 | avoid having to compile and waste memory on rarely used values (see | ||||
| 421 | L<perlsub> for details on constant subroutines). Calls to such | ||||
| 422 | constant subroutines are not optimized away at compile time because | ||||
| 423 | they can't be checked at compile time for constancy. | ||||
| 424 | |||||
| 425 | Even if a prototype is available at compile time, the body of the | ||||
| 426 | subroutine is not (it hasn't been C<AUTOLOAD>ed yet). perl needs to | ||||
| 427 | examine both the C<()> prototype and the body of a subroutine at | ||||
| 428 | compile time to detect that it can safely replace calls to that | ||||
| 429 | subroutine with the constant value. | ||||
| 430 | |||||
| 431 | A workaround for this is to call the constants once in a C<BEGIN> block: | ||||
| 432 | |||||
| 433 | package My ; | ||||
| 434 | |||||
| 435 | use Socket ; | ||||
| 436 | |||||
| 437 | foo( SO_LINGER ); ## SO_LINGER NOT optimized away; called at runtime | ||||
| 438 | BEGIN { SO_LINGER } | ||||
| 439 | foo( SO_LINGER ); ## SO_LINGER optimized away at compile time. | ||||
| 440 | |||||
| 441 | This forces the C<AUTOLOAD> for C<SO_LINGER> to take place before | ||||
| 442 | SO_LINGER is encountered later in C<My> package. | ||||
| 443 | |||||
| 444 | If you are writing a package that C<AUTOLOAD>s, consider forcing | ||||
| 445 | an C<AUTOLOAD> for any constants explicitly imported by other packages | ||||
| 446 | or which are usually used when your package is C<use>d. | ||||
| 447 | |||||
| 448 | =head1 Good Practices | ||||
| 449 | |||||
| 450 | =head2 Declaring C<@EXPORT_OK> and Friends | ||||
| 451 | |||||
| 452 | When using C<Exporter> with the standard C<strict> and C<warnings> | ||||
| 453 | pragmas, the C<our> keyword is needed to declare the package | ||||
| 454 | variables C<@EXPORT_OK>, C<@EXPORT>, C<@ISA>, etc. | ||||
| 455 | |||||
| 456 | our @ISA = qw(Exporter); | ||||
| 457 | our @EXPORT_OK = qw(munge frobnicate); | ||||
| 458 | |||||
| 459 | If backward compatibility for Perls under 5.6 is important, | ||||
| 460 | one must write instead a C<use vars> statement. | ||||
| 461 | |||||
| 462 | use vars qw(@ISA @EXPORT_OK); | ||||
| 463 | @ISA = qw(Exporter); | ||||
| 464 | @EXPORT_OK = qw(munge frobnicate); | ||||
| 465 | |||||
| 466 | =head2 Playing Safe | ||||
| 467 | |||||
| 468 | There are some caveats with the use of runtime statements | ||||
| 469 | like C<require Exporter> and the assignment to package | ||||
| 470 | variables, which can very subtle for the unaware programmer. | ||||
| 471 | This may happen for instance with mutually recursive | ||||
| 472 | modules, which are affected by the time the relevant | ||||
| 473 | constructions are executed. | ||||
| 474 | |||||
| 475 | The ideal (but a bit ugly) way to never have to think | ||||
| 476 | about that is to use C<BEGIN> blocks. So the first part | ||||
| 477 | of the L</SYNOPSIS> code could be rewritten as: | ||||
| 478 | |||||
| 479 | package YourModule; | ||||
| 480 | |||||
| 481 | use strict; | ||||
| 482 | use warnings; | ||||
| 483 | |||||
| 484 | our (@ISA, @EXPORT_OK); | ||||
| 485 | BEGIN { | ||||
| 486 | require Exporter; | ||||
| 487 | @ISA = qw(Exporter); | ||||
| 488 | @EXPORT_OK = qw(munge frobnicate); # symbols to export on request | ||||
| 489 | } | ||||
| 490 | |||||
| 491 | The C<BEGIN> will assure that the loading of F<Exporter.pm> | ||||
| 492 | and the assignments to C<@ISA> and C<@EXPORT_OK> happen | ||||
| 493 | immediately, leaving no room for something to get awry | ||||
| 494 | or just plain wrong. | ||||
| 495 | |||||
| 496 | With respect to loading C<Exporter> and inheriting, there | ||||
| 497 | are alternatives with the use of modules like C<base> and C<parent>. | ||||
| 498 | |||||
| 499 | use base qw( Exporter ); | ||||
| 500 | # or | ||||
| 501 | use parent qw( Exporter ); | ||||
| 502 | |||||
| 503 | Any of these statements are nice replacements for | ||||
| 504 | C<BEGIN { require Exporter; @ISA = qw(Exporter); }> | ||||
| 505 | with the same compile-time effect. The basic difference | ||||
| 506 | is that C<base> code interacts with declared C<fields> | ||||
| 507 | while C<parent> is a streamlined version of the older | ||||
| 508 | C<base> code to just establish the IS-A relationship. | ||||
| 509 | |||||
| 510 | For more details, see the documentation and code of | ||||
| 511 | L<base> and L<parent>. | ||||
| 512 | |||||
| 513 | Another thorough remedy to that runtime vs. | ||||
| 514 | compile-time trap is to use L<Exporter::Easy>, | ||||
| 515 | which is a wrapper of Exporter that allows all | ||||
| 516 | boilerplate code at a single gulp in the | ||||
| 517 | use statement. | ||||
| 518 | |||||
| 519 | use Exporter::Easy ( | ||||
| 520 | OK => [ qw(munge frobnicate) ], | ||||
| 521 | ); | ||||
| 522 | # @ISA setup is automatic | ||||
| 523 | # all assignments happen at compile time | ||||
| 524 | |||||
| 525 | =head2 What not to Export | ||||
| 526 | |||||
| 527 | You have been warned already in L</Selecting What To Export> | ||||
| 528 | to not export: | ||||
| 529 | |||||
| 530 | =over 4 | ||||
| 531 | |||||
| 532 | =item * | ||||
| 533 | |||||
| 534 | method names (because you don't need to | ||||
| 535 | and that's likely to not do what you want), | ||||
| 536 | |||||
| 537 | =item * | ||||
| 538 | |||||
| 539 | anything by default (because you don't want to surprise your users... | ||||
| 540 | badly) | ||||
| 541 | |||||
| 542 | =item * | ||||
| 543 | |||||
| 544 | anything you don't need to (because less is more) | ||||
| 545 | |||||
| 546 | =back | ||||
| 547 | |||||
| 548 | There's one more item to add to this list. Do B<not> | ||||
| 549 | export variable names. Just because C<Exporter> lets you | ||||
| 550 | do that, it does not mean you should. | ||||
| 551 | |||||
| 552 | @EXPORT_OK = qw( $svar @avar %hvar ); # DON'T! | ||||
| 553 | |||||
| 554 | Exporting variables is not a good idea. They can | ||||
| 555 | change under the hood, provoking horrible | ||||
| 556 | effects at-a-distance, that are too hard to track | ||||
| 557 | and to fix. Trust me: they are not worth it. | ||||
| 558 | |||||
| 559 | To provide the capability to set/get class-wide | ||||
| 560 | settings, it is best instead to provide accessors | ||||
| 561 | as subroutines or class methods instead. | ||||
| 562 | |||||
| 563 | =head1 SEE ALSO | ||||
| 564 | |||||
| 565 | C<Exporter> is definitely not the only module with | ||||
| 566 | symbol exporter capabilities. At CPAN, you may find | ||||
| 567 | a bunch of them. Some are lighter. Some | ||||
| 568 | provide improved APIs and features. Peek the one | ||||
| 569 | that fits your needs. The following is | ||||
| 570 | a sample list of such modules. | ||||
| 571 | |||||
| 572 | Exporter::Easy | ||||
| 573 | Exporter::Lite | ||||
| 574 | Exporter::Renaming | ||||
| 575 | Exporter::Tidy | ||||
| 576 | Sub::Exporter / Sub::Installer | ||||
| 577 | Perl6::Export / Perl6::Export::Attrs | ||||
| 578 | |||||
| 579 | =head1 LICENSE | ||||
| 580 | |||||
| 581 | This library is free software. You can redistribute it | ||||
| 582 | and/or modify it under the same terms as Perl itself. | ||||
| 583 | |||||
| 584 | =cut | ||||
| 585 | |||||
| 586 | |||||
| 587 | |||||
# spent 252µs within Exporter::CORE:match which was called 752 times, avg 335ns/call:
# 752 times (252µs+0s) by Exporter::import at line 58 of Exporter.pm, avg 335ns/call | |||||
# spent 118µs within Exporter::CORE:subst which was called 374 times, avg 315ns/call:
# 356 times (62µs+0s) by Exporter::import at line 50 of Exporter.pm, avg 174ns/call
# 18 times (56µs+0s) by Exporter::as_heavy at line 23 of Exporter.pm, avg 3µs/call |