trusty (3) Exporter::TypeTiny.3pm.gz
NAME
Exporter::TypeTiny - a small exporter used internally by Type::Library and friends
SYNOPSIS
package MyUtils;
use base "Exporter::TypeTiny";
our @EXPORT = qw(frobnicate);
sub frobnicate { my $n = shift; ... }
1;
package MyScript;
use MyUtils "frobnicate" => { -as => "frob" };
print frob(42);
exit;
DESCRIPTION
Exporter::TypeTiny supports many of Sub::Exporter's external-facing features including renaming imported
functions with the "-as", "-prefix" and "-suffix" options; explicit destinations with the "into" option;
and alternative installers with the "installler" option. But it's written in only about 40% as many lines
of code and with zero non-core dependencies.
Its internal-facing interface is closer to Exporter.pm, with configuration done through the @EXPORT,
@EXPORT_OK and %EXPORT_TAGS package variables.
Although generators are not an explicit part of the interface, Exporter::TypeTiny performs most of its
internal duties (including resolution of tag names to function names, resolution of function names to
coderefs, and installation of coderefs into the target package) as method calls, which means they can be
overridden to provide interesting behaviour, including an equivalent to Sub::Exporter's generators.
(Type::Library does this.) These methods are not currently documented, and are still subject to change.
Utility Functions
These are really for internal use, but can be exported if you need them.
"mkopt(\@array)"
Similar to "mkopt" from Data::OptList. It doesn't support all the fancy options that Data::OptList
does ("moniker", "require_unique", "must_be" and "name_test") but runs about 50% faster.
"mkopt_hash(\@array)"
Similar to "mkopt_hash" from Data::OptList. See also "mkopt".
TIPS AND TRICKS
For the purposes of this discussion we'll assume we have a module called "MyUtils" which exports one
function, "frobnicate". "MyUtils" inherits from Exporter::TypeTiny.
Many of these tricks may seem familiar from Sub::Exporter. That is intentional. Exporter::TypeTiny
doesn't attempt to provide every feature of Sub::Exporter, but where it does it usually uses a fairly
similar API.
Basic importing
# import "frobnicate" function
use MyUtils "frobnicate";
# import all functions that MyUtils offers
use MyUtils -all;
Renaming imported functions
# call it "frob"
use MyUtils "frobnicate" => { -as => "frob" };
# call it "my_frobnicate"
use MyUtils "frobnicate" => { -prefix => "my_" };
# call it "frobnicate_util"
use MyUtils "frobnicate" => { -suffix => "_util" };
# import it twice with two different names
use MyUtils
"frobnicate" => { -as => "frob" },
"frobnicate" => { -as => "frbnct" };
Lexical subs
{
use Sub::Exporter::Lexical lexical_installer => { -as => "lex" };
use MyUtils { installer => lex }, "frobnicate";
frobnicate(...); # ok
}
frobnicate(...); # not ok
Import functions into another package
use MyUtils { into => "OtherPkg" }, "frobnicate";
OtherPkg::frobincate(...);
Import functions into a scalar
my $func;
use MyUtils "frobnicate" => { -as => \$func };
$func->(...);
Import functions into a hash
OK, Sub::Exporter doesn't do this...
my %funcs;
use MyUtils { into => \%funcs }, "frobnicate";
$funcs{frobnicate}->(...);
HISTORY
Why bundle an exporter with Type-Tiny?
Well, it wasn't always that way. Type::Library had a bunch of custom exporting code which poked coderefs
into its caller's stash. It needed this so that it could switch between exporting Moose, Mouse and Moo-
compatible objects on request.
Meanwhile Type::Utils, Types::TypeTiny and Test::TypeTiny each used the venerable Exporter.pm. However,
this meant they were unable to use the features like Sub::Exporter-style function renaming which I'd
built into Type::Library:
## import "Str" but rename it to "String".
use Types::Standard "Str" => { -as => "String" };
And so I decided to factor out code that could be shared by all Type-Tiny's exporters into a single
place.
OBLIGATORY EXPORTER COMPARISON
Exporting is unlikely to be your application's performance bottleneck, but nonetheless here are some
comparisons.
Comparative sizes according to Devel::SizeMe:
Exporter 217.1Kb
Sub::Exporter::Progressive 263.2Kb
Exporter::TypeTiny 267.7Kb
Exporter + Exporter::Heavy 281.5Kb
Exporter::Renaming 406.2Kb
Sub::Exporter 701.0Kb
Performance exporting a single sub:
Rate SubExp ExpTT SubExpProg ExpPM
SubExp 2489/s -- -56% -85% -88%
ExpTT 5635/s 126% -- -67% -72%
SubExpProg 16905/s 579% 200% -- -16%
ExpPM 20097/s 707% 257% 19% --
(Exporter::Renaming globally changes the behaviour of Exporter.pm, so could not be included in the same
benchmarks.)
(Non-Core) Depenendencies:
Exporter -1
Exporter::Renaming 0
Exporter::TypeTiny 0
Sub::Exporter::Progressive 0
Sub::Exporter 3
Features:
ExpPM ExpTT SubExp SubExpProg
Can export code symbols............. Yes Yes Yes Yes
Can export non-code symbols......... Yes
Groups/tags......................... Yes Yes Yes Yes
Config avoids package variables..... Yes
Allows renaming of subs............. Yes Yes Maybe
Install code into scalar refs....... Yes Yes Maybe
Can be passed an "into" parameter... Yes Yes Maybe
Can be passed an "installer" sub.... Yes Yes Maybe
Supports generators................. Yes Yes
Sane API for generators............. Yes
(Certain Sub::Exporter::Progressive features are only available if Sub::Exporter is installed.)
BUGS
Please report any bugs to <http://rt.cpan.org/Dist/Display.html?Queue=Type-Tiny>.
SEE ALSO
Type::Library.
Exporter, Sub::Exporter, Sub::Exporter::Progressive.
AUTHOR
Toby Inkster <tobyink@cpan.org>.
COPYRIGHT AND LICENCE
This software is copyright (c) 2013 by Toby Inkster.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5
programming language system itself.
DISCLAIMER OF WARRANTIES
THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.