1 package MooseX::TypeLibrary;
5 MooseX::TypeLibrary - Organise your Moose types in libraries
13 use Moose::Util::TypeConstraints;
14 use MooseX::TypeLibrary::Base;
15 use MooseX::TypeLibrary::Util qw( filter_tags );
16 use MooseX::TypeLibrary::UndefinedType;
17 use Sub::Install qw( install_sub );
22 my $UndefMsg = q{Action for type '%s' not yet defined in library '%s'};
32 # predeclare our own types
33 use MooseX::TypeLibrary
34 -declare => [qw( PositiveInt NegativeInt )];
36 # import builtin types
37 use MooseX::TypeLibrary::Moose 'Int';
43 message { "Int is not larger than 0" };
48 message { "Int is not smaller than 0" };
62 use MyLibrary qw( PositiveInt NegativeInt );
64 # use the exported constants as type names
76 print "positive\n" if is_PositiveInt($value);
77 print "negative\n" if is_NegativeInt($value);
79 # coerce the value, NegativeInt doesn't have a coercion
80 # helper, since it didn't define any coercions.
81 $value = to_PositiveInt($value) or die "Cannot coerce";
88 The types provided with L<Moose> are by design global. This package helps
89 you to organise and selectively import your own and the built-in types in
90 libraries. As a nice side effect, it catches typos at compile-time too.
92 However, the main reason for this module is to provide an easy way to not
93 have conflicts with your type names, since the internal fully qualified
94 names of the types will be prefixed with the library's name.
96 This module will also provide you with some helper functions to make it
97 easier to use Moose types in your code.
99 =head1 TYPE HANDLER FUNCTIONS
103 A constant with the name of your type. It contains the type's fully
104 qualified name. Takes no value, as all constants.
108 This handler takes a value and tests if it is a valid value for this
109 C<$type>. It will return true or false.
113 A handler that will take a value and coerce it into the C<$type>. It will
114 return a false value if the type could not be coerced.
116 B<Important Note>: This handler will only be exported for types that can
117 do type coercion. This has the advantage that a coercion to a type that
118 cannot hasn't defined any coercions will lead to a compile-time error.
120 =head1 LIBRARY DEFINITION
122 A MooseX::TypeLibrary is just a normal Perl module. Unlike Moose
123 itself, it does not install C<use strict> and C<use warnings> in your
124 class by default, so this is up to you.
126 The only thing a library is required to do is
128 use MooseX::TypeLibrary -declare => \@types;
130 with C<@types> being a list of types you wish to define in this library.
131 This line will install a proper base class in your package as well as the
132 full set of L<handlers|/"TYPE HANDLER FUNCTIONS"> for your declared
133 types. It will then hand control over to L<Moose::Util::TypeConstraints>'
134 C<import> method to export the functions you will need to declare your
137 If you want to use Moose' built-in types (e.g. for subtyping) you will
140 use MooseX::TypeLibrary::Moose @types;
142 to import the helpers from the shipped L<MooseX::TypeLibrary::Moose>
143 library which can export all types that come with Moose.
145 You will have to define coercions for your types or your library won't
146 export a L</to_$type> coercion helper for it.
150 You can import the L<"type helpers"|/"TYPE HANDLER FUNCTIONS"> of a
151 library by C<use>ing it with a list of types to import as arguments. If
152 you want all of them, use the C<:all> tag. For example:
154 use MyLibrary ':all';
155 use MyOtherLibrary qw( TypeA TypeB );
157 MooseX::TypeLibrary comes with a library of Moose' built-in types called
158 L<MooseX::TypeLibrary::Moose>.
164 Installs the L<MooseX::TypeLibrary::Base> class into the caller and
165 exports types according to the specification described in
166 L</"LIBRARY DEFINITION">. This will continue to
167 L<Moose::Util::TypeConstraints>' C<import> method to export helper
168 functions you will need to declare your types.
173 my ($class, %args) = @_;
176 # inject base class into new library
178 unshift @{ $callee . '::ISA' }, 'MooseX::TypeLibrary::Base';
181 # generate predeclared type helpers
182 if (my @orig_declare = @{ $args{ -declare } || [] }) {
183 my ($tags, $declare) = filter_tags @orig_declare;
185 for my $type (@$declare) {
186 $callee->add_type($type);
187 $callee->export_type_into(
189 sprintf($UndefMsg, $type, $callee),
195 # run type constraints import
196 return Moose::Util::TypeConstraints
197 ->import({ into => $callee });
199 # Moose::Util::TypeConstraints->can('import'),
200 # 'Moose::Util::TypeConstraints';
203 =head2 type_export_generator
205 Generate a type export, e.g. C<Int()>. This will return either a
206 L<Moose::Meta::TypeConstraint> object, or alternatively a
207 L<MooseX::TypeLibrary::UndefinedType> object if the type was not
212 sub type_export_generator {
213 my ($class, $type, $full) = @_;
215 return find_type_constraint($full)
216 || MooseX::TypeLibrary::UndefinedType->new($full);
220 =head2 coercion_export_generator
222 This generates a coercion handler function, e.g. C<to_Int($value)>.
226 sub coercion_export_generator {
227 my ($class, $type, $full, $undef_msg) = @_;
231 # we need a type object
232 my $tobj = find_type_constraint($full) or croak $undef_msg;
233 my $return = $tobj->coerce($value);
235 # non-successful coercion returns false
236 return unless $tobj->check($return);
242 =head2 check_export_generator
244 Generates a constraint check closure, e.g. C<is_Int($value)>.
248 sub check_export_generator {
249 my ($class, $type, $full, $undef_msg) = @_;
253 # we need a type object
254 my $tobj = find_type_constraint($full) or croak $undef_msg;
256 return $tobj->check($value);
262 A library makes the types quasi-unique by prefixing their names with (by
263 default) the library package name. If you're only using the type handler
264 functions provided by MooseX::TypeLibrary, you shouldn't ever have to use
265 a type's actual full name.
269 L<Moose>, L<Moose::Util::TypeConstraints>, L<MooseX::TypeLibrary::Moose>
271 =head1 AUTHOR AND COPYRIGHT
273 Robert 'phaylon' Sedlacek C<E<lt>rs@474.atE<gt>>, with many thanks to
274 the C<#moose> cabal on C<irc.perl.org>.
278 This program is free software; you can redistribute it and/or modify
279 it under the same terms as perl itself.