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1 | package MooseX::Types; |
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2 | use Moose; |
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3 | |
4 | =head1 NAME |
5 | |
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6 | MooseX::Types - Organise your Moose types in libraries |
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7 | |
8 | =cut |
9 | |
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10 | #use warnings; |
11 | #use strict; |
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12 | |
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13 | use Moose::Util::TypeConstraints; |
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14 | use MooseX::Types::TypeDecorator; |
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15 | use MooseX::Types::Base (); |
16 | use MooseX::Types::Util qw( filter_tags ); |
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17 | use MooseX::Types::UndefinedType; |
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18 | use Carp::Clan qw( ^MooseX::Types ); |
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19 | |
20 | use namespace::clean -except => [qw( meta )]; |
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21 | |
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22 | use 5.008; |
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23 | our $VERSION = 0.07; |
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24 | my $UndefMsg = q{Action for type '%s' not yet defined in library '%s'}; |
25 | |
26 | =head1 SYNOPSIS |
27 | |
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28 | =head2 Library Definition |
29 | |
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30 | package MyLibrary; |
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31 | |
32 | # predeclare our own types |
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33 | use MooseX::Types |
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34 | -declare => [qw( |
35 | PositiveInt NegativeInt |
36 | ArrayRefOfPositiveInt ArrayRefOfAtLeastThreeNegativeInts |
37 | LotsOfInnerConstraints StrOrArrayRef |
38 | )]; |
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39 | |
40 | # import builtin types |
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41 | use MooseX::Types::Moose 'Int'; |
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42 | |
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43 | # type definition. |
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44 | subtype PositiveInt, |
45 | as Int, |
46 | where { $_ > 0 }, |
47 | message { "Int is not larger than 0" }; |
48 | |
49 | subtype NegativeInt, |
50 | as Int, |
51 | where { $_ < 0 }, |
52 | message { "Int is not smaller than 0" }; |
53 | |
54 | # type coercion |
55 | coerce PositiveInt, |
56 | from Int, |
57 | via { 1 }; |
58 | |
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59 | # with parameterized constraints. |
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60 | |
61 | subtype ArrayRefOfPositiveInt, |
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62 | as ArrayRef[PositiveInt]; |
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63 | |
64 | subtype ArrayRefOfAtLeastThreeNegativeInts, |
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65 | as ArrayRef[NegativeInt], |
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66 | where { scalar(@$_) > 2 }; |
67 | |
68 | subtype LotsOfInnerConstraints, |
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69 | as ArrayRef[ArrayRef[HashRef[Int]]]; |
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70 | |
71 | # with TypeConstraint Unions |
72 | |
73 | subtype StrOrArrayRef, |
74 | as Str|ArrayRef; |
75 | |
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76 | 1; |
77 | |
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78 | =head2 Usage |
79 | |
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80 | package Foo; |
81 | use Moose; |
82 | use MyLibrary qw( PositiveInt NegativeInt ); |
83 | |
84 | # use the exported constants as type names |
85 | has 'bar', |
86 | isa => PositiveInt, |
87 | is => 'rw'; |
88 | has 'baz', |
89 | isa => NegativeInt, |
90 | is => 'rw'; |
91 | |
92 | sub quux { |
93 | my ($self, $value); |
94 | |
95 | # test the value |
96 | print "positive\n" if is_PositiveInt($value); |
97 | print "negative\n" if is_NegativeInt($value); |
98 | |
99 | # coerce the value, NegativeInt doesn't have a coercion |
100 | # helper, since it didn't define any coercions. |
101 | $value = to_PositiveInt($value) or die "Cannot coerce"; |
102 | } |
103 | |
104 | 1; |
105 | |
106 | =head1 DESCRIPTION |
107 | |
108 | The types provided with L<Moose> are by design global. This package helps |
109 | you to organise and selectively import your own and the built-in types in |
110 | libraries. As a nice side effect, it catches typos at compile-time too. |
111 | |
112 | However, the main reason for this module is to provide an easy way to not |
113 | have conflicts with your type names, since the internal fully qualified |
114 | names of the types will be prefixed with the library's name. |
115 | |
116 | This module will also provide you with some helper functions to make it |
117 | easier to use Moose types in your code. |
118 | |
119 | =head1 TYPE HANDLER FUNCTIONS |
120 | |
121 | =head2 $type |
122 | |
123 | A constant with the name of your type. It contains the type's fully |
124 | qualified name. Takes no value, as all constants. |
125 | |
126 | =head2 is_$type |
127 | |
128 | This handler takes a value and tests if it is a valid value for this |
129 | C<$type>. It will return true or false. |
130 | |
131 | =head2 to_$type |
132 | |
133 | A handler that will take a value and coerce it into the C<$type>. It will |
134 | return a false value if the type could not be coerced. |
135 | |
136 | B<Important Note>: This handler will only be exported for types that can |
137 | do type coercion. This has the advantage that a coercion to a type that |
138 | cannot hasn't defined any coercions will lead to a compile-time error. |
139 | |
140 | =head1 LIBRARY DEFINITION |
141 | |
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142 | A MooseX::Types is just a normal Perl module. Unlike Moose |
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143 | itself, it does not install C<use strict> and C<use warnings> in your |
144 | class by default, so this is up to you. |
145 | |
146 | The only thing a library is required to do is |
147 | |
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148 | use MooseX::Types -declare => \@types; |
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149 | |
150 | with C<@types> being a list of types you wish to define in this library. |
151 | This line will install a proper base class in your package as well as the |
152 | full set of L<handlers|/"TYPE HANDLER FUNCTIONS"> for your declared |
153 | types. It will then hand control over to L<Moose::Util::TypeConstraints>' |
154 | C<import> method to export the functions you will need to declare your |
155 | types. |
156 | |
157 | If you want to use Moose' built-in types (e.g. for subtyping) you will |
158 | want to |
159 | |
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160 | use MooseX::Types::Moose @types; |
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161 | |
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162 | to import the helpers from the shipped L<MooseX::Types::Moose> |
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163 | library which can export all types that come with Moose. |
164 | |
165 | You will have to define coercions for your types or your library won't |
166 | export a L</to_$type> coercion helper for it. |
167 | |
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168 | Note that you currently cannot define types containing C<::>, since |
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169 | exporting would be a problem. |
170 | |
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171 | You also don't need to use C<warnings> and C<strict>, since the |
172 | definition of a library automatically exports those. |
173 | |
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174 | =head1 LIBRARY USAGE |
175 | |
176 | You can import the L<"type helpers"|/"TYPE HANDLER FUNCTIONS"> of a |
177 | library by C<use>ing it with a list of types to import as arguments. If |
178 | you want all of them, use the C<:all> tag. For example: |
179 | |
180 | use MyLibrary ':all'; |
181 | use MyOtherLibrary qw( TypeA TypeB ); |
182 | |
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183 | MooseX::Types comes with a library of Moose' built-in types called |
184 | L<MooseX::Types::Moose>. |
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185 | |
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186 | The exporting mechanism is, since version 0.5, implemented via a wrapper |
187 | around L<Sub::Exporter>. This means you can do something like this: |
188 | |
189 | use MyLibrary TypeA => { -as => 'MyTypeA' }, |
190 | TypeB => { -as => 'MyTypeB' }; |
191 | |
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192 | =head1 WRAPPING A LIBRARY |
193 | |
194 | You can define your own wrapper subclasses to manipulate the behaviour |
195 | of a set of library exports. Here is an example: |
196 | |
197 | package MyWrapper; |
198 | use strict; |
199 | use Class::C3; |
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200 | use base 'MooseX::Types::Wrapper'; |
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201 | |
202 | sub coercion_export_generator { |
203 | my $class = shift; |
204 | my $code = $class->next::method(@_); |
205 | return sub { |
206 | my $value = $code->(@_); |
207 | warn "Coercion returned undef!" |
208 | unless defined $value; |
209 | return $value; |
210 | }; |
211 | } |
212 | |
213 | 1; |
214 | |
215 | This class wraps the coercion generator (e.g., C<to_Int()>) and warns |
216 | if a coercion returned an undefined value. You can wrap any library |
217 | with this: |
218 | |
219 | package Foo; |
220 | use strict; |
221 | use MyWrapper MyLibrary => [qw( Foo Bar )], |
222 | Moose => [qw( Str Int )]; |
223 | |
224 | ... |
225 | 1; |
226 | |
227 | The C<Moose> library name is a special shortcut for |
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228 | L<MooseX::Types::Moose>. |
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229 | |
230 | =head2 Generator methods you can overload |
231 | |
232 | =over 4 |
233 | |
234 | =item type_export_generator( $short, $full ) |
235 | |
236 | Creates a closure returning the type's L<Moose::Meta::TypeConstraint> |
237 | object. |
238 | |
239 | =item check_export_generator( $short, $full, $undef_message ) |
240 | |
241 | This creates the closure used to test if a value is valid for this type. |
242 | |
243 | =item coercion_export_generator( $short, $full, $undef_message ) |
244 | |
245 | This is the closure that's doing coercions. |
246 | |
247 | =back |
248 | |
249 | =head2 Provided Parameters |
250 | |
251 | =over 4 |
252 | |
253 | =item $short |
254 | |
255 | The short, exported name of the type. |
256 | |
257 | =item $full |
258 | |
259 | The fully qualified name of this type as L<Moose> knows it. |
260 | |
261 | =item $undef_message |
262 | |
263 | A message that will be thrown when type functionality is used but the |
264 | type does not yet exist. |
265 | |
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266 | =head1 NOTES REGARDING TYPE UNIONS |
267 | |
268 | L<MooseX::Types> uses L<MooseX::Types::TypeDecorator> to do some overloading |
269 | which generally allows you to easily create union types: |
270 | |
271 | subtype StrOrArrayRef, |
272 | as Str|ArrayRef; |
273 | |
274 | As with parameterized constrains, this overloading extends to modules using the |
275 | types you define in a type library. |
276 | |
277 | use Moose; |
278 | use MooseX::Types::Moose qw(HashRef Int); |
279 | |
280 | has 'attr' => (isa=>HashRef|Int); |
281 | |
282 | And everything should just work as you'd think. |
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283 | |
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284 | =head1 METHODS |
285 | |
286 | =head2 import |
287 | |
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288 | Installs the L<MooseX::Types::Base> class into the caller and |
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289 | exports types according to the specification described in |
290 | L</"LIBRARY DEFINITION">. This will continue to |
291 | L<Moose::Util::TypeConstraints>' C<import> method to export helper |
292 | functions you will need to declare your types. |
293 | |
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294 | =cut |
295 | |
296 | sub import { |
297 | my ($class, %args) = @_; |
298 | my $callee = caller; |
299 | |
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300 | # everyone should want this |
301 | strict->import; |
302 | warnings->import; |
303 | |
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304 | # inject base class into new library |
305 | { no strict 'refs'; |
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306 | unshift @{ $callee . '::ISA' }, 'MooseX::Types::Base'; |
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307 | } |
308 | |
309 | # generate predeclared type helpers |
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310 | if (my @orig_declare = @{ $args{ -declare } || [] }) { |
311 | my ($tags, $declare) = filter_tags @orig_declare; |
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312 | my @to_export; |
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313 | |
314 | for my $type (@$declare) { |
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315 | |
316 | croak "Cannot create a type containing '::' ($type) at the moment" |
317 | if $type =~ /::/; |
318 | |
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319 | # add type to library and remember to export |
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320 | $callee->add_type($type); |
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321 | push @to_export, $type; |
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322 | } |
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323 | |
324 | $callee->import({ -full => 1, -into => $callee }, @to_export); |
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325 | } |
326 | |
327 | # run type constraints import |
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328 | return Moose::Util::TypeConstraints->import({ into => $callee }); |
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329 | } |
330 | |
331 | =head2 type_export_generator |
332 | |
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333 | Generate a type export, e.g. C<Int()>. This will return either a |
334 | L<Moose::Meta::TypeConstraint> object, or alternatively a |
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335 | L<MooseX::Types::UndefinedType> object if the type was not |
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336 | yet defined. |
337 | |
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338 | =cut |
339 | |
340 | sub type_export_generator { |
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341 | my ($class, $type, $name) = @_; |
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342 | |
343 | ## Return an anonymous subroutine that will generate the proxied type |
344 | ## constraint for you. |
345 | |
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346 | return sub { |
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347 | my $type_constraint; |
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348 | if(defined(my $params = shift @_)) { |
686e5888 |
349 | ## We currently only allow a TC to accept a single, ArrayRef |
350 | ## parameter, as in HashRef[Int], where [Int] is what's inside the |
351 | ## ArrayRef passed. |
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352 | if(ref $params eq 'ARRAY') { |
353 | $type_constraint = $class->create_arged_type_constraint($name, @$params); |
354 | } else { |
355 | croak 'Arguments must be an ArrayRef, not '. ref $params; |
356 | } |
a706b0f2 |
357 | } else { |
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358 | $type_constraint = $class->create_base_type_constraint($name); |
359 | } |
360 | $type_constraint = defined($type_constraint) ? $type_constraint |
361 | : MooseX::Types::UndefinedType->new($name); |
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362 | |
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363 | my $type_decorator = $class->create_type_decorator($type_constraint); |
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364 | |
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365 | ## If there are additional args, that means it's probably stuff that |
366 | ## needs to be returned to the subtype. Not an ideal solution here but |
367 | ## doesn't seem to cause trouble. |
368 | |
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369 | if(@_) { |
370 | return ($type_decorator, @_); |
371 | } else { |
372 | return $type_decorator; |
373 | } |
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374 | }; |
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375 | } |
376 | |
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377 | =head2 create_arged_type_constraint ($name, @args) |
378 | |
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379 | Given a String $name with @args find the matching typeconstraint and parameterize |
380 | it with @args. |
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381 | |
382 | =cut |
383 | |
384 | sub create_arged_type_constraint { |
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385 | my ($class, $name, @args) = @_; |
386 | my $type_constraint = Moose::Util::TypeConstraints::find_or_create_type_constraint("$name"); |
686e5888 |
387 | return $type_constraint->parameterize(@args); |
a706b0f2 |
388 | } |
389 | |
390 | =head2 create_base_type_constraint ($name) |
391 | |
392 | Given a String $name, find the matching typeconstraint. |
393 | |
394 | =cut |
395 | |
396 | sub create_base_type_constraint { |
397 | my ($class, $name) = @_; |
398 | return find_type_constraint($name); |
399 | } |
400 | |
401 | =head2 create_type_decorator ($type_constraint) |
402 | |
403 | Given a $type_constraint, return a lightweight L<MooseX::Types::TypeDecorator> |
404 | instance. |
405 | |
406 | =cut |
407 | |
408 | sub create_type_decorator { |
409 | my ($class, $type_constraint) = @_; |
475bbd1d |
410 | return MooseX::Types::TypeDecorator->new($type_constraint); |
a706b0f2 |
411 | } |
412 | |
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413 | =head2 coercion_export_generator |
414 | |
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415 | This generates a coercion handler function, e.g. C<to_Int($value)>. |
416 | |
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417 | =cut |
418 | |
419 | sub coercion_export_generator { |
420 | my ($class, $type, $full, $undef_msg) = @_; |
421 | return sub { |
422 | my ($value) = @_; |
423 | |
424 | # we need a type object |
425 | my $tobj = find_type_constraint($full) or croak $undef_msg; |
426 | my $return = $tobj->coerce($value); |
427 | |
428 | # non-successful coercion returns false |
429 | return unless $tobj->check($return); |
430 | |
431 | return $return; |
432 | } |
433 | } |
434 | |
435 | =head2 check_export_generator |
436 | |
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437 | Generates a constraint check closure, e.g. C<is_Int($value)>. |
438 | |
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439 | =cut |
440 | |
441 | sub check_export_generator { |
442 | my ($class, $type, $full, $undef_msg) = @_; |
443 | return sub { |
444 | my ($value) = @_; |
445 | |
446 | # we need a type object |
447 | my $tobj = find_type_constraint($full) or croak $undef_msg; |
448 | |
449 | return $tobj->check($value); |
450 | } |
451 | } |
452 | |
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453 | =head1 CAVEATS |
454 | |
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455 | The following are lists of gotcha's and their workarounds for developers coming |
456 | from the standard string based type constraint names |
457 | |
458 | =head2 Uniqueness |
459 | |
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460 | A library makes the types quasi-unique by prefixing their names with (by |
461 | default) the library package name. If you're only using the type handler |
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462 | functions provided by MooseX::Types, you shouldn't ever have to use |
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463 | a type's actual full name. |
464 | |
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465 | =head2 Argument separation ('=>' versus ',') |
466 | |
467 | The Perlop manpage has this to say about the '=>' operator: "The => operator is |
468 | a synonym for the comma, but forces any word (consisting entirely of word |
469 | characters) to its left to be interpreted as a string (as of 5.001). This |
470 | includes words that might otherwise be considered a constant or function call." |
471 | |
472 | Due to this stringification, the following will NOT work as you might think: |
473 | |
474 | subtype StrOrArrayRef => as Str|ArrayRef; |
475 | |
476 | The 'StrOrArrayRef' will have it's stringification activated this causes the |
477 | subtype to not be created. Since the bareword type constraints are not strings |
478 | you really should not try to treat them that way. You will have to use the ',' |
479 | operator instead. The author's of this package realize that all the L<Moose> |
480 | documention and examples nearly uniformly use the '=>' version of the comma |
481 | operator and this could be an issue if you are converting code. |
482 | |
483 | Patches welcome for discussion. |
484 | |
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485 | =head1 SEE ALSO |
486 | |
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487 | L<Moose>, |
488 | L<Moose::Util::TypeConstraints>, |
489 | L<MooseX::Types::Moose>, |
490 | L<Sub::Exporter> |
8af0a70d |
491 | |
492 | =head1 AUTHOR AND COPYRIGHT |
493 | |
494 | Robert 'phaylon' Sedlacek C<E<lt>rs@474.atE<gt>>, with many thanks to |
495 | the C<#moose> cabal on C<irc.perl.org>. |
496 | |
475bbd1d |
497 | Additional features by John Napiorkowski (jnapiorkowski) <jjnapiork@cpan.org>. |
498 | |
8af0a70d |
499 | =head1 LICENSE |
500 | |
501 | This program is free software; you can redistribute it and/or modify |
502 | it under the same terms as perl itself. |
503 | |
504 | =cut |
505 | |
506 | 1; |