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1 | |
2 | package Moose::Meta::TypeConstraint::Union; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | use metaclass; |
7 | |
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8 | our $VERSION = '0.04'; |
9 | our $AUTHORITY = 'cpan:STEVAN'; |
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10 | |
11 | __PACKAGE__->meta->add_attribute('type_constraints' => ( |
12 | accessor => 'type_constraints', |
13 | default => sub { [] } |
14 | )); |
15 | |
16 | sub new { |
17 | my $class = shift; |
18 | my $self = $class->meta->new_object(@_); |
19 | return $self; |
20 | } |
21 | |
22 | sub name { join ' | ' => map { $_->name } @{$_[0]->type_constraints} } |
23 | |
24 | # NOTE: |
25 | # this should probably never be used |
26 | # but we include it here for completeness |
27 | sub constraint { |
28 | my $self = shift; |
29 | sub { $self->check($_[0]) }; |
30 | } |
31 | |
32 | # conform to the TypeConstraint API |
33 | sub parent { undef } |
34 | sub message { undef } |
35 | sub has_message { 0 } |
36 | |
37 | # FIXME: |
38 | # not sure what this should actually do here |
39 | sub coercion { undef } |
40 | |
41 | # this should probably be memoized |
42 | sub has_coercion { |
43 | my $self = shift; |
44 | foreach my $type (@{$self->type_constraints}) { |
45 | return 1 if $type->has_coercion |
46 | } |
47 | return 0; |
48 | } |
49 | |
50 | # NOTE: |
51 | # this feels too simple, and may not always DWIM |
52 | # correctly, especially in the presence of |
53 | # close subtype relationships, however it should |
54 | # work for a fair percentage of the use cases |
55 | sub coerce { |
56 | my $self = shift; |
57 | my $value = shift; |
58 | foreach my $type (@{$self->type_constraints}) { |
59 | if ($type->has_coercion) { |
60 | my $temp = $type->coerce($value); |
61 | return $temp if $self->check($temp); |
62 | } |
63 | } |
64 | return undef; |
65 | } |
66 | |
67 | sub _compiled_type_constraint { |
68 | my $self = shift; |
69 | return sub { |
70 | my $value = shift; |
71 | foreach my $type (@{$self->type_constraints}) { |
72 | return 1 if $type->check($value); |
73 | } |
74 | return undef; |
75 | } |
76 | } |
77 | |
78 | sub check { |
79 | my $self = shift; |
80 | my $value = shift; |
81 | $self->_compiled_type_constraint->($value); |
82 | } |
83 | |
84 | sub validate { |
85 | my $self = shift; |
86 | my $value = shift; |
87 | my $message; |
88 | foreach my $type (@{$self->type_constraints}) { |
89 | my $err = $type->validate($value); |
90 | return unless defined $err; |
91 | $message .= ($message ? ' and ' : '') . $err |
92 | if defined $err; |
93 | } |
94 | return ($message . ' in (' . $self->name . ')') ; |
95 | } |
96 | |
97 | sub is_a_type_of { |
98 | my ($self, $type_name) = @_; |
99 | foreach my $type (@{$self->type_constraints}) { |
100 | return 1 if $type->is_a_type_of($type_name); |
101 | } |
102 | return 0; |
103 | } |
104 | |
105 | sub is_subtype_of { |
106 | my ($self, $type_name) = @_; |
107 | foreach my $type (@{$self->type_constraints}) { |
108 | return 1 if $type->is_subtype_of($type_name); |
109 | } |
110 | return 0; |
111 | } |
112 | |
113 | 1; |
114 | |
115 | __END__ |
116 | |
117 | =pod |
118 | |
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119 | =head1 NAME |
120 | |
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121 | Moose::Meta::TypeConstraint::Union - A union of Moose type constraints |
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122 | |
123 | =head1 DESCRIPTION |
124 | |
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125 | This metaclass represents a union of Moose type constraints. More |
126 | details to be explained later (possibly in a Cookbook::Recipe). |
127 | |
128 | This actually used to be part of Moose::Meta::TypeConstraint, but it |
129 | is now better off in it's own file. |
130 | |
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131 | =head1 METHODS |
132 | |
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133 | This class is not a subclass of Moose::Meta::TypeConstraint, |
134 | but it does provide the same API |
135 | |
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136 | =over 4 |
137 | |
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138 | =item B<meta> |
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139 | |
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140 | =item B<new> |
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141 | |
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142 | =item B<name> |
143 | |
144 | =item B<type_constraints> |
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145 | |
146 | =item B<constraint> |
147 | |
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148 | =back |
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149 | |
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150 | =head2 Overriden methods |
151 | |
152 | =over 4 |
153 | |
154 | =item B<check> |
155 | |
156 | =item B<coerce> |
157 | |
158 | =item B<validate> |
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159 | |
160 | =item B<is_a_type_of> |
161 | |
162 | =item B<is_subtype_of> |
163 | |
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164 | =back |
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165 | |
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166 | =head2 Empty or Stub methods |
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167 | |
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168 | These methods tend to not be very relevant in |
169 | the context of a union. Either that or they are |
170 | just difficult to specify and not very useful |
171 | anyway. They are here for completeness. |
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172 | |
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173 | =over 4 |
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174 | |
175 | =item B<parent> |
176 | |
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177 | =item B<coercion> |
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178 | |
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179 | =item B<has_coercion> |
180 | |
181 | =item B<message> |
182 | |
183 | =item B<has_message> |
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184 | |
185 | =back |
186 | |
187 | =head1 BUGS |
188 | |
189 | All complex software has bugs lurking in it, and this module is no |
190 | exception. If you find a bug please either email me, or add the bug |
191 | to cpan-RT. |
192 | |
193 | =head1 AUTHOR |
194 | |
195 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
196 | |
197 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
198 | |
199 | =head1 COPYRIGHT AND LICENSE |
200 | |
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201 | Copyright 2006, 2007 by Infinity Interactive, Inc. |
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202 | |
203 | L<http://www.iinteractive.com> |
204 | |
205 | This library is free software; you can redistribute it and/or modify |
206 | it under the same terms as Perl itself. |
207 | |
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208 | =cut |