Add definition context to every accessor defined internally
[gitmo/Moose.git] / lib / Moose / Meta / TypeConstraint / DuckType.pm
CommitLineData
0a6bff54 1package Moose::Meta::TypeConstraint::DuckType;
2
3use strict;
4use warnings;
5use metaclass;
6
964294c1 7use B;
42af2755 8use Scalar::Util 'blessed';
0a6bff54 9use List::MoreUtils qw(all);
10use Moose::Util 'english_list';
11
12use Moose::Util::TypeConstraints ();
13
0a6bff54 14use base 'Moose::Meta::TypeConstraint';
15
16__PACKAGE__->meta->add_attribute('methods' => (
17 accessor => 'methods',
dc2b7cc8 18 Class::MOP::_definition_context(),
0a6bff54 19));
20
964294c1 21my $inliner = sub {
22 my $self = shift;
23 my $val = shift;
24
3975b592 25 return 'Scalar::Util::blessed(' . $val . ') '
26 . '&& Scalar::Util::blessed(' . $val . ') ne "Regexp" '
27 . '&& &List::MoreUtils::all('
28 . 'sub { ' . $val . '->can($_) }, '
29 . join(', ', map { B::perlstring($_) } @{ $self->methods })
30 . ')';
964294c1 31};
32
0a6bff54 33sub new {
34 my ( $class, %args ) = @_;
35
964294c1 36 $args{parent}
37 = Moose::Util::TypeConstraints::find_type_constraint('Object');
38
39 my @methods = @{ $args{methods} };
40 $args{constraint} = sub {
41 blessed( $_[0] ) ne 'Regexp'
42 && all { $_[0]->can($_) } @methods;
43 };
44
45 $args{inlined} = $inliner;
0a6bff54 46
92a88343 47 my $self = $class->SUPER::new(\%args);
0a6bff54 48
49 $self->compile_type_constraint()
50 unless $self->_has_compiled_type_constraint;
51
52 return $self;
53}
54
55sub equals {
56 my ( $self, $type_or_name ) = @_;
57
58 my $other = Moose::Util::TypeConstraints::find_type_constraint($type_or_name);
59
60 return unless $other->isa(__PACKAGE__);
61
62 my @self_methods = sort @{ $self->methods };
63 my @other_methods = sort @{ $other->methods };
64
65 return unless @self_methods == @other_methods;
66
67 while ( @self_methods ) {
68 my $method = shift @self_methods;
69 my $other_method = shift @other_methods;
70
71 return unless $method eq $other_method;
72 }
73
74 return 1;
75}
76
77sub constraint {
78 my $self = shift;
79
80 my @methods = @{ $self->methods };
81
82 return sub {
83 my $obj = shift;
84 return all { $obj->can($_) } @methods
85 };
86}
87
0a6bff54 88sub create_child_type {
89 my ($self, @args) = @_;
90 return Moose::Meta::TypeConstraint->new(@args, parent => $self);
91}
92
93sub get_message {
94 my $self = shift;
95 my ($value) = @_;
96
97 if ($self->has_message) {
98 return $self->SUPER::get_message(@_);
99 }
100
101 my @methods = grep { !$value->can($_) } @{ $self->methods };
102 my $class = blessed $value;
d9f45e2e 103 $class ||= $value;
104
0a6bff54 105 return $class
106 . " is missing methods "
107 . english_list(map { "'$_'" } @methods);
108}
109
1101;
111
ad46f524 112# ABSTRACT: Type constraint for duck typing
113
0a6bff54 114__END__
115
116=pod
117
0a6bff54 118=head1 DESCRIPTION
119
120This class represents type constraints based on an enumerated list of
121required methods.
122
123=head1 INHERITANCE
124
125C<Moose::Meta::TypeConstraint::DuckType> is a subclass of
126L<Moose::Meta::TypeConstraint>.
127
128=head1 METHODS
129
130=over 4
131
132=item B<< Moose::Meta::TypeConstraint::DuckType->new(%options) >>
133
134This creates a new duck type constraint based on the given
135C<%options>.
136
137It takes the same options as its parent, with several
138exceptions. First, it requires an additional option, C<methods>. This
139should be an array reference containing a list of required method
140names. Second, it automatically sets the parent to the C<Object> type.
141
142Finally, it ignores any provided C<constraint> option. The constraint
143is generated automatically based on the provided C<methods>.
144
145=item B<< $constraint->methods >>
146
147Returns the array reference of required methods provided to the
148constructor.
149
150=item B<< $constraint->create_child_type >>
151
152This returns a new L<Moose::Meta::TypeConstraint> object with the type
153as its parent.
154
155Note that it does I<not> return a C<Moose::Meta::TypeConstraint::DuckType>
156object!
157
158=back
159
160=head1 BUGS
161
d4048ef3 162See L<Moose/BUGS> for details on reporting bugs.
0a6bff54 163
0a6bff54 164=cut
165