1Type::Tiny::IntersectioUns(e3r)Contributed Perl DocumentTaytpieo:n:Tiny::Intersection(3)
2
3
4

NAME

6       Type::Tiny::Intersection - intersection type constraints
7

SYNOPSIS

9       Using via the "&" operator overload:
10
11         package Local::Stash {
12           use Moo;
13           use Types::Common qw( LowerCaseStr StrLength );
14
15           has identifier => (
16             is   => 'ro',
17             isa  => (LowerCaseStr) & (StrLength[4, 8]),
18           );
19         }
20
21         my $x = Local::Stash->new( data => {} );  # not ok
22         my $y = Local::Stash->new( data => [] );  # not ok
23
24       Note that it is a good idea to enclose each type being intersected in
25       parentheses to avoid Perl thinking the "&" is the sigil for a coderef.
26
27       Using Type::Tiny::Intersection's object-oriented interface:
28
29         package Local::Stash {
30           use Moo;
31           use Types::Common qw( LowerCaseStr StrLength );
32           use Type::Tiny::Intersection;
33
34           my $ShortLcStr = Type::Tiny::Intersection->new(
35             name             => 'AnyData',
36             type_constraints => [ LowerCaseStr, StrLength[4, 8] ],
37           );
38
39           has identifier => (
40             is   => 'ro',
41             isa  => $ShortLcStr,
42           );
43         }
44
45       Using Type::Utils's functional interface:
46
47         package Local::Stash {
48           use Moo;
49           use Types::Common qw( LowerCaseStr StrLength );
50           use Type::Utils;
51
52           my $ShortLcStr = intersection ShortLcStr => [ LowerCaseStr, StrLength[4, 8] ];
53
54           has identifier => (
55             is   => 'ro',
56             isa  => $ShortLcStr,
57           );
58         }
59

STATUS

61       This module is covered by the Type-Tiny stability policy.
62

DESCRIPTION

64       Intersection type constraints.
65
66       Intersection type constraints are not often very useful. Consider the
67       intersection of HashRef and ArrayRef. A value will only pass if it is
68       both a hashref and an arrayref. Given that neither of those type
69       constraints accept "undef" or overloaded objects, there is no possible
70       value that can pass both.
71
72       Which is not to say that intersections are never useful, but it happens
73       quite rarely.
74
75       This package inherits from Type::Tiny; see that for most documentation.
76       Major differences are listed below:
77
78   Constructor
79       The "new" constructor from Type::Tiny still works, of course. But there
80       is also:
81
82       new_by_overload(%attributes)
83           Like the "new" constructor, but will sometimes return another type
84           constraint which is not strictly an instance of
85           Type::Tiny::Intersection, but still encapsulates the same meaning.
86           This constructor is used by Type::Tiny's overloading of the "&"
87           operator.
88
89   Attributes
90       "type_constraints"
91           Arrayref of type constraints.
92
93           When passed to the constructor, if any of the type constraints in
94           the intersection is itself an intersection type constraint, this is
95           "exploded" into the new intersection.
96
97       "constraint"
98           Unlike Type::Tiny, you cannot pass a constraint coderef to the
99           constructor.  Instead rely on the default.
100
101       "inlined"
102           Unlike Type::Tiny, you cannot pass an inlining coderef to the
103           constructor.  Instead rely on the default.
104
105       "parent"
106           Unlike Type::Tiny, you cannot pass an inlining coderef to the
107           constructor.  A parent will instead be automatically calculated.
108
109           (Technically any of the types in the intersection could be treated
110           as a parent type; we choose the first arbitrarily.)
111
112   Methods
113       stringifies_to($constraint)
114           See Type::Tiny::ConstrainedObject.
115
116       numifies_to($constraint)
117           See Type::Tiny::ConstrainedObject.
118
119       "with_attribute_values($attr1 => $constraint1, ...)"
120           See Type::Tiny::ConstrainedObject.
121
122   Overloading
123       •   Arrayrefification calls "type_constraints".
124

BUGS

126       Please report any bugs to
127       <https://github.com/tobyink/p5-type-tiny/issues>.
128

SEE ALSO

130       Type::Tiny::Manual.
131
132       Type::Tiny.
133
134       MooseX::Meta::TypeConstraint::Intersection.
135

AUTHOR

137       Toby Inkster <tobyink@cpan.org>.
138

140       This software is copyright (c) 2013-2014, 2017-2023 by Toby Inkster.
141
142       This is free software; you can redistribute it and/or modify it under
143       the same terms as the Perl 5 programming language system itself.
144

DISCLAIMER OF WARRANTIES

146       THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
147       WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
148       MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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152perl v5.36.0                      2023-04-24       Type::Tiny::Intersection(3)
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