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6 Type::Tiny::Manual::UsingWithMoose - how to use Type::Tiny with Moose
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9 First read Type::Tiny::Manual::Moo, Type::Tiny::Manual::Moo2, and
10 Type::Tiny::Manual::Moo3. Everything in those parts of the manual
11 should work exactly the same in Moose.
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13 This part of the manual will focus on Moose-specifics.
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15 Why Use Type::Tiny At All?
16 Moose does have a built-in type constraint system which is fairly
17 convenient to use, but there are several reasons you should consider
18 using Type::Tiny instead.
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20 • Type::Tiny type constraints will usually be faster than Moose
21 built-ins. Even without Type::Tiny::XS installed, Type::Tiny
22 usually produces more efficient inline code than Moose. Coercions
23 will usually be a lot faster.
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25 • Type::Tiny provides helpful methods like "where" and
26 "plus_coercions" that allow type constraints and coercions to be
27 easily tweaked on a per-attribute basis.
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29 Something like this is much harder to do with plain Moose types:
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31 has name => (
32 is => "ro",
33 isa => Str->plus_coercions(
34 ArrayRef[Str], sub { join " ", @$_ },
35 ),
36 coerce => 1,
37 );
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39 Moose tends to encourage defining coercions globally, so if you
40 wanted one Str attribute to be able to coerce from ArrayRef[Str],
41 then all Str attributes would coerce from ArrayRef[Str], and they'd
42 all do that coercion in the same way. (Even if it might make sense
43 to join by a space in some places, a comma in others, and a line
44 break in others!)
45
46 • Type::Tiny provides automatic deep coercions, so if type Xyz has a
47 coercion, the following should "just work":
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49 has xyzlist => ( is => 'ro', isa => ArrayRef[Xyz], coerce => 1 );
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51 • Type::Tiny offers a wider selection of built-in types.
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53 • By using Type::Tiny, you can use the same type constraints and
54 coercions for attributes and method parameters, in Moose and non-
55 Moose code.
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57 Type::Utils
58 If you've used Moose::Util::TypeConstraints, you may be accustomed to
59 using a DSL for declaring type constraints:
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61 use Moose::Util::TypeConstraints;
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63 subtype 'Natural',
64 as 'Int',
65 where { $_ > 0 };
66
67 There's a module called Type::Utils that provides a very similar DSL
68 for declaring types in Type::Library-based type libraries.
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70 package My::Types {
71 use Type::Library -base;
72 use Type::Utils;
73 use Types::Standard qw( Int );
74
75 declare 'Natural',
76 as Int,
77 where { $_ > 0 };
78 }
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80 Personally I prefer the more object-oriented way to declare types
81 though.
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83 Since Type::Library 1.012, a shortcut has been available for importing
84 Type::Library and Type::Utils at the same time:
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86 package MyType {
87 use Type::Library -base, -utils;
88
89 ...;
90 }
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92 In Moose you might also declare types like this within classes and
93 roles too. Unlike Moose, Type::Tiny doesn't keep types in a single
94 global flat namespace, so this doesn't work quite the same with
95 Type::Utils. It still creates the type, but it doesn't store it in any
96 type library; the type is returned.
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98 package My::Class {
99 use Moose;
100 use Type::Utils;
101 use Types::Standard qw( Int );
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103 my $Natural = # store type in a variable
104 declare 'Natural',
105 as Int,
106 where { $_ > 0 };
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108 has number => ( is => 'ro', isa => $Natural );
109 }
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111 But really, isn't the object-oriented way cleaner?
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113 package My::Class {
114 use Moose;
115 use Types::Standard qw( Int );
116
117 has number => (
118 is => 'ro',
119 isa => Int->where('$_ > 0'),
120 );
121 }
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123 Type::Tiny and MooseX::Types
124 Types::Standard should be a drop-in replacement for MooseX::Types. And
125 Types::Common::Numeric and Types::Common::String should easily replace
126 MooseX::Types::Common::Numeric and MooseX::Types::Common::String.
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128 That said, if you do with to use a mixture of Type::Tiny and
129 MooseX::Types, they should fit together pretty seamlessly.
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131 use Types::Standard qw( ArrayRef );
132 use MooseX::Types::Common::Numeric qw( PositiveInt );
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134 # this should just work
135 my $list_of_nums = ArrayRef[PositiveInt];
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137 # and this
138 my $list_or_num = ArrayRef | PositiveInt;
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140 "-moose" Import Parameter
141 If you have read this far in the manual, you will know that this is the
142 usual way to import type constraints:
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144 use Types::Standard qw( Int );
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146 And the "Int" which is imported is a function that takes no arguments
147 and returns the Int type constraint, which is a blessed object in the
148 Type::Tiny class.
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150 Type::Tiny mocks the Moose::Meta::TypeConstraint API so well that most
151 Moose and MooseX code will not be able to tell the difference.
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153 But what if you need a real Moose::Meta::TypeConstraint object?
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155 use Types::Standard -moose, qw( Int );
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157 Now the "Int" function imported will return a genuine native Moose type
158 constraint.
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160 This flag is mostly a throwback from when Type::Tiny native objects
161 didn't directly work in Moose. In 99.9% of cases, there is no reason to
162 use it and plenty of reasons not to. (Moose native type constraints
163 don't offer helpful methods like "plus_coercions" and "where".)
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165 "moose_type" Method
166 Another quick way to get a native Moose type constraint object from a
167 Type::Tiny object is to call the "moose_type" method:
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169 use Types::Standard qw( Int );
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171 my $tiny_type = Int;
172 my $moose_type = $tiny_type->moose_type;
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174 Internally, this is what the "-moose" flag makes imported functions do.
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177 Here's your next step:
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179 • Type::Tiny::Manual::UsingWithMouse
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181 How to use Type::Tiny with Mouse, including the advantages of
182 Type::Tiny over built-in type constraints, and Mouse-specific
183 features.
184
186 Toby Inkster <tobyink@cpan.org>.
187
189 This software is copyright (c) 2013-2014, 2017-2023 by Toby Inkster.
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191 This is free software; you can redistribute it and/or modify it under
192 the same terms as the Perl 5 programming language system itself.
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195 THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
196 WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
197 MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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201perl v5.38.0 2023-07-T2y1pe::Tiny::Manual::UsingWithMoose(3)