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6 Type::Tiny::Manual::UsingWithMoose - how to use Type::Tiny with Moose
7
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.
12 This part of the manual will focus on Moose-specifics.
14 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.
19 · 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.
24 · 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.
28 Something like this is much harder to do with plain Moose types:
30 has name => (
32 is => "ro",
33 isa => Str->plus_coercions(
34 ArrayRef[Str], sub { join " ", @$_ },
35 ),
36 coerce => 1,
37 );
38 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 · Type::Tiny provides automatic deep coercions, so if type Xyz has a
47 coercion, the following should "just work":
48 isa xyzlist => ( is => 'ro', isa => ArrayRef[Xyz], coerce => 1 );
50 · Type::Tiny offers a wider selection of built-in types.
52 · 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.
56 Type::Utils
58 If you've used Moose::Util::TypeConstraints, you may be accustomed to
59 using a DSL for declaring type constraints:
60 use Moose::Util::TypeConstraints;
62 subtype 'Natural',
64 as 'Int',
65 where { $_ > 0 };
66 There's a module called Type::Utils that provides a very similar DSL
68 for declaring types in Type::Library-based type libraries.
69 package My::Types {
71 use Type::Library -base;
72 use Type::Utils;
73 use Types::Standard qw( Int );
74 declare 'Natural',
76 as Int,
77 where { $_ > 0 };
78 }
79 Personally I prefer the more object-oriented way to declare types
81 though.
82 In Moose you might also declare types like this within classes and
84 roles too. Unlike Moose, Type::Tiny doesn't keep types in a single
85 global flat namespace, so this doesn't work quite the same with
86 Type::Utils. It still creates the type, but it doesn't store it in any
87 type library; the type is returned.
88 package My::Class {
90 use Moose;
91 use Type::Utils;
92 use Types::Standard qw( Int );
93 my $Natural = # store type in a variable
95 declare 'Natural',
96 as Int,
97 where { $_ > 0 };
98 has number => ( is => 'ro', isa => $Natural );
100 }
101 But really, isn't the object-oriented way cleaner?
103 package My::Class {
105 use Moose;
106 use Types::Standard qw( Int );
107 has number => (
109 is => 'ro',
110 isa => Int->where('$_ > 0'),
111 );
112 }
113 Type::Tiny and MooseX::Types
115 Types::Standard should be a drop-in replacement for MooseX::Types. And
116 Types::Common::Numeric and Types::Common::String should easily replace
117 MooseX::Types::Common::Numeric and MooseX::Types::Common::String.
118 That said, if you do with to use a mixture of Type::Tiny and
120 MooseX::Types, they should fit together pretty seamlessly.
121 use Types::Standard qw( ArrayRef );
123 use MooseX::Types::Common::Numeric qw( PositiveInt );
124 # this should just work
126 my $list_of_nums = ArrayRef[PositiveInt];
127 # and this
129 my $list_or_num = ArrayRef | PositiveInt;
130 "-moose" Import Parameter
132 If you have read this far in the manual, you will know that this is the
133 usual way to import type constraints:
134 use Types::Standard qw( Int );
136 And the "Int" which is imported is a function that takes no arguments
138 and returns the Int type constraint, which is a blessed object in the
139 Type::Tiny class.
140 Type::Tiny mocks the Moose::Meta::TypeConstraint API so well that most
142 Moose and MooseX code will not be able to tell the difference.
143 But what if you need a real Moose::Meta::TypeConstraint object?
145 use Types::Standard -moose, qw( Int );
147 Now the "Int" function imported will return a genuine native Moose type
149 constraint.
150 This flag is mostly a throwback from when Type::Tiny native objects
152 didn't directly work in Moose. In 99.9% of cases, there is no reason to
153 use it and plenty of reasons not to. (Moose native type constraints
154 don't offer helpful methods like "plus_coercions" and "where".)
155 "moose_type" Method
157 Another quick way to get a native Moose type constraint object from a
158 Type::Tiny object is to call the "moose_type" method:
159 use Types::Standard qw( Int );
161 my $tiny_type = Int;
163 my $moose_type = $tiny_type->moose_type;
164 Internally, this is what the "-moose" flag makes imported functions do.
166
168 Here's your next step:
169 · Type::Tiny::Manual::UsingWithMouse
171 How to use Type::Tiny with Mouse, including the advantages of
173 Type::Tiny over built-in type constraints, and Mouse-specific
174 features.
175
177 Toby Inkster <tobyink@cpan.org>.
178
180 This software is copyright (c) 2013-2014, 2017-2020 by Toby Inkster.
181 This is free software; you can redistribute it and/or modify it under
183 the same terms as the Perl 5 programming language system itself.
184
186 THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
187 WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
188 MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
189perl v5.32.0 2020-09-T1y7pe::Tiny::Manual::UsingWithMoose(3)