# Type::Tiny::Manual::UsingWithMoose - how to use Type::Tiny with Moose - perldoc - [phpMan] ## NAME [Type::Tiny::Manual::UsingWithMoose](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny%3A%3AManual%3A%3AUsingWithMoose/markdown) - how to use [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) with Moose ## MANUAL First read [Type::Tiny::Manual::Moo](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny%3A%3AManual%3A%3AMoo/markdown), [Type::Tiny::Manual::Moo2](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny%3A%3AManual%3A%3AMoo2/markdown), and [Type::Tiny::Manual::Moo3](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny%3A%3AManual%3A%3AMoo3/markdown). Everything in those parts of the manual should work exactly the same in Moose. This part of the manual will focus on Moose-specifics. Why Use [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) At All? Moose does have a built-in type constraint system which is fairly convenient to use, but there are several reasons you should consider using [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) instead. * [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) type constraints will usually be faster than Moose built-ins. Even without [Type::Tiny::XS](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny%3A%3AXS/markdown) installed, [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) usually produces more efficient inline code than Moose. Coercions will usually be a lot faster. * [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) provides helpful methods like "where" and "plus_coercions" that allow type constraints and coercions to be easily tweaked on a per-attribute basis. Something like this is much harder to do with plain Moose types: has name => ( is => "ro", isa => Str->plus_coercions( ArrayRef[Str], sub { join " ", @$_ }, ), coerce => 1, ); Moose tends to encourage defining coercions globally, so if you wanted one Str attribute to be able to coerce from ArrayRef[Str], then *all* Str attributes would coerce from ArrayRef[Str], and they'd all do that coercion in the same way. (Even if it might make sense to join by a space in some places, a comma in others, and a line break in others!) * [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) provides automatic deep coercions, so if type Xyz has a coercion, the following should "just work": has xyzlist => ( is => 'ro', isa => ArrayRef[Xyz], coerce => 1 ); * [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) offers a wider selection of built-in types. * By using [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown), you can use the same type constraints and coercions for attributes and method parameters, in Moose and non-Moose code. ### [Type::Utils](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3AUtils/markdown) If you've used [Moose::Util::TypeConstraints](https://www.chedong.com/phpMan.php/perldoc/Moose%3A%3AUtil%3A%3ATypeConstraints/markdown), you may be accustomed to using a DSL for declaring type constraints: use [Moose::Util::TypeConstraints](https://www.chedong.com/phpMan.php/perldoc/Moose%3A%3AUtil%3A%3ATypeConstraints/markdown); subtype 'Natural', as 'Int', where { $_ > 0 }; There's a module called [Type::Utils](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3AUtils/markdown) that provides a very similar DSL for declaring types in [Type::Library](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ALibrary/markdown)-based type libraries. package [My::Types](https://www.chedong.com/phpMan.php/perldoc/My%3A%3ATypes/markdown) { use [Type::Library](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ALibrary/markdown) -base; use [Type::Utils](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3AUtils/markdown); use [Types::Standard](https://www.chedong.com/phpMan.php/perldoc/Types%3A%3AStandard/markdown) qw( Int ); declare 'Natural', as Int, where { $_ > 0 }; } Personally I prefer the more object-oriented way to declare types though. Since [Type::Library](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ALibrary/markdown) 1.012, a shortcut has been available for importing [Type::Library](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ALibrary/markdown) and [Type::Utils](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3AUtils/markdown) at the same time: package MyType { use [Type::Library](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ALibrary/markdown) -base, -utils; ...; } In Moose you might also declare types like this within classes and roles too. Unlike Moose, [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) doesn't keep types in a single global flat namespace, so this doesn't work quite the same with [Type::Utils](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3AUtils/markdown). It still creates the type, but it doesn't store it in any type library; the type is returned. package [My::Class](https://www.chedong.com/phpMan.php/perldoc/My%3A%3AClass/markdown) { use Moose; use [Type::Utils](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3AUtils/markdown); use [Types::Standard](https://www.chedong.com/phpMan.php/perldoc/Types%3A%3AStandard/markdown) qw( Int ); my $Natural = # store type in a variable declare 'Natural', as Int, where { $_ > 0 }; has number => ( is => 'ro', isa => $Natural ); } But really, isn't the object-oriented way cleaner? package [My::Class](https://www.chedong.com/phpMan.php/perldoc/My%3A%3AClass/markdown) { use Moose; use [Types::Standard](https://www.chedong.com/phpMan.php/perldoc/Types%3A%3AStandard/markdown) qw( Int ); has number => ( is => 'ro', isa => Int->where('$_ > 0'), ); } ### [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) and [MooseX::Types](https://www.chedong.com/phpMan.php/perldoc/MooseX%3A%3ATypes/markdown) [Types::Standard](https://www.chedong.com/phpMan.php/perldoc/Types%3A%3AStandard/markdown) should be a drop-in replacement for [MooseX::Types](https://www.chedong.com/phpMan.php/perldoc/MooseX%3A%3ATypes/markdown). And [Types::Common::Numeric](https://www.chedong.com/phpMan.php/perldoc/Types%3A%3ACommon%3A%3ANumeric/markdown) and [Types::Common::String](https://www.chedong.com/phpMan.php/perldoc/Types%3A%3ACommon%3A%3AString/markdown) should easily replace [MooseX::Types::Common::Numeric](https://www.chedong.com/phpMan.php/perldoc/MooseX%3A%3ATypes%3A%3ACommon%3A%3ANumeric/markdown) and [MooseX::Types::Common::String](https://www.chedong.com/phpMan.php/perldoc/MooseX%3A%3ATypes%3A%3ACommon%3A%3AString/markdown). That said, if you do with to use a mixture of [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) and [MooseX::Types](https://www.chedong.com/phpMan.php/perldoc/MooseX%3A%3ATypes/markdown), they should fit together pretty seamlessly. use [Types::Standard](https://www.chedong.com/phpMan.php/perldoc/Types%3A%3AStandard/markdown) qw( ArrayRef ); use [MooseX::Types::Common::Numeric](https://www.chedong.com/phpMan.php/perldoc/MooseX%3A%3ATypes%3A%3ACommon%3A%3ANumeric/markdown) qw( PositiveInt ); # this should just work my $list_of_nums = ArrayRef[PositiveInt]; # and this my $list_or_num = ArrayRef | PositiveInt; "-moose" Import Parameter If you have read this far in the manual, you will know that this is the usual way to import type constraints: use [Types::Standard](https://www.chedong.com/phpMan.php/perldoc/Types%3A%3AStandard/markdown) qw( Int ); And the "Int" which is imported is a function that takes no arguments and returns the Int type constraint, which is a blessed object in the [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) class. [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) mocks the [Moose::Meta::TypeConstraint](https://www.chedong.com/phpMan.php/perldoc/Moose%3A%3AMeta%3A%3ATypeConstraint/markdown) API so well that most Moose and MooseX code will not be able to tell the difference. But what if you need a real [Moose::Meta::TypeConstraint](https://www.chedong.com/phpMan.php/perldoc/Moose%3A%3AMeta%3A%3ATypeConstraint/markdown) object? use [Types::Standard](https://www.chedong.com/phpMan.php/perldoc/Types%3A%3AStandard/markdown) -moose, qw( Int ); Now the "Int" function imported will return a genuine native Moose type constraint. This flag is mostly a throwback from when [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) native objects *didn't* directly work in Moose. In 99.9% of cases, there is no reason to use it and plenty of reasons not to. (Moose native type constraints don't offer helpful methods like "plus_coercions" and "where".) "moose_type" Method Another quick way to get a native Moose type constraint object from a [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) object is to call the "moose_type" method: use [Types::Standard](https://www.chedong.com/phpMan.php/perldoc/Types%3A%3AStandard/markdown) qw( Int ); my $tiny_type = Int; my $moose_type = $tiny_type->moose_type; Internally, this is what the "-moose" flag makes imported functions do. ## NEXT STEPS Here's your next step: * [Type::Tiny::Manual::UsingWithMouse](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny%3A%3AManual%3A%3AUsingWithMouse/markdown) How to use [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) with Mouse, including the advantages of [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) over built-in type constraints, and Mouse-specific features. ## AUTHOR Toby Inkster <>. ## COPYRIGHT AND LICENCE This software is copyright (c) 2013-2014, 2017-2023 by Toby Inkster. This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself. ## DISCLAIMER OF WARRANTIES THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.