NAME

Type::Tiny::Manual::UsingWithMouse - how to use Type::Tiny with Mouse

MANUAL

First read Type::Tiny::Manual::Moo, Type::Tiny::Manual::Moo2, and Type::Tiny::Manual::Moo3. Everything in those parts of the manual should work exactly the same in Mouse.

This part of the manual will focus on Mouse-specifics.

Overall, Type::Tiny is less well-tested with Mouse than it is with Moose and Moo, but there are still a good number of test cases for using Type::Tiny with Mouse, and there are no known major issues with Type::Tiny's Mouse support.

Why Use Type::Tiny At All?

Mouse 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 instead.

• Type::Tiny 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 Mouse types:

    has name => (
      is      => "ro",
      isa     => Str->plus_coercions(
        ArrayRef[Str], sub { join " ", @$_ },
      ),
      coerce  => 1,
    );

  Mouse 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 provides automatic deep coercions, so if type Xyz has a coercion, the following should "just work":

    isa xyzlist => ( is => 'ro', isa => ArrayRef[Xyz], coerce => 1 );

• Type::Tiny offers a wider selection of built-in types.

• By using Type::Tiny, you can use the same type constraints and coercions for attributes and method parameters, in Mouse and non-Mouse code.

Type::Utils

TODO

Type::Tiny and MouseX::Types

Types::Standard should be a drop-in replacement for MooseX::Types. And Types::Common::Numeric and Types::Common::String should easily replace MouseX::Types::Common::Numeric and MouseX::Types::Common::String.

That said, if you do with to use a mixture of Type::Tiny and MouseX::Types, they should fit together pretty seamlessly.

  use Types::Standard qw( ArrayRef );
  use MouseX::Types::Mouse qw( Int );
  
  # this should just work
  my $list_of_nums = ArrayRef[Int];
  
  # and this
  my $list_or_num = ArrayRef | Int;

-mouse Import Parameter

TODO

mouse_type Method

TODO

Type::Tiny Performance

Type::Tiny should run pretty much as fast as Mouse types do. This is because, when possible, it will use Mouse's XS implementations of type checks to do the heavy lifting.

There are a few type constraints where Type::Tiny prefers to do things without Mouse's help though, for consistency and correctness. For example, the Mouse XS implementation of Bool is... strange... it accepts blessed objects that overload bool, but only if they return false. If they return true, it's a type constraint error.

Using Type::Tiny instead of Mouse's type constraints shouldn't make a significant difference to the performance of your code.

NEXT STEPS

Here's your next step:

• Type::Tiny::Manual::UsingWithClassTiny

  Including how to Type::Tiny in your object's BUILD method, and third-party shims between Type::Tiny and Class::Tiny.

AUTHOR

Toby Inkster <tobyink@cpan.org>.

COPYRIGHT AND LICENCE

This software is copyright (c) 2013-2014, 2017-2019 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.

cpanm Type::Tiny

perl -MCPAN -e shell
install Type::Tiny