Type::Library(3) User Contributed Perl Documentation Type::Library(3)

Type::Library - tiny, yet Moo(se)-compatible type libraries

   package Types::Mine {
      use Scalar::Util qw(looks_like_number);
      use Type::Library -base;
      use Type::Tiny;
      
      my $NUM = "Type::Tiny"->new(
         name       => "Number",
         constraint => sub { looks_like_number($_) },
         message    => sub { "$_ ain't a number" },
      );
      
      __PACKAGE__->meta->add_type($NUM);
      
      __PACKAGE__->meta->make_immutable;
   }
      
   package Ermintrude {
      use Moo;
      use Types::Mine qw(Number);
      has favourite_number => (is => "ro", isa => Number);
   }
   
   package Bullwinkle {
      use Moose;
      use Types::Mine qw(Number);
      has favourite_number => (is => "ro", isa => Number);
   }
   
   package Maisy {
      use Mouse;
      use Types::Mine qw(Number);
      has favourite_number => (is => "ro", isa => Number);
   }

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

Type::Library is a tiny class for creating MooseX::Types-like type libraries which are compatible with Moo, Moose and Mouse.

If you're reading this because you want to create a type library, then you're probably better off reading Type::Tiny::Manual::Libraries.

A type library is a singleton class. Use the "meta" method to get a blessed object which other methods can get called on. For example:

   Types::Mine->meta->add_type($foo);
"add_type($type)" or "add_type(%opts)"
Add a type to the library. If %opts is given, then this method calls "Type::Tiny->new(%opts)" first, and adds the resultant type.

Adding a type named "Foo" to the library will automatically define four functions in the library's namespace:

"Foo"
Returns the Type::Tiny object.
"is_Foo($value)"
Returns true iff $value passes the type constraint.
"assert_Foo($value)"
Returns $value iff $value passes the type constraint. Dies otherwise.
"to_Foo($value)"
Coerces the value to the type.
"get_type($name)"
Gets the "Type::Tiny" object corresponding to the name.
"has_type($name)"
Boolean; returns true if the type exists in the library.
"type_names"
List all types defined by the library.
"add_coercion($c)" or "add_coercion(%opts)"
Add a standalone coercion to the library. If %opts is given, then this method calls "Type::Coercion->new(%opts)" first, and adds the resultant coercion.

Adding a coercion named "FooFromBar" to the library will automatically define a function in the library's namespace:

"FooFromBar"
Returns the Type::Coercion object.
"get_coercion($name)"
Gets the "Type::Coercion" object corresponding to the name.
"has_coercion($name)"
Boolean; returns true if the coercion exists in the library.
"coercion_names"
List all standalone coercions defined by the library.
"import(@args)"
Type::Library-based libraries are exporters.
"make_immutable"
A shortcut for calling "$type->coercion->freeze" on every type constraint in the library.

"NICE_PROTOTYPES"
If this is true, then Type::Library will give parameterizable type constraints slightly the nicer prototype of "(;$)" instead of the default "(;@)". This allows constructs like: 

   ArrayRef[Int] | HashRef[Int]

... to "just work".

Type libraries are exporters. For the purposes of the following examples, assume that the "Types::Mine" library defines types "Number" and "String".

   # Exports nothing.
   # 
   use Types::Mine;
   
   # Exports a function "String" which is a constant returning
   # the String type constraint.
   #
   use Types::Mine qw( String );
   
   # Exports both String and Number as above.
   #
   use Types::Mine qw( String Number );
   
   # Same.
   #
   use Types::Mine qw( :types );
   
   # Exports "coerce_String" and "coerce_Number", as well as any other
   # coercions
   #
   use Types::Mine qw( :coercions );
   
   # Exports a sub "is_String" so that "is_String($foo)" is equivalent
   # to "String->check($foo)".
   #
   use Types::Mine qw( is_String );
   
   # Exports "is_String" and "is_Number".
   #
   use Types::Mine qw( :is );
   
   # Exports a sub "assert_String" so that "assert_String($foo)" is
   # equivalent to "String->assert_return($foo)".
   #
   use Types::Mine qw( assert_String );
   
   # Exports "assert_String" and "assert_Number".
   #
   use Types::Mine qw( :assert );
   
   # Exports a sub "to_String" so that "to_String($foo)" is equivalent
   # to "String->coerce($foo)".
   #
   use Types::Mine qw( to_String );
   
   # Exports "to_String" and "to_Number".
   #
   use Types::Mine qw( :to );
   
   # Exports "String", "is_String", "assert_String" and "coerce_String".
   #
   use Types::Mine qw( +String );
   
   # Exports everything.
   #
   use Types::Mine qw( :all );

Type libraries automatically inherit from Exporter::Tiny; see the documentation of that module for tips and tricks importing from libraries.

Please report any bugs to <http://rt.cpan.org/Dist/Display.html?Queue=Type-Tiny>.

Type::Tiny::Manual.

Type::Tiny, Type::Utils, Types::Standard, Type::Coercion.

Moose::Util::TypeConstraints, Mouse::Util::TypeConstraints.

Toby Inkster <tobyink@cpan.org>.

This software is copyright (c) 2013-2014, 2017-2020 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.

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.

2020-10-28 perl v5.34.0