Type-Tiny — Type::Library

Synopsis

   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);
   }

Status

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

Description

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 .

Type library methods

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

Prevents new type constraints and coercions from being added to the library, and also calls $type->coercion->freeze on every type constraint in the library.

(Prior to Type::Library v2, make_immutable would call $type->coercion->freeze on every constraint in the library, but not prevent new type constraints and coercions from being added to the library.)

Type library exported functions

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.

Type::Library's methods

The above sections describe the characteristics of libraries built with Type::Library. The following methods are available on Type::Library itself.

setup_type_library( $package, $utils, \@extends ): Sets up a package to be a type library. $utils is a boolean indicating whether to import Type::Utils into the package. @extends is a list of existing type libraries the package should extend.