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:

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:

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.