NAME

Type::Registry - a glorified hashref for looking up type constraints

SYNOPSIS

   package Foo::Bar;
   
   use Type::Registry;
   
   my $reg = "Type::Registry"->for_me;  # a registry for Foo::Bar
   
   # Register all types from Types::Standard
   $reg->add_types(-Standard);
   
   # Register just one type from Types::XSD
   $reg->add_types(-XSD => ["NonNegativeInteger"]);
   
   # Register all types from MyApp::Types
   $reg->add_types("MyApp::Types");
   
   # Create a type alias
   $reg->alias_type("NonNegativeInteger" => "Count");
   
   # Look up a type constraint
   my $type = $reg->lookup("ArrayRef[Count]");
   
   $type->check([1, 2, 3.14159]);  # croaks

Alternatively:

   package Foo::Bar;
   
   use Type::Registry qw( t );
   
   # Register all types from Types::Standard
   t->add_types(-Standard);
   
   # Register just one type from Types::XSD
   t->add_types(-XSD => ["NonNegativeInteger"]);
   
   # Register all types from MyApp::Types
   t->add_types("MyApp::Types");
   
   # Create a type alias
   t->alias_type("NonNegativeInteger" => "Count");
   
   # Look up a type constraint
   my $type = t("ArrayRef[Count]");
   
   $type->check([1, 2, 3.14159]);  # croaks

STATUS

Type::Registry (and Type::Parser) is currently a pretty isolated part of this distribution. It seems like something that would be useful, but it's not heavily integrated with everything else. In particular, if you do:

   use Type::Registry qw(t);
   use Types::Standard -types;

Then the Str, Num, etc keywords imported from Types::Standard will work fine, but t->lookup("Str") and t->lookup("Num") will fail, because importing types from a library does not automatically add them to your registry.

Clearly some kind of integration is desirable between Type::Registry and Type::Library, but exactly what form that will take is still to be decided.

So if you decide to use Type::Registry, be aware of its somewhat experimental status. It's not likely to disappear completely, but there may be changes ahead.

DESCRIPTION

A type registry is basically just a hashref mapping type names to type constraint objects.

Constructors

new

Create a new glorified hashref.

for_class($class)

Create or return the existing glorified hashref associated with the given class.

for_me

Create or return the existing glorified hashref associated with the caller.

Methods

add_types(@libraries)

The libraries list is treated as an "optlist" (a la Data::OptList).

Strings are the names of type libraries; if the first character is a hyphen, it is expanded to the "Types::" prefix. If followed by an arrayref, this is the list of types to import from that library. Otherwise, imports all types from the library.

   use Type::Registry qw(t);
   
   t->add_types(-Standard);  # OR: t->add_types("Types::Standard");
   
   t->add_types(
      -TypeTiny => ['HashLike'],
      -Standard => ['HashRef' => { -as => 'RealHash' }],
   );

alias_type($oldname, $newname)

Create an alias for an existing type.

simple_lookup($name)

Look up a type in the registry by name.

Returns undef if not found.

lookup($name)

Look up by name, with a DSL.

   t->lookup("Int|ArrayRef[Int]")

The DSL can be summed up as:

   X               type from this registry
   My::Lib::X      type from a type library
   ~X              complementary type
   X | Y           union
   X & Y           intersection
   X[...]          parameterized type
   slurpy X        slurpy type
   Foo::Bar::      class type

Croaks if not found.

AUTOLOAD

Overloaded to call lookup.

   $registry->Str;  # like $registry->lookup("Str")

Functions

t

This class can export a function t which acts like "Type::Registry"->for_class($importing_class).

BUGS

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

SEE ALSO

Type::Library.

AUTHOR

Toby Inkster <tobyink@cpan.org>.

COPYRIGHT AND LICENCE

This software is copyright (c) 2013 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