From: Dave Rolsky <autarch@urth.org>
Date: Sun, 5 Jun 2011 16:04:00 +0000 (-0500)
Subject: Some cleanup of docs in main module (still needs a lot of work)
X-Git-Tag: 0.26~5
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=gitmo%2FMooseX-Types.git;a=commitdiff_plain;h=93f28db70d0b49bdeb4d1132bf390aeca61abe55

Some cleanup of docs in main module (still needs a lot of work)
---

diff --git a/lib/MooseX/Types.pm b/lib/MooseX/Types.pm
index c011815..8d769ba 100644
--- a/lib/MooseX/Types.pm
+++ b/lib/MooseX/Types.pm
@@ -117,41 +117,30 @@ my $UndefMsg = q{Action for type '%s' not yet defined in library '%s'};
 
 =head1 DESCRIPTION
 
-The types provided with L<Moose> are by design global. This package helps
-you to organise and selectively import your own and the built-in types in
-libraries. As a nice side effect, it catches typos at compile-time too.
+The type system provided by Moose effectively makes all of its builtin type
+global, as are any types you declare with Moose. This means that every module
+that declares a type named "PositiveInt" is sharing the same type object. This
+can be a problem when different parts of the code base want to use the same
+name for different things.
 
-However, the main reason for this module is to provide an easy way to not
-have conflicts with your type names, since the internal fully qualified
-names of the types will be prefixed with the library's name.
+This package lets you declare types using short names, but behind the scenes
+it namespaces all your type declarations, effectively prevent name clashes
+between packages.
 
-This module will also provide you with some helper functions to make it 
-easier to use Moose types in your code.
+This is done by creating a type library module like C<MyApp::Types> and then
+importing types from that module into other modules.
 
-String type names will produce a warning, unless it's for a C<class_type> or
-C<role_type> declared within the library, or a fully qualified name like
-C<'MyTypeLibrary::Foo'>.
+As a side effect, the declaration mechanism allows you to write type names as
+barewords (really function calls), which catches typos in names at compile
+time rather than run time.
 
-=head1 TYPE HANDLER FUNCTIONS
-
-=head2 $type
-
-A constant with the name of your type. It contains the type's fully
-qualified name. Takes no value, as all constants.
-
-=head2 is_$type
-
-This handler takes a value and tests if it is a valid value for this
-C<$type>. It will return true or false.
-
-=head2 to_$type
-
-A handler that will take a value and coerce it into the C<$type>. It will
-return a false value if the type could not be coerced.
+This module also provides some helper functions for using Moose types outside
+of attribute declarations.
 
-B<Important Note>: This handler will only be exported for types that can
-do type coercion. This has the advantage that a coercion to a type that
-has not defined any coercions will lead to a compile-time error.
+If you mix string-based names with types created by this module, it will warn,
+with a few exceptions. If you are declaring a C<class_type()> or
+c<role_type()> within your type library, or if you use a fully qualified name
+like C<"MyApp::Foo">.
 
 =head1 LIBRARY DEFINITION
 
@@ -205,6 +194,27 @@ around L<Sub::Exporter>. This means you can do something like this:
   use MyLibrary TypeA => { -as => 'MyTypeA' },
                 TypeB => { -as => 'MyTypeB' };
 
+=head1 TYPE HANDLER FUNCTIONS
+
+=head2 $type
+
+A constant with the name of your type. It contains the type's fully
+qualified name. Takes no value, as all constants.
+
+=head2 is_$type
+
+This handler takes a value and tests if it is a valid value for this
+C<$type>. It will return true or false.
+
+=head2 to_$type
+
+A handler that will take a value and coerce it into the C<$type>. It will
+return a false value if the type could not be coerced.
+
+B<Important Note>: This handler will only be exported for types that can
+do type coercion. This has the advantage that a coercion to a type that
+has not defined any coercions will lead to a compile-time error.
+
 =head1 WRAPPING A LIBRARY
 
 You can define your own wrapper subclasses to manipulate the behaviour
@@ -240,8 +250,7 @@ with this:
   ...
   1;
 
-The C<Moose> library name is a special shortcut for 
-L<MooseX::Types::Moose>.
+The C<Moose> library name is a special shortcut for L<MooseX::Types::Moose>.
 
 =head2 Generator methods you can overload
 
@@ -249,8 +258,7 @@ L<MooseX::Types::Moose>.
 
 =item type_export_generator( $short, $full )
 
-Creates a closure returning the type's L<Moose::Meta::TypeConstraint> 
-object. 
+Creates a closure returning the type's L<Moose::Meta::TypeConstraint> object.
 
 =item check_export_generator( $short, $full, $undef_message )
 
@@ -292,7 +300,7 @@ Which validates things like:
 
     {key=>'value'};
     {key=>{subkey1=>'value', subkey2=>'value'}}
-    
+
 And so on.  This feature is new and there may be lurking bugs so don't be afraid
 to hunt me down with patches and test cases if you have trouble.
 
@@ -302,15 +310,15 @@ L<MooseX::Types> uses L<MooseX::Types::TypeDecorator> to do some overloading
 which generally allows you to easily create union types:
 
   subtype StrOrArrayRef,
-    as Str|ArrayRef;    
+      as Str|ArrayRef;
 
 As with parameterized constrains, this overloading extends to modules using the
 types you define in a type library.
 
-    use Moose;
-    use MooseX::Types::Moose qw(HashRef Int);
-    
-    has 'attr' => (isa=>HashRef|Int);
+  use Moose;
+  use MooseX::Types::Moose qw(HashRef Int);
+
+  has 'attr' => ( isa => HashRef | Int );
 
 And everything should just work as you'd think.
 
@@ -318,11 +326,10 @@ And everything should just work as you'd think.
 
 =head2 import
 
-Installs the L<MooseX::Types::Base> class into the caller and 
-exports types according to the specification described in 
-L</"LIBRARY DEFINITION">. This will continue to 
-L<Moose::Util::TypeConstraints>' C<import> method to export helper
-functions you will need to declare your types.
+Installs the L<MooseX::Types::Base> class into the caller and exports types
+according to the specification described in L</"LIBRARY DEFINITION">. This
+will continue to L<Moose::Util::TypeConstraints>' C<import> method to export
+helper functions you will need to declare your types.
 
 =cut
 
@@ -370,8 +377,7 @@ sub import {
 
 Generate a type export, e.g. C<Int()>. This will return either a
 L<Moose::Meta::TypeConstraint> object, or alternatively a
-L<MooseX::Types::UndefinedType> object if the type was not
-yet defined.
+L<MooseX::Types::UndefinedType> object if the type was not yet defined.
 
 =cut
 
@@ -442,7 +448,7 @@ sub create_arged_type_constraint {
 
 =head2 create_base_type_constraint ($name)
 
-Given a String $name, find the matching typeconstraint.
+Given a String $name, find the matching type constraint.
 
 =cut
 
@@ -465,7 +471,7 @@ sub create_type_decorator {
 
 =head2 coercion_export_generator
 
-This generates a coercion handler function, e.g. C<to_Int($value)>. 
+This generates a coercion handler function, e.g. C<to_Int($value)>.
 
 =cut
 
@@ -505,7 +511,7 @@ sub check_export_generator {
 
 =head1 CAVEATS
 
-The following are lists of gotcha's and their workarounds for developers coming
+The following are lists of gotchas and their workarounds for developers coming
 from the standard string based type constraint names
 
 =head2 Uniqueness
@@ -517,15 +523,15 @@ a type's actual full name.
 
 =head2 Argument separation ('=>' versus ',')
 
-The Perlop manpage has this to say about the '=>' operator: "The => operator is
+The L<perlop> manpage has this to say about the '=>' operator: "The => operator is
 a synonym for the comma, but forces any word (consisting entirely of word
 characters) to its left to be interpreted as a string (as of 5.001). This
 includes words that might otherwise be considered a constant or function call."
 
 Due to this stringification, the following will NOT work as you might think:
 
-  subtype StrOrArrayRef => as Str|ArrayRef;
-  
+  subtype StrOrArrayRef => as Str | ArrayRef;
+
 The 'StrOrArrayRef' will have its stringification activated this causes the
 subtype to not be created.  Since the bareword type constraints are not strings
 you really should not try to treat them that way.  You will have to use the ','
@@ -541,30 +547,28 @@ If you want to use L<Sub::Exporter> with a Type Library, you need to make sure
 you export all the type constraints declared AS WELL AS any additional export
 targets. For example if you do:
 
-    package TypeAndSubExporter; {
-        
-        use MooseX::Types::Moose qw(Str);
-        use MooseX::Types -declare => [qw(MyStr)];
-        use Sub::Exporter -setup => { exports => [ qw(something) ] };
-        
-        subtype MyStr,
-         as Str;
-         
-        sub something {
-            return 1;
-        }    
-        
-    } 1;
-    
-    package Foo; {
-        use TypeAndSubExporter qw(MyStr);
-    } 1;
+  package TypeAndSubExporter;
+
+  use MooseX::Types::Moose qw(Str);
+  use MooseX::Types -declare => [qw(MyStr)];
+  use Sub::Exporter -setup => { exports => [qw(something)] };
+
+  subtype MyStr, as Str;
+
+  sub something {
+      return 1;
+  }
+
+  # then in another module ...
+
+  package Foo;
+  use TypeAndSubExporter qw(MyStr);
 
 You'll get a '"MyStr" is not exported by the TypeAndSubExporter module' error.
 Upi can workaround by:
 
-        - use Sub::Exporter -setup => { exports => [ qw(something) ] };
-        + use Sub::Exporter -setup => { exports => [ qw(something MyStr) ] };
+  - use Sub::Exporter -setup => { exports => [ qw(something) ] };
+  + use Sub::Exporter -setup => { exports => [ qw(something MyStr) ] };
 
 This is a workaround and I am exploring how to make these modules work better
 together.  I realize this workaround will lead a lot of duplication in your
@@ -581,9 +585,7 @@ of type libraries together.
 
 =head1 SEE ALSO
 
-L<Moose>, 
-L<Moose::Util::TypeConstraints>, 
-L<MooseX::Types::Moose>,
+L<Moose>, L<Moose::Util::TypeConstraints>, L<MooseX::Types::Moose>,
 L<Sub::Exporter>
 
 =head1 ACKNOWLEDGEMENTS