finished the big rename and directory shuffle.

[gitmo/MooseX-Dependent.git] / lib / MooseX / Meta / TypeCoercion / Parameterizable.pm

diff --git a/lib/MooseX/Meta/TypeCoercion/Parameterizable.pm b/lib/MooseX/Meta/TypeCoercion/Parameterizable.pm
new file mode 100644 (file)
index 0000000..6a07ac6
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+++ b/lib/MooseX/Meta/TypeCoercion/Parameterizable.pm
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+package ## Hide from PAUSE
+ MooseX::Meta::TypeCoercion::Parameterizable;
+
+use Moose;
+extends 'Moose::Meta::TypeCoercion';
+
+=head1 NAME
+
+MooseX::Meta::TypeCoercion::Parameterizable - Coerce Parameterizable type constraints.
+
+=head1 DESCRIPTION
+
+This class is not intended for public consumption.  Please don't subclass it
+or rely on it.  Chances are high stuff here is going to change a lot.
+
+=head1 METHODS
+
+This class defines the following methods.
+
+=head add_type_coercions
+
+method modification to throw exception should we try to add a coercion on a
+parameterizable type that is already defined by a constraining value.  We do this
+since defined parameterizable type constraints inherit their coercion from the parent
+constraint.  It makes no sense to even be using parameterizable types if you know the
+constraining value beforehand!
+
+=cut
+
+around 'add_type_coercions' => sub {
+    my ($add_type_coercions, $self, @args) = @_;
+    if($self->type_constraint->has_constraining_value) {
+        Moose->throw_error("Cannot add type coercions to a parameterizable type constraint that's been defined.");
+    } else {
+        return $self->$add_type_coercions(@args);
+    }
+};
+
+
+## These two are here until I can merge change upstream to Moose.  These are two
+## very minor changes we can probably just put into Moose without breaking stuff
+sub coerce {
+    my $self = shift @_;
+    my $coderef = $self->_compiled_type_coercion;
+    return $coderef->(@_);
+}
+
+sub compile_type_coercion {
+    my $self = shift;
+    my @coercion_map = @{$self->type_coercion_map};
+    my @coercions;
+    while (@coercion_map) {
+        my ($constraint_name, $action) = splice(@coercion_map, 0, 2);
+        my $type_constraint = ref $constraint_name ? $constraint_name : Moose::Util::TypeConstraints::find_or_parse_type_constraint($constraint_name);
+
+        unless ( defined $type_constraint ) {
+            require Moose;
+            Moose->throw_error("Could not find the type constraint ($constraint_name) to coerce from");
+        }
+
+        push @coercions => [
+            $type_constraint->_compiled_type_constraint,
+            $action
+        ];
+    }
+    $self->_compiled_type_coercion(sub {
+        my $thing = shift;
+        foreach my $coercion (@coercions) {
+            my ($constraint, $converter) = @$coercion;
+            if ($constraint->($thing)) {
+                local $_ = $thing;
+                return $converter->($thing, @_);
+            }
+        }
+        return $thing;
+    });
+}
+
+=head1 SEE ALSO
+
+The following modules or resources may be of interest.
+
+L<Moose>, L<Moose::Meta::TypeCoercion>
+
+=head1 AUTHOR
+
+John Napiorkowski, C<< <jjnapiork@cpan.org> >>
+
+=head1 COPYRIGHT & LICENSE
+
+This program is free software; you can redistribute it and/or modify
+it under the same terms as Perl itself.
+
+=cut
+
+__PACKAGE__->meta->make_immutable(inline_constructor => 0);