X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=gitmo%2FMouse.git;a=blobdiff_plain;f=lib%2FMouse%2FMeta%2FTypeConstraint.pm;h=aa4e9fc292343f753f5e0f99e115b2606269b4b8;hp=3aa4592ff8cd67310ea01f7ebf6fc65463fe6b0f;hb=eed39dffe505fa8df062e315c23c1fbe36f9c95b;hpb=913b59645bf5e7f16128c0e20711090a43676096

diff --git a/lib/Mouse/Meta/TypeConstraint.pm b/lib/Mouse/Meta/TypeConstraint.pm
index 3aa4592..aa4e9fc 100644
--- a/lib/Mouse/Meta/TypeConstraint.pm
+++ b/lib/Mouse/Meta/TypeConstraint.pm
@@ -1,59 +1,78 @@
 package Mouse::Meta::TypeConstraint;
 use Mouse::Util qw(:meta); # enables strict and warnings
 
-use overload
-    'bool'   => sub (){ 1 },           # always true
-    '""'     => sub { $_[0]->name },   # stringify to tc name
-    '|'      => sub {                  # or-combination
-        require Mouse::Util::TypeConstraints;
-        return Mouse::Util::TypeConstraints::find_or_parse_type_constraint(
-            "$_[0] | $_[1]",
-        );
-    },
-
-    fallback => 1;
-
 sub new {
-    my($class, %args) = @_;
+    my $class = shift;
+    my %args  = @_ == 1 ? %{$_[0]} : @_;
 
     $args{name} = '__ANON__' if !defined $args{name};
 
-    my $check = delete $args{optimized};
+    my $type_parameter;
+    if(defined $args{parent}) { # subtyping
+        %args = (%{$args{parent}}, %args);
+
+        # a child type must not inherit 'compiled_type_constraint'
+        # and 'hand_optimized_type_constraint' from the parent
+        delete $args{compiled_type_constraint};       # don't inherit it
+        delete $args{hand_optimized_type_constraint}; # don't inherit it
+
+        $type_parameter = $args{type_parameter};
+        if(defined(my $parent_tp = $args{parent}{type_parameter})) {
+            if($parent_tp != $type_parameter) {
+                $type_parameter->is_a_type_of($parent_tp)
+                    or $class->throw_error(
+                        "$type_parameter is not a subtype of $parent_tp",
+                    );
+            }
+        }
+    }
 
-    if($check){
+    my $check;
+
+    if($check = delete $args{optimized}) { # likely to be builtins
         $args{hand_optimized_type_constraint} = $check;
         $args{compiled_type_constraint}       = $check;
     }
-
-    $check = $args{constraint};
+    elsif(defined $type_parameter) { # parameterizing
+        my $generator = $args{constraint_generator}
+            || $class->throw_error(
+                  "The $args{name} constraint cannot be used,"
+                . " because $type_parameter doesn't subtype"
+                . " from a parameterizable type");
+
+        my $parameterized_check = $generator->($type_parameter);
+        if(defined(my $my_check = $args{constraint})) {
+            $check = sub {
+                return $parameterized_check->($_) && $my_check->($_);
+            };
+        }
+        else {
+            $check = $parameterized_check;
+        }
+        $args{constraint} = $check;
+    }
+    else { # common cases
+        $check = $args{constraint};
+    }
 
     if(defined($check) && ref($check) ne 'CODE'){
-        $class->throw_error("Constraint for $args{name} is not a CODE reference");
+        $class->throw_error(
+            "Constraint for $args{name} is not a CODE reference");
     }
 
     my $self = bless \%args, $class;
-    $self->compile_type_constraint() if !$self->{hand_optimized_type_constraint};
+    $self->compile_type_constraint()
+        if !$args{hand_optimized_type_constraint};
 
-    $self->_compile_union_type_coercion() if $self->{type_constraints};
+    if($args{type_constraints}) {
+        $self->_compile_union_type_coercion();
+    }
     return $self;
 }
 
-sub create_child_type{
+sub create_child_type {
     my $self = shift;
-    return ref($self)->new(
-        # a child inherits its parent's attributes
-        %{$self},
-
-        # but does not inherit 'compiled_type_constraint' and 'hand_optimized_type_constraint'
-        compiled_type_constraint       => undef,
-        hand_optimized_type_constraint => undef,
-
-        # and is given child-specific args, of course.
-        @_,
-
-        # and its parent
-        parent => $self,
-   );
+    return ref($self)->new(@_, parent => $self);
 }
 
 sub name;
@@ -72,9 +91,14 @@ sub _compiled_type_coercion;
 sub compile_type_constraint;
 
 
-sub _add_type_coercions{
+sub _add_type_coercions { # ($self, @pairs)
     my $self = shift;
 
+    if(exists $self->{type_constraints}){ # union type
+        $self->throw_error(
+            "Cannot add additional type coercions to Union types '$self'");
+    }
+
     my $coercions = ($self->{coercion_map} ||= []);
     my %has       = map{ $_->[0] => undef } @{$coercions};
 
@@ -87,18 +111,13 @@ sub _add_type_coercions{
         }
 
         my $type = Mouse::Util::TypeConstraints::find_or_parse_type_constraint($from)
-            or $self->throw_error("Could not find the type constraint ($from) to coerce from");
+            or $self->throw_error(
+                "Could not find the type constraint ($from) to coerce from");
 
         push @{$coercions}, [ $type => $action ];
     }
 
-    # compile
-    if(exists $self->{type_constraints}){ # union type
-        $self->throw_error("Cannot add additional type coercions to Union types");
-    }
-    else{
-        $self->_compile_type_coercion();
-    }
+    $self->_compile_type_coercion();
     return;
 }
 
@@ -145,14 +164,10 @@ sub _compile_union_type_coercion {
 
 sub coerce {
     my $self = shift;
-
-    my $coercion = $self->_compiled_type_coercion;
-    if(!$coercion){
-        $self->throw_error("Cannot coerce without a type coercion");
-    }
-
     return $_[0] if $self->check(@_);
 
+    my $coercion = $self->{_compiled_type_coercion}
+        or $self->throw_error("Cannot coerce without a type coercion");
     return  $coercion->(@_);
 }
 
@@ -163,12 +178,17 @@ sub get_message {
         return $msg->($value);
     }
     else {
-        $value = ( defined $value ? overload::StrVal($value) : 'undef' );
+        if(not defined $value) {
+            $value = 'undef';
+        }
+        elsif( ref($value) && defined(&overload::StrVal) ) {
+            $value = overload::StrVal($value);
+        }
         return "Validation failed for '$self' with value $value";
     }
 }
 
-sub is_a_type_of{
+sub is_a_type_of {
     my($self, $other) = @_;
 
     # ->is_a_type_of('__ANON__') is always false
@@ -179,20 +199,20 @@ sub is_a_type_of{
     return 1 if $self->name eq $other_name;
 
     if(exists $self->{type_constraints}){ # union
-        foreach my $type(@{$self->{type_constraints}}){
+        foreach my $type(@{$self->{type_constraints}}) {
             return 1 if $type->name eq $other_name;
         }
     }
 
-    for(my $parent = $self->parent; defined $parent; $parent = $parent->parent){
-        return 1 if $parent->name eq $other_name;
+    for(my $p = $self->parent; defined $p; $p = $p->parent) {
+        return 1 if $p->name eq $other_name;
     }
 
     return 0;
 }
 
 # See also Moose::Meta::TypeConstraint::Parameterizable
-sub parameterize{
+sub parameterize {
     my($self, $param, $name) = @_;
 
     if(!ref $param){
@@ -201,15 +221,10 @@ sub parameterize{
     }
 
     $name ||= sprintf '%s[%s]', $self->name, $param->name;
-
-    my $generator = $self->{constraint_generator}
-        || $self->throw_error("The $name constraint cannot be used, because $param doesn't subtype from a parameterizable type");
-
     return Mouse::Meta::TypeConstraint->new(
         name           => $name,
         parent         => $self,
         type_parameter => $param,
-        constraint     => $generator->($param), # must be 'constraint', not 'optimized'
     );
 }
 
@@ -222,9 +237,15 @@ sub assert_valid {
     return 1;
 }
 
-sub throw_error {
-    require Mouse::Meta::Module;
-    goto &Mouse::Meta::Module::throw_error;
+sub _as_string { $_[0]->name                  } # overload ""
+sub _identity;                                  # overload 0+
+
+sub _unite { # overload infix:<|>
+    my($lhs, $rhs) = @_;
+    require Mouse::Util::TypeConstraints;
+    return Mouse::Util::TypeConstraints::find_or_parse_type_constraint(
+       " $lhs | $rhs",
+    );
 }
 
 1;
@@ -236,25 +257,42 @@ Mouse::Meta::TypeConstraint - The Mouse Type Constraint metaclass
 
 =head1 VERSION
 
-This document describes Mouse version 0.61
+This document describes Mouse version 0.81
 
 =head1 DESCRIPTION
 
-For the most part, the only time you will ever encounter an
-instance of this class is if you are doing some serious deep
-introspection. This API should not be considered final, but
-it is B<highly unlikely> that this will matter to a regular
-Mouse user.
-
-Don't use this.
+This class represents a type constraint, including built-in
+type constraints, union type constraints, parameterizable/
+parameterized type constraints, as well as custom type
+constraints
 
 =head1 METHODS
 
-=over 4
+=over
+
+=item C<< Mouse::Meta::TypeConstraint->new(%options) >>
+
+=item C<< $constraint->name >>
+
+=item C<< $constraint->parent >>
+
+=item C<< $constraint->constraint >>
+
+=item C<< $constraint->has_coercion >>
+
+=item C<< $constraint->message >>
+
+=item C<< $constraint->is_a_type_of($name or $object) >>
+
+=item C<< $constraint->coerce($value) >>
+
+=item C<< $constraint->check($value) >>
+
+=item C<< $constraint->assert_valid($value) >>
 
-=item B<new>
+=item C<< $constraint->get_message($value) >>
 
-=item B<name>
+=item C<< $constraint->create_child_type(%options) >>
 
 =back