X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FMouse%2FMeta%2FTypeConstraint.pm;h=284e9cc4e5fa89a658a572f1289d6c583770890f;hb=refs%2Ftags%2F0.81;hp=cfc1aed4ea0ac0b4bbfc3ad15e6727152f2929b1;hpb=5c26929eb451b1545366943d5dd330bcd6fe140d;p=gitmo%2FMouse.git

diff --git a/lib/Mouse/Meta/TypeConstraint.pm b/lib/Mouse/Meta/TypeConstraint.pm
index cfc1aed..284e9cc 100644
--- a/lib/Mouse/Meta/TypeConstraint.pm
+++ b/lib/Mouse/Meta/TypeConstraint.pm
@@ -1,71 +1,154 @@
 package Mouse::Meta::TypeConstraint;
-use strict;
-use warnings;
-
-use overload
-    '""'     => sub { shift->{name} },   # stringify to tc name
-    fallback => 1;
-
-use Carp qw(confess);
-use Scalar::Util qw(blessed reftype);
-
-use Mouse::Util qw(:meta);
-
-my $null_check = sub { 1 };
+use Mouse::Util qw(:meta); # enables strict and warnings
 
 sub new {
-    my($class, %args) = @_;
+    my $class = shift;
+    my %args  = @_ == 1 ? %{$_[0]} : @_;
 
     $args{name} = '__ANON__' if !defined $args{name};
 
-    my $check = $args{_compiled_type_constraint} || $args{constraint};
+    if(defined $args{parent}) {
+        %args = (%{$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};
+        delete $args{hand_optimized_type_constraint};
+        if(defined(my $parent_tp = $args{parent}{type_parameter})) {
+            delete $args{type_parameter} if $parent_tp == $args{type_parameter};
+        }
+    }
+
+    my $check;
 
-    if(blessed($check)){
-        Carp::cluck("'constraint' must be a CODE reference");
-        $check = $check->{_compiled_type_constraint};
+    if($check = delete $args{optimized}) {
+        $args{hand_optimized_type_constraint} = $check;
+        $args{compiled_type_constraint}       = $check;
+    }
+    elsif(my $param = $args{type_parameter}) {
+        my $generator = $args{constraint_generator}
+            || $class->throw_error("The $args{name} constraint cannot be used,"
+                . " because $param doesn't subtype from a parameterizable type");
+        # it must be 'constraint'
+        $check = $args{constraint} = $generator->($param);
+    }
+    else {
+        $check = $args{constraint};
     }
 
     if(defined($check) && ref($check) ne 'CODE'){
-        confess("Type 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->{_compiled_type_constraint} ||= $self->_compile();
+    $self->compile_type_constraint()
+        if !$args{hand_optimized_type_constraint};
 
+    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(@_, parent => $self);
 }
 
-sub name    { $_[0]->{name}    }
-sub parent  { $_[0]->{parent}  }
-sub message { $_[0]->{message} }
+sub name;
+sub parent;
+sub message;
+sub has_coercion;
+
+sub check;
+
+sub type_parameter;
+sub __is_parameterized;
+
+sub _compiled_type_constraint;
+sub _compiled_type_coercion;
+
+sub compile_type_constraint;
 
-sub check {
+
+sub _add_type_coercions { # ($self, @pairs)
     my $self = shift;
-    $self->{_compiled_type_constraint}->(@_);
-}
 
-sub validate {
-    my ($self, $value) = @_;
-    if ($self->{_compiled_type_constraint}->($value)) {
-        return undef;
+    if(exists $self->{type_constraints}){ # union type
+        $self->throw_error(
+            "Cannot add additional type coercions to Union types '$self'");
     }
-    else {
-        $self->get_message($value);
+
+    my $coercions = ($self->{coercion_map} ||= []);
+    my %has       = map{ $_->[0] => undef } @{$coercions};
+
+    for(my $i = 0; $i < @_; $i++){
+        my $from   = $_[  $i];
+        my $action = $_[++$i];
+
+        if(exists $has{$from}){
+            $self->throw_error("A coercion action already exists for '$from'");
+        }
+
+        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");
+
+        push @{$coercions}, [ $type => $action ];
     }
+
+    $self->_compile_type_coercion();
+    return;
 }
 
-sub assert_valid {
-    my ($self, $value) = @_;
+sub _compile_type_coercion {
+    my($self) = @_;
+
+    my @coercions = @{$self->{coercion_map}};
+
+    $self->{_compiled_type_coercion} = sub {
+       my($thing) = @_;
+       foreach my $pair (@coercions) {
+            #my ($constraint, $converter) = @$pair;
+            if ($pair->[0]->check($thing)) {
+              local $_ = $thing;
+              return $pair->[1]->($thing);
+            }
+       }
+       return $thing;
+    };
+    return;
+}
+
+sub _compile_union_type_coercion {
+    my($self) = @_;
+
+    my @coercions;
+    foreach my $type(@{$self->{type_constraints}}){
+        if($type->has_coercion){
+            push @coercions, $type;
+        }
+    }
+    if(@coercions){
+        $self->{_compiled_type_coercion} = sub {
+            my($thing) = @_;
+            foreach my $type(@coercions){
+                my $value = $type->coerce($thing);
+                return $value if $self->check($value);
+            }
+            return $thing;
+        };
+    }
+    return;
+}
 
-    my $error = $self->validate($value);
-    return 1 if ! defined $error;
+sub coerce {
+    my $self = shift;
+    return $_[0] if $self->check(@_);
 
-    confess($error);
+    my $coercion = $self->{_compiled_type_coercion}
+        or $self->throw_error("Cannot coerce without a type coercion");
+    return  $coercion->(@_);
 }
 
 sub get_message {
@@ -75,78 +158,74 @@ sub get_message {
         return $msg->($value);
     }
     else {
-        $value = ( defined $value ? overload::StrVal($value) : 'undef' );
-        return
-            "Validation failed for '"
-          . $self->name
-          . "' failed with value $value";
+        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
-    return 0 if !blessed($other) && $other eq '__ANON__';
+    return 0 if !ref($other) && $other eq '__ANON__';
 
     (my $other_name = $other) =~ s/\s+//g;
 
     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;
 }
 
-sub _compile{
-    my($self) = @_;
+# See also Moose::Meta::TypeConstraint::Parameterizable
+sub parameterize {
+    my($self, $param, $name) = @_;
 
-    # add parents first
-    my @checks;
-    for(my $parent = $self->parent; defined $parent; $parent = $parent->parent){
-        if($parent->{constraint}){
-            push @checks, $parent->{constraint};
-         }
-         elsif($parent->{_compiled_type_constraint} && $parent->{_compiled_type_constraint} != $null_check){
-            # hand-optimized constraint
-            push @checks, $parent->{_compiled_type_constraint};
-            last;
-        }
-    }
-    # then add child
-    if($self->{constraint}){
-        push @checks, $self->{constraint};
+    if(!ref $param){
+        require Mouse::Util::TypeConstraints;
+        $param = Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($param);
     }
 
-    if(@checks == 0){
-        return $null_check;
-    }
-    elsif(@checks == 1){
-        my $c = $checks[0];
-        return sub{
-            my(@args) = @_;
-            local $_ = $args[0];
-            return $c->(@args);
-        };
-    }
-    else{
-        return sub{
-            my(@args) = @_;
-            local $_ = $args[0];
-            foreach my $c(@checks){
-                return undef if !$c->(@args);
-            }
-            return 1;
-        };
+    $name ||= sprintf '%s[%s]', $self->name, $param->name;
+    return Mouse::Meta::TypeConstraint->new(
+        name           => $name,
+        parent         => $self,
+        type_parameter => $param,
+    );
+}
+
+sub assert_valid {
+    my ($self, $value) = @_;
+
+    if(!$self->check($value)){
+        $self->throw_error($self->get_message($value));
     }
+    return 1;
+}
+
+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;
@@ -156,23 +235,44 @@ __END__
 
 Mouse::Meta::TypeConstraint - The Mouse Type Constraint metaclass
 
-=head1 DESCRIPTION
+=head1 VERSION
+
+This document describes Mouse version 0.81
 
-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.
+=head1 DESCRIPTION
 
-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<< $constraint->is_a_subtype_of($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