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] | $_[1]",
- );
- },
-
- fallback => 1;
-
-use Carp ();
-
sub new {
- my($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",
+ );
+ }
+ else {
+ $type_parameter = undef;
+ }
+ }
+ }
- if($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'){
- Carp::confess("Constraint for $args{name} is not a CODE reference");
+ $class->throw_error(
+ "Constraint for $args{name} is not a CODE reference");
}
- $args{package_defined_in} ||= caller;
-
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};
+
+ if($args{type_constraints}) { # union types
+ foreach my $type(@{$self->{type_constraints}}){
+ if($type->has_coercion){
+ # set undef for has_coercion()
+ $self->{_compiled_type_coercion} = undef;
+ last;
+ }
+ }
+ }
- $self->_compile_union_type_coercion() if $self->{type_constraints};
return $self;
}
-sub create_child_type{
+sub create_child_type {
my $self = shift;
- # XXX: FIXME
- return ref($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 => $self);
}
sub name;
sub message;
sub has_coercion;
+sub check;
+
sub type_parameter;
sub __is_parameterized;
sub compile_type_constraint;
-sub _add_type_coercions{
+
+sub _add_type_coercions { # ($self, @pairs)
my $self = shift;
- my $coercions = ($self->{_coercion_map} ||= []);
- my %has = map{ $_->[0] => undef } @{$coercions};
+ if(exists $self->{type_constraints}){ # union type
+ $self->throw_error(
+ "Cannot add additional type coercions to Union types '$self'");
+ }
+
+ my $coercion_map = ($self->{coercion_map} ||= []);
+ my %has = map{ $_->[0]->name => undef } @{$coercion_map};
for(my $i = 0; $i < @_; $i++){
my $from = $_[ $i];
my $action = $_[++$i];
if(exists $has{$from}){
- Carp::confess("A coercion action already exists for '$from'");
+ $self->throw_error("A coercion action already exists for '$from'");
}
my $type = Mouse::Util::TypeConstraints::find_or_parse_type_constraint($from)
- or Carp::confess("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 => $action ];
+ push @{$coercion_map}, [ $type => $action ];
}
- # compile
- if(exists $self->{type_constraints}){ # union type
- Carp::confess("Cannot add additional type coercions to Union types");
- }
- else{
- $self->_compile_type_coercion();
- }
+ $self->{_compiled_type_coercion} = undef;
return;
}
-sub _compile_type_coercion {
+sub _compiled_type_coercion {
my($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;
-}
+ my $coercion = $self->{_compiled_type_coercion};
+ return $coercion if defined $coercion;
-sub _compile_union_type_coercion {
- my($self) = @_;
-
- my @coercions;
- foreach my $type(@{$self->{type_constraints}}){
- if($type->has_coercion){
- push @coercions, $type;
+ if(!$self->{type_constraints}) {
+ my @coercions;
+ foreach my $pair(@{$self->{coercion_map}}) {
+ push @coercions,
+ [ $pair->[0]->_compiled_type_constraint, $pair->[1] ];
}
+
+ $coercion = sub {
+ my($thing) = @_;
+ foreach my $pair (@coercions) {
+ #my ($constraint, $converter) = @$pair;
+ if ($pair->[0]->($thing)) {
+ local $_ = $thing;
+ return $pair->[1]->($thing);
+ }
+ }
+ return $thing;
+ };
}
- if(@coercions){
- $self->{_compiled_type_coercion} = sub {
- my($thing) = @_;
- foreach my $type(@coercions){
- my $value = $type->coerce($thing);
- return $value if $self->check($value);
+ else { # for union type
+ my @coercions;
+ foreach my $type(@{$self->{type_constraints}}){
+ if($type->has_coercion){
+ push @coercions, $type;
}
- return $thing;
- };
+ }
+ if(@coercions){
+ $coercion = sub {
+ my($thing) = @_;
+ foreach my $type(@coercions){
+ my $value = $type->coerce($thing);
+ return $value if $self->check($value);
+ }
+ return $thing;
+ };
+ }
}
- return;
-}
-sub check {
- my $self = shift;
- return $self->_compiled_type_constraint->(@_);
+ return( $self->{_compiled_type_coercion} = $coercion );
}
sub coerce {
my $self = shift;
+ return $_[0] if $self->check(@_);
- my $coercion = $self->_compiled_type_coercion;
- if(!$coercion){
- Carp::confess("Cannot coerce without a type coercion");
- }
-
- return $_[0] if $self->_compiled_type_constraint->(@_);
-
+ my $coercion = $self->_compiled_type_coercion
+ or $self->throw_error("Cannot coerce without a type coercion");
return $coercion->(@_);
}
return $msg->($value);
}
else {
- $value = ( defined $value ? overload::StrVal($value) : 'undef' );
- return "Validation failed for '$self' 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 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){
}
$name ||= sprintf '%s[%s]', $self->name, $param->name;
-
- my $generator = $self->{constraint_generator}
- || Carp::confess("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'
-
- type => 'Parameterized',
);
}
sub assert_valid {
my ($self, $value) = @_;
- if(!$self->_compiled_type_constraint->($value)){
- Carp::confess($self->get_message($value));
+ if(!$self->check($value)){
+ $self->throw_error($self->get_message($value));
}
return 1;
}
+# overloading stuff
+
+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_create_union_type(
+ $lhs,
+ Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($rhs),
+ );
+}
+
1;
__END__
=head1 VERSION
-This document describes Mouse version 0.50_01
+This document describes Mouse version 0.95
=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
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