package MooseX::Types::Structured;
-use Moose;
+use 5.008;
use Moose::Util::TypeConstraints;
-use MooseX::Meta::TypeConstraint::Structured::Positional;
-use MooseX::Meta::TypeConstraint::Structured::Named;
+use MooseX::Meta::TypeConstraint::Structured;
+use MooseX::Types -declare => [qw(Dict Tuple Optional)];
-use MooseX::Types -declare => [qw(Dict Tuple Optional)];
- #use Sub::Exporter
- # -setup => { exports => [ qw( Optional) ] };
-
-our $VERSION = '0.01';
+our $VERSION = '0.06';
our $AUTHORITY = 'cpan:JJNAPIORK';
=head1 NAME
-MooseX::Types::Structured; Structured Type Constraints for Moose
+MooseX::Types::Structured - Structured Type Constraints for Moose
=head1 SYNOPSIS
-The following is example usage for this module. You can define a class that has
-an attribute with a structured type like so:
+The following is example usage for this module.
- package MyApp::MyClass;
-
- use Moose;
- use MooseX::Types::Moose qw(Str Int);
- use MooseX::Types::Structured qw(Dict Tuple);
-
- has name => (isa=>Dict[first_name=>Str, last_name=>Str]);
+ package MyApp::MyClass;
+ use Moose;
+ use MooseX::Types::Moose qw(Str Int);
+ use MooseX::Types::Structured qw(Dict Optional);
+
+ ## A name has a first and last part, but middle names are not required
+ has name => (
+ isa=>Dict[
+ first=>Str,
+ last=>Str,
+ middle=>Optional[Str],
+ ],
+ );
+
Then you can instantiate this class with something like:
- my $instance = MyApp::MyClass->new(
- name=>{first_name=>'John', last_name=>'Napiorkowski'},
- );
+ my $john = MyApp::MyClass->new(
+ name => {
+ first=>'John',
+ middle=>'James'
+ last=>'Napiorkowski',
+ },
+ );
+
+Or with:
+
+ my $vanessa = MyApp::MyClass->new(
+ name => {
+ first=>'Vanessa',
+ last=>'Li'
+ },
+ );
+
+But all of these would cause a constraint error for the 'name' attribute:
+
+ MyApp::MyClass->new( name=>'John' );
+ MyApp::MyClass->new( name=>{first_name=>'John'} );
+ MyApp::MyClass->new( name=>{first_name=>'John', age=>39} );
+ MyApp::MyClass->new( name=>{first=>'Vanessa', middle=>[1,2], last=>'Li'} );
+
+Please see the test cases for more examples.
-But all of these would cause an error:
+=head1 DESCRIPTION
- my $instance = MyApp::MyClass->new(name=>'John');
- my $instance = MyApp::MyClass->new(name=>{first_name=>'John'});
- my $instance = MyApp::MyClass->new(name=>{first_name=>'John', age=>39});
+A structured type constraint is a standard container L<Moose> type constraint,
+such as an arrayref or hashref, which has been enhanced to allow you to
+explicitly name all the allow type constraints inside the structure. The
+generalized form is:
-Please see the test cases for more examples.
+ TypeConstraint[@TypeParameters|%TypeParameters]
-=head1 DESCRIPTION
+Where 'TypeParameters' is an array or hash of L<Moose::Meta::TypeConstraint>.
-This type library enables structured type constraints. Basically, this is very
-similar to parameterized constraints that are built into the core Moose types,
-except that you are allowed to define the container's entire structure. For
-example, you could define a parameterized constraint like so:
+This type library enables structured type constraints. It is built on top of the
+L<MooseX::Types> library system, so you should review the documentation for that
+if you are not familiar with it.
- subtype HashOfInts, as Hashref[Int];
+=head2 Comparing Parameterized types to Structured types
-which would constraint a value to something like [1,2,3,...] and so one. A
-structured constraint like so:
+Parameterized constraints are built into core Moose and you are probably already
+familuar with the type constraints 'HashRef' and 'ArrayRef'. Structured types
+have similar functionality, so their syntax is likewise similar. For example,
+you could define a parameterized constraint like:
- subtype StringFollowedByInt, as Tuple[Str,Int];
+ subtype ArrayOfInts,
+ as Arrayref[Int];
+
+which would constraint a value to something like [1,2,3,...] and so on. On the
+other hand, a structured type constraint explicitly names all it's allowed
+'internal' type parameter constraints. For the example:
+
+ subtype StringFollowedByInt,
+ as Tuple[Str,Int];
-would constrain it's value to something like ['hello', 111];
+would constrain it's value to something like ['hello', 111] but ['hello', 'world']
+would fail, as well as ['hello', 111, 'world'] and so on. Here's another
+example:
+
+ subtype StringIntOptionalHashRef,
+ as Tuple[
+ Str, Int,
+ Optional[HashRef]
+ ];
+
+This defines a type constraint that validates values like:
+
+ ['Hello', 100, {key1=>'value1', key2=>'value2'}];
+ ['World', 200];
+
+Notice that the last type constraint in the structure is optional. This is
+enabled via the helper Optional type constraint, which is a variation of the
+core Moose type constraint Maybe. The main difference is that Optional type
+constraints are required to validate if they exist, while Maybe permits undefined
+values. So the following example would not validate:
+
+ StringIntOptionalHashRef->validate(['Hello Undefined', 1000, undef]);
+
+Please note the subtle difference between undefined and null. If you wish to
+allow both null and undefined, you should use the core Moose Maybe type constraint
+instead:
+
+ use MooseX::Types -declare [qw(StringIntOptionalHashRef)];
+ use MooseX::Types::Moose qw(Maybe);
+ use MooseX::Types::Structured qw(Tuple);
+
+ subtype StringIntOptionalHashRef,
+ as Tuple[
+ Str, Int, Maybe[HashRef]
+ ];
+
+This would validate the following:
+
+ ['Hello', 100, {key1=>'value1', key2=>'value2'}];
+ ['World', 200, undef];
+ ['World', 200];
+
+Structured Constraints are not limited to arrays. You can define a structure
+against a hashref with 'Dict' as in this example:
+
+ subtype FirstNameLastName,
+ as Dict[firstname=>Str, lastname=>Str];
+
+This would constrain a hashref to something like:
+
+ {firstname=>'Vanessa', lastname=>'Li'};
+
+but all the following would fail validation:
+
+ {first=>'Vanessa', last=>'Li'};
+ {firstname=>'Vanessa', lastname=>'Li', middlename=>'NA'};
+ ['Vanessa', 'Li'];
These structures can be as simple or elaborate as you wish. You can even
combine various structured, parameterized and simple constraints all together:
- subtype crazy, as Tuple[Int, Dict[name=>Str, age=>Int], ArrayRef[Int]];
+ subtype crazy,
+ as Tuple[
+ Int,
+ Dict[name=>Str, age=>Int],
+ ArrayRef[Int]
+ ];
-Which would match "[1, {name=>'John', age=>25},[10,11,12]]".
+Which would match "[1, {name=>'John', age=>25},[10,11,12]]". Please notice how
+the type parameters can be visually arranged to your liking and to improve the
+clarity of your meaning. You don't need to run then altogether onto a single
+line.
+
+=head2 Alternatives
You should exercise some care as to whether or not your complex structured
constraints would be better off contained by a real object as in the following
example:
- {
- package MyApp::MyStruct;
- use Moose;
-
- has $_ for qw(name age);
-
- package MyApp::MyClass;
- use Moose;
-
- has person => (isa=>'MyApp::MyStruct');
- }
-
- my $instance = MyApp::MyClass
- ->new( person=>MyApp::MyStruct->new(name=>'John', age=>39) );
+ package MyApp::MyStruct;
+ use Moose;
+
+ has $_ for qw(full_name age_in_years);
+
+ package MyApp::MyClass;
+ use Moose;
+
+ has person => (isa=>'MyApp::MyStruct');
+
+ my $instance = MyApp::MyClass->new(
+ person=>MyApp::MyStruct->new(full_name=>'John', age_in_years=>39),
+ );
This method may take some additional time to setup but will give you more
flexibility. However, structured constraints are highly compatible with this
method, granting some interesting possibilities for coercion. Try:
- subtype 'MyStruct',
- as 'MyApp::MyStruct';
+ use MyApp::MyStruct;
+ use MooseX::Types::DateTime qw(DateTime);
+ use MooseX::Types -declare [qw(MyStruct)];
+ use MooseX::Types::Moose qw(Str Int);
+ use MooseX::Types::Structured qw(Dict);
+
+ ## Use class_type to create an ISA type constraint if your object doesn't
+ ## inherit from Moose::Object.
+ class_type 'MyApp::MyStruct';
+
+ ## Just a shorter version really.
+ subtype MyStruct,
+ as 'MyApp::MyStruct';
+
+ ## Add the coercions.
+ coerce MyStruct,
+ from Dict[
+ full_name=>Str,
+ age_in_years=>Int
+ ], via {
+ MyApp::MyStruct->new(%$_);
+ },
+ from Dict[
+ lastname=>Str,
+ firstname=>Str,
+ dob=>DateTime
+ ], via {
+ my $name = $_->{firstname} .' '. $_->{lastname};
+ my $age = DateTime->now - $_->{dob};
+ MyApp::MyStruct->new( full_name=>$name, age_in_years=>$age->years );
+ };
+
+If you are not familiar with how coercions work, check out the L<Moose> cookbook
+entry L<Moose::Cookbook::Recipe5> for an explanation. The section L</Coercions>
+has additional examples and discussion.
+
+=head2 Subtyping a Structured type constraint
+
+You need to exercise some care when you try to subtype a structured type
+as in this example:
+
+ subtype Person,
+ as Dict[name=>Str, age=>Int];
- coerce 'MyStruct',
- from (Dict[name=>Str, age=>Int]),
- via {
- MyApp::MyStruct->new(%$_);
- },
- from (Dict[last_name=>Str, first_name=>Str, dob=>DateTime]),
- via {
- my $name = _->{first_name} .' '. $_->{last_name};
- my $age = $_->{dob} - DateTime->now;
- MyApp::MyStruct->new(
- name=>$name,
- age=>$age->years );
- };
-
+ subtype FriendlyPerson,
+ as Person[name=>Str, age=>Int, totalFriends=>Int];
+
+This will actually work BUT you have to take care that the subtype has a
+structure that does not contradict the structure of it's parent. For now the
+above works, but I will clarify the syntax for this at a future point, so
+it's recommended to avoid (should not really be needed so much anyway). For
+now this is supported in an EXPERIMENTAL way. Your thoughts, test cases and
+patches are welcomed for discussion.
-=head1 TYPES
+=head2 Coercions
-This class defines the following types and subtypes.
+Coercions currently work for 'one level' deep. That is you can do:
-=cut
+ subtype Person,
+ as Dict[name=>Str, age=>Int];
+
+ subtype Fullname,
+ as Dict[first=>Str, last=>Str];
+
+ coerce Person,
+ ## Coerce an object of a particular class
+ from BlessedPersonObject,
+ via { +{name=>$_->name, age=>$_->age} },
+ ## Coerce from [$name, $age]
+ from ArrayRef,
+ via { +{name=>$_->[0], age=>$_->[1] },
+ ## Coerce from {fullname=>{first=>...,last=>...}, dob=>$DateTimeObject}
+ from Dict[fullname=>Fullname, dob=>DateTime],
+ via {
+ my $age = $_->dob - DateTime->now;
+ +{
+ name=> $_->{fullname}->{first} .' '. $_->{fullname}->{last},
+ age=>$age->years
+ }
+ };
+
+And that should just work as expected. However, if there are any 'inner'
+coercions, such as a coercion on 'Fullname' or on 'DateTime', that coercion
+won't currently get activated.
-use MooseX::Meta::TypeConstraint::Structured::Positionable;
+Please see the test '07-coerce.t' for a more detailed example. Discussion on
+extending coercions to support this welcome on the Moose development channel or
+mailing list.
-my $tuple = MooseX::Meta::TypeConstraint::Structured::Positionable->new(
- name => 'Tuple',
- package_defined_in => __PACKAGE__,
- parent => find_type_constraint('Ref'),
- );
+=head1 TYPE CONSTRAINTS
-Moose::Util::TypeConstraints::register_type_constraint($tuple);
+This type library defines the following constraints.
-subtype Tuple, as 'Tuple';
+=head2 Tuple[@constraints]
+This defines an arrayref based constraint which allows you to validate a specific
+list of constraints. For example:
-sub Optional($) {
- return bless {args=>shift}, 'MooseX::Types::Optional';
-}
+ Tuple[Int,Str]; ## Validates [1,'hello']
+ Tuple[Str|Object, Int]; ##Validates ['hello', 1] or [$object, 2]
-sub TupleX($) {
- my ($args, $optional) = _normalize_args(@_);
- my @args = @$args;
- my @optional = ref $optional eq 'ARRAY' ? @$optional : ();
+=head2 Dict[%constraints]
- return MooseX::Meta::TypeConstraint::Structured::Positional->new(
- name => 'Tuple',
- parent => find_type_constraint('ArrayRef'),
- package_defined_in => __PACKAGE__,
- signature => [map {
- _normalize_type_constraint($_);
- } @args],
- optional_signature => [map {
- _normalize_type_constraint($_);
- } @optional],
- );
-}
+This defines a hashref based constraint which allowed you to validate a specific
+hashref. For example:
-sub DictX($) {
- my ($args, $optional) = _normalize_args(@_);
- my %args = @$args;
- my %optional = ref $optional eq 'ARRAY' ? @$optional : ();
-
- return MooseX::Meta::TypeConstraint::Structured::Named->new(
- name => 'Dict',
- parent => find_type_constraint('HashRef'),
- package_defined_in => __PACKAGE__,
- signature => {map {
- $_ => _normalize_type_constraint($args{$_});
- } keys %args},
- optional_signature => {map {
- $_ => _normalize_type_constraint($optional{$_});
- } keys %optional},
- );
-}
+ Dict[name=>Str, age=>Int]; ## Validates {name=>'John', age=>39}
-sub _normalize_args {
- my $args = shift @_;
- confess "Structured Type Constraints can only accept an ArrayRef as arguments"
- unless ref $args eq 'ARRAY';
-
- my @args = @$args;
- my $last = pop @args;
+=head2 Optional[$constraint]
+
+This is primarily a helper constraint for Dict and Tuple type constraints. What
+this allows if for you to assert that a given type constraint is allowed to be
+null (but NOT undefined). If the value is null, then the type constraint passes
+but if the value is defined it must validate against the type constraint. This
+makes it easy to make a Dict where one or more of the keys doesn't have to exist
+or a tuple where some of the values are not required. For example:
+
+ subtype Name() => as Dict[
+ first=>Str,
+ last=>Str,
+ middle=>Optional[Str],
+ ];
+
+Creates a constraint that validates against a hashref with the keys 'first' and
+'last' being strings and required while an optional key 'middle' is must be a
+string if it appears but doesn't have to appear. So in this case both the
+following are valid:
+
+ {first=>'John', middle=>'James', last=>'Napiorkowski'}
+ {first=>'Vanessa', last=>'Li'}
- if(blessed $last && $last->isa('MooseX::Types::Optional')) {
- return ([@args], $last->{args});
- } else {
- return ([@args, $last]);
- }
+=head1 EXAMPLES
+
+Here are some additional example usage for structured types. All examples can
+be found also in the 't/examples.t' test. Your contributions are also welcomed.
+
+=head2 Normalize a HashRef
+
+You need a hashref to conform to a canonical structure but are required accept a
+bunch of different incoming structures. You can normalize using the Dict type
+constraint and coercions. This example also shows structured types mixed which
+other MooseX::Types libraries.
+
+ package Test::MooseX::Meta::TypeConstraint::Structured::Examples::Normalize;
-}
-sub _normalize_type_constraint {
- my $tc = shift @_;
+ use Moose;
+ use DateTime;
+
+ use MooseX::Types::Structured qw(Dict Tuple);
+ use MooseX::Types::DateTime qw(DateTime);
+ use MooseX::Types::Moose qw(Int Str Object);
+ use MooseX::Types -declare => [qw(Name Age Person)];
+
+ subtype Person,
+ as Dict[name=>Str, age=>Int];
+
+ coerce Person,
+ from Dict[first=>Str, last=>Str, years=>Int],
+ via { +{
+ name => "$_->{first} $_->{last}",
+ age=>$_->{years},
+ }},
+ from Dict[fullname=>Dict[last=>Str, first=>Str], dob=>DateTime],
+ via { +{
+ name => "$_->{fullname}{first} $_->{fullname}{last}",
+ age => ($_->{dob} - 'DateTime'->now)->years,
+ }};
+
+ has person => (is=>'rw', isa=>Person, coerce=>1);
+
+=cut
+
+Moose::Util::TypeConstraints::get_type_constraint_registry->add_type_constraint(
+ MooseX::Meta::TypeConstraint::Structured->new(
+ name => "MooseX::Types::Structured::Tuple" ,
+ parent => find_type_constraint('ArrayRef'),
+ constraint_generator=> sub {
+ ## Get the constraints and values to check
+ my ($type_constraints, $values) = @_;
+ my @type_constraints = defined $type_constraints ? @$type_constraints: ();
+ my @values = defined $values ? @$values: ();
+ ## Perform the checking
+ while(@type_constraints) {
+ my $type_constraint = shift @type_constraints;
+ if(@values) {
+ my $value = shift @values;
+ unless($type_constraint->check($value)) {
+ return;
+ }
+ } else {
+ unless($type_constraint->check()) {
+ return;
+ }
+ }
+ }
+ ## Make sure there are no leftovers.
+ if(@values) {
+ return;
+ } elsif(@type_constraints) {
+ return;
+ }else {
+ return 1;
+ }
+ }
+ )
+);
- ## If incoming is an object, we will assume it's something that implements
- ## what a type constraint is. We should probably have a Role for this...
- if(defined $tc && blessed $tc) {
- return $tc;
- } elsif($tc) {
- return Moose::Util::TypeConstraints::find_or_parse_type_constraint($tc);
- }
+Moose::Util::TypeConstraints::get_type_constraint_registry->add_type_constraint(
+ MooseX::Meta::TypeConstraint::Structured->new(
+ name => "MooseX::Types::Structured::Dict",
+ parent => find_type_constraint('HashRef'),
+ constraint_generator=> sub {
+ ## Get the constraints and values to check
+ my ($type_constraints, $values) = @_;
+ my %type_constraints = defined $type_constraints ? @$type_constraints: ();
+ my %values = defined $values ? %$values: ();
+ ## Perform the checking
+ while(%type_constraints) {
+ my($key, $type_constraint) = each %type_constraints;
+ delete $type_constraints{$key};
+ if(exists $values{$key}) {
+ my $value = $values{$key};
+ delete $values{$key};
+ unless($type_constraint->check($value)) {
+ return;
+ }
+ } else {
+ unless($type_constraint->check()) {
+ return;
+ }
+ }
+ }
+ ## Make sure there are no leftovers.
+ if(%values) {
+ return;
+ } elsif(%type_constraints) {
+ return;
+ }else {
+ return 1;
+ }
+ },
+ )
+);
+
+OPTIONAL: {
+ my $Optional = Moose::Meta::TypeConstraint::Parameterizable->new(
+ name => 'MooseX::Types::Structured::Optional',
+ package_defined_in => __PACKAGE__,
+ parent => find_type_constraint('Item'),
+ constraint => sub { 1 },
+ constraint_generator => sub {
+ my ($type_parameter, @args) = @_;
+ my $check = $type_parameter->_compiled_type_constraint();
+ return sub {
+ my (@args) = @_;
+ if(exists($args[0])) {
+ ## If it exists, we need to validate it
+ $check->($args[0]);
+ } else {
+ ## But it's is okay if the value doesn't exists
+ return 1;
+ }
+ }
+ }
+ );
+
+ Moose::Util::TypeConstraints::register_type_constraint($Optional);
+ Moose::Util::TypeConstraints::add_parameterizable_type($Optional);
}
+
=head1 SEE ALSO
The following modules or resources may be of interest.
-L<Moose>, L<MooseX::TypeLibrary>, L<Moose::Meta::TypeConstraint>
+L<Moose>, L<MooseX::Types>, L<Moose::Meta::TypeConstraint>,
+L<MooseX::Meta::TypeConstraint::Structured>
-=head1 BUGS
+=head1 TODO
-No known or reported bugs.
+Need to clarify deep coercions, need to clarify subtypes of subtypes.
=head1 AUTHOR
it under the same terms as Perl itself.
=cut
-
-1;
\ No newline at end of file
+
+1;
projects / gitmo/MooseX-Types-Structured.git / blobdiff