MooX::Struct - make simple lightweight record-like structures that make sounds like cows
use MooX::Struct Point => [ 'x', 'y' ], Point3D => [ -extends => ['Point'], 'z' ], ; my $origin = Point3D->new( x => 0, y => 0, z => 0 );
MooX::Struct allows you to create cheap struct-like classes for your data using Moo.
While similar in spirit to MooseX::Struct and Class::Struct, MooX::Struct has a somewhat different usage pattern. Rather than providing you with a struct keyword which can be used to define structs, you define all the structs as part of the use statement. This means they happen at compile time.
struct
use
A struct is just an "anonymous" Moo class. MooX::Struct creates this class for you, and installs a lexical alias for it in your namespace. Thus your module can create a "Point3D" struct, and some other module can too, and they won't interfere with each other. All struct classes inherit from MooX::Struct; and MooX::Struct provides a useful method: object_id (see Object::ID).
object_id
Arguments for MooX::Struct are key-value pairs, where keys are the struct names, and values are arrayrefs.
use MooX::Struct Person => [qw/ name address /], Company => [qw/ name address registration_number /];
The elements in the array are the attributes for the struct (which will be created as read-only attributes), however certain array elements are treated specially.
As per the example in the "SYNOPSIS", -extends introduces a list of parent classes for the struct. If not specified, then classes inherit from MooX::Struct itself.
-extends
Structs can inherit from other structs, or from normal classes. If inheriting from another struct, then you must define both in the same use statement.
# Not like this. use MooX::Struct Point => [ 'x', 'y' ]; use MooX::Struct Point3D => [ -extends => ['Point'], 'z' ]; # Like this. use MooX::Struct Point => [ 'x', 'y' ], Point3D => [ -extends => ['Point'], 'z' ], ;
If an attribute name is followed by a coderef, this is installed as a method instead.
use MooX::Struct Person => [ qw( name age sex ), greet => sub { my $self = shift; CORE::say "Hello ", $self->name; }, ];
But if you're defining methods for your structs, then you've possibly missed the point of them.
If an attribute name is followed by an arrayref, these are used to set the options for the attribute. For example:
use MooX::Struct Person => [ name => [ is => 'ro', required => 1 ] ];
Attribute names may be "decorated" with prefix and postfix "sigils". The prefix sigils of @ and % specify that the attribute isa arrayref or hashref respectively. (Blessed arrayrefs and hashrefs are accepted; as are objects which overload @{} and %{}.) The prefix sigil $ specifies that the attribute value must not be an unblessed arrayref or hashref. The postfix sigil ! specifies that the attribute is required.
@
%
@{}
%{}
$
!
use MooX::Struct Person => [qw( $name! @children )]; Person->new(); # dies, name is required Person->new( # dies, children should be arrayref name => 'Bob', children => 2, );
Prior to the key-value list, some additional flags can be given. These begin with hyphens. The flag -rw indicates that attributes should be read-write rather than read-only.
-rw
use MooX::Struct -rw, Person => [ qw( name age sex ), greet => sub { my $self = shift; CORE::say "Hello ", $self->name; }, ];
Flags -trace and -deparse may be of use debugging.
-trace
-deparse
Please report any bugs to http://rt.cpan.org/Dist/Display.html?Queue=MooX-Struct.
Moo, MooseX::Struct, Class::Struct.
Toby Inkster <tobyink@cpan.org>.
This software is copyright (c) 2012 by Toby Inkster.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
To install MooX::Struct, copy and paste the appropriate command in to your terminal.
cpanm
cpanm MooX::Struct
CPAN shell
perl -MCPAN -e shell install MooX::Struct
For more information on module installation, please visit the detailed CPAN module installation guide.