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+.\" ========================================================================
+.\"
+.IX Title "Moose::Cookbook::Basics::Recipe1 3"
+.TH Moose::Cookbook::Basics::Recipe1 3 "2009-05-01" "perl v5.8.7" "User Contributed Perl Documentation"
+.SH "NAME"
+Moose::Cookbook::Basics::Recipe1 \- The (always classic) \fBPoint\fR example.
+.SH "SYNOPSIS"
+.IX Header "SYNOPSIS"
+.Vb 2
+\& package Point;
+\& use Moose;
+.Ve
+.PP
+.Vb 2
+\& has 'x' => (isa => 'Int', is => 'rw', required => 1);
+\& has 'y' => (isa => 'Int', is => 'rw', required => 1);
+.Ve
+.PP
+.Vb 5
+\& sub clear {
+\& my $self = shift;
+\& $self\->x(0);
+\& $self\->y(0);
+\& }
+.Ve
+.PP
+.Vb 2
+\& package Point3D;
+\& use Moose;
+.Ve
+.PP
+.Vb 1
+\& extends 'Point';
+.Ve
+.PP
+.Vb 1
+\& has 'z' => (isa => 'Int', is => 'rw', required => 1);
+.Ve
+.PP
+.Vb 4
+\& after 'clear' => sub {
+\& my $self = shift;
+\& $self\->z(0);
+\& };
+.Ve
+.PP
+.Vb 1
+\& package main;
+.Ve
+.PP
+.Vb 3
+\& # hash or hashrefs are ok for the constructor
+\& my $point1 = Point\->new(x => 5, y => 7);
+\& my $point2 = Point\->new({x => 5, y => 7});
+.Ve
+.PP
+.Vb 1
+\& my $point3d = Point3D\->new(x => 5, y => 42, z => \-5);
+.Ve
+.SH "DESCRIPTION"
+.IX Header "DESCRIPTION"
+This is the classic Point example. It is taken directly from the Perl
+6 Apocalypse 12 document, and is similar to the example found in the
+classic K&R C book as well.
+.PP
+As with all Perl 5 classes, a Moose class is defined in a package.
+Moose handles turning on \f(CW\*(C`strict\*(C'\fR and \f(CW\*(C`warnings\*(C'\fR for us, so all we
+need to do is say \f(CW\*(C`use Moose\*(C'\fR, and no kittens will die.
+.PP
+When Moose is loaded, it exports a set of sugar functions into our
+package. This means that we import some functions which serve as Moose
+\&\*(L"keywords\*(R". These aren't real language keywords, they're just Perl
+functions exported into our package.
+.PP
+Moose automatically makes our package a subclass of Moose::Object.
+The Moose::Object class provides us with a constructor that
+respects our attributes, as well other features. See Moose::Object
+for details.
+.PP
+Now, onto the keywords. The first one we see here is \f(CW\*(C`has\*(C'\fR, which
+defines an instance attribute in our class:
+.PP
+.Vb 1
+\& has 'x' => (isa => 'Int', is => 'rw', required => 1);
+.Ve
+.PP
+This will create an attribute named \f(CW\*(C`x\*(C'\fR. The \f(CW\*(C`isa\*(C'\fR parameter says
+that we expect the value stored in this attribute to pass the type
+constraint for \f(CW\*(C`Int\*(C'\fR (1). The accessor generated for this attribute
+will be read\-write.
+.PP
+The \f(CW\*(C`requires => 1\*(C'\fR parameter means that this attribute must be
+provided when a new object is created. A point object without
+coordinates doesn't make much sense, so we don't allow it.
+.PP
+We have defined our attributes; next we define our methods. In Moose,
+as with regular Perl 5 \s-1OO\s0, a method is just a subroutine defined
+within the package:
+.PP
+.Vb 5
+\& sub clear {
+\& my $self = shift;
+\& $self\->x(0);
+\& $self\->y(0);
+\& }
+.Ve
+.PP
+That concludes the \fBPoint\fR class.
+.PP
+Next we have a subclass of \fBPoint\fR, \fBPoint3D\fR. To declare our
+superclass, we use the Moose keyword \f(CW\*(C`extends\*(C'\fR:
+.PP
+.Vb 1
+\& extends 'Point';
+.Ve
+.PP
+The \f(CW\*(C`extends\*(C'\fR keyword works much like \f(CW\*(C`use base\*(C'\fR. First, it will
+attempt to load your class if needed. However, unlike \f(CW\*(C`base\*(C'\fR, the
+\&\f(CW\*(C`extends\*(C'\fR keyword will \fIoverwrite\fR any previous values in your
+package's \f(CW@ISA\fR, where \f(CW\*(C`use base\*(C'\fR will \f(CW\*(C`push\*(C'\fR values onto the
+package's \f(CW@ISA\fR.
+.PP
+It is my opinion that the behavior of \f(CW\*(C`extends\*(C'\fR is more intuitive.
+(2).
+.PP
+Next we create a new attribute for \fBPoint3D\fR called \f(CW\*(C`z\*(C'\fR.
+.PP
+.Vb 1
+\& has 'z' => (isa => 'Int', is => 'rw', required => 1);
+.Ve
+.PP
+This attribute is just like \fBPoint\fR's \f(CW\*(C`x\*(C'\fR and \f(CW\*(C`y\*(C'\fR attributes.
+.PP
+The \f(CW\*(C`after\*(C'\fR keyword demonstrates a Moose feature called \*(L"method
+modifiers\*(R" (or \*(L"advice\*(R" for the \s-1AOP\s0 inclined):
+.PP
+.Vb 4
+\& after 'clear' => sub {
+\& my $self = shift;
+\& $self\->z(0);
+\& };
+.Ve
+.PP
+When \f(CW\*(C`clear\*(C'\fR is called on a \fBPoint3D\fR object, our modifier method
+gets called as well. Unsurprisingly, the modifier is called \fIafter\fR
+the real method.
+.PP
+In this case, the real \f(CW\*(C`clear\*(C'\fR method is inherited from \fBPoint\fR. Our
+modifier method receives the same arguments as those passed to the
+modified method (just \f(CW$self\fR here).
+.PP
+Of course, using the \f(CW\*(C`after\*(C'\fR modifier is not the only way to
+accomplish this. This \fBis\fR Perl, right? You can get the same results
+with this code:
+.PP
+.Vb 5
+\& sub clear {
+\& my $self = shift;
+\& $self\->SUPER::clear();
+\& $self\->z(0);
+\& }
+.Ve
+.PP
+You could also use another Moose method modifier, \f(CW\*(C`override\*(C'\fR:
+.PP
+.Vb 5
+\& override 'clear' => sub {
+\& my $self = shift;
+\& super();
+\& $self\->z(0);
+\& };
+.Ve
+.PP
+The \f(CW\*(C`override\*(C'\fR modifier allows you to use the \f(CW\*(C`super\*(C'\fR keyword to
+dispatch to the superclass's method in a very Ruby-ish style.
+.PP
+The choice of whether to use a method modifier, and which one to use,
+is often a question of style as much as functionality.
+.PP
+Since \fBPoint\fR inherits from Moose::Object, it will also inherit
+the default Moose::Object constructor:
+.PP
+.Vb 2
+\& my $point1 = Point\->new(x => 5, y => 7);
+\& my $point2 = Point\->new({x => 5, y => 7});
+.Ve
+.PP
+.Vb 1
+\& my $point3d = Point3D\->new(x => 5, y => 42, z => \-5);
+.Ve
+.PP
+The \f(CW\*(C`new\*(C'\fR constructor accepts a named argument pair for each
+attribute defined by the class, which you can provide as a hash or
+hash reference. In this particular example, the attributes are
+required, and calling \f(CW\*(C`new\*(C'\fR without them will throw an error.
+.PP
+.Vb 1
+\& my $point = Point\->new( x => 5 ); # no y, kaboom!
+.Ve
+.PP
+From here on, we can use \f(CW$point\fR and \f(CW$point3d\fR just as you would
+any other Perl 5 object. For a more detailed example of what can be
+done, you can refer to the
+\&\fIt/000_recipes/moose_cookbook_basics_recipe1.t\fR test file.
+.Sh "Moose Objects are Just Hashrefs"
+.IX Subsection "Moose Objects are Just Hashrefs"
+While this all may appear rather magical, it's important to realize
+that Moose objects are just hash references under the hood (3). For
+example, you could pass \f(CW$self\fR to \f(CW\*(C`Data::Dumper\*(C'\fR and you'd get
+exactly what you'd expect.
+.PP
+You could even poke around inside the object's data structure, but
+that is strongly discouraged.
+.PP
+The fact that Moose objects are hashrefs means it is easy to use Moose
+to extend non-Moose classes, as long as they too are hash
+references. If you want to extend a non-hashref class, check out
+\&\f(CW\*(C`MooseX::InsideOut\*(C'\fR.
+.SH "CONCLUSION"
+.IX Header "CONCLUSION"
+This recipe demonstrates some basic Moose concepts, attributes,
+subclassing, and a simple method modifier.
+.SH "FOOTNOTES"
+.IX Header "FOOTNOTES"
+.IP "(1)" 4
+.IX Item "(1)"
+Moose provides a number of builtin type constraints are provided by,
+of which \f(CW\*(C`Int\*(C'\fR is one. For more information on the type constraint
+system, see Moose::Util::TypeConstraints.
+.IP "(2)" 4
+.IX Item "(2)"
+The \f(CW\*(C`extends\*(C'\fR keyword support multiple inheritance. Simply pass all
+of your superclasses to \f(CW\*(C`extends\*(C'\fR as a list:
+.Sp
+.Vb 1
+\& extends 'Foo', 'Bar', 'Baz';
+.Ve
+.IP "(3)" 4
+.IX Item "(3)"
+Moose supports using instance structures other than blessed hash
+references (such as in a glob reference \- see
+MooseX::GlobRef::Object).
+.SH "SEE ALSO"
+.IX Header "SEE ALSO"
+.IP "Method Modifiers" 4
+.IX Item "Method Modifiers"
+The concept of method modifiers is directly ripped off from \s-1CLOS\s0. A
+great explanation of them can be found by following this link.
+.Sp
+<http://www.gigamonkeys.com/book/object\-reorientation\-generic\-functions.html>
+.SH "AUTHORS"
+.IX Header "AUTHORS"
+Stevan Little <stevan@iinteractive.com>
+.PP
+Dave Rolsky <autarch@urth.org>
+.SH "COPYRIGHT AND LICENSE"
+.IX Header "COPYRIGHT AND LICENSE"
+Copyright 2006\-2009 by Infinity Interactive, Inc.
+.PP
+<http://www.iinteractive.com>
+.PP
+This library is free software; you can redistribute it and/or modify
+it under the same terms as Perl itself.
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