<div id="header"></div>
<div id="footer">
<div id="license">
- <a rel="license" href="http://creativecommons.org/licenses/by-sa/3.0/us/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-sa/3.0/us/88x31.png" /></a>
+ <a rel="license" href="http://creativecommons.org/licenses/by-sa/3.0/us/"><img alt="Creative Commons License" style="border-width:0" src="ui/creative-commons.png" /></a>
<br /><span xmlns:dc="http://purl.org/dc/elements/1.1/" href="http://purl.org/dc/dcmitype/Text" property="dc:title" rel="dc:type">Introduction to Moose</span> by <span xmlns:cc="http://creativecommons.org/ns#" property="cc:attributionName">David Rolsky</span> is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-sa/3.0/us/">Creative Commons Attribution-Share Alike 3.0 United States License</a>.
</div>
<div class="slide">
<h1>Introduction to Moose</h1>
- <h2>YAPC 2009</h2>
+ <h2><a href="git://git.moose.perl.org/moose-presentations.git"><tt>git://git.moose.perl.org/moose-presentations.git</tt></a></h2>
</div>
<div class="slide">
<li>
Attributes have ...
<ul>
- <li>Access-control (read-only vs read-write)</li>
+ <li>Mutability (read-only vs read-write)</li>
<li>An optional type</li>
<li>Accessor methods</li>
<li>Delegation methods</li>
my @return =
$self->$real_foo( @_, bar => 42 );
- return ( @return, 'modify return values' );
+ return (
+ @return,
+ 'modify return values'
+ );
};</code></pre>
</div>
has blog_uri => (
is => 'rw',
isa => 'URI',
- <span class="highlight">handles => { 'blog_hostname' => 'host' },</span>
+ <span class="highlight">handles => { 'blog_host' => 'host' },</span>
);
-<span class="highlight">$person->blog_hostname;</span>
+<span class="highlight">$person->blog_host;</span>
# really calls $person->blog_uri->host</code></pre>
</div>
<ul>
<li>Moose creates <code>new()</code> for you</li>
- <li>Provide an optional <code>BUILDARGS()</code> and <code>BUILD()</code></li>
+ <li>Provide an optional <code>BUIDARGS()</code> and <code>BUILD()</code></li>
</ul>
</div>
sub BUILDARGS {
my $class = shift;
- if ( @_ == 1 && ! ref $_[0] ) {
+ if ( @_ == 1 && ! ref $_[0] ) {
<span class="highlight">return { ssn => $_[0] };</span>
}
-
<span class="highlight">return $class->SUPER::BUILDARGS(@_)</span>;
}
</div>
<div class="slide">
+ <h1>Object Construction a la Moose</h1>
+
+ <pre><code>Person->new(@_)</code></pre>
+
+ <ol>
+ <li>Calls <code>Person->BUILDARGS(@_)</code> to turn <code>@_</code> into a hashref</li>
+ <li>Blesses a reference</li>
+ <li>Populates attributes based on the hashref from #1</li>
+ <li>Calls <code>$new_object->BUILDALL($constructor_args)</code>
+ <br />... which calls all <code>BUILD</code> methods</li>
+ <li>Returns the object</li>
+ </ol>
+</div>
+
+<div class="slide">
+ <h1>The Object is Opaque</h1>
+
+ <ul>
+ <li>Technically it's a hash reference</li>
+ <li><span class="wrong">If you <em>ever</em> treat it as one <strong>you are doing it wrong!</strong></span></li>
+ </ul>
+</div>
+
+<div class="slide">
<h1>DEMOLISH</h1>
<ul>
<span class="incremental">override</span> work => sub {
my $self = shift;
- die "Pay me first" unless $self->got_paid;
+ die "Pay me first"
+ unless $self->got_paid;
<span class="incremental">super();</span>
}<span class="incremental">;</span></code></pre>
</div>
<ul>
<li><code>no Moose</code> at the end of a package is a best practice</li>
+ <li>Or <code>use namespace::autoclean</code> at the top</li>
<li>Just do it</li>
</ul>
</div>
<h1>Exercises</h1>
<pre># cd exercises
-$ perl bin/prove -lv t/00-prereq.t
-Missing anything? Install it. (see tarballs/)
+# perl bin/prove -lv t/00-prereq.t
+
+# perl install-moose (if needed)
# perl bin/prove -lv t/01-classes.t
+# edit lib/Person.pm and lib/Employee.pm
+
Iterate til this passes all its tests</pre>
</div>
</div>
<div class="slide">
- <h1>Roles Can Have State <strong>and</strong> Behavior</h1>
+ <h1>Roles - State <strong>and</strong> Behavior</h1>
<pre><code>package HasPermissions;
use Moose::Role;
-
<span class="current incremental"># state
has access_level => ( is => 'rw' );</span>
my $self = shift;
my $required = shift;
- return $self->access_level >= $required;
+ return $self->access_level
+ >= $required;
}</span></code></pre>
</div>
<h1>Classes Consume Roles</h1>
<pre><code>my $person = Person->new(
- first_name => 'Kenichi',
- last_name => 'Asai',
+ first_name => 'Kenichi',
+ last_name => 'Asai',
access_level => 42,
);
# or ...
-if ( Person->meta->does('Printable') ) { ... }</code></pre>
+Person->meta->does('Printable')</code></pre>
</div>
use Moose;
<span class="highlight">with 'IsFragile' =>
- { alias =>
+ { -alias =>
{ break => 'break_bone' } },
'CanBreakdance' =>
- { alias =>
+ { -alias =>
{ break => 'break_it_down' } };</span></code></pre>
<ul>
use Moose;
<span class="highlight">with 'IsFragile' =>
- { alias =>
+ { -alias =>
{ break => 'break_bone' },
- exclude => 'break' },
+ -excludes => 'break' },
'CanBreakdance' =>
- { alias =>
- { break => 'break_dance' },
- exclude => 'break' };</span></code></pre>
+ { -alias =>
+ { break => 'break_it_down' },
+ -excludes => 'break' };</span></code></pre>
</div>
<div class="slide">
sub break {
my $self = shift;
- $self->break_dance;
+ $self->break_it_down;
if ( rand(1) < 0.5 ) {
$self->break_bone;
}
<pre><code>use Moose::Util qw( apply_all_roles );
my $fragile_person = Person->new( ... );
-apply_all_roles( $fragile_person, 'IsFragile' );</code></pre>
+apply_all_roles( $fragile_person,
+ 'IsFragile' );</code></pre>
<ul>
<li>Does not change the <code>Person</code> class</li>
<ul>
<li>Attributes can have defaults</li>
- <li>Simple non-referecne scalars (number, string)</li>
+ <li>Simple non-reference scalars (number, string)</li>
<li>Subroutine reference</li>
<li>A builder method</li>
</ul>
</div>
<div class="slide">
- <h1>Default as a Subroutine Reference</h1>
+ <h1>Subroutine Reference Default</h1>
<ul>
<li>Called as a method on the object</li>
sub _build_bank {
my $self = shift;
- return Bank->new( name => 'Spire FCU' );
+ return Bank->new(
+ name => 'Spire FCU' );
}</code></pre>
</div>
</div>
<div class="slide">
- <h1>Lazy, Good for Nothing Attributes</h1>
+ <h1>Lazy, Good for Nothin' Attributes</h1>
<ul>
<li>Normally, defaults are generated during object construction</li>
<h1>Exercises</h1>
<pre># cd exercises
-# perl bin/prove -lv t/03-basic-attributes.t
+# perl bin/prove -lv \
+ t/03-basic-attributes.t
Iterate til this passes all its tests</pre>
</div>
my $self = shift;
return unless $DEBUG;
- warn "Called work on ", $self->full_name,
+ warn "Called work on ",
+ $self->full_name,
"with the arguments: [@_]\n";
};</code></pre>
</div>
</div>
<div class="slide">
- <h1>Other Uses Example</h1>
+ <h1>More Modifier Examples</h1>
<pre><code>has password => (
is => 'rw',
clearer => 'clear_password',
);
-
has hashed_password => (
is => 'ro',
builder => '_build_hashed_password',
clearer => '_clear_hashed_password',
);
-
after clear_password => sub {
my $self = shift;
$self->_clear_hashed_password;
$self->_munge_insert(@_) );
$new_user->_assign_uri;
-
return $new_user;
};</code></pre>
</div>
package Report;
extends 'Document';
-
<span class="highlight">augment xml</span> =>
sub { title() . <span class="highlight">inner()</span> . summary() };
package TPSReport;
extends 'Report';
-
<span class="highlight">augment xml</span> =>
sub { tps_xml() . <span class="highlight">inner()</span> };</code></pre>
</div>
<h1>Exercises</h1>
<pre># cd exercises
-# perl bin/prove -lv t/04-method-modifiers.t
+# perl bin/prove -lv \
+ t/04-method-modifiers.t
Iterate til this passes all its tests</pre>
</div>
<h1>Part 5: Types</h1>
</div>
+<div class="slide">
+ <h1>A Type System for Perl</h1>
+
+ <ul>
+ <li>Sort of ...</li>
+ <li><em>Variables</em> are not typed</li>
+ <li>Attributes can have types</li>
+ <li>MooseX modules let you define method signatures</li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Components of a Moose Type</h1>
+
+ <ul>
+ <li>A type is a name and a constraint</li>
+ <li>Types have a hierarchy</li>
+ <li>Constraints are cumulative from parents</li>
+ <li>Types can have associated coercions</li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Built-in Type Hierarchy</h1>
+
+ <pre>
+Any
+Item
+ Bool
+ Maybe[`a]
+ Undef
+ Defined
+ Value
+ Num
+ Int
+ Str
+ ClassName
+ RoleName
+</pre>
+</div>
+
+<div class="slide">
+ <h1>Built-in Type Hierarchy</h1>
+
+<pre>
+(Item)
+ (Defined)
+ Ref
+ ScalarRef
+ ArrayRef[`a]
+ HashRef[`a]
+ CodeRef
+ RegexpRef
+ GlobRef
+ FileHandle
+ Object
+</pre>
+</div>
+
+<div class="slide">
+ <h1>Bool</h1>
+
+ <h2>True</h2>
+ <pre><code>1
+924.1
+'true'
+{}</code></pre>
+
+ <h2>False</h2>
+ <pre><code>0
+0.0
+'0'
+undef</code></pre>
+
+ <ul>
+ <li>Like Perl's <code>if ($foo)</code></li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Value (and subtypes)</h1>
+
+ <ul>
+ <li><code>Value</code> is true when <code>! ref $thing</code></li>
+ <li><code>Value</code> and <code>Str</code> are effectively the same, but <code>Str</code> is more expressive</li>
+ <li>An overloaded object which numifies does not pass the <code>Num</code> constraint!</li>
+ <li>Perl 5's overloading is hopelessly broken</li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>ClassName and RoleName</h1>
+
+ <ul>
+ <li>A string with a package name</li>
+ <li>The package <strong>must already be loaded</strong></li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Parameterizable Types</h1>
+
+ <ul>
+ <li>What does <code>ArrayRef[`a]</code> mean?</li>
+ <li><code>s/`a/Int/</code> (or <code>Str</code> or ...)</li>
+ <li>When you use it you can write ...
+ <ul>
+ <li><code>ArrayRef</code> (== <code>ArrayRef[Item]</code>)</li>
+ <li><code>ArrayRef[Str]</code></li>
+ <li><code>ArrayRef[MyTypeName]</code></li>
+ <li><code>ArrayRef[HashRef[Maybe[Int]]]</code></li>
+ </ul>
+ </li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Maybe[`a]</h1>
+
+ <ul>
+ <li>Maybe means either the named type or <code>undef</code></li>
+ <li><code>Maybe[Int]</code> accepts integers or <code>undef</code></li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Type Union</h1>
+
+ <ul>
+ <li>This or that (or that or ...)</li>
+ <li><code>Int | ArrayRef[Int]</code></li>
+ <li>But use a coercion instead when possible</li>
+ <li>Or use a <code>role_type</code>, <code>duck_type</code>, or anything not a union</li>
+ <li>A union is often a code smell</li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Making Your Own Types</h1>
+
+ <pre><code>use Moose::Util::TypeConstraints;
+
+<span class="incremental current">subtype 'PositiveInt',</span>
+ <span class="incremental">as 'Int',</span>
+ <span class="incremental">where { $_ > 0 },</span>
+ <span class="incremental">message
+ { "The value you provided ($_)"
+ . " was not a positive int." };</span>
+
+has size => (
+ is => 'ro',
+ <span class="incremental">isa => 'PositiveInt',</span>
+);</code></pre>
+</div>
+
+<div class="slide">
+ <h1>Automatic Types</h1>
+
+ <ul>
+ <li>Moose creates a type for every Moose class and role</li>
+ <li>Unknown names are assumed to be classes</li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Automatic Types</h1>
+
+ <pre><code>package Employee;
+use Moose;
+
+has manager => (
+ is => 'rw',
+ <span class="highlight">isa => 'Employee',</span>
+);
+
+has start_date => (
+ is => 'ro',
+ <span class="highlight">isa => 'DateTime',</span>
+);</code></pre>
+</div>
+
+<div class="slide">
+ <h1>Subtype Shortcuts - <code>class_type</code></h1>
+
+ <pre><code>use Moose::Util::TypeConstraints;
+class_type 'DateTime';
+
+subtype 'DateTime',
+ as 'Object',
+ where { $_->isa('DateTime') },
+ message { ... };</code></pre>
+</div>
+
+<div class="slide">
+ <h1>Subtype Shortcuts - <code>role_type</code></h1>
+
+ <pre><code>use Moose::Util::TypeConstraints;
+role_type 'Printable';
+
+subtype 'Printable',
+ as 'Object',
+ where
+ { Moose::Util::does_role(
+ $_, 'Printable' ) },
+ message { ... };</code></pre>
+</div>
+
+<div class="slide">
+ <h1>Subtype Shortcuts - <code>duck_type</code></h1>
+
+ <pre><code>use Moose::Util::TypeConstraints;
+duck_type Car => qw( run break_down );
+
+subtype 'Car',
+ as 'Object',
+ where { all { $_->can($_) }
+ qw( run break_down ) },
+ message { ... };</code></pre>
+</div>
+
+<div class="slide">
+ <h1>Subtype Shortcuts - <code>enum</code></h1>
+
+ <pre><code>use Moose::Util::TypeConstraints;
+enum Color => qw( red blue green ) );
+
+my %ok = map { $_ => 1 }
+ qw( red blue green );
+
+subtype 'Color'
+ as 'Str',
+ where { $ok{$_} },
+ message { ... };</code></pre>
+</div>
+
+<div class="slide">
+ <h1>Anonymous Subtypes</h1>
+
+ <pre><code>package Person;
+
+<span class="highlight">my $posint =
+ subtype as 'Int', where { $_ > 0 };</span>
+
+has size => (
+ is => 'ro',
+ <span class="highlight">isa => $posint,</span>
+);</code></pre>
+
+ <ul>
+ <li>Shortcuts have anonymous forms as well</li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Coercions</h1>
+
+ <pre><code>use Moose::Util::TypeConstraints;
+
+subtype 'UCStr',
+ as 'Str',
+ where { ! /[a-z]/ };</code></pre>
+</div>
+
+<div class="slide">
+ <h1>Coercions</h1>
+
+ <pre><code><span class="incremental current">coerce 'UCStr',</span>
+ <span class="incremental">from 'Str',</span>
+ <span class="incremental">via { uc };</span>
+
+has shouty_name => (
+ is => 'ro',
+ isa => 'UCStr',
+ <span class="incremental">coerce => 1,</span>
+);</code></pre>
+</div>
+
+<div class="slide">
+ <h1>Coercion Examples</h1>
+
+ <pre><code>subtype 'My::DateTime',
+ as class_type 'DateTime';
+
+coerce 'My::DateTime',
+ from 'HashRef',
+ via { DateTime->new( %{$_} ) };
+
+coerce 'My::DateTime',
+ from 'Int',
+ via { DateTime->from_epoch(
+ epoch => $_ ) };</code></pre>
+
+ <ul>
+ <li>Use coercion to inflate a value</li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Coercion Examples</h1>
+
+ <pre><code>coerce 'ArrayRef[Int]',
+ from 'Int',
+ via { [ $_ ] };</code></pre>
+
+ <ul>
+ <li>Coerce instead of a union like <code style="white-space: nowrap">Int | ArrayRef[Int]</code></li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Using Types with Attributes</h1>
+
+ <pre><code>package Person;
+
+has height => (
+ is => 'rw',
+ <span class="highlight">isa => 'Num',</span>
+);
+
+has favorite_numbers => (
+ is => 'rw',
+ <span class="highlight">isa => 'ArrayRef[Int]',
+ coerce => 1,</span>
+);</code></pre>
+</div>
+
+<div class="slide">
+ <h1>More Droppings</h1>
+
+ <ul>
+ <li><code>Moose::Util::TypeConstraints</code> also needs cleanup</li>
+ </ul>
+
+ <pre><code>package Person;
+
+use Moose;
+use Moose::Util::TypeConstraints;
+
+subtype ...;
+
+no Moose;
+<span class="highlight">no Moose::Util::TypeConstraints;</span></code></pre>
+</div>
+
+<div class="slide">
+ <h1>Typed Methods (Low-tech)</h1>
+
+ <pre class="medium"><code>package Person;
+<span class="highlight">use MooseX::Params::Validate qw( validated_list );</span>
+
+sub work {
+ my $self = shift;
+ <span class="highlight">my ( $tasks, $can_rest ) =
+ validated_list(
+ \@_,
+ tasks =>
+ { isa => 'ArrayRef[Task]',
+ coerce =>1 },
+ can_rest =>
+ { isa => 'Bool',
+ default => 0 },
+ );</span>
+ ...
+}</code></pre>
+</div>
+
+<div class="slide">
+ <h1>Typed Methods (High-tech)</h1>
+
+ <pre class="medium"><code>package Person;
+
+<span class="highlight">use MooseX::Method::Signatures;</span>
+
+<span class="highlight">method work ( ArrayRef[Task] :$tasks,
+ Bool :$can_rest = 0 )</span> {
+ my $self = shift;
+
+ ...
+}</code></pre>
+</div>
+
+<div class="slide">
+ <h1>Digression: The Type Registry</h1>
+
+ <ul>
+ <li>Types are actually <code>Moose::Meta::TypeConstraints</code> <em>objects</em></li>
+ <li>Stored in an interpreter-global registry mapping names to objects</li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Danger!</h1>
+
+ <ul>
+ <li>Coercions are attached to type objects</li>
+ <li>Therefore also global</li>
+ <li>Name conflicts between modules!</li>
+ <li>Coercion conflicts between modules!</li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Namespace Fix</h1>
+
+ <ul>
+ <li>Use some sort of pseudo-namespacing scheme</li>
+ <li>Never coerce directly to a class name, or <em>to</em> built-in types</li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Namespace Fix</h1>
+
+ <pre><code>use Moose::Util::TypeConstraints;
+subtype <span class="highlight">'MyApp::Type::DateTime',</span>
+ as 'DateTime';
+
+<span class="highlight">coerce 'MyApp::Type::DateTime',</span>
+ from 'HashRef',
+ via { DateTime->new( %{$_} ) }
+
+has creation_date => (
+ is => 'ro',
+ <span class="highlight">isa => 'MyApp::Type::DateTime',</span>
+ coerce => 1,
+);</code></pre>
+</div>
+
+<div class="slide">
+ <h1>Namespace Fix</h1>
+
+ <pre><code>subtype 'MyApp::Type::ArrayOfInt',
+ as 'ArrayRef[Int]';
+
+coerce 'MyApp::Type::ArrayOfInt',
+ from 'Int',
+ via { [ $_ ] };</code></pre>
+</div>
+
+<div class="slide">
+ <h1>Namespace Fix Pros and Cons</h1>
+
+ <ul>
+ <li><span class="right">Relatively simple</span></li>
+ <li><span class="right">Already built into Moose</span></li>
+ <li><span class="wrong">Conflates type and module namespaces</span></li>
+ <li><span class="wrong">Type names are strings, so typos are easy to make and may be hard to find</span></li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>MooseX::Types</h1>
+
+ <pre><code>package MyApp::Types;
+
+use MooseX::Types
+ <span class="highlight">-declare => [ qw( ArrayOfInt ) ]</span>;
+use MooseX::Types::Moose
+ qw( ArrayRef Int );
+
+subtype <span class="highlight">ArrayOfInt</span>,
+ as ArrayRef[Int];
+
+coerce <span class="highlight">ArrayOfInt</span>
+ from Int,
+ via { [ $_ ] };</code></pre>
+</div>
+
+<div class="slide">
+ <h1>MooseX::Types</h1>
+
+ <pre><code>package MyApp::Account;
+
+use MyApp::Types qw( ArrayOfInt );
+
+has transaction_history => (
+ is => 'rw',
+ isa => ArrayOfInt,
+);</code></pre>
+</div>
+
+<div class="slide">
+ <h1>MooseX::Types</h1>
+
+ <ul>
+ <li>Type names are exported functions, catches typos early</li>
+ <li>Types must be pre-declared</li>
+ <li>Types are stored with namespaces internally, but externally are short</li>
+ <li>Import existing Moose types as functions from <code>MooseX::Types::Moose</code></li>
+ <li>Still need string names for things like <code>ArrayRef['Email::Address']</code></li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>MooseX::Types Pros and Cons</h1>
+
+ <ul>
+ <li><span class="right">Catches typos at compile time</span></li>
+ <li><span class="right">Automatic namespacing</span></li>
+ <li><span class="wrong">One more thing to install and learn</span></li>
+ <li><span class="wrong">Every name gets types twice (declared and then defined)</span></li>
+ <li><span class="wrong">Still stuck with strings when referring to class or role names</span></li>
+ <li><span class="wrong">Coercion gotcha from earlier still applies to types exported from <code>MooseX::Types::Moose</code></span></li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Recommendation</h1>
+
+ <ul>
+ <li>Use <code>MooseX::Types</code></li>
+ <li>Compile time error catching and automatic namespacing are huge wins</li>
+ <li>Docs from <code>Moose::Util::TypeConstraints</code> are 98% compatible with <code>MooseX::Types</code> anyway</li>
+ <li>A function exported by a type library works wherever a type name would</li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Questions?</h1>
+</div>
+
+<div class="slide">
+ <h1>Exercises</h1>
+
+ <pre># cd exercises
+# perl bin/prove -lv t/05-types.t
+
+Iterate til this passes all its tests</pre>
+</div>
+
<div class="slide fake-slide0">
<h1>Part 6: Advanced Attributes</h1>
</div>
use Moose;
has name => ( is => 'ro' );
-has friend => ( is => 'rw', <span class="highlight">weak_ref => 1</span> );
+has friend => ( is => 'rw',
+ <span class="highlight">weak_ref => 1</span> );
my $alice = Person->new( name => 'Alice' );
my $bob = Person->new( name => 'Bob' );
<pre><code>package Person;
use Moose;
-
has account => (
is => 'ro',
isa => 'BankAccount',
<pre><code>package Auditor;
use Moose::Role;
-
sub record_change { ... }
sub change_history { ... }
</div>
<div class="slide">
+ <h1>Native Delegation</h1>
+
+ <ul>
+ <li>Delegate to <em>unblessed</em> Perl types</li>
+ <li>Scalar, array or hash ref, etc</li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Native Delegation - Array</h1>
+
+ <pre><code>package Person;
+use Moose;
+has _favorite_numbers => (
+ traits => [ 'Array' ],
+ is => 'ro',
+ isa => 'ArrayRef[Int]',
+ default => sub { [] },
+ init_arg => undef,
+ <span class="highlight">handles =>
+ { favorite_numbers => 'elements',
+ add_favorite_number => 'push',
+ },</span>
+);</code></pre>
+</div>
+
+<div class="slide">
+ <h1>Native Delegation - Counter</h1>
+
+ <pre><code>package Stack;
+use Moose;
+has depth => (
+ traits => [ 'Counter' ],
+ is => 'ro',
+ isa => 'Int',
+ default => 0,
+ init_arg => undef,
+ <span class="highlight">handles =>
+ { _inc_depth => 'inc',
+ _dec_depth => 'dec',
+ },</span>
+);</code></pre>
+</div>
+
+
+<div class="slide">
<h1>Traits and Metaclasses</h1>
<ul>
isa => 'Str',
<span class="highlight">label => 'Social Security Number',</span>
);
-
print <span class="highlight">Person->meta
->get_attribute('ssn')->label;</span></code></pre>
</div>
isa => 'Str',
<span class="highlight">label => 'Social Security Number',</span>
);
-
print <span class="highlight">Person->meta
->get_attribute('ssn')->label;</span></code></pre>
</div>
<h1>Exercises</h1>
<pre># cd exercises
-# perl bin/prove -lv t/06-advanced-attributes.t
+# perl bin/prove -lv \
+ t/06-advanced-attributes.t
Iterate til this passes all its tests</pre>
</div>
</div>
<div class="slide fake-slide0">
- <h1>The End<?h1>
+ <h1>The End</h1>
</div>
<div class="slide">
<li>mailing list - <a href="mailto:moose@perl.org">moose@perl.org</a></li>
<li>Slides and exercises are in Moose's git repo:
<br />
- <nobr>git://jules.scsys.co.uk/gitmo/moose-presentations</nobr></li>
+ <span style="white-space: nowrap">git://jules.scsys.co.uk/gitmo/moose-presentations</span></li>
</ul>
</div>
projects / gitmo/moose-presentations.git / blobdiff