book

Beginning Perl

by Curtis Ovid Poe

September 2012

Beginner

744 pages

15h 48m

English

Wrox

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Perl TodayGetting PerlThe Perl CommunityUsing perldocUsing a Terminal WindowCreating Hello, World!Summary
CPAN and METACPANCPAN ClientsSummary
What is Programming?A Few Things to Note Before Getting StartedScalarsArraysHashesSlicesContextScopeStrict, Warnings, and DiagnosticsPerl’s Built-in VariablesSummary
Using ScalarsArray and List FunctionsBuilt-in Hash FunctionsScoping KeywordsSummary
Using the if Statementfor/foreach loopsUsing while/until LoopsStatement Modifiersgiven/whenSummary
References 101Working with ReferencesSummary
Subroutine SyntaxReturning DataFAIL!Subroutine ReferencesPrototypesRecursionThings to Watch ForSummary

Basic MatchingAdvanced MatchingCommon Regular Expression IssuesSummary
Basic File HandlingDirectoriesUnicodeUseful ModulesSummary
Basic Sortingmap and grepPutting It All TogetherSummary
Namespaces and PackagesSubroutines in Other PackagesBEGIN, UNITCHECK, CHECK, INIT, and ENDPlain Old Documentation (POD)Creating and Installing ModulesSummary
What Are Objects? The Ævar the Personal ShopperThree Rules of Perl OOObjects – Another ViewA Brief RecapGotchasSummary
Understanding Basic Moose SyntaxAdvanced Moose SyntaxMoose Best PracticesSummary
Basic TestsUnderstanding Test::More Test FunctionsUsing Other Testing ModulesUnderstanding xUnit Style Using TestingSummary
A Brief Introduction to HTTPWeb ClientsSummary
Using the DBISelecting Basic DataSummary
The Command LineOther ProgramsSummary
Using CSV DataUnderstanding Basic XMLHandling DatesUnderstanding Your ProgramSummary
What Next?Understanding Object-Relational MappersUsing the Template ToolkitUsing Catalyst to Build AppsSummary

Content preview from Beginning Perl

Chapter 13 Moose

WHAT YOU WILL LEARN IN THIS CHAPTER:

Understanding Moose Syntax including attributes, constructors, and inheritance
Using Type constraints, Method modifiers, roles, and popular Moose extensions
Understanding Moose Best Practices

WROX.COM CODE DOWNLOAD FOR THIS CHAPTER

The wrox.com code downloads for this chapter are found at http://www.wrox.com/remtitle.cgi?isbn=1118013847 on the Download Code tab. The code for this chapter is divided into the following major examples:

example_13_1_person.pl
example_13_2_episode.pl
lib/Person.pm
lib/My/Company/Moose/Types.pm
lib/TV/Episode.pm
lib/TV/Episode/Broadcast.pm
listing_13_1_age.pl

In the beginning there was Perl and on the fifth version Larry blessed references and said, “Let there be objects” and all was good.

Well, sort of. Chapter 12 showed how to create objects with Perl’s builtin bless syntax, but there’s a lot of tedium in validating that your data is correct and setting up your classes properly. If you’re familiar with object-oriented programming (OOP) in other languages, you may have found Perl’s implementation to be a bit crufty. You’d be right.

To work around Perl’s rather simple object facilities, many programmers have taken a swing at making it easier to write objects. There is Class::MakeMethods, Class::MethodMaker, Class::BuildMethods, Class::Accessor, Object::Tiny, and so on. As of this writing, there are approximately 500 different packages in the Class:: and Object:: namespaces, many of which aren’t ...