The Ruby Programming Language

Ryan Farnell

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History

• 1995

• July 2004 (Ruby on Rails)

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pure object-orientated

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What is an object?

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1. The data an object contains is unique to itself

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2. Only the object that contains the data can manipulate that data

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one logical unit with data and functions grouped together

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demo

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basic data as objects

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Value Type of Object

123 Fixnum

“Ruby” String

TRUE TrueClass

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functions as objects

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Value Type of Object

function Proc

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blocks allow for the passing of a function as

a parameter

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Ways to Use Blocks

• internal iterators

• resource allocation/deallocation

• changing functionality

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demo

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Conditionals

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Ruby supports standard conditionals

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Ruby also allows post conditions

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Ruby uses the normal case/when statement as

in other languages

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Ruby supports standard looping structures

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internal iterators are often used in place of standard structures

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demo

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Classes

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act as templates for the beginning functionality

of an object

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class inheritance

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a class can gain functionality (inherit) from other classes

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all classes inherit from exactly one class

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mixins can be used to add extra functionality

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class gains all the methods in the mixin

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Mixins

• Have access to all instance variables

• Have access to all private and public methods

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demo

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Ruby has some problems

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Disadvantages• Slow Execution

• Problems with threading

• No specification

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Virtual Machines• Ruby 1.9 YARV

• JRuby

• IronRuby

• Rubinius

• MacRuby

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http://www.ruby-lang.org/en/downloads/

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Books

• Programming Ruby 2nd Edition

• by Dave Thomas, Chad Fowler, and Andy Hunt

• Ruby From Novice to Professional

• Peter Cooper

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Q & A

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Metaprogramming

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code that writes code

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Ruby has many metaprogramming

hook

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demo

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