Piter.rb #2 - Ruby 1.8 vs Ruby 1.9

What's new in Ruby 1.9.x ?
Artem Harmaty

Introduction
1.9 just like 1.7
1.8 - 2003 1.9.0 - Dec 2007
1.8.7 - May 2008
1.9.1 - Jan 2009
1.9.2 - 18 Aug 2010
2.0 - ???

Ruby 1.9
Faster (YARV)
Native threads
Multilingualized (M17N)
Clearer Syntax

Rails 3.0 is stable on Ruby 1.9.2

Benchmarks: Ruby 1.9 vs Ruby1.8
http://shootout.alioth.debian.org/

Benchmarks: Ruby 1.9 vs PHP

Benchmarks: Ruby 1.9 vs Python 3

Installation
http://rvm.beginrescueend.com/
$ rvm install 1.9.2
$ rvm 1.9.2 --default
$ ruby -v
ruby 1.9.2p0 (2010-08-18 revision 29036) [x86_64-linux]
$ rvm system
$ ruby -v
ruby 1.8.7 (2010-01-10 patchlevel 249) [i486-linux]

Standard library changes
+ Rubygems
no longer needed require ‘rubygems’
no longer gem install rake

Lambda
c = lambda {| a , b | a*b }
c = ->( a , b ) { a*b }
1.8 1.9

Implicit #call
c = lambda {| a , b | a*b } c.call( 3 , 4 )
c = ->( a , b ) { a*b } c.( 3 , 4 )
1.8 1.9

Block Parameters
lambda {| a , b , c = 1, & d | d.call } ^ syntax error, unexpected '=', expecting '|'
->( a , b , c = 1 , & d ) { d.call }
1.8 1.9

def foo (a, b = 100 , c) puts “ #{a} #{b} #{c} ” end foo( 3 ) => ArgumentError foo( 3 , 5 ) => 3, 100, 5 foo( 3 , 4 , 5 )
=> 3, 4, 5
1.9

Block Local Variables
i = ' Hello! ' [ 1 , 2 , 3 ].map {| i | i * 2 }
i => 'Hello!'
i => 3
1.8 1.9

Literal Hashes
{ :a => 1 , :b => 2 , :c => 3 , :d => 4 }
{ a: 1 , b: 2 , c: 3 , d: 4 }
1.8 1.9

Symbol Changes
Symbol. ancestors
=> [Symbol, Object, Kernel]
Symbol .ancestors
=> [Symbol, Comparable, Object, Kernel, BasicObject]
:step1 < :step2
=> true
1.8 1.9

M17N (Multilingualization)
In Ruby 1.8 a String is always just a collection of bytes In Ruby 1.9 a String is a collection of encoded characters.

M17N
" борщ " .size => 8
" борщ " .size => 4 " борщ " .bytesize => 8 " борщ " .encoding.name => "UTF-8"
1.8 1.9

M17N
" пример " [ 2 ] => 209
" пример " [ 2 ] => и
1.8 1.9

String Iteration
Strings are no longer enumerable Ruby 1.8 each() has been removed Ruby 1.9 use explicit iterator
each_line
each_byte
each_char

Magic comment
#!/usr/bin/env ruby -w # encoding: UTF-8 # coding: UTF-8 # -*- coding: UTF-8 -*-
1.9

M17N
$ ruby foobar.rb # US-ASCII $ ruby -KU foobar.rb # UTF-8

M17N
# coding: UTF-8 def √(x) Math .sqrt(x) end √ 2 => 1.4142135623730951
1.9

M17N
# coding: UTF-8 π = Math :: PI def ∑(r) r.inject{| sum , val | sum + (block_given? ? yield (val) : val)} end def ∏(r) r.inject( 1 ){| mul , val | mul * (block_given? ? yield (val) : val)} end
1.9

Regular Expression
Regexp has encoding too:
/w/ .encoding => #<Encoding:US-ASCII> / пример / .encoding => #<Encoding:UTF-8>
Integrated the 'Oniguruma' engine

Reg u lar Expression - (?<name>pattern)
if /(?<key>w+) = (?<value>.*)/ =~ " ruby=cool and fun " puts key puts value end
1.9

Object#tap
puts " dog " .reverse .tap{ | o | puts " reversed: #{ o }" } .upcase # reversed: god
# GOD
1.9

Fibers
f = Fiber .new { 2 .times do puts " Fiber say hi " Fiber .yield puts " Fiber say bye " end }
1.9

Fibers
f = Fiber .new { 2 .times do puts " Fiber say hi " Fiber .yield puts " Fiber say bye " end }
f.resume => Fiber say hi f.resume => Fiber say bye => Fiber say hi f.resume => Fiber say bye f.resume => FiberError: dead fiber called
1.9

BasicObject
String .superclass => Object Object .superclass => BasicObject BasicObject .superclass => nil BasicObject .instance_methods => [:==, :equal?, :!, :!=, :instance_eval, :instance_exec, :__send__]
1.9

Recommended Literature
Programming Ruby 1.9. The Pragmatic Programmers’ Guide
Dave Thomas, Chad Fowler, Andy Hunt
The Ruby Programming Language
David Flanagan, Yukihiro Matsumoto

Questions? Email: [email_address]
Skype: harmaty

Piter.rb #2 - Ruby 1.8 vs Ruby 1.9

by Pavel Timofeev on Sep 19, 2010

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