Sam Ruby有 cool slideshow that outline the differences .

为了让这些信息更容易被引用,并且万一链接在抽象的未来失效,下面是山姆幻灯片的概述。幻灯片放映不太容易被审查,但是把它全部放在这样的列表中也很有帮助。

Ruby 1.9-主要功能

• 性能
• 螺纹/纤维
• 编码/unicode
• 宝石现在(大部分)是内置的
• if语句不在Ruby中引入范围。

发生了什么变化?

单个字符串。

红宝石1.9

irb(main):001:0> ?c
=> "c"

红宝石1.8

irb(main):001:0> ?c
=> 99

字符串索引。

红宝石1.9

irb(main):001:0> "cat"[1]
=> "a"

红宝石1.8

irb(main):001:0> "cat"[1]
=> 97

“A”、“B”不再支持

红宝石1.9

irb(main):002:0> {1,2}
SyntaxError: (irb):2: syntax error, unexpected ',', expecting tASSOC

红宝石1.8

irb(main):001:0> {1,2}
=> {1=>2}

行动: 转换为1=>2

Array.to_s 现在包含标点符号

红宝石1.9

irb(main):001:0> [1,2,3].to_s
=> "[1, 2, 3]"

红宝石1.8

irb(main):001:0> [1,2,3].to_s
=> "123"

行动: 改用.join

冒号在WHEN语句中不再有效

红宝石1.9

irb(main):001:0> case 'a'; when /\w/: puts 'word'; end
SyntaxError: (irb):1: syntax error, unexpected ':',
expecting keyword_then or ',' or ';' or '\n'

红宝石1.8

irb(main):001:0> case 'a'; when /\w/: puts 'word'; end
word

行动: 然后使用分号或换行符

块变量现在隐藏局部变量

红宝石1.9

irb(main):001:0> i=0; [1,2,3].each {|i|}; i
=> 0
irb(main):002:0> i=0; for i in [1,2,3]; end; i
=> 3

红宝石1.8

irb(main):001:0> i=0; [1,2,3].each {|i|}; i
=> 3

Hash.index 贬低

红宝石1.9

irb(main):001:0> {1=>2}.index(2)
(irb):18: warning: Hash#index is deprecated; use Hash#key
=> 1
irb(main):002:0> {1=>2}.key(2)
=> 1

红宝石1.8

irb(main):001:0> {1=>2}.index(2)
=> 1

行动: 使用哈希键

Fixnum.to_sym 现在走了

红宝石1.9

irb(main):001:0> 5.to_sym
NoMethodError: undefined method 'to_sym' for 5:Fixnum

红宝石1.8

irb(main):001:0> 5.to_sym
=> nil

(继续)红宝石1.9

# Find an argument value by name or index.
def [](index)
  lookup(index.to_sym)
end

svn.ruby-lang.org/repos/ruby/trunk/lib/rake.rb

哈希键现在无序

红宝石1.9

irb(main):001:0> {:a=>"a", :c=>"c", :b=>"b"}
=> {:a=>"a", :c=>"c", :b=>"b"}

红宝石1.8

irb(main):001:0> {:a=>"a", :c=>"c", :b=>"b"}
=> {:a=>"a", :b=>"b", :c=>"c"}

顺序是插入顺序

更严格的Unicode正则表达式

红宝石1.9

irb(main):001:0> /\x80/u
SyntaxError: (irb):2: invalid multibyte escape: /\x80/

红宝石1.8

irb(main):001:0> /\x80/u
=> /\x80/u

tr 和 Regexp 现在了解Unicode

红宝石1.9

unicode(string).tr(CP1252_DIFFERENCES, UNICODE_EQUIVALENT).
  gsub(INVALID_XML_CHAR, REPLACEMENT_CHAR).
  gsub(XML_PREDEFINED) {|c| PREDEFINED[c.ord]}

pack 和 unpack

红宝石1.8

def xchr(escape=true)
  n = XChar::CP1252[self] || self
  case n when *XChar::VALID
    XChar::PREDEFINED[n] or 
      (n>128 ? n.chr : (escape ? "&##{n};" : [n].pack('U*')))
  else
    Builder::XChar::REPLACEMENT_CHAR
  end
end
unpack('U*').map {|n| n.xchr(escape)}.join

BasicObject 比…更残忍 BlankSlate

红宝石1.9

irb(main):001:0> class C < BasicObject; def f; Math::PI; end; end; C.new.f
NameError: uninitialized constant C::Math

红宝石1.8

irb(main):001:0> require 'blankslate'
=> true
irb(main):002:0> class C < BlankSlate; def f; Math::PI; end; end; C.new.f
=> 3.14159265358979

行动: 用途::数学::PI

irb(main):002:0> class C < SimpleDelegator; end
=> nil
irb(main):003:0> C.new('').class
=> String

irb(main):002:0> class C < SimpleDelegator; end
=> nil
irb(main):003:0> C.new('').class
=> C
irb(main):004:0>

irb(main):004:1> $KCODE = 'UTF8'
(irb):4: warning: variable $KCODE is no longer effective; ignored
=> "UTF8"

irb(main):001:0> $KCODE = 'UTF8'
=> "UTF8"

irb(main):001:0> {}.methods.sort.last
=> :zip

irb(main):001:0> {}.methods.sort.last
=> "zip"

# coding: utf-8

# -*- encoding: utf-8 -*-

#!/usr/local/rubybook/bin/ruby
# encoding: utf-8

{a: b}

redirect_to action: show

{:a => b}

redirect_to :action => show

[1,2].each {|value; t| t=value*value}

[1,2].inject(:+)

[1,2].inject {|a,b| a+b}

short_enum = [1, 2, 3].to_enum
long_enum = ('a'..'z').to_enum
loop do
  puts "#{short_enum.next} #{long_enum.next}"
end

e = [1,2,3].each

p = -> a,b,c {a+b+c}
puts p.(1,2,3)
puts p[1,2,3]

p = lambda {|a,b,c| a+b+c}
puts p.call(1,2,3)

Complex(3,4) == 3 + 4.im

irb(main):001:0> 1.2-1.1
=> 0.0999999999999999

/\p{Space}/

/[:space:]/

def foo(first, *middle, last)

(->a, *b, c {p a-c}).(*5.downto(1))

f = Fiber.new do
  a,b = 0,1
  Fiber.yield a
  Fiber.yield b
  loop do
    a,b = b,a+b
    Fiber.yield b
  end
end
10.times {puts f.resume}

match =
   while line = gets
     next if line =~ /^#/
     break line if line.find('ruby')
   end

def toggle
  def toggle
    "subsequent times"
  end
  "first time"
end

一个巨大的区别是从Matz的翻译到 YARV ,一个字节码虚拟机,对性能有很大帮助。

现在很多人推荐 The Ruby Programming Language 在鹤嘴锄上-更重要的是,它有1.8/1.9差异的所有细节。

其他一些更改:

返回splat singleton数组:

def function
  return *[1]
end

a=function

• 红宝石1.9:[ 1 ]
• 红宝石1.8:1

数组参数

def function(array)
  array.each { |v| p v }
end
function "1"

• 红宝石1.8:“1”
• Ruby1.9:“1”的未定义方法“each”:字符串