ruby1.8 1.9问题

Ruby1.8至1.9迁移指南

最新推荐文章于 2025-12-04 15:09:56 发布

最新推荐文章于 2025-12-04 15:09:56 发布 · 92 阅读

文章标签：

#ruby

本文概述了从Ruby1.8升级到Ruby1.9时需要注意的重要变化，包括参数处理方式的不同、hash语法的变化、字符编码的默认设置、String方法的更新等。此外还介绍了语法调整及内置库的变动。

1：正式的参数不能使实例变量

Ruby1.8

class Foo attr_accessor :bar def test [1,2,3].each {|@bar| } # @bar will be 3 here end end

Ruby1.9

class Foo attr_accessor :bar def test [1,2,3].each {|bar| @bar=bar } # @bar will be 3 here end end

2：覆盖外部局部变量

i =0 [1,2,3].each { |i| } puts i ruby1.8输出3 ruby1.9输出0

3: hash语法 ” , “ 问题

ruby 1.8 {"a","b"} => {"a"=> "b"}

ruby 1.9 {"a" =>＂ｂ＂}

４：字符

默认是 US-ASCIi 码如果不是的话用 coding :utf-8

5: String的 ‘to_a’方法未定义

1.8 : string.to_a

1.9 : string.lines.to_a

为了解决兼容性问题keyi :

if str.respond_to?(:lines) then lines = string.lines.to_a else lines = string.to_a end

6: 关键字 then , ; /n case if 可以使用：代替

1.8:

case 'test' when'test':print 'OK' end

1.9:

case 'test' when'test' then print 'OK' end

7:no such file to load -base64:

require "base64": ruby 1.9 ships without base64. You should use Array#pack, unpack require 'base64' enc = Base64.encode64('Send reinforcements') plain = Base64.decode64(enc) In ruby1.9 you can write: enc = ['Send reinforcements'].pack( 'm' ) plain = enc.unpack( 'm' )[0]

8:'结构体 RStirng没有成员‘ptr’ len

In ruby1.9 for the RString in C extensions was changed because of optimization, you should use the RSTRING_LEN, RSTRING_PTR macros instead of directly accessing the len, ptr members. len = RSTRING(foo)->len ptr = RSTRING(foo)->ptr Should be changed to len = RSTRING_LEN(foo); ptr = RSTRING_PTR(foo);

9:成员改变从Strings转化到Symbols

Object.methods.include?("to_s") The ruby1.9 version is: Object.methods.include?(:to_s) And the following works in ruby1.8 and 1.9: object.respond_to?(:some_method)

10：TypeErro：不能分配nil；要用Hash#delete 代替

n ruby1.8 you can remove an environment variable by setting it to nil. In ruby1.9 use the delete method instead: ENV.delete('MY_ENV_VARIABLE')