GBString是一個可以識別GB18030編碼的ruby字串類，它改寫了String類的一些方法，可以很方便地處理內碼是GB18030/GBK/GB2312的字串。

專案的homepage
http://rubyforge.org/projects/gbstring/

License
====================
GBString, a ruby class simliar to String class but with GB18030 encoding aware style.

Copyright (C) <2007>  <Bob Yang>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

Email: bob.yang.dev at gmail.com
====================

一、快速開始
====================
1、構造一個GBString物件
require "g_b_string"
gbstr = GBString.new("這是一個GB18030編碼的字串！") # 注意，檔案的編碼方式要是GB18030

或者使用下面的簡單方式

gbstr = _c("這也是一個GB18303編碼的字串！")

2、按中文字元為基本單位計算字串長度
gbstr = _c("中文串")
puts( gbstr.size ) # => 3 而不是 6

3、遍歷中文字串
_c("中文串abc").each do |char|
  puts char
end
# => 中
# => 文
# => 串
# => a
# => b
# => c

二、更多用法
====================
可以參考 test/tc_g_b_string.rb

1、each, each_with_index
  每個元素是一箇中文字元，型別為String.

2、split

  cstr = _c"第一 第二  第三"
  tokens = cstr.split(" ")
  tokens[0] # => 第一
  tokens[1] # => 第二
  tokens[3] # => 第三

3、下標操作符'[ ]', 注意得到的物件是GBString型別的

  cstr = _c"甲A"
  puts( cstr[0] ) # => 甲
  puts( cstr[1] ) # => A
  puts( cstr[0].class ) # => GBString
  puts( cstr[1].class ) # => GBString
  
4、型別轉換，to_a, range
  # 轉換到陣列, to_a
  gbstr = _c("型別map")
  array = gbstr.to_a
  puts array.size # => 5
  puts array[0]   # => 類
  puts array[3]   # => a
  
  # 作為range使用, 得到的物件是GBString類的
  gbstr = _c"This is a /"中文字串/"！"
  puts( gbstr[10..16] )   # => "中文字串"
  puts( gbstr[-8..-1] )   # => "中文字串"！
  puts( gbstr[10, 7] )    # => "中文字串"
  
5、作為Hash的key使用, 與相同內容的String物件相等.
  hash = {_c("中國")=>1, _c("貴州省")=>2, _c("貴陽市")=>3}
  puts( hash[_c("貴陽市")] )   # => 3
  puts( hash["貴陽市"] )       # => 3
  
三、執行單元測試
====================
進入 test 目錄，執行 ruby tc_g_b_string.rb 即可。
如果一切正常，會提示：
7 tests, 56 assertions, 0 failures, 0 errors