binary

标签：io   ar   os   使用   sp   strong   数据   on   art   

模块说明

• 函数经过优化，比等价Erlang实现（比如位语法）更快，更节省内存
• 大部分可用位语法等价实现
• 模块的实现根据EEP(Erlang Enhancement Proposal)31
• 模块只处理面向字节的数据binary，位串Bitstring不是binary，使用会badarg异常
• 操作基于0索引
• 所有的选项列表，后面的选项覆盖前面的选项
• 超出范围的操作会导致badarg异常

数据类型

cp() 编译过的搜索模式

part() ={Pos,Len}部分，{基于0的开始，长度}  ，长度可为负

导出函数

• at(Bin,Pos) : 返回Pos处的字节
• bin_to_list(Bin) ：等同 bin_to_list(Bin,PosLen={0,byte_size(Bin)})
• bin_to_list(Bin,PosLen):  返回Bin从Pos起Len长的字节数组
• bin_to_list(Bin,Pos,Len) ： 参上，参数分开而已
• compile_pattern(Bin | [Bin])  :  返回编译好的搜索模式cp()
• copy(Bin)   : 返回Bin的一份拷贝； Bin可能引用着更大的binary，继续使用Bin就继续引用着，使用拷贝，则大的binary可能回收
• copy(Bin,N)  : 返回N倍的Bin拷贝
• decode_unsigned(Bin)  ： 把Bin表示的整数解码成无符号整数，默认big 大端记法
• decode_unsigned(Bin,Endianess)  ：同上，只是以Endianess 解释， Endianess=big | little
• encode_unsigned(Unsigned)   : 参见decode_unsigned(Bin)
• encode_unsigned(Unsigned,Endianess)  : 参见 decode_unsigned(Bin,Endianess)
• first(Bin)  : 获取第1个字节，超出范围badarg 异常
• last(Bin)  ： 最后1个字节，超出范围badarg异常
• list_to_bin(ByteList)   : 和erlang:list_to_binary 一样，只是为了完整性。 字节列表转成Bin，字节列表时iodata() ，即可嵌套
• longest_common_preifx([Bin]) ： Bin 列表最长前缀长度
• longest_common_suffix([Bin])  :  Bin 列表最长后缀长度
• match(Bin, Pattern)    ：  只返回第1处匹配；没有返回nomatch；Pattern=Bin | [Bin] | cp() ; 重叠的匹配首先以起始位置优先，然后以长度最大优先
• match(Bin,Pattern,[Option])  :  同上， 增加了选项列表。 Option = {scope, {Pos, Len}}  ，后面的覆盖前面的
• matches(Bin, Pattern)   : 等同  matches(Bin, Pattern,[]) ，返回全部非重叠的匹配 {Pos,Len} 列表
• matches(Bin, Pattern, [Option])  :  同上， 可通过Option指定匹配范围 Option={scope,{Pos,Len}}
• part(Bin, PosLen)   ： 返回 Bin 中 {Pos,Len} 的部分
• part(Bin, Pos, Len) : 同上，参数分开
• referenced_byte_size(Bin)   : 返回 Bin 引用的更大binary的字节长度
• replace(Bin, Pattern, Replacement)  ： 根据Pattern把匹配的替换成Replacement = binary() , 只替换一次
• replace(Bin, Patter, Replacement, [Option]) : 同上，增加了Option = global | {scope,PosLen} | {insert_replaced, [Pos]} , scope 会取消global的作用， scope后面的覆盖前面的，insert_replaced 也是这样
• split(Bin,Pattern)  :  根据模式拆分Bin，返回拆分SubBin列表，等同split(Bin,Pattern,[])
• split(Bin,Pattern,[Option])  : 同上。增加了选项。Option = {scope, PosLen} | trim | global ;同上，scope会取消global；trim会移除结果列表末尾空<<>>

例子

6> binary:replace(<<"abcdabc">>,<<"abc">>,<<"ef">>).
<<"efdabc">>

7> binary:replace(<<"abcdabc">>,[<<"abc">>,<<"bc">>],<<"ef">>).
<<"efdabc">>
8> binary:replace(<<"abcdefg">>,[<<"abc">>,<<"efg">>],<<"ef">>).
<<"efdefg">>

9> binary:replace(<<"abcde">>,<<"b">>,<<"[{]">>,[{insert_replaced,1}]).
<<"a[b{]cde">>
10> binary:replace(<<"abcde">>,<<"b">>,<<"[{]">>,[{insert_replaced,2}]).
<<"a[{b]cde">>

11> binary:replace(<<"abcde">>,<<"b">>,<<"[{]">>,[{insert_replaced,1},{insert_replaced,2}]).
<<"a[{b]cde">>
12> binary:replace(<<"abcde">>,<<"b">>,<<"[{]">>,[{insert_replaced,3},{insert_replaced,2}]).
<<"a[{b]cde">>
13> binary:replace(<<"abcde">>,<<"b">>,<<"[{]">>,[{insert_replaced,3},{insert_replaced,3}]).
<<"a[{]bcde">>
14> binary:replace(<<"abcde">>,<<"b">>,<<"[{]">>,[{insert_replaced,4},{insert_replaced,3}]).
<<"a[{]bcde">>
15> binary:replace(<<"abcde">>,<<"b">>,<<"[{]">>,[{insert_replaced,4},{insert_replaced,4}]).
** exception error: bad argument
in function binary:replace/4 (binary.erl, line 317)

17> binary:replace(<<"abcde">>,<<"b">>,<<"[{]">>,[{scope,{0,5}},{insert_replaced,0}]).
<<"ab[{]cde">>
18> binary:replace(<<"abcde">>,<<"b">>,<<"[{]">>,[{scope,{0,6}},{insert_replaced,0}]).
** exception error: bad argument
in function binary:replace/4 (binary.erl, line 317)
19> binary:split(<<0,100,4,255,255,9>>,[<<0,0>>,<<255,255>>],[global]).
[<<0,100,4>>,<<"\t">>]
20> binary:split(<<0,1,0,0,4,255,255,9>>,[<<0,0>>,<<255,255>>],[global]).
[<<0,1>>,<<4>>,<<"\t">>]
21> binary:split(<<0,1,0,0,4,255,255,0,9>>,[<<0,0>>,<<255,255>>],[global]).
[<<0,1>>,<<4>>,<<0,9>>]
22> binary:split(<<0,1,0,0,4,255,255,0,9>>,[<<0,0>>,<<255,255>>],[global,trim]).
[<<0,1>>,<<4>>,<<0,9>>]
23> binary:split(<<0,1,0,0,255,255,0,9>>,[<<0,0>>,<<255,255>>],[global,trim]).
[<<0,1>>,<<>>,<<0,9>>]
24> binary:split(<<0,1,0,0,255,255,0,9>>,[<<0,0>>,<<255,255>>],[global]).
[<<0,1>>,<<>>,<<0,9>>]

25> binary:split(<<0,1,0,0,0,9,255,255>>,[<<0,0>>,<<255,255>>],[global]).
[<<0,1>>,<<0,9>>,<<>>]
26> binary:split(<<0,1,0,0,0,9,255,255>>,[<<0,0>>,<<255,255>>],[global,trim]).
[<<0,1>>,<<0,9>>]
27> binary:split(<<0,0,1,1,0,9,255,255>>,[<<0,0>>,<<255,255>>],[global,trim]).
[<<>>,<<1,1,0,9>>]
28> binary:split(<<0,0,1,1,0,9,255,255>>,[<<0,0>>,<<255,255>>],[global]).
[<<>>,<<1,1,0,9>>,<<>>]

30> binary:split(<<"banana">>,<<"a">>,[{scope,{2,3}}]).
[<<"ban">>,<<"na">>]
31> binary:split(<<"banana">>,<<"a">>,[{scope,{2,3}},global]).
[<<"ban">>,<<"na">>]
32> binary:split(<<"banana">>,<<"a">>,[global]).
[<<"b">>,<<"n">>,<<"n">>,<<>>]
33> binary:split(<<"banana">>,<<"a">>,[{scope,{2,3}},global]).
[<<"ban">>,<<"na">>]
34> binary:split(<<"banana,banana">>,<<"a">>,[{scope,{2,3}},global]).
[<<"ban">>,<<"na,banana">>]
35> binary:split(<<"banana,banana">>,<<"a">>,[{scope,{2,3}},{scope,{9,3}}]).
[<<"banana,ban">>,<<"na">>]

36> binary:split(<<"banana,banana">>,<<"a">>,[{scope,{2,3}},{scope,{9,3}},gloabl]).
** exception error: bad argument
in function binary:split/3 (binary.erl, line 242)
37> binary:split(<<"banana,banana">>,<<"a">>,[{scope,{2,3}},{scope,{9,3}},global]).
[<<"banana,ban">>,<<"na">>]
38> binary:split(<<"banana,banana">>,<<"a">>,[{scope,{2,3}},global]).
[<<"ban">>,<<"na,banana">>]
39> binary:replace(<<"abcdefabc">>,
39> <<"abc">>,
39> [{scope,{0,4}},
39> {cope,{5,8}}]).
** exception error: bad argument
in function binary:replace/4 (binary.erl, line 317)

49> binary:replace(<<"abcdefok">>,[<<"abc">>,<<"ok">>],<<"HH">>,[global,{scope,{0,4}}]).
<<"HHdefok">>
50> binary:replace(<<"abcdefok">>,[<<"abc">>,<<"ok">>],<<"HH">>,[global,{scope,{0,4}},{scope,{5,3}}]).
<<"abcdefHH">>
51> binary:replace(<<"abcdefok">>,[<<"abc">>,<<"ok">>],<<"HH">>,[{scope,{0,4}},global]).
<<"HHdefok">>
52> binary:replace(<<"abcdefok">>,[<<"abc">>,<<"ok">>],<<"HH">>,[{scope,{0,4}},{scope,{5,3}},global]).
<<"abcdefHH">>
53> binary:replace(<<"abcdefok">>,[<<"abc">>,<<"ok">>],<<"HH">>,[{global,{5,3}},{scope,{0,4}},global]).
** exception error: bad argument
in function binary:replace/4 (binary.erl, line 317)
54> binary:replace(<<"abcdefok">>,[<<"abc">>,<<"ok">>],<<"HH">>,[{scope,{5,3}},{scope,{0,4}},global]).
<<"HHdefok">>
55> binary:referenced_byte_size(<<"yao">>).
256
56> binary:referenced_byte_size(<<"yaos">>).
256

binary

标签：io   ar   os   使用   sp   strong   数据   on   art   

原文地址：http://www.cnblogs.com/rubyist/p/4113222.html