Haskell语言学习笔记（52）正则表达式

Text.Regex.PCRE.Heavy

$ brew install pcre

$ cabal install pcre-heavy

Installed pcre-heavy-1.0.0.2

Prelude> :m +Text.Regex.PCRE.Heavy

Prelude Text.Regex.PCRE.Heavy>

Prelude Text.Regex.PCRE.Heavy> :set -XQuasiQuotes

Prelude Text.Regex.PCRE.Heavy> :set -XFlexibleContexts

Prelude Text.Regex.PCRE.Heavy> "123-4567-89" =~ [re|\d{3}-(\d{4})-\d{2}|]

True

Prelude Text.Regex.PCRE.Heavy> scan [re|\d{3}-(\d{4})-\d{2}|] "123-4567-89"

[("123-4567-89",["4567"])]

Prelude Text.Regex.PCRE.Heavy> scanRanges [re|\d{3}-(\d{4})-\d{2}|] "123-4567-89"

[((0,11),[(4,8)])]

Prelude Text.Regex.PCRE.Heavy> sub [re|(\d+)-(\d+)-(\d+)|] (\(d1:d2:d3:_) -> d3 ++ "-" ++ d1 ++ "-" ++ d2)  "123-4567-89"

"89-123-4567"

Prelude Text.Regex.PCRE.Heavy> :set -XScopedTypeVariables

Prelude Text.Regex.PCRE.Heavy> sub [re|\d+|] (\(s::String) -> reverse s) "123-4567-89"

"321-4567-89"

Prelude Text.Regex.PCRE.Heavy> gsub [re|\d+|] (\(s::String) -> reverse s) "123-4567-89"

"321-7654-98"

Prelude Text.Regex.PCRE.Heavy> split [re|%(begin|next|end)%|] ("%begin%hello%next%world%end%" :: String)

["","hello","world",""]

• (=~) :: (ConvertibleStrings SBS a, ConvertibleStrings a SBS) => a -> Regex -> Bool
  
  (=~) 操作符函数检查字符串是否匹配指定正则表达式。
• scan :: (ConvertibleStrings SBS a, ConvertibleStrings a SBS) => Regex -> a -> [(a, [a])]
  
  scan 函数查找并返回字符串中所有出现的指定正则表达式。
• scanRanges :: (ConvertibleStrings SBS a, ConvertibleStrings a SBS) => Regex -> a -> [((Int, Int), [(Int, Int)])]
  
  scanRanges 函数查找字符串中所有出现的指定正则表达式，返回出现的所有位置。
• sub :: (ConvertibleStrings SBS a, ConvertibleStrings a SBS, RegexReplacement r) => Regex -> r -> a -> a
  
  sub 函数替换字符串中第一次出现的指定正则表达式。
• gsub :: (ConvertibleStrings SBS a, ConvertibleStrings a SBS, RegexReplacement r) => Regex -> r -> a -> a
  
  gsub 函数替换字符串中所有出现的指定正则表达式。
• split :: (ConvertibleStrings SBS a, ConvertibleStrings a SBS) => Regex -> a -> [a]
  
  split 函数使用指定正则表达式分割字符串。