Documentation

>>> Test ("в"::ByteString) =~ "тихо в лесу"

True

>>> Test (toByteString "в") =~ toByteString "тихо в лесу"

True

>>> Once ("^all"::String) =~ "all the time"

["all"]

>>> Once ("^all"::String) =~ "all the time"

["all"]

static replace for simple (no group) needle

for no-regex ByteString replacement see Text.Regex.Do.Split

>>> replace (Once (Pattern "^a\\s")) (Replacement "A") (Body "a bc")

"Abc"

dynamic group replace

>>> replace (Once (Pattern "\\w=(\\d{1,3})")) replacer $ Body "a=101 b=3 12"

"a=[1 0 1] b=3 12"

to tweak regex with Comp or Exec, see Text.Regex.Do.Type.Regex

dynamic group replace

custom replacer fn returns replacement value. See defaultReplacer

>>> replacer::GroupReplacer String
    replacer = defaultReplacer 1 tweak1
          where tweak1 str1 = case str1 of
                                "101" -> "[1 0 1]"
                                "3" -> "[ 3 ]"
                                otherwise -> trace str1 "?"

>>> replace (All (Pattern "\\w=(\\d{1,3})")) replacer $ Body "a=101 b=3 12"

"a=[1 0 1] b=[ 3 ] 12"

>>> replacer::GroupReplacer (Utf8_ ByteString)
        replacer = defaultReplacer 1 tweak1
         where tweak1 bs1 = toByteString' $
                               if bs1 == toByteString' "左" then
                                     "ー右ー"
                                      else "?"

>>> runFn1 `shouldBe` toByteString "100メートルー右ー折後、左"
       where runFn1 =
                let rx1 = Pattern $ toByteString' "(?<=ル)(左)"
                    body1 = Body $ toByteString' "100メートル左折後、左"
                in replace (All rx1) replacer body1        

>>> PosLen' ("и"::String) =~ "бывает и хуже"

[(13,2)]

>>> PosLen' ("и"::String) =~ "бывает и хуже"

[(13,2)]