fix a regexReplaceCI bug

hledger-lib/Hledger/Utils/Regex.hs

@@ -32,7 +32,7 @@ module Hledger.Utils.Regex (
   ,regexReplace
   ,regexReplaceCI
   ,regexReplaceBy
-  ,regexToCaseInsensitive
+  -- ,regexpToCI
   ,regexSplit
   ,toRegex
   )
@@ -52,9 +52,6 @@ type Replacement = String
 containsRegex :: Regexp -> String -> Bool
 containsRegex = regexMatchesCI
 
-regexToCaseInsensitive :: Regexp -> Regexp
-regexToCaseInsensitive r = "(?i)"++ r
-
 -- regexpr - may be slow
 
 regexSplit :: Regexp -> String -> [Regexp]
@@ -64,19 +61,19 @@ regexSplit = splitRegexPR
 -- regexMatch r s = matchRegexPR r s
 
 -- regexMatchCI :: Regexp -> String -> MatchFun Maybe
--- regexMatchCI r s = regexMatch (regexToCaseInsensitive r) s
+-- regexMatchCI r s = regexMatch (regexpToCI r) s
 
 -- regexMatches :: Regexp -> String -> Bool
 -- regexMatches r s = isJust $ matchRegexPR r s
 
 -- regexMatchesCI :: Regexp -> String -> Bool
--- regexMatchesCI r s = regexMatches (regexToCaseInsensitive r) s
+-- regexMatchesCI r s = regexMatches (regexpToCI r) s
 
 -- regexReplace :: Regexp -> Replacement -> String -> String
 -- regexReplace r repl s = gsubRegexPR r repl s
 
 -- regexReplaceCI :: Regexp -> Replacement -> String -> String
--- regexReplaceCI r s = regexReplace (regexToCaseInsensitive r) s
+-- regexReplaceCI r s = regexReplace (regexpToCI r) s
 
 -- regexReplaceBy :: Regexp -> (String -> Replacement) -> String -> String
 -- regexReplaceBy r replfn s = gsubRegexPRBy r replfn s
@@ -101,18 +98,31 @@ regexMatches :: Regexp -> String -> Bool
 regexMatches = flip (=~)
 
 regexMatchesCI :: Regexp -> String -> Bool
-regexMatchesCI r = match (makeRegexOpts compOpt{caseSensitive=False} execOpt r)
+regexMatchesCI r = match (toRegexCI r)
 
 regexReplace :: Regexp -> Replacement -> String -> String
 regexReplace r repl = regexReplaceBy r (const repl)
 
 regexReplaceCI :: Regexp -> Replacement -> String -> String
-regexReplaceCI r s = regexReplace (regexToCaseInsensitive r) s
+regexReplaceCI r repl = regexReplaceByCI r (const repl)
 
 regexReplaceBy :: Regexp -> (String -> Replacement) -> String -> String
 regexReplaceBy r = replaceAll (toRegex r)
 
--- from http://stackoverflow.com/questions/9071682/replacement-substition-with-haskell-regex-libraries
+regexReplaceByCI :: Regexp -> (String -> Replacement) -> String -> String
+regexReplaceByCI r = replaceAll (toRegexCI r)
+
+toRegexCI :: Regexp -> Regex
+toRegexCI = makeRegexOpts compOpt{caseSensitive=False} execOpt
+
+-- regexpToCI :: Regexp -> Regexp
+-- regexpToCI r = "(?i)"++ r
+
+-- from
+-- http://stackoverflow.com/questions/9071682/replacement-substition-with-haskell-regex-libraries
+-- | Replace all occurrences of a regexp in a string using a replacer
+-- function, which receives the matched string as its argument.
+-- Does not support standard RE syntax such as \1.
 replaceAll :: Regex -> (String -> Replacement) -> String -> String
 replaceAll re f s = start end
   where