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-rw-r--r--src/Hakyll/Core/Util/String.hs48
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diff --git a/src/Hakyll/Core/Util/String.hs b/src/Hakyll/Core/Util/String.hs
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+-- | Miscellaneous string manipulation functions.
+--
+module Hakyll.Core.Util.String
+ ( trim
+ , replaceAll
+ , splitAll
+ ) where
+
+import Data.Char (isSpace)
+import Data.Maybe (listToMaybe)
+
+import Text.Regex.PCRE ((=~~))
+
+-- | Trim a string (drop spaces, tabs and newlines at both sides).
+--
+trim :: String -> String
+trim = reverse . trim' . reverse . trim'
+ where
+ trim' = dropWhile isSpace
+
+-- | A simple (but inefficient) regex replace funcion
+--
+replaceAll :: String -- ^ Pattern
+ -> (String -> String) -- ^ Replacement (called on capture)
+ -> String -- ^ Source string
+ -> String -- ^ Result
+replaceAll pattern f source = replaceAll' source
+ where
+ replaceAll' src = case listToMaybe (src =~~ pattern) of
+ Nothing -> src
+ Just (o, l) ->
+ let (before, tmp) = splitAt o src
+ (capture, after) = splitAt l tmp
+ in before ++ f capture ++ replaceAll' after
+
+-- | A simple regex split function. The resulting list will contain no empty
+-- strings.
+--
+splitAll :: String -- ^ Pattern
+ -> String -- ^ String to split
+ -> [String] -- ^ Result
+splitAll pattern = filter (not . null) . splitAll'
+ where
+ splitAll' src = case listToMaybe (src =~~ pattern) of
+ Nothing -> [src]
+ Just (o, l) ->
+ let (before, tmp) = splitAt o src
+ in before : splitAll' (drop l tmp)