1 files changed, 35 insertions, 9 deletions
diff --git a/src/Hakyll/Web/CompressCss.hs b/src/Hakyll/Web/CompressCss.hs
index 58d52b4..0371d8b 100644
--- a/src/Hakyll/Web/CompressCss.hs
+++ b/src/Hakyll/Web/CompressCss.hs
@@ -8,14 +8,12 @@ module Hakyll.Web.CompressCss
 
 
 --------------------------------------------------------------------------------
-import           Data.Char               (isSpace)
 import           Data.List               (isPrefixOf)
 
 
 --------------------------------------------------------------------------------
 import           Hakyll.Core.Compiler
 import           Hakyll.Core.Item
-import           Hakyll.Core.Util.String
 
 
 --------------------------------------------------------------------------------
@@ -33,27 +31,55 @@ compressCss = compressSeparators . stripComments . compressWhitespace
 --------------------------------------------------------------------------------
 -- | Compresses certain forms of separators.
 compressSeparators :: String -> String
-compressSeparators =
-    replaceAll "; *}" (const "}") .
-    replaceAll " *([{};]) *" (take 1 . dropWhile isSpace) .
-    replaceAll ";+" (const ";")
-
+compressSeparators [] = []
+compressSeparators str
+    | isConstant = head str : retainConstants compressSeparators (head str) (drop 1 str)
+    | stripFirst  = compressSeparators (drop 1 str)
+    | stripSecond = compressSeparators (head str : (drop 2 str))
+    | otherwise   = head str : compressSeparators (drop 1 str)
+  where
+    isConstant  = or $ map (isOfPrefix str) ["\"", "'"]
+    stripFirst  = or $ map (isOfPrefix str) ["  ", " {", " }", " :", ";;", ";}"]
+    stripSecond = or $ map (isOfPrefix str) ["{ ", "} ", ": ", "; "]
 
 --------------------------------------------------------------------------------
 -- | Compresses all whitespace.
 compressWhitespace :: String -> String
-compressWhitespace = replaceAll "[ \t\n\r]+" (const " ")
-
+compressWhitespace [] = []
+compressWhitespace str
+    | isConstant = head str : retainConstants compressWhitespace (head str) (drop 1 str)
+    | replaceOne = compressWhitespace (' ' : (drop 1 str))
+    | replaceTwo = compressWhitespace (' ' : (drop 2 str))
+    | otherwise = head str : compressWhitespace (drop 1 str)
+  where
+    isConstant = or $ map (isOfPrefix str) ["\"", "'"]
+    replaceOne = or $ map (isOfPrefix str) ["\t", "\n", "\r"]
+    replaceTwo = or $ map (isOfPrefix str) [" \t", " \n", " \r", "  "]
 
 --------------------------------------------------------------------------------
 -- | Function that strips CSS comments away.
 stripComments :: String -> String
 stripComments [] = []
 stripComments str
+    | isConstant = head str : retainConstants stripComments (head str) (drop 1 str)
     | isPrefixOf "/*" str = stripComments $ eatComments $ drop 2 str
     | otherwise = head str : stripComments (drop 1 str)
   where
+    isConstant  = or $ map (isOfPrefix str) ["\"", "'"]
     eatComments str'
         | null str' = []
         | isPrefixOf "*/" str' = drop 2 str'
         | otherwise = eatComments $ drop 1 str'
+
+--------------------------------------------------------------------------------
+-- | Helper function to handle string constants correctly.
+retainConstants :: (String -> String) -> Char -> String -> String
+retainConstants f delim str
+    | null str = []
+    | isPrefixOf [delim] str = head str : f (drop 1 str)
+    | otherwise = head str : retainConstants f delim (drop 1 str)
+
+--------------------------------------------------------------------------------
+-- | Helper function to determine whether a string is a substring.
+isOfPrefix :: String -> String -> Bool
+isOfPrefix = flip isPrefixOf