+\begin{code}
+pprFSInCStyle :: FAST_STRING -> SDoc
+-- Assumes it contains only characters '\0'..'\xFF'!
+pprFSInCStyle fs = pprStringInCStyle (_UNPK_ fs)
+
+pprStringInCStyle :: String -> SDoc
+pprStringInCStyle s = doubleQuotes (text (concatMap charToC s))
+
+charToC :: Char -> String
+charToC '\"' = "\\\""
+charToC '\'' = "\\\'"
+charToC '\\' = "\\\\"
+charToC c | c >= ' ' && c <= '~' = [c]
+ | c > '\xFF' = panic ("charToC "++show c)
+ | otherwise = ['\\',
+ chr (ord '0' + ord c `div` 64),
+ chr (ord '0' + ord c `div` 8 `mod` 8),
+ chr (ord '0' + ord c `mod` 8)]
+\end{code}