-showLitChar c | c > '\DEL' = showChar '\\' . protectEsc isDigit (shows (ord c))
-showLitChar '\DEL' = showString "\\DEL"
-showLitChar '\\' = showString "\\\\"
-showLitChar c | c >= ' ' = showChar c
-showLitChar '\a' = showString "\\a"
-showLitChar '\b' = showString "\\b"
-showLitChar '\f' = showString "\\f"
-showLitChar '\n' = showString "\\n"
-showLitChar '\r' = showString "\\r"
-showLitChar '\t' = showString "\\t"
-showLitChar '\v' = showString "\\v"
-showLitChar '\SO' = protectEsc (== 'H') (showString "\\SO")
-showLitChar c = showString ('\\' : asciiTab!!ord c)
+showLitChar c s | c > '\DEL' = showChar '\\' (protectEsc isDigit (shows (ord c)) s)
+showLitChar '\DEL' s = showString "\\DEL" s
+showLitChar '\\' s = showString "\\\\" s
+showLitChar c s | c >= ' ' = showChar c s
+showLitChar '\a' s = showString "\\a" s
+showLitChar '\b' s = showString "\\b" s
+showLitChar '\f' s = showString "\\f" s
+showLitChar '\n' s = showString "\\n" s
+showLitChar '\r' s = showString "\\r" s
+showLitChar '\t' s = showString "\\t" s
+showLitChar '\v' s = showString "\\v" s
+showLitChar '\SO' s = protectEsc (== 'H') (showString "\\SO") s
+showLitChar c s = showString ('\\' : asciiTab!!ord c) s
+ -- I've done manual eta-expansion here, becuase otherwise it's
+ -- impossible to stop (asciiTab!!ord) getting floated out as an MFE