Spelling correction for LANGUAGE pragmas

[ghc-hetmet.git] / compiler / main / HeaderInfo.hs

diff --git a/compiler/main/HeaderInfo.hs b/compiler/main/HeaderInfo.hs
index e16c2ce..b520098 100644 (file)
--- a/compiler/main/HeaderInfo.hs
+++ b/compiler/main/HeaderInfo.hs
@@ -264,7 +264,6 @@ checkExtension (L l ext)
 -- its corresponding flag. Otherwise it throws an exception.
  =  let ext' = unpackFS ext in
     if ext' `elem` supportedLanguages
-       || ext' `elem` (map ("No"++) supportedLanguages)
     then L l ("-X"++ext')
     else unsupportedExtnError l ext'
 
@@ -281,7 +280,9 @@ unsupportedExtnError :: SrcSpan -> String -> a
 unsupportedExtnError loc unsup =
   throw $ mkSrcErr $ unitBag $
     mkPlainErrMsg loc $
-        text "Unsupported extension: " <> text unsup
+        text "Unsupported extension: " <> text unsup $$
+        if null suggestions then empty else text "Perhaps you meant" <+> quotedListWithOr (map text suggestions)
+  where suggestions = fuzzyMatch unsup supportedLanguages
 
 
 optionsErrorMsgs :: [String] -> [Located String] -> FilePath -> Messages