[Haskell-cafe] Help using catch in 6.10

[Victor Nazarov]

Hello, cafe.

I whant to switch to GHC 6.10

My application compiled fine with 6.8.3, but after switchin to 6.10,
I've got errors about usage of catch function:

Main.hs:165:14:
    Ambiguous type variable `e2' in the constraint:
      `Exception e2' arising from a use of `catch' at Main.hs:165:14-38
    Probable fix: add a type signature that fixes these type variable(s)

Main.hs:261:17:
    Ambiguous type variable `e' in the constraint:
      `Exception e' arising from a use of `handle' at Main.hs:261:17-118
    Probable fix: add a type signature that fixes these type variable(s)

Relevant places in code are:

...
         getNSteps f =
           do text <- get entryNSteps entryText
              catch (readIO text >>= f) $ \_e ->
                do msgBox (Just window) [] MessageWarning ButtonsOk $
"Число шагов указано неверно: " ++ show text
                   return ()
...
loadData :: IO ([Term], Map.Map String Term)
loadData =
  do examples <- handle (\_e -> msgBox Nothing [] MessageWarning
ButtonsOk "Ошибка чтения файла примеров" >> return []) $
       do examplesLines <- fmap lines $ readFile "examples.txt"
          let parsings :: [Term]
              parsings = concatMap (fromEither . parse) examplesLines
              parse :: String -> Either ParseError Term
              parse = Parsec.parse (Lambda.parser >>= \t -> skipMany
space >> eof >> return t) ""
              fromEither :: Either ParseError Term -> [Term]
              fromEither = either (const []) (\t -> [t])
          return parsings
...


-- 
Victor