Re: How to catch an exception

21 Jul 2003


      On Mon, Jul 21, 2003 at 02:12:02PM +0100, Bayley, Alistair wrote:
...
...
module Main where
import Control.Exception hiding (GHC.Prelude.catch)
This hiding clause is illegal.  But anyway what you want is
...
import Prelude hiding (catch)
import Control.Exception
Prelude.catch only catches Haskell 98 exceptions; Control.Exception.catch
catches everything.
...
...
temp :: IO ()
temp = do
  putStrLn "line 1"
  ioError (AssertionFailed "my temp")
...
From GHC 6.0, Exception is not the same as IOError: say throwIO instead
of ioError here.  (So GHC 6.0 flags your error as a type error.)

Re: How to catch an exception

Ross Paterson