On Saturday 26 February 2011 02:08:48, Xavier Shay wrote:
Excellent. I had to update the code to use the new Control.Exception (rather than Control.OldException), and ended up with:
import Control.Exception
TestCase $ do handle (\(_ :: ErrorCall) -> return ()) $ do evaluate ( myFunc 3 [False, False, True] ) assertFailure "must raise an error on invalid state"
The only issue is that I now require the -XScopedTypeVariables flag, otherwise it fails to compile with:
Illegal signature in pattern: ErrorCall Use -XScopedTypeVariables to permit it
I am not sure whether this is an acceptable solution or not.
ScopedTypeVariables is harmless, so it is accetable. But if you prefer, you can avoid it with a top-level handler ignoreErrorCalls :: ErrorCall -> IO () ignoreErrorCalls _ = return () TestCase $ ignoreErrorCalls $ do evaluate ( myFunc 3 [False, False, True] ) assertFailure "must raise an error on invalid state" or an explicit pattern in the handler, TestCase $ handle (\(ErrorCall _) -> return ()) $ do evaluate ... I think (code untested).
I tried reading this: http://www.haskell.org/ghc/docs/latest/html/users_guide/other-type-exten sions.html#pattern-type-sigs
... but I don't know enough about haskell for it to make any sense to me yet.
Cheers, Xavier