Non-exhaustive pattern match(es) warning in lambda functions
Christian.Maeder at dfki.de
Tue Nov 16 11:49:02 EST 2010
What was the name of the flag for ghc-7.0.1?
I did not find it in the documentation. -fwarn-incomplete-patterns does
not work for my lambda expressions.
Am 22.09.2010 18:05, schrieb Simon Peyton-Jones:
> Good point. Simon and I have decided we agree. I'll push a patch shortly.
> | -----Original Message-----
> | From: glasgow-haskell-users-bounces at haskell.org [mailto:glasgow-haskell-
> | users-bounces at haskell.org] On Behalf Of Mitar
> | Sent: 21 September 2010 07:44
> | To: glasgow-haskell-users
> | Subject: Non-exhaustive pattern match(es) warning in lambda functions
> | Hi!
> | Why GHC does not warn (with -Wall) about non-exhaustive pattern
> | match(es) warning in lambda functions? For example, this code:
> | data Foo = Bar | Baz
> | test1 :: Foo -> IO ()
> | test1 Bar = return () -- Pattern match(es) are non-exhaustive warning, OK
> | test2 :: Foo -> IO ()
> | test2 = \Bar -> return () -- No pattern match(es) are non-exhaustive, BAD
> | I think it would be quite useful to also catch such situations and
> | issue a warning.
> | Mitar
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