Simon Peyton-Jones schrieb:
Aha! You are the second real customer to discover a change I made to
"customer" sounds as if I will have to pay next time.
GHC 6.6, namely that pattern bindings are not generalised. It's a documented change (see "Monomorphic pattern bindings" in the 6.6 user manual), but it means that 6.6 is not, by default, exactly Haskell 98. To recover the previous behaviour use -fno-mono-pat-binds.
thanks for pointing this out!
You can solve your problem in three ways * -fno-mono-pat-binds * use the fst/snd thing as you suggest * put the polymorphic function in the tuple as Bulat suggested (this makes use of GHC's new ability to impredicative polymorphism.
Last question, is using "fst/snd" really a problem as I suspected by using the constant twice? (I actually didn't explicitly inline the constant by two calls of unsafePerfromIO.) Thanks again, Christian
| -----Original Message-----
| mkSimpleFallOut :: (ObjectID,IO a -> IO (Either String a)) | mkSimpleFallOut = unsafePerformIO newFallOut | {-# NOINLINE mkSimpleFallOut #-} | | newFallOut :: IO (ObjectID, IO a -> IO (Either String a))
| simpleFallOutId = fst mkSimpleFallOut | addSimpleFallOut = snd mkSimpleFallOut | | However, in this case I have inlined mkSimpleFallOut manually! Does this | matter? If so, how could I rewrite the above code?