[Haskell-beginners] Strange behavior

[Daniel Fischer]

On Monday 29 August 2011, 08:41:35, Luca Ciciriello wrote:
> Hi Alba.
> Since I've got no answer to my question I think that my strange behavior
>  is a very deep problem.

Well, perhaps it's not very deep, just not enough people on this list are 
familiar with dph.
In such cases, ask on haskell-cafe or #haskell to reach a wider audience.

Anyway, I'm pretty sure it's a bug in dph. If you change your code to avoid 
elemP:


isElement :: String -> Bool
isElement x = x `elemP1` parArr
  where
    elemP1 :: Eq a => a -> [:a:] -> Bool
    elemP1 v ar = lengthP (filterP (== v) ar) /= 0

you get the expected result(s) [but not with HEAD].

I've opened a ticket: http://hackage.haskell.org/trac/ghc/ticket/5438

>  I let you know when I have news.
> 
> Bye.
> 
> Luca.

Cheers,
Daniel