bug?

Levent Erkok erkokl at gmail.com
Fri May 12 19:44:01 EDT 2006


for the following program:
----------------------------
module Bug where

f :: Maybe Bool
f = g ()

g () = do f
          error "bug?"
----------------------------

If I ask ghci (version: 6.4.1) what the type of g is, it says:
----------------------------
*Bug> :t g
g :: () -> Maybe Bool
----------------------------

However, I think it should be:
----------------------------
Bug> :t g
g :: () -> Maybe a
----------------------------
as reported by Hugs (version: March 2005).

I first thought this was a monomorphism-restriction gotcha, but g is
obviously a function, not a constant. And Hugs reports the more general
expected type anyhow.

I'm curious to see if this is a real bug or some weird interaction with
ghci..

-Levent.

PS. I've submitted through "trac" as well, but the formatting was all messed
up; so resending via e-mail.
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