Andy Stewart wrote:

Now GHC use .hs-boot fix "mutually recursive modules" problem, yes it can work, but it not pretty.

So GHC can fix this problem automatically at next release version?

Please add yourself (that is, your e-mail address) to the "cc:" on the corresponding bug-report, if you want to vote for this feature: http://hackage.haskell.org/trac/ghc/ticket/1409 (you can login as user "guest", password "guest") If enough people do this, then GHC HQ might start to believe that it's an important feature. (Right now they/we seem to think it's a little absurd... probably because it would require some implementation/design work in GHC...) -Isaac