GHC 6.4 release candidates available

Simon Peyton-Jones simonpj at
Wed Mar 2 11:14:30 EST 2005


You have a pragma "-fallow-overlapping-instances" in Test.hs, and indeed
it is honoured when compiling Test.hs.  But it's not taken into account
when compiling top-level expressions, or, indeed, if you were to import
Test into another module.

If you say ":set -falllow-overlapping-instances" it'll work fine.

Now, maybe you'd like the flag to attach permanently to the *instance*,
so that if an instance decl is compiled with
-fallow-overlapping-instances, then no complaint will ever be issued for
its overlaps, even if it is imported into a module that doesn't have
-fallow-overlapping-instances.  That would make sense, I think, but it's
not implemented and never has been.  


| -----Original Message-----
| From: glasgow-haskell-users-bounces at
| bounces at] On Behalf Of Ralf Lammel
| Sent: 02 March 2005 08:45
| To: glasgow-haskell-users at
| Subject: RE: GHC 6.4 release candidates available
| I think this is an old bug,
| or at least I have seen it months back.
| The "overlapping instances" directive does not make it to the
| See attached sample with the offending session.
| Thanks for fixing.
| Ralf

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