base-18.104.22.168 not backwards compatible with base-22.214.171.124
igloo at earth.li
Wed Nov 19 09:21:10 EST 2008
On Wed, Nov 19, 2008 at 03:06:04PM +0100, Stefan Holdermans wrote:
> Could anyone confirm the following claims?
> * base-126.96.36.199 (shipped with GHC 6.10.1) is supposed to be backwards
> compatible with base-188.8.131.52 (shipped with GHC 6.8.3) ...
> * ... but it isn't! (For example, the Arrow class from Control.Arrow
> is a subclass of Category from Control.Category in base-184.108.40.206, but
> not in base-220.127.116.11.)
Yes. It wasn't possible to handle this change in a compatible way, I'm
> Do we know of any similar issues?
I think the Arrow/Category changes are the only issue. I think one of
the methods moved from one class to the other as well.
> What's the recommended workaround
> when shipping code that is to support both GHC 6.8.* and GHC 6.10.*?)
CPP is the best solution I can think of.
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