The dreaded M-R

[Andrew Pimlott]

On Tue, Jan 31, 2006 at 12:52:51AM +0000, Neil Mitchell wrote:
> > Second, a warning about "loss of sharing" may befuddle beginners (who
> > are usually not taught to write type signatures at the start).
> 
> Are standards documents the place for prescribing which warnings
> should be raised, and under what circumstances?
> 
> If someone is using GHC, and has specified -O2 then clearly something
> that causes vastly more time is a problem. If someone is learning
> Haskell and is using Hugs then they probably couldn't care less.
> Perhaps some warnings should be left up to the implementation to
> decide...

My ultimate point was that the possibility of a warning should carry
very little weight (if any) when analyzing the pros and cons of a
language change.  If you want to argue that a warning would mitigate a
disadvantage of a change, you need to think about when the warning would
be emitted, which I agree should be outside the scope of a standards
discussion.  So I am just suggesting that we simplify the discussion by
not talking about warnings (which suggestion I will follow as soon as I
hit send!).

Andrew