A more useful Monoid instance for Data.Map

[Ian Lynagh]

On Tue, Mar 12, 2013 at 11:06:22AM -0400, Ben Gamari wrote:
> 
>   2) We decide it is acceptable to break users code multiple times, drop
>      the Monoid instance and reintroduce the new instance after some
>      delay. The length of this delay could range from no delay at all
>      (allowing folks to quickly move to the new instance, although
>      potentially unwittingly) to several months (hoping that most users
>      will realize the change during this window).

If we're talking about containers, if you want a meaningful delay, you'd
probably need at least one GHC+HP major release with no instance, and
and then the new instance would come with the next GHC+HP major release.
i.e. the delay would be at least a year.


Thanks
Ian