Make TimeLocale an instance of Def

[chrisdone]

Whenever I use formatTime it's always with defaultTimeLocale. Why not make TimeLocale? an instance of Def from Data.Default?  http://hackage.haskell.org/package/data-default where def = defaultTimeLocale.

This would mean having to add data-default to GHC's distribution, but it's rather small and useful. The alternative is adding the instance in the data-default package, but then data-default depends on time-locale and we're still encouraging use of defaultTimeLocale. Swings and roundabouts.

Just an idea.

[snoyberg]

I like this idea. I also like the side-effect a lot: having Default in GHC's distribution would be a good thing IMO. I already use it in a number of places, and would encourage others to do so as well.

[igloo]

You mean "data-default depends on old-locale" I assume? If so then that's not a problem, as everyone will already have old-locale anyway as it comes with GHC and the Haskell Platform. Adding packages to GHC unnecessarily is a bad idea as it increases our workload, and makes it harder for other people to maintain them.