26 Nov
2008
26 Nov
'08
4:38 p.m.
On Wed, Nov 26, 2008 at 04:02:36PM -0500, David Menendez wrote:
I also think trying to shoe-horn a new, incompatible definition for Arrow into a base-3.0.* release was a mistake. The whole point of having a versioning policy is lost if you don't follow it. Given how isolated Arrow is in the standard libraries, they could have just created a new class and deprecated the old one without causing much fuss.
It is isolated in base, but it's also wired into GHC. The whole point of base-compat is to present a different view of the same entities, so that packages using the base-3 interface and those using the base-4 interface can be combined. There was no way that could work with a changed Arrow class.