proposal #2254: have Control.Arrow re-export (>>>) and (<<<)

[Don Stewart]

ross:
> On Wed, Apr 30, 2008 at 04:55:47PM -0700, Don Stewart wrote:
> > ross:
> > > A previous proposal:
> > > 
> > > 	http://hackage.haskell.org/trac/ghc/ticket/1773
> > > 
> > > split the Arrow class, making (>>>) and (<<<) functions in
> > > Control.Category.  This breaks programs that use Control.Arrow.
> > > 
> > > To avoid some of the breakage, the proposal is that Control.Arrow should
> > > re-export (>>>) and (<<<), imported from Control.Category.
> > 
> > This patch has been applied (xmonad was broken due to the change, so I
> > thought it best to act).
> 
> I thought we had a process for API changes.

Yeah, that's my fault. I saw Duncan submitted the proposal about a week
ago, and no one had objected, and then I ran into xmonad breaking due to
it.
  
> I'm not sure what the right thing is here.  I usually prefer to avoid
> re-exports because they create problems with warnings.

If it is objected to we can revert.

-- Don