FunctorM

[Ross Paterson]

On Thu, Mar 02, 2006 at 05:02:39AM -0800, John Meacham wrote:
> On Thu, Mar 02, 2006 at 12:41:22PM +0000, Ross Paterson wrote:
> > I propose to deprecate Data.FunctorM in favour of Data.Traversable:
> 
> I have no particular objection, The applicative stuff looks interesting,
> though I have not explored it too much.
> 
> my only request is that we add 'mapM_' and 'sequence_' to the
> traversable class, there are many monads for which they are vital for
> controlling space leaks.

They're in Data.Foldable, though not as class methods:

http://www.haskell.org/ghc/dist/current/docs/libraries/base/Data-Foldable.html

e.g. Set is an instance of Foldable but not Traversable.