Proposal: keep Data.Map.foldWithKey

[Ross Paterson]

On Fri, Jan 14, 2011 at 11:13:31AM +0100, Gregory Collins wrote:
> hunk ./Data/IntMap.hs 117
>              -- ** Fold
>              , fold
>              , foldWithKey
> +            , foldlWithKey
> +            , foldrWithKey
> +            , foldlWithKey'
> +            , foldrWithKey'
>  
> [...]
> +{-# DEPRECATED foldWithKey "Use foldrWithKey instead" #-}

The additions improve consistency between Data.Map and Data.IntMap,
which is clearly the right thing to do.

I also believe that deprecating the redundant foldWithKey in both modules
is also a good first step toward trimming the redundancy from these APIs.
I would also favour deprecating fold in all four modules in favour of
Data.Foldable.foldr.