Add Data.Eq.equating to match Data.Ord.comparing?

I recently wanted to group a list of pairs by the second item in the pairs. So I tried writing

x = groupBy (comparing snd) pairs

But this threw a type error because groupBy expects its first argument to return a Bool and comparing returns an Ordering. So I had to write

x = groupBy ((== EQ) . comparing snd) pairs

Which is clunky. What I needed was a function in Data.Eq such as

equating :: Eq a => (b -> a) -> b -> b -> Bool

This could be generalised to a function such as

pairWise :: (b -> b -> c) -> (a -> b) -> a -> a -> c pairWise pair project x y = pair (project x) (project y)

Then we can write

comparing = pairWise compare equating = pairWise (==)

Should I submit a patch to add this? And is "pairWise" the right name? Paul.