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Comment by thomasahle | Hacker News Reader

(.g) us a field selector, is (. g) then a function :: (a -> b) -> c -> b?

Yep! You could check this in GHCi (the repl), for example:

  > :t (. id)
  > (. id) :: (b -> c) -> b -> c

(:t prints the type of an expression, and id is the "identity function" that's b -> b here.)

(EDIT: Maybe you know the above and you're asking if it's being changed in the proposal. It doesn't seem so to me.)

I'm just pointing out that the difference between (.g) and (. g) is potentially easy to miss.