Missing brackets when replacing flip(:)

[feature-not-a-bug]

I discovered this while getting haskell-language-server set up. haskell/haskell-language-server#3020

Original file

$ cat foo.hlint.hs
foo :: [a] -> [a]
foo = foldl (\xs x -> x : xs) []

Refactored version:

$ hlint --refactor foo.hlint.hs
foo :: [a] -> [a]
foo = foldl (flip :) []

The expected code would be:

foo :: [a] -> [a]
foo = foldl (flip (:)) []

Using apply-refact-0.10.0.0 and The Glorious Glasgow Haskell Compilation System, version 9.2.3