haskell-definition-face not used when as-pattern precedes infix function definition

[eigengrau]

When a function is defined in infix syntax, haskell-definition-face applies to the function name. So in the following, op will bear the definition face.

foo `op` bar = undefined

However, haskell-definition-face will fail to be assigned when an as-pattern precedes the function name. So, op below receives haskell-operator-face.

foo@Nothing `op` bar = undefined

[gracjan]

Ugh, this one is real tough, if we complicate a little:

foo@RadomRecord { withFields = (_,Just assignAVar) } `op` bar

going over the part after @ needs more than a regexp. I'm guessing it is doable in Emacs, but current haskell-font-lock.el does not allow for an easy way of doing it.

[gracjan]

Not only tokenizer, full parser is needed. The one from haskell-indentation could be retroffieted to do what we need.

[gracjan]

See also #1122.

[gracjan]

No semantic therefore no fix for this one.