Where is the source for: “Function application has higher precedence than infix operators” [Haskell]

问题

I'm learning about operator precedence in Haskell. Several places across the web mention that function application has higher precedence than operators, but I couldn't find a definitive source for that.

Here is one such mention from A Gentle Introduction To Haskell:

Function application has higher precedence than any infix operator

There is a section in the Haskell 98 Report that alludes to it:

normal constructor application has higher precedence than infix constructor application

Where is a definitive source? I would expect it to be included in the Haskell 98 Report, perhaps I'm not reading it correctly.

回答1:

You can find it here in the EBNF:

exp^10 -> ...
        | fexp

fexp -> [fexp] aexp

which basically means that function application has precedence 10, higher than any you are allowed to give to an operator.

回答2:

The Haskell Report is itself a definitive reference, so the quote you found is sufficient.

You can also find the same information in the grammar.

fexp -> [fexp] aexp
exp_10 -> ... | fexp

You can see that function application has precedence "10" whereas all the infix / prefix operators are 9 or lower.

来源：https://stackoverflow.com/questions/39750651/where-is-the-source-for-function-application-has-higher-precedence-than-infix