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haskelloperator-precedence
cdosborn
cdosborn

Reputation: 3459

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

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.

Upvotes: 2

Views: 248

Answers (2)

Dietrich Epp
Dietrich Epp

Reputation: 213578

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.

Upvotes: 6

Tarmil
Tarmil

Reputation: 11372

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.

Upvotes: 6

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