Parsing function application with Happy

How would I parse something like

f x y

Into

APPLY (APPLY f x) y

using Happy? Right now I have a rule that says

%left APP
Expr : Expr Expr %prec APP { APPLY $1 $2 }

But that parses the above as

APPLY f (APPLY x y)

You can encode left/right associativity using grammar rules.

For example, have a look at this basic lambda calculus parser:

https://github.com/ghulette/haskell-parser-examples/blob/master/src/HappyParser.y

The operative productions are:

Expr : let VAR '=' Expr in Expr    { App (Abs $2 $6) $4 }
     | '\\' VAR '->' Expr          { Abs $2 $4 }
     | Form                        { $1 }

Form : Form '+' Form               { Binop Add $1 $3 }
     | Juxt                        { $1 }

Juxt : Juxt Atom                   { App $1 $2 }
     | Atom                        { $1 }

Atom : '(' Expr ')'                { $2 }
     | NUM                         { Num $1 }
     | VAR                         { Var $1 }