Function Declaration Test

======

let add a b = a + b
let add1 a = add a 1

======

(file
  (statement
    (decl
      (ident: "add")
      (ident: "a")
      (ident: "b")
      (expr
        (infix_expr
          (ident: "a")
          (operator: "+")
          (ident: "b")
        )
      )
    )
  )
	(statement
    (decl
      (ident: "add1")
      (ident: "a")
      (expr
        (call_expr
          (ident: "add")
          (ident: "a")
          (literal
            (integer: "1")
          )
        )
      )
    )
  )
  (EOI: "")
)