Declaration with types test

======

let a: Num = 1 + 1
let add_a x: Num -> Num = x + a

======

(file
  (statement
    (decl
      (ident: "a")
      (type_annot
        (type_expr
          (type_ident
            (type_name: "Num")
          )
        )
      )
      (expr
        (infix_expr
          (literal
            (integer: "1")
          )
          (operator: "+")
          (literal
            (integer: "1")
          )
        )
      )
    )
  )
  (statement
    (decl
      (ident: "add_a")
      (ident: "x")
      (type_annot
        (type_expr
          (func
            (type_ident
              (type_name: "Num")
            )
            (type_expr
              (type_ident
                (type_name: "Num")
              )
            )
          )
        )
      )
      (expr
        (infix_expr
          (ident: "x")
          (operator: "+")
          (ident: "a")
        )
      )
    )
  )
  (EOI: "")
)