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; behaves like `car&cdr` [see exercise 1.18.2], but does not use `compose` in its output
(define car&cdr2
  (lambda (s slist errvalue)
    (let ((result (car&cdr2-2 s slist errvalue 'x)))
      (if (equal? result errvalue)
          errvalue
          (cons 'lambda (cons '(x) (list result)))))))

(define car&cdr2-2
  (lambda (s slist errvalue path)
    (cond
      ((null? slist) errvalue)
      ((equal? (car slist) s) (cons 'car (list path)))
      (else (let (
                   (car-result 
                    (if (list? (car slist)) 
                        (car&cdr2-2 s (car slist) errvalue (cons 'car (list path))) 
                        errvalue)))
               (if (equal? car-result errvalue)
                   (car&cdr2-2 s (cdr slist) errvalue (cons 'cdr (list path)))
                   car-result))))))



(car&cdr2 'a '(a b c) 'fail)
; (lambda (x) (car x))

(car&cdr2 'c '(a b c) 'fail)
; (lambda (x) (car (cdr (cdr x))))

(car&cdr2 'dog '(cat lion (fish dog ()) pig) 'fail)
; (lambda (x) (car (cdr (car (cdr (cdr x))))))

(car&cdr2 'a '(b c) 'fail)
; fail