(define-syntax define-memoize
  (syntax-rules ()
    ((_ (name arg ...) body ...)
     (define name
       (let ((cache (make-hash-table 'equal?)))
         (lambda (arg ...)
           (let ((val (hash-table-get cache `(,arg ...) #f)))
             (if val
                 val
                 (let ((val (begin body ...)))
                   (hash-table-put! cache `(,arg ...) val)
                   val)))))))))


(define-memoize (fib n)
  (if (< n 2)
      1
      (+ (fib (- n 1))
         (fib (- n 2)))))

;(time (fib 100))
; real   0.000
; user   0.000
; sys    0.000
573147844013817084101


(define-syntax define-memoize
  (syntax-rules ()
    ((_ (name arg ...) body ...)
     (define name
       (let ((cache (make-hash-table 'equal?)))
         (lambda (arg ...)
           (let ((al `(,arg ...)))
             (let ((val (hash-table-get cache al #f)))
               (if val
                   val
                   (let ((val (begin body ...)))
                     (hash-table-put! cache al val)
                     val))))))))))