; fibonacci hash

(define (fibhash h)
  (let ((two64 (expt 2 64)) (two54 (expt 2 54)))
    (quotient (modulo (* h 11400714819323198485) two64)
              two54)))

(display (fibhash 123412341234)) (newline)
(display (fibhash 12341234123412341234)) (newline)
(display (fibhash 1234123412341234123412341234)) (newline)