;; なんか普通のオブジェクト指向っぽい感じだ。(define(make-from-mag-arg r a)(define(dispatch op)(cond((eq? op 'real-part)(* r (cos a)))((eq? op 'imag-pert)(* r (sin a)))((eq? op 'magnitude) r)((eq? op 'angle) a)(else(error "Unknown op -- MAKE-FROM-MAG-ARG" op))))
dispatch)