[Haskell] Continuation Monad (1) [id:yts:20050102#p2] の続き。 13.2 Escaping continuations Example (define list-product (lambda (s) (call/cc (lambda (exit) (let recur ((s s)) (if (null? s) 1 (if (= (car s) 0) (exit 0) (* (car s) (recur (cd…