問題4.1
;; 4.1 ;L->R (define (list-of-values exps env) (if (no-operands? exps) '() (let ((val (eval (first-operand exps) env))) (cons val (list-of-values (rest-operands exps) env))))) ;R->L (define (list-of-values exps env) (if (no-operands? exps) '() (let ((val (list-of-values (rest-operands exps) env))) (cons (eval (first-operand exps) env) val))))