RosettaCodeData/Task/Runtime-evaluation-In-an-environment/EchoLisp/runtime-evaluation-in-an-environment.echolisp
2016-12-05 23:44:36 +01:00

12 lines
325 B
Text

(define (eval-with-x prog x)
(eval prog (environment-new (list (list 'x x)))))
(define prog '( + 1 (* x x)))
(eval-with-x prog 10) → 101
(eval-with-x prog 1000) → 1000001
(- (eval-with-x prog 1000) (eval-with-x prog 10)) → 999900
;; check x is unbound (no global)
x
😖️ error: #|user| : unbound variable : x