Hello plt-scheme users ,
I am new to scheme and sorry to ask a newbie question.
I want to let function return the value , for example , in Drscheme :
>(define add2 (lambda (i) (+ i i)))
>(add2 2)
4
I type (add2 2) in command line and it will return a value 4.
But when I type my function foo in the command line
>(define y '(1 2 3 4))
>(define dt 1)
>(define foo
(lambda (t) (do ((i 0 (+ i 1))) ((> i 3)) (if (and (>= t 0) (and (>= t (*
i dt)) (< t (* (+ i 1) dt)))) (list-ref y i) #f))))
>(foo 0) ---->this should return 1 , but there is no value to come out.
>(foo 1) ---->this should return 2
.
.
.
and so on.
Can anyone tell me how to solve this problem ? I really appreciate your
knowledge and hope I won't cause your inconvenience.
Best Regards ,
Hsiu-Hao Tsao
Master Student
Ultrafast Photonics Laboratory ,
Institute Photonics of Technologies ,
National Tsing Hua University , Taiwan
Lab : +8863-5715131-34178
Office : +8863-5715131-34007
Cell Phone : +886920158033
