info
Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
Changing Elements in a list with skill
4,024 views
Skip to first unread message
Ralf Geiger
Dec 12, 2002, 5:43:38 AM12/12/02
to
Hello *,
Suppose I have a list
(1 2 3 4 5 6 7 8 9 10) and I'd like to change the seventh element to a value
e.g. 10. So that the result looks like this: (1 2 3 4 5 6 10 8 9 10)
What is the best way to do this since there is no function like
setnth ...
Best regards
Ralf
--
no signature
Andrew Beckett
Dec 12, 2002, 9:09:05 AM12/12/02
to
Well, in general operations which require you to change the nth entry in a list
suggest to me that you shouldn't be using a list but an array type structure
(either an array or an association table), because lists are sequentially
accessed from the beginning rather than being random access (or
near-random in the case of association tables). However, provided
the entry you're trying to modify is not too far along the list, you can do:
suggest to me that you shouldn't be using a list but an array type structure
(either an array or an association table), because lists are sequentially
accessed from the beginning rather than being random access (or
near-random in the case of association tables). However, provided
the entry you're trying to modify is not too far along the list, you can do:
n=7
a='(1 2 3 4 5 6 7 8 9 10)
rplaca(nthcdr(sub1(n) a) 10)
Note that rplaca is a destructive operation - so it changes the list
in situ.
Regards,
Andrew.
--
Andrew Beckett
Senior Technical Leader
Custom IC Solutions
Cadence Design Systems Ltd
Ralf Geiger
Dec 12, 2002, 9:26:29 AM12/12/02
to
Andrew Beckett schrieb:
[...]
[...]
Thanks Andrew!
Best regards
Ralf
0 new messages