Re: Proposal: count

[David Van Horn <dvanhorn@xxxxxxxxxxx>]

Taylor R Campbell wrote:
>    Date: Sun, 20 Sep 2009 18:58:38 -0400
>    From: David Van Horn <dvanhorn@xxxxxxxxxxx>
>
>    While `length' gives you number of pairs in a list, it's also useful to 
>    determine the number of pairs in a (potentially) improper list.
>
> When might one want to do this?

It's useful for bounds checking.  Actually, I think a more useful 
operation would be something like:

   (lenth<=? obj k) -> bool

Which would be the same as (<= (count obj) k).   This operation would 
take O(min(log(count obj),log k)).  It's important to note that obj need 
not be a list.

David