Re: srfi-1 take and drop

[Kevin Ryde]

Rob Browning <address@hidden> writes:
>
> I was planning on doing a little hacking on srfi-1.scm too,

I arrived in srfi-1 because I managed to hit a stack overflow in
delete-duplicates on just a few hundred elements, then got to looking
around at what was there.

I've written some non-tail-recursive C versions of delete and delete!,
and I've got a bit towards delete-duplicates, delete-duplicates! and
alist-copy.  I guess a lot of stuff could be coded in C, but start at
least with things that will show a definite benefit.

> One thing I was planning to do was alter null-list? to be less
> careful.  The spec doesn't require it, and what we do now is more
> expensive.

Does the spec say it has to chase down to check it's not an improper
list?  I guess at least that can be done in one loop and not separate
proper-list? and circular-list? calls.