did you try ?substring("abcde",1,3);
probably it will be off by 1, since the string will
be |&abcde|, at least that is what it is in the
commercial macsyma.
I'm not sure why you want eval_string.
There is a macro-expansion
facility which involves buildq and related stuff. I don't
know if it is useful to you, but the idea is you can
create a program in one step, and in the next,
evaluate it. Usually people don't use strings in lisp
to represent programs, since lists are so much better
supported.
RJF
Dan Stanger wrote:
> Has anyone written string functions for maxima? I need eval_string and
> substring.
> Can someone suggest how to write eval_string if not?
> Thanks,
> Dan Stanger
>