Re: cl-lib questions

[Stefan Monnier via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org>]

> Can you perhaps say a couple of words on the intended use for
> `setf', I get it it is a generic function (macro) but is there
> in your mind say one or two typical use cases or something
> like that to exemplify?

A typical example for me is when you want to modify the field of
a struct:

    (cl-defstruct my-foo a b c)

then you can set the field `b` of a my-foo struct X to value V with:

    (setf (my-foo-b X) V)

I also like to (ab)use it for things like

    (push (make-new-element)
          (if (something)
              x
            y))

> Also, what is the difference between setf and `setq' with
> respect to setting `let'/`let*' variables?

None.

> Another cl-lib question is the type of clause usable with
> `cl-loop' that are described like this in the docstring:

I wouldn't know, I never use `cl-loop`.


        Stefan