RE: Working with constansts

[Drew Adams]

> I would like to work with constants in my elisp code. I thought that I
> could do this with defconst, but that doen not work.
> After: (defconst dummy "testing")
> The variable dummy has the value "testing".
> But after: (setq dummy "changed")
> The variable dummy has the value "changed".
> What am I doing wrong.

>From the Elisp manual:

"The difference between `defconst' and `defvar' is primarily a matter
of intent, serving to inform human readers of whether the value should
ever change.  Emacs Lisp does not restrict the ways in which a variable
can be used based on `defconst' or `defvar' declarations.  However, it
does make a difference for initialization: `defconst' unconditionally
initializes the variable, while `defvar' initializes it only if it is
void."

Nothing prevents a user or program from changing the value of a `defconst'
variable. Unless you somehow cripple Emacs Lisp, you can always find a way to
modify something. That's about the only constant. ;-)