Re: Determining validity of mathematical expression before evaluation

On Saturday, March 28th, 2026 at 3:40 AM, Rudolf Adamkovič <[email protected]> wrote:

> Heime <[email protected]> writes:
> 
> [I forgot to CC the list; sorry for the duplicate message.]
> 
> >> Is it possible to determine whether an elisp mathematical expression
> >> is valid before evaluating it?
> 
> That depends entirely on what you consider a valid mathematical
> expression. :)

Valid for lisp eval.
 
> > I call bc.
> 
> Why not Lisp instead?
> 
> (string-to-number (calc-eval "10 + 5 * 2")) => 20

I'll consider lisp then.
 
> Rudy
> --
> "One can begin to reason only when a clear picture has been formed in
> the imagination."
> 
> --- Walter Warwick Sawyer, Mathematician's Delight, 1943
> 
> Rudolf Adamkovič <[email protected]> [he/him]
> http://adamkovic.org
> 
>