Re: How to read an integer from the minibuffer

[Jean Louis]

* tomas@tuxteam.de <tomas@tuxteam.de> [2021-11-12 23:25]:
> On Fri, Nov 12, 2021 at 11:02:10PM +0300, Jean Louis wrote:
> > Improved check for number:
> > 
> > (defun string-is-number-p (s)
> >   "Return number only if string is actual number, otherwise NIL."
> >   (let* ((s (string-trim s)))
> >     (cond ((seq-empty-p s) nil)
> >       ((string-match "[^0123456789\\.-]" s) nil)
> >       ((string-match "-" s 1) nil)
> >       ((numberp (string-to-number s)) (string-to-number s)))))
> 
> Why not simply numberp?
> 
>   (and (numberp s) (string-to-number s))

(numberp "123") ⇒ nil

It checks if object is number. That is why it is not usable to check
if string is actual number.


-- 
Jean

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