Re: How to read an integer from the minibuffer

[Jean Louis]

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)))))

(string-is-number-p "-0.1") ⇒ -0.1
(string-is-number-p "0.1") ⇒ 0.1
(string-is-number-p "0.1-") ⇒ nil
(string-is-number-p "  1 ") ⇒ 1
(string-is-number-p " a 1 ") ⇒ nil


-- 
Jean

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