bug#59531: 29.0.50: An alternative to `string-to-number` which throws an error (or returns a NIL value) when input is non-parseable as number

[Jean Louis]

(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)))))


I use this function to make sure string is number and it
returns either the number of nil, and function is not
exhaustive.


Jean

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