Function: rx--charset-p

rx--charset-p is a byte-compiled function defined in rx.el.gz.

Signature

(rx--charset-p FORM)

Documentation

Whether FORM looks like a charset, only consisting of character intervals and set operations.

Source Code

;; Defined in /usr/src/emacs/lisp/emacs-lisp/rx.el.gz
(defun rx--charset-p (form)
  "Whether FORM looks like a charset, only consisting of character intervals
and set operations."
  (or (and (consp form)
           (or (and (memq (car form) '(any in char))
                    (rx--every (lambda (x) (not (symbolp x))) (cdr form)))
               (and (memq (car form) '(not or | intersection))
                    (rx--every #'rx--charset-p (cdr form)))))
      (characterp form)
      (and (stringp form) (= (length form) 1))
      (and (or (symbolp form) (consp form))
           (let ((expanded (rx--expand-def form)))
             (and expanded
                  (rx--charset-p expanded))))))