Modify syntax-table in some modes while iedit-mode is running.

iedit-change-syntax.el

;; Modify syntax-table in some modes while iedit-mode is running.
(defvar tv-syntax-for-iedit-alist
  '((ninja-mode . ((?/ . ".") (?$ . "'")))))

(defvar tv--syntax-for-iedit-modified nil)

(defun tv-iedit-syntax-hook-fn ()
  (let ((mode-syntax (assoc-default major-mode tv-syntax-for-iedit-alist))
        (table (copy-syntax-table)))
    (when mode-syntax
      (set-syntax-table table)
      (cl-loop for (x . y) in mode-syntax
               do (modify-syntax-entry x y table))
      (setq tv--syntax-for-iedit-modified t))))

(defun tv-iedit-restore-syntax-fn ()
  (when tv--syntax-for-iedit-modified
    (set-syntax-table (symbol-value
                       (intern (format "%s-syntax-table" major-mode))))
    (setq tv--syntax-for-iedit-modified nil)))

(add-hook 'iedit-mode-before-hook #'tv-iedit-syntax-hook-fn)
(add-hook 'iedit-mode-end-hook #'tv-iedit-restore-syntax-fn)