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overlay-test.el

1234567890

(defun overlay-test (begin end text color)
  (let ((o (make-overlay begin end)))
    (overlay-put o 'window
                 (selected-window))
    (overlay-put o 'face
                 `(background-color . ,color))
    (overlay-put o 'display text)
    o))

;; eval in window 1. expect => bar4567890
(overlay-test 1 4 "bar" "red")

;; eval in window 2. expect => fooo567890
(overlay-test 1 5 "fooo" "blue")

;; delete overlays
(mapcar 'delete-overlay
        (overlays-in (point-min)
                     (point-max)))