Searching for Overlays
----------------------
- Function: overlays-at pos
This function returns a list of all the overlays that cover the
character at position POS in the current buffer. The list is in
no particular order. An overlay contains position POS if it
begins at or before POS, and ends after POS.
To illustrate usage, here is a Lisp function that returns a list
of the overlays that specify property PROP for the character at
point:
(defun find-overlays-specifying (prop)
(let ((overlays (overlays-at (point)))
found)
(while overlays
(let ((overlay (car overlays)))
(if (overlay-get overlay prop)
(setq found (cons overlay found))))
(setq overlays (cdr overlays)))
found))
- Function: overlays-in beg end
This function returns a list of the overlays that overlap the
region BEG through END. "Overlap" means that at least one
character is contained within the overlay and also contained
within the specified region; however, empty overlays are included
in the result if they are located at BEG, or strictly between BEG
and END.
- Function: next-overlay-change pos
This function returns the buffer position of the next beginning or
end of an overlay, after POS.
- Function: previous-overlay-change pos
This function returns the buffer position of the previous
beginning or end of an overlay, before POS.
Here's an easy way to use `next-overlay-change' to search for the
next character which gets a non-`nil' `happy' property from either its
overlays or its text properties (Note:Property Search):
(defun find-overlay-prop (prop)
(save-excursion
(while (and (not (eobp))
(not (get-char-property (point) 'happy)))
(goto-char (min (next-overlay-change (point))
(next-single-property-change (point) 'happy))))
(point)))