When you create a new marker, you can make it point nowhere, or point to the present position of point, or to the beginning or end of the accessible portion of the buffer, or to the same place as another given marker.
The next four functions all return markers with insertion type
nil
. See Marker Insertion Types.
This function returns a newly created marker that does not point anywhere.
(make-marker) ⇒ #<marker in no buffer>
This function returns a new marker that points to the present position
of point in the current buffer. See Point. For an example, see
copy-marker
, below.
This function returns a new marker that points to the beginning of the accessible portion of the buffer. This will be the beginning of the buffer unless narrowing is in effect. See Narrowing.
This function returns a new marker that points to the end of the accessible portion of the buffer. This will be the end of the buffer unless narrowing is in effect. See Narrowing.
Here are examples of this function and point-min-marker
, shown in
a buffer containing a version of the source file for the text of this
chapter.
(point-min-marker) ⇒ #<marker at 1 in markers.texi> (point-max-marker) ⇒ #<marker at 24080 in markers.texi>
(narrow-to-region 100 200) ⇒ nil
(point-min-marker) ⇒ #<marker at 100 in markers.texi>
(point-max-marker) ⇒ #<marker at 200 in markers.texi>
If passed a marker as its argument, copy-marker
returns a
new marker that points to the same place and the same buffer as does
marker-or-integer. If passed an integer as its argument,
copy-marker
returns a new marker that points to position
marker-or-integer in the current buffer.
The new marker’s insertion type is specified by the argument insertion-type. See Marker Insertion Types.
(copy-marker 0) ⇒ #<marker at 1 in markers.texi>
(copy-marker 90000) ⇒ #<marker at 24080 in markers.texi>
An error is signaled if marker is neither a marker nor an integer.
Two distinct markers are considered equal
(even though not
eq
) to each other if they have the same position and buffer, or
if they both point nowhere.
(setq p (point-marker)) ⇒ #<marker at 2139 in markers.texi>
(setq q (copy-marker p)) ⇒ #<marker at 2139 in markers.texi>
(eq p q) ⇒ nil
(equal p q) ⇒ t