The first part of this section gives details of commands associated with marking, while the second provides details of a few commands whose area is limited to a region. Other region specific commands are available but are dealt with in more appropriate sections of this manual. For example, Write Region is dealt with under the File handling as it involves writing a region to a file.
Details of marks are kept in a mark ring so that previously defined marks can be accessed. The mark ring works like a stack, in that marks are pushed onto the ring and can only be popped off on a "last in first out" basis. Each buffer has its own mark ring.
Note that marks may also be set by using the mouse--see Buffers, windows and the mouse--but also note that a region must be defined
by using the mouse
by using editor key sequences, as the region may become unset if a combination of the two is used. For example, using
Ctrl+Space to set a mark and then using the mouse to go to the start of the required region unsets the mark.
Note: the editor also records locations of the current point which can be revisited by the commands listed in Locations. Unlike marks, these locations do not interact with the region.
Moves the current point to the mark without saving the current point on the mark ring (in contrast with Exchange Point and Mark). After the current point has been moved to the mark, the mark ring is rotated. The current region is de-activated.
editor:exchange-point-and-mark-command p &optional buffer
Puts the mark at the end of the current sentence and the current point at the start of the current sentence. The sentence thereby becomes the current region. If the current point is initially located between two sentences then the mark and current point are placed around the next sentence.
Puts the mark at the end of the current paragraph and the current point at the start of the current paragraph. The paragraph thereby becomes the current region. If the current point is initially located between two paragraphs, then the mark and current point are placed around the next paragraph.
Records the starting location (see Locations).
If the region between the current point and the mark contains more lines than the value of this editor variable, then any destructive operation on the region prompts the user for confirmation before being executed.
LispWorks Editor User Guide (Unix version) - 9 Dec 2014