+++ /dev/null
-This is Info file ../../info/lispref.info, produced by Makeinfo version
-1.68 from the input file lispref.texi.
-
-INFO-DIR-SECTION XEmacs Editor
-START-INFO-DIR-ENTRY
-* Lispref: (lispref). XEmacs Lisp Reference Manual.
-END-INFO-DIR-ENTRY
-
- Edition History:
-
- GNU Emacs Lisp Reference Manual Second Edition (v2.01), May 1993 GNU
-Emacs Lisp Reference Manual Further Revised (v2.02), August 1993 Lucid
-Emacs Lisp Reference Manual (for 19.10) First Edition, March 1994
-XEmacs Lisp Programmer's Manual (for 19.12) Second Edition, April 1995
-GNU Emacs Lisp Reference Manual v2.4, June 1995 XEmacs Lisp
-Programmer's Manual (for 19.13) Third Edition, July 1995 XEmacs Lisp
-Reference Manual (for 19.14 and 20.0) v3.1, March 1996 XEmacs Lisp
-Reference Manual (for 19.15 and 20.1, 20.2, 20.3) v3.2, April, May,
-November 1997 XEmacs Lisp Reference Manual (for 21.0) v3.3, April 1998
-
- Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995 Free Software
-Foundation, Inc. Copyright (C) 1994, 1995 Sun Microsystems, Inc.
-Copyright (C) 1995, 1996 Ben Wing.
-
- Permission is granted to make and distribute verbatim copies of this
-manual provided the copyright notice and this permission notice are
-preserved on all copies.
-
- Permission is granted to copy and distribute modified versions of
-this manual under the conditions for verbatim copying, provided that the
-entire resulting derived work is distributed under the terms of a
-permission notice identical to this one.
-
- Permission is granted to copy and distribute translations of this
-manual into another language, under the above conditions for modified
-versions, except that this permission notice may be stated in a
-translation approved by the Foundation.
-
- Permission is granted to copy and distribute modified versions of
-this manual under the conditions for verbatim copying, provided also
-that the section entitled "GNU General Public License" is included
-exactly as in the original, and provided that the entire resulting
-derived work is distributed under the terms of a permission notice
-identical to this one.
-
- Permission is granted to copy and distribute translations of this
-manual into another language, under the above conditions for modified
-versions, except that the section entitled "GNU General Public License"
-may be included in a translation approved by the Free Software
-Foundation instead of in the original English.
-
-\1f
-File: lispref.info, Node: Finding All Frames, Next: Frames and Windows, Prev: Deleting Frames, Up: Frames
-
-Finding All Frames
-==================
-
- - Function: frame-list
- The function `frame-list' returns a list of all the frames that
- have not been deleted. It is analogous to `buffer-list' for
- buffers. The list that you get is newly created, so modifying the
- list doesn't have any effect on the internals of XEmacs.
-
- - Function: device-frame-list &optional DEVICE
- This function returns a list of all frames on DEVICE. If DEVICE
- is `nil', the selected device will be used.
-
- - Function: visible-frame-list &optional DEVICE
- This function returns a list of just the currently visible frames.
- If DEVICE is specified only frames on that device will be returned.
- *Note Visibility of Frames::. (TTY frames always count as
- "visible", even though only the selected one is actually
- displayed.)
-
- - Function: next-frame &optional FRAME MINIBUF
- The function `next-frame' lets you cycle conveniently through all
- the frames from an arbitrary starting point. It returns the "next"
- frame after FRAME in the cycle. If FRAME is omitted or `nil', it
- defaults to the selected frame.
-
- The second argument, MINIBUF, says which frames to consider:
-
- `nil'
- Exclude minibuffer-only frames.
-
- `visible'
- Consider all visible frames.
-
- 0
- Consider all visible or iconified frames.
-
- a window
- Consider only the frames using that particular window as their
- minibuffer.
-
- the symbol `visible'
- Include all visible frames.
-
- `0'
- Include all visible and iconified frames.
-
- anything else
- Consider all frames.
-
- - Function: previous-frame &optional FRAME MINIBUF
- Like `next-frame', but cycles through all frames in the opposite
- direction.
-
- See also `next-window' and `previous-window', in *Note Cyclic Window
-Ordering::.
-
-\1f
-File: lispref.info, Node: Frames and Windows, Next: Minibuffers and Frames, Prev: Finding All Frames, Up: Frames
-
-Frames and Windows
-==================
-
- Each window is part of one and only one frame; you can get the frame
-with `window-frame'.
-
- - Function: frame-root-window &optional FRAME
- This returns the root window of frame FRAME. FRAME defaults to
- the selected frame if not specified.
-
- - Function: window-frame &optional WINDOW
- This function returns the frame that WINDOW is on. WINDOW
- defaults to the selected window if omitted.
-
- All the non-minibuffer windows in a frame are arranged in a cyclic
-order. The order runs from the frame's top window, which is at the
-upper left corner, down and to the right, until it reaches the window at
-the lower right corner (always the minibuffer window, if the frame has
-one), and then it moves back to the top.
-
- - Function: frame-top-window FRAME
- This returns the topmost, leftmost window of frame FRAME.
-
- At any time, exactly one window on any frame is "selected within the
-frame". The significance of this designation is that selecting the
-frame also selects this window. You can get the frame's current
-selected window with `frame-selected-window'.
-
- - Function: frame-selected-window &optional FRAME
- This function returns the window on FRAME that is selected within
- FRAME. FRAME defaults to the selected frame if not specified.
-
- Conversely, selecting a window for XEmacs with `select-window' also
-makes that window selected within its frame. *Note Selecting Windows::.
-
- Another function that (usually) returns one of the windows in a
-frame is `minibuffer-window'. *Note Minibuffer Misc::.
-
-\1f
-File: lispref.info, Node: Minibuffers and Frames, Next: Input Focus, Prev: Frames and Windows, Up: Frames
-
-Minibuffers and Frames
-======================
-
- Normally, each frame has its own minibuffer window at the bottom,
-which is used whenever that frame is selected. If the frame has a
-minibuffer, you can get it with `minibuffer-window' (*note Minibuffer
-Misc::.).
-
- However, you can also create a frame with no minibuffer. Such a
-frame must use the minibuffer window of some other frame. When you
-create the frame, you can specify explicitly the minibuffer window to
-use (in some other frame). If you don't, then the minibuffer is found
-in the frame which is the value of the variable
-`default-minibuffer-frame'. Its value should be a frame which does
-have a minibuffer.
-
- - Variable: default-minibuffer-frame
- This variable specifies the frame to use for the minibuffer
- window, by default.
-
-\1f
-File: lispref.info, Node: Input Focus, Next: Visibility of Frames, Prev: Minibuffers and Frames, Up: Frames
-
-Input Focus
-===========
-
- At any time, one frame in XEmacs is the "selected frame". The
-selected window always resides on the selected frame. As the focus
-moves from device to device, the selected frame on each device is
-remembered and restored when the focus moves back to that device.
-
- - Function: selected-frame &optional DEVICE
- This function returns the selected frame on DEVICE. If DEVICE is
- not specified, the selected device will be used. If no frames
- exist on the device, `nil' is returned.
-
- The X server normally directs keyboard input to the X window that the
-mouse is in. Some window managers use mouse clicks or keyboard events
-to "shift the focus" to various X windows, overriding the normal
-behavior of the server.
-
- Lisp programs can switch frames "temporarily" by calling the
-function `select-frame'. This does not override the window manager;
-rather, it escapes from the window manager's control until that control
-is somehow reasserted.
-
- When using a text-only terminal, there is no window manager;
-therefore, `select-frame' is the only way to switch frames, and the
-effect lasts until overridden by a subsequent call to `select-frame'.
-Only the selected terminal frame is actually displayed on the terminal.
-Each terminal screen except for the initial one has a number, and the
-number of the selected frame appears in the mode line after the word
-`XEmacs' (*note Modeline Variables::.).
-
- - Function: select-frame FRAME
- This function selects frame FRAME, temporarily disregarding the
- focus of the X server if any. The selection of FRAME lasts until
- the next time the user does something to select a different frame,
- or until the next time this function is called.
-
- Note that `select-frame' does not actually cause the window-system
- focus to be set to this frame, or the `select-frame-hook' or
- `deselect-frame-hook' to be run, until the next time that XEmacs is
- waiting for an event.
-
- Also note that when the variable `focus-follows-mouse' is
- non-`nil', the frame selection is temporary and is reverted when
- the current command terminates, much like the buffer selected by
- `set-buffer'. In order to effect a permanent focus change use
- `focus-frame'.
-
- - Function: focus-frame FRAME
- This function selects FRAME and gives it the window system focus.
- The operation of `focus-frame' is not affected by the value of
- `focus-follows-mouse'.
-
- - Macro: save-selected-frame FORMS...
- This macro records the selected frame, executes FORMS in sequence,
- then restores the earlier selected frame. The value returned is
- the value of the last form.
-
- - Macro: with-selected-frame FRAME FORMS...
- This macro records the selected frame, then selects FRAME and
- executes FORMS in sequence. After the last form is finished, the
- earlier selected frame is restored. The value returned is the
- value of the last form.
-
-\1f
-File: lispref.info, Node: Visibility of Frames, Next: Raising and Lowering, Prev: Input Focus, Up: Frames
-
-Visibility of Frames
-====================
-
- An X window frame may be "visible", "invisible", or "iconified". If
-it is visible, you can see its contents. If it is iconified, the
-frame's contents do not appear on the screen, but an icon does. If the
-frame is invisible, it doesn't show on the screen, not even as an icon.
-
- Visibility is meaningless for TTY frames, since only the selected
-one is actually displayed in any case.
-
- - Command: make-frame-visible &optional FRAME
- This function makes frame FRAME visible. If you omit FRAME, it
- makes the selected frame visible.
-
- - Command: make-frame-invisible &optional FRAME
- This function makes frame FRAME invisible.
-
- - Command: iconify-frame &optional FRAME
- This function iconifies frame FRAME.
-
- - Command: deiconify-frame &optional FRAME
- This function de-iconifies frame FRAME. Under X, this is
- equivalent to `make-frame-visible'.
-
- - Function: frame-visible-p FRAME
- This returns whether FRAME is currently "visible" (actually in use
- for display). A frame that is not visible is not updated, and, if
- it works through a window system, may not show at all.
-
- - Function: frame-iconified-p FRAME
- This returns whether FRAME is iconified. Not all window managers
- use icons; some merely unmap the window, so this function is not
- the inverse of `frame-visible-p'. It is possible for a frame to
- not be visible and not be iconified either. However, if the frame
- is iconified, it will not be visible. (Under FSF Emacs, the
- functionality of this function is obtained through
- `frame-visible-p'.)
-
- - Function: frame-totally-visible-p FRAME
- This returns whether FRAME is not obscured by any other X windows.
- On TTY frames, this is the same as `frame-visible-p'.
-
-\1f
-File: lispref.info, Node: Raising and Lowering, Next: Frame Configurations, Prev: Visibility of Frames, Up: Frames
-
-Raising and Lowering Frames
-===========================
-
- The X Window System uses a desktop metaphor. Part of this metaphor
-is the idea that windows are stacked in a notional third dimension
-perpendicular to the screen surface, and thus ordered from "highest" to
-"lowest". Where two windows overlap, the one higher up covers the one
-underneath. Even a window at the bottom of the stack can be seen if no
-other window overlaps it.
-
- A window's place in this ordering is not fixed; in fact, users tend
-to change the order frequently. "Raising" a window means moving it
-"up", to the top of the stack. "Lowering" a window means moving it to
-the bottom of the stack. This motion is in the notional third
-dimension only, and does not change the position of the window on the
-screen.
-
- You can raise and lower XEmacs's X windows with these functions:
-
- - Command: raise-frame &optional FRAME
- This function raises frame FRAME.
-
- - Command: lower-frame &optional FRAME
- This function lowers frame FRAME.
-
- You can also specify auto-raise (raising automatically when a frame
-is selected) or auto-lower (lowering automatically when it is
-deselected). Under X, most ICCCM-compliant window managers will have
-an option to do this for you, but the following variables are provided
-in case you're using a broken WM. (Under FSF Emacs, the same
-functionality is provided through the `auto-raise' and `auto-lower'
-frame properties.)
-
- - Variable: auto-raise-frame
- This variable's value is `t' if frames will be raised to the top
- when selected.
-
- - Variable: auto-lower-frame
- This variable's value is `t' if frames will be lowered to the
- bottom when no longer selected.
-
- Auto-raising and auto-lowering is implemented through functions
-attached to `select-frame-hook' and `deselect-frame-hook' (*note Frame
-Hooks::.). Under normal circumstances, you should not call these
-functions directly.
-
- - Function: default-select-frame-hook
- This hook function implements the `auto-raise-frame' variable; it
- is for use as the value of `select-frame-hook'.
-
- - Function: default-deselect-frame-hook
- This hook function implements the `auto-lower-frame' variable; it
- is for use as the value of `deselect-frame-hook'.
-
-\1f
-File: lispref.info, Node: Frame Configurations, Next: Frame Hooks, Prev: Raising and Lowering, Up: Frames
-
-Frame Configurations
-====================
-
- A "frame configuration" records the current arrangement of frames,
-all their properties, and the window configuration of each one.
-
- - Function: current-frame-configuration
- This function returns a frame configuration list that describes
- the current arrangement of frames and their contents.
-
- - Function: set-frame-configuration CONFIGURATION
- This function restores the state of frames described in
- CONFIGURATION.
-
-\1f
-File: lispref.info, Node: Frame Hooks, Prev: Frame Configurations, Up: Frames
-
-Hooks for Customizing Frame Behavior
-====================================
-
- XEmacs provides many hooks that are called at various times during a
-frame's lifetime. *Note Hooks::.
-
- - Variable: create-frame-hook
- This hook is called each time a frame is created. The functions
- are called with one argument, the newly-created frame.
-
- - Variable: delete-frame-hook
- This hook is called each time a frame is deleted. The functions
- are called with one argument, the about-to-be-deleted frame.
-
- - Variable: select-frame-hook
- This is a normal hook that is run just after a frame is selected.
- The function `default-select-frame-hook', which implements
- auto-raising (*note Raising and Lowering::.), is normally attached
- to this hook.
-
- Note that calling `select-frame' does not necessarily set the
- focus: The actual window-system focus will not be changed until
- the next time that XEmacs is waiting for an event, and even then,
- the window manager may refuse the focus-change request.
-
- - Variable: deselect-frame-hook
- This is a normal hook that is run just before a frame is deselected
- (and another frame is selected). The function
- `default-deselect-frame-hook', which implements auto-lowering
- (*note Raising and Lowering::.), is normally attached to this hook.
-
- - Variable: map-frame-hook
- This hook is called each time a frame is mapped (i.e. made
- visible). The functions are called with one argument, the newly
- mapped frame.
-
- - Variable: unmap-frame-hook
- This hook is called each time a frame is unmapped (i.e. made
- invisible or iconified). The functions are called with one
- argument, the newly unmapped frame.
-
-\1f
-File: lispref.info, Node: Consoles and Devices, Next: Positions, Prev: Frames, Up: Top
-
-Consoles and Devices
-********************
-
- A "console" is an object representing a single input connection to
-XEmacs, such as an X display or a TTY connection. It is possible for
-XEmacs to have frames on multiple consoles at once (even on
-heterogeneous types - you can simultaneously have a frame on an X
-display and a TTY connection). Normally, there is only one console in
-existence.
-
- A "device" is an object representing a single output device, such as
-a particular screen on an X display. (Usually there is exactly one
-device per X console connection, but there may be more than one if you
-have a multi-headed X display. For TTY connections, there is always
-exactly one device per console.)
-
- Each device has one or more "frames" in which text can be displayed.
-For X displays and the like, a frame corresponds to the normal
-window-system concept of a window. Frames can overlap, be displayed at
-various locations within the display, be resized, etc. For TTY, only
-one frame can be displayed at a time, and it occupies the entire TTY
-display area.
-
- However, you can still define multiple frames and switch between
-them. Their contents are entirely separate from each other. These
-sorts of frames resemble the "virtual console" capability provided
-under Linux or the multiple screens provided by the multiplexing program
-`screen' under Unix.
-
- When you start up XEmacs, an initial console and device are created
-to receive input and display frames on. This will either be an X
-display or a TTY connection, depending on what mode you started XEmacs
-in (this is determined by the `DISPLAY' environment variable, the
-`-nw', `-t' and `-display' command-line options, etc.).
-
- You can connect to other X displays and TTY connections by creating
-new console objects, and to other X screens on an existing display by
-creating new device objects, as described below. Many functions (for
-example the frame-creation functions) take an optional device argument
-specifying which device the function pertains to. If the argument is
-omitted, it defaults to the selected device (see below).
-
- - Function: consolep OBJECT
- This returns non-`nil' if OBJECT is a console.
-
- - Function: devicep OBJECT
- This returns non-`nil' if OBJECT is a device.
-
-* Menu:
-
-* Basic Console Functions:: Functions for working with consoles.
-* Basic Device Functions:: Functions for working with devices.
-* Console Types and Device Classes::
- I/O and color characteristics.
-* Connecting to a Console or Device::
-* The Selected Console and Device::
-* Console and Device I/O:: Controlling input and output.
-
-\1f
-File: lispref.info, Node: Basic Console Functions, Next: Basic Device Functions, Up: Consoles and Devices
-
-Basic Console Functions
-=======================
-
- - Function: console-list
- This function returns a list of all existing consoles.
-
- - Function: console-device-list &optional CONSOLE
- This function returns a list of all devices on CONSOLE. If
- CONSOLE is `nil', the selected console will be used.
-
-\1f
-File: lispref.info, Node: Basic Device Functions, Next: Console Types and Device Classes, Prev: Basic Console Functions, Up: Consoles and Devices
-
-Basic Device Functions
-======================
-
- - Function: device-list
- This function returns a list of all existing devices.
-
- - Function: device-or-frame-p OBJECT
- This function returns non-`nil' if OBJECT is a device or frame.
- This function is useful because devices and frames are similar in
- many respects and many functions can operate on either one.
-
- - Function: device-frame-list DEVICE
- This function returns a list of all frames on DEVICE.
-
- - Function: frame-device FRAME
- This function returns the device that FRAME is on.
-
-\1f
-File: lispref.info, Node: Console Types and Device Classes, Next: Connecting to a Console or Device, Prev: Basic Device Functions, Up: Consoles and Devices
-
-Console Types and Device Classes
-================================
-
- Every device is of a particular "type", which describes how the
-connection to that device is made and how the device operates, and a
-particular "class", which describes other characteristics of the device
-(currently, the color capabilities of the device).
-
- The currently-defined device types are
-
-`x'
- A connection to an X display (such as `willow:0').
-
-`tty'
- A connection to a tty (such as `/dev/ttyp3').
-
-`stream'
- A stdio connection. This describes a device for which input and
- output is only possible in a stream-like fashion, such as when
- XEmacs in running in batch mode. The very first device created by
- XEmacs is a terminal device and is used to print out messages of
- various sorts (for example, the help message when you use the
- `-help' command-line option).
-
- The currently-defined device classes are
-`color'
- A color device.
-
-`grayscale'
- A grayscale device (a device that can display multiple shades of
- gray, but no color).
-
-`mono'
- A device that can only display two colors (e.g. black and white).
-
- - Function: device-type DEVICE
- This function returns the type of DEVICE. This is a symbol whose
- name is one of the device types mentioned above.
-
- - Function: device-or-frame-type DEVICE-OR-FRAME
- This function returns the type of DEVICE-OR-FRAME.
-
- - Function: device-class DEVICE
- This function returns the class (color behavior) of DEVICE. This
- is a symbol whose name is one of the device classes mentioned
- above.
-
- - Function: valid-device-type-p DEVICE-TYPE
- This function returns whether DEVICE-TYPE (which should be a
- symbol) species a valid device type.
-
- - Function: valid-device-class-p DEVICE-CLASS
- This function returns whether DEVICE-CLASS (which should be a
- symbol) species a valid device class.
-
- - Variable: terminal-device
- This variable holds the initial terminal device object, which
- represents XEmacs's stdout.
-
-\1f
-File: lispref.info, Node: Connecting to a Console or Device, Next: The Selected Console and Device, Prev: Console Types and Device Classes, Up: Consoles and Devices
-
-Connecting to a Console or Device
-=================================
-
- - Function: make-device &optional TYPE DEVICE-DATA
- This function creates a new device.
-
- The following two functions create devices of specific types and are
-written in terms of `make-device'.
-
- - Function: make-tty-device &optional TTY TERMINAL-TYPE
- This function creates a new tty device on TTY. This also creates
- the tty's first frame. TTY should be a string giving the name of
- a tty device file (e.g. `/dev/ttyp3' under SunOS et al.), as
- returned by the `tty' command issued from the Unix shell. A value
- of `nil' means use the stdin and stdout as passed to XEmacs from
- the shell. If TERMINAL-TYPE is non-`nil', it should be a string
- specifying the type of the terminal attached to the specified tty.
- If it is `nil', the terminal type will be inferred from the
- `TERM' environment variable.
-
- - Function: make-x-device &optional DISPLAY ARGV-LIST
- This function creates a new device connected to DISPLAY. Optional
- argument ARGV-LIST is a list of strings describing command line
- options.
-
- - Function: delete-device DEVICE
- This function deletes DEVICE, permanently eliminating it from use.
- This disconnects XEmacs's connection to the device.
-
- - Variable: create-device-hook
- This variable, if non-`nil', should contain a list of functions,
- which are called when a device is created.
-
- - Variable: delete-device-hook
- This variable, if non-`nil', should contain a list of functions,
- which are called when a device is deleted.
-
- - Function: console-live-p OBJECT
- This function returns non-`nil' if OBJECT is a console that has
- not been deleted.
-
- - Function: device-live-p OBJECT
- This function returns non-`nil' if OBJECT is a device that has not
- been deleted.
-
- - Function: device-x-display DEVICE
- This function returns the X display which DEVICE is connected to,
- if DEVICE is an X device.
-
-\1f
-File: lispref.info, Node: The Selected Console and Device, Next: Console and Device I/O, Prev: Connecting to a Console or Device, Up: Consoles and Devices
-
-The Selected Console and Device
-===============================
-
- - Function: select-console CONSOLE
- This function selects the console CONSOLE. Subsequent editing
- commands apply to its selected device, selected frame, and selected
- window. The selection of CONSOLE lasts until the next time the
- user does something to select a different console, or until the
- next time this function is called.
-
- - Function: selected-console
- This function returns the console which is currently active.
-
- - Function: select-device DEVICE
- This function selects the device DEVICE.
-
- - Function: selected-device &optional CONSOLE
- This function returns the device which is currently active. If
- optional CONSOLE is non-`nil', this function returns the device
- that would be currently active if CONSOLE were the selected
- console.
-
-\1f
-File: lispref.info, Node: Console and Device I/O, Prev: The Selected Console and Device, Up: Consoles and Devices
-
-Console and Device I/O
-======================
-
- - Function: console-disable-input CONSOLE
- This function disables input on console CONSOLE.
-
- - Function: console-enable-input CONSOLE
- This function enables input on console CONSOLE.
-
- Each device has a "baud rate" value associated with it. On most
-systems, changing this value will affect the amount of padding and
-other strategic decisions made during redisplay.
-
- - Function: device-baud-rate &optional DEVICE
- This function returns the output baud rate of DEVICE.
-
- - Function: set-device-baud-rate DEVICE RATE
- This function sets the output baud rate of DEVICE to RATE.
-
-\1f
-File: lispref.info, Node: Positions, Next: Markers, Prev: Consoles and Devices, Up: Top
-
-Positions
-*********
-
- A "position" is the index of a character in the text of a buffer.
-More precisely, a position identifies the place between two characters
-(or before the first character, or after the last character), so we can
-speak of the character before or after a given position. However, we
-often speak of the character "at" a position, meaning the character
-after that position.
-
- Positions are usually represented as integers starting from 1, but
-can also be represented as "markers"--special objects that relocate
-automatically when text is inserted or deleted so they stay with the
-surrounding characters. *Note Markers::.
-
-* Menu:
-
-* Point:: The special position where editing takes place.
-* Motion:: Changing point.
-* Excursions:: Temporary motion and buffer changes.
-* Narrowing:: Restricting editing to a portion of the buffer.
-
-\1f
-File: lispref.info, Node: Point, Next: Motion, Up: Positions
-
-Point
-=====
-
- "Point" is a special buffer position used by many editing commands,
-including the self-inserting typed characters and text insertion
-functions. Other commands move point through the text to allow editing
-and insertion at different places.
-
- Like other positions, point designates a place between two characters
-(or before the first character, or after the last character), rather
-than a particular character. Usually terminals display the cursor over
-the character that immediately follows point; point is actually before
-the character on which the cursor sits.
-
- The value of point is a number between 1 and the buffer size plus 1.
-If narrowing is in effect (*note Narrowing::.), then point is
-constrained to fall within the accessible portion of the buffer
-(possibly at one end of it).
-
- Each buffer has its own value of point, which is independent of the
-value of point in other buffers. Each window also has a value of point,
-which is independent of the value of point in other windows on the same
-buffer. This is why point can have different values in various windows
-that display the same buffer. When a buffer appears in only one window,
-the buffer's point and the window's point normally have the same value,
-so the distinction is rarely important. *Note Window Point::, for more
-details.
-
- - Function: point &optional BUFFER
- This function returns the value of point in BUFFER, as an integer.
- BUFFER defaults to the current buffer if omitted.
-
- (point)
- => 175
-
- - Function: point-min &optional BUFFER
- This function returns the minimum accessible value of point in
- BUFFER. This is normally 1, but if narrowing is in effect, it is
- the position of the start of the region that you narrowed to.
- (*Note Narrowing::.) BUFFER defaults to the current buffer if
- omitted.
-
- - Function: point-max &optional BUFFER
- This function returns the maximum accessible value of point in
- BUFFER. This is `(1+ (buffer-size buffer))', unless narrowing is
- in effect, in which case it is the position of the end of the
- region that you narrowed to. (*note Narrowing::.). BUFFER
- defaults to the current buffer if omitted.
-
- - Function: buffer-end FLAG &optional BUFFER
- This function returns `(point-min buffer)' if FLAG is less than 1,
- `(point-max buffer)' otherwise. The argument FLAG must be a
- number. BUFFER defaults to the current buffer if omitted.
-
- - Function: buffer-size &optional BUFFER
- This function returns the total number of characters in BUFFER.
- In the absence of any narrowing (*note Narrowing::.), `point-max'
- returns a value one larger than this. BUFFER defaults to the
- current buffer if omitted.
-
- (buffer-size)
- => 35
- (point-max)
- => 36
-
- - Variable: buffer-saved-size
- The value of this buffer-local variable is the former length of the
- current buffer, as of the last time it was read in, saved or
- auto-saved.
-
-\1f
-File: lispref.info, Node: Motion, Next: Excursions, Prev: Point, Up: Positions
-
-Motion
-======
-
- Motion functions change the value of point, either relative to the
-current value of point, relative to the beginning or end of the buffer,
-or relative to the edges of the selected window. *Note Point::.
-
-* Menu:
-
-* Character Motion:: Moving in terms of characters.
-* Word Motion:: Moving in terms of words.
-* Buffer End Motion:: Moving to the beginning or end of the buffer.
-* Text Lines:: Moving in terms of lines of text.
-* Screen Lines:: Moving in terms of lines as displayed.
-* List Motion:: Moving by parsing lists and sexps.
-* Skipping Characters:: Skipping characters belonging to a certain set.
-
-\1f
-File: lispref.info, Node: Character Motion, Next: Word Motion, Up: Motion
-
-Motion by Characters
---------------------
-
- These functions move point based on a count of characters.
-`goto-char' is the fundamental primitive; the other functions use that.
-
- - Command: goto-char POSITION &optional BUFFER
- This function sets point in `buffer' to the value POSITION. If
- POSITION is less than 1, it moves point to the beginning of the
- buffer. If POSITION is greater than the length of the buffer, it
- moves point to the end. BUFFER defaults to the current buffer if
- omitted.
-
- If narrowing is in effect, POSITION still counts from the
- beginning of the buffer, but point cannot go outside the accessible
- portion. If POSITION is out of range, `goto-char' moves point to
- the beginning or the end of the accessible portion.
-
- When this function is called interactively, POSITION is the
- numeric prefix argument, if provided; otherwise it is read from the
- minibuffer.
-
- `goto-char' returns POSITION.
-
- - Command: forward-char &optional COUNT BUFFER
- This function moves point COUNT characters forward, towards the
- end of the buffer (or backward, towards the beginning of the
- buffer, if COUNT is negative). If the function attempts to move
- point past the beginning or end of the buffer (or the limits of
- the accessible portion, when narrowing is in effect), an error is
- signaled with error code `beginning-of-buffer' or `end-of-buffer'.
- BUFFER defaults to the current buffer if omitted.
-
- In an interactive call, COUNT is the numeric prefix argument.
-
- - Command: backward-char &optional COUNT BUFFER
- This function moves point COUNT characters backward, towards the
- beginning of the buffer (or forward, towards the end of the
- buffer, if COUNT is negative). If the function attempts to move
- point past the beginning or end of the buffer (or the limits of
- the accessible portion, when narrowing is in effect), an error is
- signaled with error code `beginning-of-buffer' or `end-of-buffer'.
- BUFFER defaults to the current buffer if omitted.
-
- In an interactive call, COUNT is the numeric prefix argument.
-
-\1f
-File: lispref.info, Node: Word Motion, Next: Buffer End Motion, Prev: Character Motion, Up: Motion
-
-Motion by Words
----------------
-
- These functions for parsing words use the syntax table to decide
-whether a given character is part of a word. *Note Syntax Tables::.
-
- - Command: forward-word COUNT &optional BUFFER
- This function moves point forward COUNT words (or backward if
- COUNT is negative). Normally it returns `t'. If this motion
- encounters the beginning or end of the buffer, or the limits of the
- accessible portion when narrowing is in effect, point stops there
- and the value is `nil'. BUFFER defaults to the current buffer if
- omitted.
-
- In an interactive call, COUNT is set to the numeric prefix
- argument.
-
- - Command: backward-word COUNT &optional BUFFER
- This function is just like `forward-word', except that it moves
- backward until encountering the front of a word, rather than
- forward. BUFFER defaults to the current buffer if omitted.
-
- In an interactive call, COUNT is set to the numeric prefix
- argument.
-
- This function is rarely used in programs, as it is more efficient
- to call `forward-word' with a negative argument.
-
- - Variable: words-include-escapes
- This variable affects the behavior of `forward-word' and everything
- that uses it. If it is non-`nil', then characters in the "escape"
- and "character quote" syntax classes count as part of words.
- Otherwise, they do not.
-
-\1f
-File: lispref.info, Node: Buffer End Motion, Next: Text Lines, Prev: Word Motion, Up: Motion
-
-Motion to an End of the Buffer
-------------------------------
-
- To move point to the beginning of the buffer, write:
-
- (goto-char (point-min))
-
-Likewise, to move to the end of the buffer, use:
-
- (goto-char (point-max))
-
- Here are two commands that users use to do these things. They are
-documented here to warn you not to use them in Lisp programs, because
-they set the mark and display messages in the echo area.
-
- - Command: beginning-of-buffer &optional N
- This function moves point to the beginning of the buffer (or the
- limits of the accessible portion, when narrowing is in effect),
- setting the mark at the previous position. If N is non-`nil',
- then it puts point N tenths of the way from the beginning of the
- buffer.
-
- In an interactive call, N is the numeric prefix argument, if
- provided; otherwise N defaults to `nil'.
-
- Don't use this function in Lisp programs!
-
- - Command: end-of-buffer &optional N
- This function moves point to the end of the buffer (or the limits
- of the accessible portion, when narrowing is in effect), setting
- the mark at the previous position. If N is non-`nil', then it puts
- point N tenths of the way from the end of the buffer.
-
- In an interactive call, N is the numeric prefix argument, if
- provided; otherwise N defaults to `nil'.
-
- Don't use this function in Lisp programs!
-
-\1f
-File: lispref.info, Node: Text Lines, Next: Screen Lines, Prev: Buffer End Motion, Up: Motion
-
-Motion by Text Lines
---------------------
-
- Text lines are portions of the buffer delimited by newline
-characters, which are regarded as part of the previous line. The first
-text line begins at the beginning of the buffer, and the last text line
-ends at the end of the buffer whether or not the last character is a
-newline. The division of the buffer into text lines is not affected by
-the width of the window, by line continuation in display, or by how
-tabs and control characters are displayed.
-
- - Command: goto-line LINE
- This function moves point to the front of the LINEth line,
- counting from line 1 at beginning of the buffer. If LINE is less
- than 1, it moves point to the beginning of the buffer. If LINE is
- greater than the number of lines in the buffer, it moves point to
- the end of the buffer--that is, the *end of the last line* of the
- buffer. This is the only case in which `goto-line' does not
- necessarily move to the beginning of a line.
-
- If narrowing is in effect, then LINE still counts from the
- beginning of the buffer, but point cannot go outside the accessible
- portion. So `goto-line' moves point to the beginning or end of the
- accessible portion, if the line number specifies an inaccessible
- position.
-
- The return value of `goto-line' is the difference between LINE and
- the line number of the line to which point actually was able to
- move (in the full buffer, before taking account of narrowing).
- Thus, the value is positive if the scan encounters the real end of
- the buffer. The value is zero if scan encounters the end of the
- accessible portion but not the real end of the buffer.
-
- In an interactive call, LINE is the numeric prefix argument if one
- has been provided. Otherwise LINE is read in the minibuffer.
-
- - Command: beginning-of-line &optional COUNT BUFFER
- This function moves point to the beginning of the current line.
- With an argument COUNT not `nil' or 1, it moves forward COUNT-1
- lines and then to the beginning of the line. BUFFER defaults to
- the current buffer if omitted.
-
- If this function reaches the end of the buffer (or of the
- accessible portion, if narrowing is in effect), it positions point
- there. No error is signaled.
-
- - Command: end-of-line &optional COUNT BUFFER
- This function moves point to the end of the current line. With an
- argument COUNT not `nil' or 1, it moves forward COUNT-1 lines and
- then to the end of the line. BUFFER defaults to the current
- buffer if omitted.
-
- If this function reaches the end of the buffer (or of the
- accessible portion, if narrowing is in effect), it positions point
- there. No error is signaled.
-
- - Command: forward-line &optional COUNT BUFFER
- This function moves point forward COUNT lines, to the beginning of
- the line. If COUNT is negative, it moves point -COUNT lines
- backward, to the beginning of a line. If COUNT is zero, it moves
- point to the beginning of the current line. BUFFER defaults to
- the current buffer if omitted.
-
- If `forward-line' encounters the beginning or end of the buffer (or
- of the accessible portion) before finding that many lines, it sets
- point there. No error is signaled.
-
- `forward-line' returns the difference between COUNT and the number
- of lines actually moved. If you attempt to move down five lines
- from the beginning of a buffer that has only three lines, point
- stops at the end of the last line, and the value will be 2.
-
- In an interactive call, COUNT is the numeric prefix argument.
-
- - Function: count-lines START END
- This function returns the number of lines between the positions
- START and END in the current buffer. If START and END are equal,
- then it returns 0. Otherwise it returns at least 1, even if START
- and END are on the same line. This is because the text between
- them, considered in isolation, must contain at least one line
- unless it is empty.
-
- Here is an example of using `count-lines':
-
- (defun current-line ()
- "Return the vertical position of point..."
- (+ (count-lines (window-start) (point))
- (if (= (current-column) 0) 1 0)
- -1))
-
- Also see the functions `bolp' and `eolp' in *Note Near Point::.
-These functions do not move point, but test whether it is already at the
-beginning or end of a line.
-
-\1f
-File: lispref.info, Node: Screen Lines, Next: List Motion, Prev: Text Lines, Up: Motion
-
-Motion by Screen Lines
-----------------------
-
- The line functions in the previous section count text lines,
-delimited only by newline characters. By contrast, these functions
-count screen lines, which are defined by the way the text appears on
-the screen. A text line is a single screen line if it is short enough
-to fit the width of the selected window, but otherwise it may occupy
-several screen lines.
-
- In some cases, text lines are truncated on the screen rather than
-continued onto additional screen lines. In these cases,
-`vertical-motion' moves point much like `forward-line'. *Note
-Truncation::.
-
- Because the width of a given string depends on the flags that control
-the appearance of certain characters, `vertical-motion' behaves
-differently, for a given piece of text, depending on the buffer it is
-in, and even on the selected window (because the width, the truncation
-flag, and display table may vary between windows). *Note Usual
-Display::.
-
- These functions scan text to determine where screen lines break, and
-thus take time proportional to the distance scanned. If you intend to
-use them heavily, Emacs provides caches which may improve the
-performance of your code. *Note cache-long-line-scans: Text Lines.
-
- - Function: vertical-motion COUNT &optional WINDOW PIXELS
- This function moves point to the start of the frame line COUNT
- frame lines down from the frame line containing point. If COUNT
- is negative, it moves up instead. The optional second argument
- WINDOW may be used to specify a window other than the selected
- window in which to perform the motion.
-
- Normally, `vertical-motion' returns the number of lines moved. The
- value may be less in absolute value than COUNT if the beginning or
- end of the buffer was reached. If the optional third argument,
- PIXELS is non-`nil', the vertical pixel height of the motion which
- took place is returned instead of the actual number of lines
- moved. A motion of zero lines returns the height of the current
- line.
-
- Note that `vertical-motion' sets WINDOW's buffer's point, not
- WINDOW's point. (This differs from FSF Emacs, which buggily always
- sets current buffer's point, regardless of WINDOW.)
-
- - Function: vertical-motion-pixels COUNT &optional WINDOW HOW
- This function moves point to the start of the frame line PIXELS
- vertical pixels down from the frame line containing point, or up if
- PIXELS is negative. The optional second argument WINDOW is the
- window to move in, and defaults to the selected window. The
- optional third argument HOW specifies the stopping condition. A
- negative integer indicates that the motion should be no more than
- PIXELS. A positive value indicates that the motion should be at
- least PIXELS. Any other value indicates that the motion should be
- as close as possible to PIXELS.
-
- - Command: move-to-window-line COUNT &optional WINDOW
- This function moves point with respect to the text currently
- displayed in WINDOW, which defaults to the selected window. It
- moves point to the beginning of the screen line COUNT screen lines
- from the top of the window. If COUNT is negative, that specifies a
- position -COUNT lines from the bottom (or the last line of the
- buffer, if the buffer ends above the specified screen position).
-
- If COUNT is `nil', then point moves to the beginning of the line
- in the middle of the window. If the absolute value of COUNT is
- greater than the size of the window, then point moves to the place
- that would appear on that screen line if the window were tall
- enough. This will probably cause the next redisplay to scroll to
- bring that location onto the screen.
-
- In an interactive call, COUNT is the numeric prefix argument.
-
- The value returned is the window line number point has moved to,
- with the top line in the window numbered 0.
-
-\1f
-File: lispref.info, Node: List Motion, Next: Skipping Characters, Prev: Screen Lines, Up: Motion
-
-Moving over Balanced Expressions
---------------------------------
-
- Here are several functions concerned with balanced-parenthesis
-expressions (also called "sexps" in connection with moving across them
-in XEmacs). The syntax table controls how these functions interpret
-various characters; see *Note Syntax Tables::. *Note Parsing
-Expressions::, for lower-level primitives for scanning sexps or parts of
-sexps. For user-level commands, see *Note Lists and Sexps:
-(emacs)Lists and Sexps.
-
- - Command: forward-list &optional ARG
- This function moves forward across ARG balanced groups of
- parentheses. (Other syntactic entities such as words or paired
- string quotes are ignored.) ARG defaults to 1 if omitted. If ARG
- is negative, move backward across that many groups of parentheses.
-
- - Command: backward-list &optional ARG
- This function moves backward across ARG balanced groups of
- parentheses. (Other syntactic entities such as words or paired
- string quotes are ignored.) ARG defaults to 1 if omitted. If ARG
- is negative, move forward across that many groups of parentheses.
-
- - Command: up-list ARG
- This function moves forward out of ARG levels of parentheses. A
- negative argument means move backward but still to a less deep
- spot.
-
- - Command: down-list ARG
- This function moves forward into ARG levels of parentheses. A
- negative argument means move backward but still go deeper in
- parentheses (-ARG levels).
-
- - Command: forward-sexp &optional ARG
- This function moves forward across ARG balanced expressions.
- Balanced expressions include both those delimited by parentheses
- and other kinds, such as words and string constants. ARG defaults
- to 1 if omitted. If ARG is negative, move backward across that
- many balanced expressions. For example,
-
- ---------- Buffer: foo ----------
- (concat-!- "foo " (car x) y z)
- ---------- Buffer: foo ----------
-
- (forward-sexp 3)
- => nil
-
- ---------- Buffer: foo ----------
- (concat "foo " (car x) y-!- z)
- ---------- Buffer: foo ----------
-
- - Command: backward-sexp &optional ARG
- This function moves backward across ARG balanced expressions. ARG
- defaults to 1 if omitted. If ARG is negative, move forward across
- that many balanced expressions.
-
- - Command: beginning-of-defun &optional ARG
- This function moves back to the ARGth beginning of a defun. If
- ARG is negative, this actually moves forward, but it still moves
- to the beginning of a defun, not to the end of one. ARG defaults
- to 1 if omitted.
-
- - Command: end-of-defun &optional ARG
- This function moves forward to the ARGth end of a defun. If ARG
- is negative, this actually moves backward, but it still moves to
- the end of a defun, not to the beginning of one. ARG defaults to
- 1 if omitted.
-
- - User Option: defun-prompt-regexp
- If non-`nil', this variable holds a regular expression that
- specifies what text can appear before the open-parenthesis that
- starts a defun. That is to say, a defun begins on a line that
- starts with a match for this regular expression, followed by a
- character with open-parenthesis syntax.
-
-\1f
-File: lispref.info, Node: Skipping Characters, Prev: List Motion, Up: Motion
-
-Skipping Characters
--------------------
-
- The following two functions move point over a specified set of
-characters. For example, they are often used to skip whitespace. For
-related functions, see *Note Motion and Syntax::.
-
- - Function: skip-chars-forward CHARACTER-SET &optional LIMIT BUFFER
- This function moves point in BUFFER forward, skipping over a given
- set of characters. It examines the character following point,
- then advances point if the character matches CHARACTER-SET. This
- continues until it reaches a character that does not match. The
- function returns `nil'. BUFFER defaults to the current buffer if
- omitted.
-
- The argument CHARACTER-SET is like the inside of a `[...]' in a
- regular expression except that `]' is never special and `\' quotes
- `^', `-' or `\'. Thus, `"a-zA-Z"' skips over all letters,
- stopping before the first non-letter, and `"^a-zA-Z'" skips
- non-letters stopping before the first letter. *Note Regular
- Expressions::.
-
- If LIMIT is supplied (it must be a number or a marker), it
- specifies the maximum position in the buffer that point can be
- skipped to. Point will stop at or before LIMIT.
-
- In the following example, point is initially located directly
- before the `T'. After the form is evaluated, point is located at
- the end of that line (between the `t' of `hat' and the newline).
- The function skips all letters and spaces, but not newlines.
-
- ---------- Buffer: foo ----------
- I read "-!-The cat in the hat
- comes back" twice.
- ---------- Buffer: foo ----------
-
- (skip-chars-forward "a-zA-Z ")
- => nil
-
- ---------- Buffer: foo ----------
- I read "The cat in the hat-!-
- comes back" twice.
- ---------- Buffer: foo ----------
-
- - Function: skip-chars-backward CHARACTER-SET &optional LIMIT BUFFER
- This function moves point backward, skipping characters that match
- CHARACTER-SET, until LIMIT. It just like `skip-chars-forward'
- except for the direction of motion.
-
projects / chise / xemacs-chise.git.1 / blobdiff