Glossary

Emacs jargon predates most user interfaces used today. See EmacsJargon for an introductory translation to/from Emacs-speak. See EmacsSymbolNotation for the ways Emacs and EmacsLisp types are presented.

See also Emacs’ official Glossary.

• atom – a Lisp entity that is not a cons. This includes symbols and strings.
• alist – a list whose elements are conses.
• bookmark – just what it sounds like: a saved location in a file or buffer
• bound variable – a variable that has a symbol value
• buffer – editing happens in buffers (workspaces)
• car – see cons
• cdr – see cons
• character property – “a named attribute of a character that specifies how the character behaves and how it should be handled during text processing and display” as the elisp manual says.
• chord – a key sequence with keys pressed simultaneously
• command – an InteractiveFunction
• completion – completing input in the minibuffer or text in another buffer
• cons (aka cons cell) – A Lisp object that is composed of a pair of Lisp objects of any kind. The first is called the car; the second is called the cdr. See also atom.
• cursor (text cursor) – how it differs from the pointer (mouse pointer); its relation with point
• custom file – file, other than your init file (~/.emacs), where customizations from Customize are saved. It is the value of variable ‘custom-file’.
• Customize – Emacs user interface for changing and saving preferences (settings)
• default directory – directory assumed for the current buffer; it is the value of variable ‘default-directory’
• device – Under XEmacs, frames are shown on devices (TTY, X, MS Windows, GTK)
• display – Under GNU Emacs, frames are shown on displays (TTY, X)
• doc string – self-documentation for functions and variables
• DWIM – DoWhatIMean: sophisticated user-interface design that sometimes doesn’t do what you intend or expect ;-)
• dynamic scoping – variable binding (value) behavior that means the last binding of a given variable wins – lexical context does not govern binding
• echo area – Occupies the same frame space as the minibuffer. Used to display messages.
• Electricity – extra or sophisticated behavior (see also DWIM)
• Emacsen – different Emacs implementations
• Emacs Lisp – the Lisp dialect that Emacs uses. Much of Emacs is written in Emacs Lisp, and you can use Emacs Lisp to customize or extend Emacs.
• extensible – the ‘E’ in “Emacs”
• face – Is it a font? Is it a color? No, it is a face!
• font – ???????? FIXME
• frame – Emacs windows are shown in frames (called “windows” outside of Emacs)
• fringe – thin strips at the left and right edges of a window, with glyphs that indicate various things
• function cell – the function associated with a symbol; aka symbol function
• GPL – GNU General Public License: publishing license used for free software
• header line – at the top of a window, used by some modes
• Info – Emacs’s on-board help system: hypertext manuals (see InfoMode)
• init file – your personal startup file, loaded when Emacs starts up: ~/.emacs or ~/_emacs
• InteractiveFunction – command
• key binding – a mapping (relation) between an Emacs command and a key sequence. A key binding can be a global key binding, a local key binding (enabled only for a given major mode), or a minor-mode key binding (enabled only for a given minor mode)
• isearch – incremental search, which interactively searches for the search string character-by-character as you type it
• keyboard macro – a recording of key sequences that you can replay
• keymap – a collection of key bindings, that is, a mapping (relation) between Emacs commands and key sequences. A keymap can be a global keymap, a local keymap (applicable only to a given major mode), or a minor-mode keymap (applicable only to a given minor mode)
• key sequence – a key sequence can be bound to a command, to execute it
• kill – cut, that is, delete and copy to the kill ring
• kill ring – ring of previously killed (cut) or copied text snippets; the value of variable ‘kill-ring’
• lambda expression – a function representation that is a sexp that evaluates to a cons whose car is the symbol ‘lambda’. (See WikiPedia:Lambda calculus.)
• line – a line of text. See also line ending.
• line ending – one or more characters at the end of a line
• line wrap – how lines that are wider than a window are displayed (unless they are truncated at the right edge)
• list – A list is the symbol ‘nil’ or a cons whose cdr is a list.
• macro – An EmacsLisp form that, when evaluated, translates a sexp that is a list into another such, which is then evaluated and its result is returned. IOW, it rewrites (without evaluating) one sexp as another and then evaluates the latter. It is typically defined using ‘defmacro’. It can be expanded without evaluating the result, using ‘macroexpand’. See macros.
• major mode – each buffer is in one major mode
• mark – a buffer location that you can change, return to…
• marker – a Lisp object that contains information about a position in a buffer that is updated to track the same location should edits insert or delete text around it
• mark ring – ring of marks. Variable ‘mark-ring’ holds the marks of the current buffer; variable ‘global-mark-ring’ holds the global marks (across all buffers).
• menu bar – menus at the top of an Emacs frame
• Meta key (written ‘M-’) – a logical modifier key that is usually realized as the Alt keyboard key
• minibuffer – special buffer at the bottom of a frame, which you use to enter commands
• minor mode – several minor modes can be active at the same time
• mode line – at the bottom of a window, it describes the current buffer status
• modifier key – (1) a keyboard key that, when pressed, modifies the behavior of another keyboard key pressed at the same time (e.g. Control, Shift, Alt); (2) a soft key that does the same thing (e.g. Control, Shift, Meta, Hyper, Super)
• mule – multilingual environment
• narrowing – limiting buffer scope temporarily
• obarray – a symbol table implemented as a special kind of vector. Think of it as a hash table for looking up symbols. The value of variable ‘obarray’ is the obarray used by default by ‘intern’ and ‘read’. See Creating Symbols.
• overlay – a property list that is similar to a text property list, but which is associated with buffer positions, not with characters. Typically used to highlight text.
• page – A block of text delimited by form feed (aka page break) characters or the beginning or end of the buffer. See Pages
• plist (aka property list) – A list with an even number of elements that are treated alternately as keys and their values. Both keys and values can be any Lisp objects. A plist can be part of a symbol or disembodied (independent of any symbol).
• point – where text insertion occurs (sometimes called “cursor position” outside Emacs).
• pointer (mouse pointer) – how it differs from the cursor (text cursor)
• prefix argument – a simple way to provide arguments to some commands: ‘C-u’, `C-+’, ‘C--’, C-N (N a digit)
• prefix key – a key that is bound to a keymap, which is called a prefix keymap
• rectangle – characters between a pair of columns on the screen.
• regexp – a regular expression
• regexp search ring – ring of previously used regexp search strings; the value of variable ‘regexp-search-ring’ (see also search ring)
• region – the area between point and mark, sometimes active, sometimes inactive
• register – a location for temporarily saving text (a string), a rectangle, a buffer position, a frame or window configuration
• regular expression (aka regexp) – a symbolic expression with wildcards often used as a search pattern
• RequiredFeature – when Lisp code ‘require’s a Lisp library, or feature, the requirement can be hard or soft
• ring – a data structure that acts as if it is circular (no end)
• scroll bar – just what you think, controlled by command and variable ‘scroll-bar-mode’
• search ring – ring of previously used search strings; the value of variable ‘search-ring’ (see also regexp search ring)
• secondary selection – like an additional region, but less ephemeral
• sexp – a symbolic expression in Lisp
• special display buffer (aka special buffer) – a buffer that is always displayed in its own, dedicated frame
• symbol (aka variable) – a Lisp object that has a name, a value cell, a function cell, and a plist (property list)
• tag – a name indexed in a tags file so you can quickly look up its definition
• text property – a property attached to a character that affects its display or behavior
• TtyFrames – Teletype (TTY), or terminal, screens
• universal argument – the command bound to ‘C-u’
• user option (aka user variable, aka option) – a variable that can be customized using Customize or set using ‘M-x set-variable’
• value cell – the value of a symbol (variable); aka symbol value
• variable – a symbol, whether bound or not
• window – a frame pane; it shows a buffer
• yank – paste

CategoryGlossary