From ebea8363cc02fded1a98d0fffcda460faee9e72d Mon Sep 17 00:00:00 2001 From: Noam Postavsky Date: Wed, 4 Jan 2017 20:35:13 -0500 Subject: [PATCH] Clarify major mode switching * doc/emacs/modes.texi (Major Modes): * doc/lispref/modes.texi (Modes, Major Modes): Explictly say that each buffer has exactly one major mode and can't be "turned off", only switched away from (Bug#25357). --- doc/emacs/modes.texi | 5 ++++- doc/lispref/modes.texi | 20 +++++++++++--------- 2 files changed, 15 insertions(+), 10 deletions(-) diff --git a/doc/emacs/modes.texi b/doc/emacs/modes.texi index 0acb82d..6b8bd92 100644 --- a/doc/emacs/modes.texi +++ b/doc/emacs/modes.texi @@ -66,7 +66,10 @@ Major Modes first visit a file or create a buffer (@pxref{Choosing Modes}). You can explicitly select a new major mode by using an @kbd{M-x} command. Take the name of the mode and add @code{-mode} to get the name of the -command to select that mode (e.g., @kbd{M-x lisp-mode} enters Lisp mode). +command to select that mode (e.g., @kbd{M-x lisp-mode} enters Lisp +mode). Since every buffer has exactly one major mode, there is no way +to ``turn off'' a major mode, instead you must switch to a different +one. @vindex major-mode The value of the buffer-local variable @code{major-mode} is a symbol diff --git a/doc/lispref/modes.texi b/doc/lispref/modes.texi index b24ab36..3704e03 100644 --- a/doc/lispref/modes.texi +++ b/doc/lispref/modes.texi @@ -7,11 +7,11 @@ Modes @chapter Major and Minor Modes @cindex mode - A @dfn{mode} is a set of definitions that customize Emacs and can be -turned on and off while you edit. There are two varieties of modes: -@dfn{major modes}, which are mutually exclusive and used for editing -particular kinds of text, and @dfn{minor modes}, which provide features -that users can enable individually. + A @dfn{mode} is a set of definitions that customize Emacs' behavior +in useful ways. There are two varieties of modes: @dfn{minor modes}, +which provide features that users can turn on and off while editing. +And @dfn{major modes}, which are used for editing a particular kind of +text. Each buffer has exactly one @dfn{major mode}. This chapter describes how to write both major and minor modes, how to indicate them in the mode line, and how they run hooks supplied by the @@ -197,11 +197,13 @@ Major Modes @cindex major mode command Major modes specialize Emacs for editing particular kinds of text. -Each buffer has one major mode at a time. Every major mode is +Each buffer has exactly one major mode at a time. Every major mode is associated with a @dfn{major mode command}, whose name should end in -@samp{-mode}. This command takes care of switching to that mode in the -current buffer, by setting various buffer-local variables such as a -local keymap. @xref{Major Mode Conventions}. +@samp{-mode}. This command takes care of switching to that mode in +the current buffer, by setting various buffer-local variables such as +a local keymap. @xref{Major Mode Conventions}. Note that unlike +minor modes, the only way to ``turn off'' a major mode is to switch to +a different one. The least specialized major mode is called @dfn{Fundamental mode}, which has no mode-specific definitions or variable settings. -- 2.9.3