@c This is part of the Emacs manual.
@c Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1997, 1999, 2000,
-@c 2001, 2005 Free Software Foundation, Inc.
+@c 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
@c See file emacs.texi for copying conditions.
@node Programs, Building, Text, Top
@chapter Editing Programs
@cindex Shell-script mode
@cindex Delphi mode
@cindex PostScript mode
+@cindex Conf mode
+@cindex DNS mode
The existing programming language major modes include Lisp, Scheme (a
variant of Lisp) and the Scheme-based DSSSL expression language, Ada,
ASM, AWK, C, C++, Delphi (Object Pascal), Fortran (free format and fixed
format), Icon, IDL (CORBA), IDLWAVE, Java, Metafont (@TeX{}'s
companion for font creation), Modula2, Objective-C, Octave, Pascal,
-Perl, Pike, PostScript, Prolog, Python, Simula, Tcl, and VHDL. There is
-also a major mode for makefiles, called Makefile mode. An alternative
-mode for Perl is called CPerl mode. Modes are available for the
-scripting languages of the common GNU and Unix shells, VMS DCL, and
+Perl, Pike, PostScript, Prolog, Python, Simula, Tcl, and VHDL. An
+alternative mode for Perl is called CPerl mode. Modes are available for
+the scripting languages of the common GNU and Unix shells, VMS DCL, and
MS-DOS/MS-Windows @samp{BAT} files. There are also major modes for
-editing various sorts of configuration files.
+editing makefiles, DNS master files, and various sorts of configuration
+files.
@kindex DEL @r{(programming modes)}
@findex c-electric-backspace
@node Defuns
@section Top-Level Definitions, or Defuns
- In Emacs, a major definition at the top level in the buffer is
-called a @dfn{defun}. The name comes from Lisp, but in Emacs we use
-it for all languages.
+ In Emacs, a major definition at the top level in the buffer,
+something like a function, is called a @dfn{defun}. The name comes
+from Lisp, but in Emacs we use it for all languages.
- In most programming language modes, Emacs assumes that a defun is
+ In many programming language modes, Emacs assumes that a defun is
any pair of parentheses (or braces, if the language uses braces this
way) that starts at the left margin. For example, in C, the body of a
-function definition is normally a defun, because the open-brace that
-begins it is normally at the left margin. A variable's initializer
-can also count as a defun, if the open-brace that begins the
-initializer is at the left margin.
+function definition is a defun, usually recognized as an open-brace
+that begins at the left margin@footnote{Alternatively, you can set up
+C Mode to recognize a defun at an opening brace at the outermost
+level. @xref{Movement Commands,,, ccmode, the CC Mode Manual}.}. A
+variable's initializer can also count as a defun, if the open-brace
+that begins the initializer is at the left margin.
However, some language modes provide their own code for recognizing
defuns in a way that suits the language syntax and conventions better.
@cindex open-parenthesis in leftmost column
@cindex ( in leftmost column
- In most major modes, Emacs assumes that any opening delimiter found
-at the left margin is the start of a top-level definition, or defun.
-Therefore, @strong{never put an opening delimiter at the left margin
-unless it should have that significance.} For instance, never put an
+ Emacs assumes by default that any opening delimiter found at the
+left margin is the start of a top-level definition, or defun. You can
+override this default by setting this user option:
+
+@defvar open-paren-in-column-0-is-defun-start
+If this user option is set to @code{t} (the default), opening
+parentheses or braces at column zero always start defuns. When it's
+@code{nil}, defuns are found by searching for parens or braces at the
+outermost level. Some major modes, including C and related modes, set
+@code{open-paren-in-column-0-is-defun-start} buffer-locally to
+@code{nil}
+@end defvar
+
+ In modes where @code{open-paren-in-column-0-is-defun-start} is
+@code{t}, @strong{don't put an opening delimiter at the left margin
+unless it is a defun start}. For instance, never put an
open-parenthesis at the left margin in a Lisp file unless it is the
-start of a top-level list. Never put an open-brace or other opening
-delimiter at the beginning of a line of C code unless it is at top
-level.
+start of a top-level list.
If you don't follow this convention, not only will you have trouble
when you explicitly use the commands for motion by defuns; other
The most likely problem case is when you want an opening delimiter
at the start of a line inside a string. To avoid trouble, put an
-escape character (@samp{\}, in C and Emacs Lisp, @samp{/} in some
-other Lisp dialects) before the opening delimiter. This will not
-affect the contents of the string, but will prevent that opening
-delimiter from starting a defun. Here's an example:
+escape character (@samp{\}, in Emacs Lisp, @samp{/} in some other Lisp
+dialects) before the opening delimiter. This will not affect the
+contents of the string, but will prevent that opening delimiter from
+starting a defun. Here's an example:
@example
(insert "Foo:
the operation, we changed Emacs to assume that any opening delimiter
at the left margin is the start of a defun. This heuristic is nearly
always right, and avoids the need to scan back to the beginning of the
-buffer. However, it mandates following the convention described
-above.
+buffer. However, now that modern computers are so powerful, this
+scanning is rarely slow enough to annoy, so we've provided a way to
+disable the heuristic.
@node Moving by Defuns
@subsection Moving by Defuns
order to move it to a different place in the file. If you use the
command while point is between defuns, it uses the following defun.
Successive uses of @kbd{C-M-h}, or using it in Transient Mark mode
-when the mark is active, includes an additional defun in the region
-each time.
+when the mark is active, extends the end of the region to include one
+more defun each time.
In C mode, @kbd{C-M-h} runs the function @code{c-mark-function},
which is almost the same as @code{mark-defun}; the difference is that
@code{imenu-add-menubar-index}. If you want to have this menu bar
item available for all buffers in a certain major mode, you can do
this by adding @code{imenu-add-menubar-index} to its mode hook. But
-if you have done that, you will have to wait each time you visit a
-file in that mode, while Emacs finds all the definitions in that
-buffer.
+if you have done that, you will have to wait a little while each time
+you visit a file in that mode, while Emacs finds all the definitions
+in that buffer.
@vindex imenu-auto-rescan
When you change the contents of a buffer, if you add or delete
Adjust indentation of current line.
@item C-j
Equivalent to @key{RET} followed by @key{TAB} (@code{newline-and-indent}).
-@item @key{LINEFEED}
-This key, if the keyboard has it, is another way to enter @kbd{C-j}.
@end table
@kindex TAB @r{(programming modes)}
@kindex C-j
@findex newline-and-indent
When entering lines of new code, use @kbd{C-j}
-(@code{newline-and-indent}), which is equivalent to a @key{RET}
-followed by a @key{TAB}. @kbd{C-j} at the end of a line creates a
+(@code{newline-and-indent}), which is equivalent to @key{RET}
+followed by @key{TAB}. @kbd{C-j} at the end of a line creates a
blank line and then gives it the appropriate indentation.
@key{TAB} indents a line that starts within a parenthetical grouping
result of @key{TAB} because you find it unaesthetic for a particular
line.
- Remember that an open-parenthesis, open-brace or other opening delimiter
-at the left margin is assumed by Emacs (including the indentation routines)
-to be the start of a function. Therefore, you must never have an opening
-delimiter in column zero that is not the beginning of a function, not even
-inside a string. This restriction is vital for making the indentation
-commands fast; you must simply accept it. @xref{Left Margin Paren},
-for more information on this.
+ In some modes, an open-parenthesis, open-brace or other opening
+delimiter at the left margin is assumed by Emacs (including the
+indentation routines) to be the start of a function. This speeds up
+indentation commands. If you will be editing text which contains
+opening delimiters in column zero that aren't the beginning of a
+functions, even inside strings or comments, you must set
+@code{open-paren-in-column-0-is-defun-start}. @xref{Left Margin
+Paren}, for more information on this.
Normally, lines are indented with tabs and spaces. If you want Emacs
-to use spaces only, see @ref{Just Spaces}.
+to use spaces only, set @code{indent-tabs-mode} (@pxref{Just Spaces}).
@node Multi-line Indent
@subsection Indenting Several Lines
Select a predefined style @var{style} (@code{c-set-style}).
@end table
- A @dfn{style} is a named collection of customizations that can
-be used in C mode and the related modes. Emacs comes with several
+ A @dfn{style} is a named collection of customizations that can be
+used in C mode and the related modes. @ref{Styles,,, ccmode, The CC
+Mode Manual}, for a complete description. Emacs comes with several
predefined styles, including @code{gnu}, @code{k&r}, @code{bsd},
@code{stroustrup}, @code{linux}, @code{python}, @code{java},
-@code{whitesmith}, @code{ellemtel}, @code{cc-mode}, and @code{user}.
-Some of these styles are primarily intended for one language, but any
-of them can be used with any of the languages supported by these
-modes. To find out what a style looks like, select it and reindent
-some code, e.g., by typing @key{C-M-q} at the start of a function
-definition.
+@code{whitesmith}, @code{ellemtel}, and @code{awk}. Some of these
+styles are primarily intended for one language, but any of them can be
+used with any of the languages supported by these modes. To find out
+what a style looks like, select it and reindent some code, e.g., by
+typing @key{C-M-q} at the start of a function definition.
@kindex C-c . @r{(C mode)}
@findex c-set-style
- To choose a style for the current buffer, use the command @kbd{C-c
-.}. Specify a style name as an argument (case is not significant).
+ To choose a style for the current buffer, use the command @w{@kbd{C-c
+.}}. Specify a style name as an argument (case is not significant).
This command affects the current buffer only, and it affects only
future invocations of the indentation commands; it does not reindent
-the code in the buffer. To reindent the whole buffer in the new
-style, you can type @kbd{C-x h C-M-\}.
+the code already in the buffer. To reindent the whole buffer in the
+new style, you can type @kbd{C-x h C-M-\}.
@vindex c-default-style
You can also set the variable @code{c-default-style} to specify the
@example
(setq c-default-style
- '((java-mode . "java") (other . "gnu")))
+ '((java-mode . "java") (awk-mode . "awk") (other . "gnu")))
@end example
@noindent
-specifies an explicit choice for Java mode, and the default @samp{gnu}
-style for the other C-like modes. (These settings are actually the
-defaults.) This variable takes effect when you select one of the
-C-like major modes; thus, if you specify a new default style for Java
-mode, you can make it take effect in an existing Java mode buffer by
-typing @kbd{M-x java-mode} there.
+specifies explicit choices for Java and AWK modes, and the default
+@samp{gnu} style for the other C-like modes. (These settings are
+actually the defaults.) This variable takes effect when you select
+one of the C-like major modes; thus, if you specify a new default
+style for Java mode, you can make it take effect in an existing Java
+mode buffer by typing @kbd{M-x java-mode} there.
The @code{gnu} style specifies the formatting recommended by the GNU
Project for C; it is the default, so as to encourage use of our
recommended style.
- @xref{Customizing Indentation,,, ccmode, the CC Mode Manual}, for
-more information on customizing indentation for C and related modes,
+ @xref{Indentation Engine Basics,,, ccmode, the CC Mode Manual}, and
+@ref{Customizing Indentation,,, ccmode, the CC Mode Manual}, for more
+information on customizing indentation for C and related modes,
including how to override parts of an existing style and how to define
your own styles.
A somewhat random-sounding command which is nevertheless handy is
@kbd{C-M-t} (@code{transpose-sexps}), which drags the previous
balanced expression across the next one. An argument serves as a
-repeat count, and a negative argument drags the previous balanced
-expression backwards across those before it (thus canceling out the
-effect of @kbd{C-M-t} with a positive argument). An argument of zero,
-rather than doing nothing, transposes the balanced expressions ending
-at or after point and the mark.
+repeat count, moving the previous expression over that many following
+ones. A negative argument drags the previous balanced expression
+backwards across those before it (thus canceling out the effect of
+@kbd{C-M-t} with a positive argument). An argument of zero, rather
+than doing nothing, transposes the balanced expressions ending at or
+after point and the mark.
@kindex C-M-@@
@kindex C-M-@key{SPC}
that @kbd{C-M-f} would move to. @kbd{C-M-@@} takes arguments like
@kbd{C-M-f}. In particular, a negative argument is useful for putting
the mark at the beginning of the previous balanced expression. The
-alias @kbd{C-M-@key{SPC}} is equivalent to @kbd{C-M-@@}. If you use
-this command repeatedly, or in Transient Mark mode whenever the mark
-is active, it extends the region by one sexp each time.
+alias @kbd{C-M-@key{SPC}} is equivalent to @kbd{C-M-@@}. When you
+repeat this command, or use it in Transient Mark mode when the mark is
+active, it extends the end of the region by one sexp each time.
In languages that use infix operators, such as C, it is not possible
to recognize all balanced expressions as such because there can be
that doesn't include meaningful parentheses (symbols, strings, etc.).
@kindex C-M-u
-@kindex C-M-d
@findex backward-up-list
-@findex down-list
@kbd{C-M-n} and @kbd{C-M-p} try to stay at the same level in the
parenthesis structure. To move @emph{up} one (or @var{n}) levels, use
@kbd{C-M-u} (@code{backward-up-list}). @kbd{C-M-u} moves backward up
repeat count; a negative argument reverses the direction of motion, so
that the command moves forward and up one or more levels.
+@kindex C-M-d
+@findex down-list
To move @emph{down} in the parenthesis structure, use @kbd{C-M-d}
(@code{down-list}). In Lisp mode, where @samp{(} is the only opening
delimiter, this is nearly the same as searching for a @samp{(}. An
that case, because the cursor appears on top of that character.) Use
the command @kbd{M-x show-paren-mode} to enable or disable this mode.
- By default, @code{show-paren-mode} uses colors to highlight the
-parentheses. However, if your display doesn't support colors, you can
-customize the faces @code{show-paren-match-face} and
-@code{show-paren-mismatch-face} to use other attributes, such as bold or
-underline. @xref{Face Customization}.
+ Show Paren mode uses the faces @code{show-paren-match} and
+@code{show-paren-mismatch} to highlight parentheses; you can customize
+them to control how highlighting looks. @xref{Face Customization}.
@node Comments
@section Manipulating Comments
@item @kbd{C-M-j}
@itemx @kbd{M-j}
Like @key{RET} followed by inserting and aligning a comment
-(@code{comment-indent-new-line}).
+(@code{comment-indent-new-line}). @xref{Multi-Line Comments}.
@item @kbd{M-x comment-region}
@itemx @kbd{C-c C-c} (in C-like modes)
Add or remove comment delimiters on all the lines in the region.
start with (the value of @code{comment-start}; see below). Point is
after that string, so you can insert the text of the comment right
away. If the major mode has specified a string to terminate comments,
-@kbd{M-;} inserts that too, to keep the syntax valid.
+@kbd{M-;} inserts that after point, to keep the syntax valid.
- If the text of the line extends past the comment column, then the
-comment start string is indented to a suitable boundary (usually, at
-least one space is inserted).
+ If the text of the line extends past the comment column, this
+command indents the comment start string to a suitable boundary
+(usually, at least one space is inserted).
You can also use @kbd{M-;} to align an existing comment. If a line
already contains the comment-start string, @kbd{M-;} reindents it to
is a comment, it removes comment delimiters from each; otherwise, it
adds comment delimiters to each.) If you are not using Transient Mark
mode, then you should use the commands @code{comment-region} and
-@code{uncomment-region} to do these jobs (@pxref{Multi-Line Comments}).
+@code{uncomment-region} to do these jobs (@pxref{Multi-Line Comments}),
+or else enable Transient Mark mode momentarily (@pxref{Momentary Mark}).
A prefix argument used in these circumstances specifies how many
comment delimiters to add or how many to delete.
(1+ x)) ; This line adds one.
@end example
- In C code, a comment preceded on its line by nothing but whitespace
-is indented like a line of code.
+ For C-like modes, you can configure the exact effect of @kbd{M-;}
+more flexibly than for most buffers by setting the variables
+@code{c-indent-comment-alist} and
+@code{c-indent-comments-syntactically-p}. For example, on a line
+ending in a closing brace, @kbd{M-;} puts the comment one space after
+the brace rather than at @code{comment-column}. For full details see
+@ref{Comment Commands,,, ccmode, The CC Mode Manual}.
@node Multi-Line Comments
@subsection Multiple Lines of Comments
@kindex M-j
@cindex blank lines in programs
@findex comment-indent-new-line
+
If you are typing a comment and wish to continue it on another line,
you can use the command @kbd{C-M-j} or @kbd{M-j}
-(@code{comment-indent-new-line}). This terminates the comment you are
-typing, creates a new blank line afterward, and begins a new comment
-indented under the old one. When Auto Fill mode is on, going past the
+(@code{comment-indent-new-line}). If @code{comment-multi-line}
+(@pxref{Options for Comments}) is non-@code{nil}, it moves to a new
+line within the comment. Otherwise it closes the comment and starts a
+new comment on a new line. When Auto Fill mode is on, going past the
fill column while typing a comment causes the comment to be continued
-in just this fashion. If point is not at the end of the line when you
-type the command, the text on the rest of the line becomes part of the
-new comment line.
+in just this fashion.
@kindex C-c C-c (C mode)
@findex comment-region
To turn existing lines into comment lines, use the @kbd{M-x
-comment-region} command. It adds comment delimiters to the lines that start
-in the region, thus commenting them out. With a negative argument, it
-does the opposite---it deletes comment delimiters from the lines in the
-region.
+comment-region} command (or type @kbd{C-c C-c} in C-like modes). It
+adds comment delimiters to the lines that start in the region, thus
+commenting them out. With a negative argument, it does the
+opposite---it deletes comment delimiters from the lines in the region.
With a positive argument, @code{comment-region} duplicates the last
character of the comment start sequence it adds; the argument specifies
indentation, you should use an argument of two or three, if between defuns;
if within a defun, it must be three.
+ You can configure C Mode such that when you type a @samp{/} at the
+start of a line in a multi-line block comment, this closes the
+comment. Enable the @code{comment-close-slash} clean-up for this.
+@xref{Clean-ups,,, ccmode, The CC Mode Manual}.
+
@node Options for Comments
@subsection Options Controlling Comments
after the @samp{/*} itself, and accepts C++ style comments also.
(Note that @samp{\\} is needed in Lisp syntax to include a @samp{\} in
the string, which is needed to deny the first star its special meaning
-in regexp syntax. @xref{Regexps}.)
+in regexp syntax. @xref{Regexp Backslash}.)
@vindex comment-start
@vindex comment-end
When a comment command makes a new comment, it inserts the value of
@code{comment-start} to begin it. The value of @code{comment-end} is
-inserted after point, so that it will follow the text that you will insert
-into the comment. In C mode, @code{comment-start} has the value
-@w{@code{"/* "}} and @code{comment-end} has the value @w{@code{" */"}}.
+inserted after point, so that it will follow the text that you will
+insert into the comment. When @code{comment-end} is non-empty, it
+should start with a space. For example, in C mode,
+@code{comment-start} has the value @w{@code{"/* "}} and
+@code{comment-end} has the value @w{@code{" */"}}.
@vindex comment-padding
The variable @code{comment-padding} specifies how many spaces
@vindex comment-multi-line
The variable @code{comment-multi-line} controls how @kbd{C-M-j}
(@code{indent-new-comment-line}) behaves when used inside a comment.
-Specifically, when @code{comment-multi-line} is @code{nil} (the
-default value), the command inserts a comment terminator, begins a new
-line, and finally inserts a comment starter. Otherwise it does not
-insert the terminator and starter, so it effectively continues the
-current comment across multiple lines. In languages that allow
-multi-line comments, the choice of value for this variable is a matter
-of taste.
+Specifically, when @code{comment-multi-line} is @code{nil}, the
+command inserts a comment terminator, begins a new line, and finally
+inserts a comment starter. Otherwise it does not insert the
+terminator and starter, so it effectively continues the current
+comment across multiple lines. In languages that allow multi-line
+comments, the choice of value for this variable is a matter of taste.
+The default for this variable depends on the major mode.
@vindex comment-indent-function
The variable @code{comment-indent-function} should contain a function
@findex info-lookup-symbol
@findex info-lookup-file
@kindex C-h S
- For C, Lisp, and other languages that have documentation in Info,
-you can use @kbd{C-h S} (@code{info-lookup-symbol}) to view the Info
-documentation for a symbol used in the program. You specify the
-symbol with the minibuffer; the default is the symbol appearing in the
-buffer at point. For example, in C mode this looks for the symbol in
-the C Library Manual.
+ For many major modes, that apply to languages that have
+documentation in Info, you can use @kbd{C-h S}
+(@code{info-lookup-symbol}) to view the Info documentation for a
+symbol used in the program. You specify the symbol with the
+minibuffer; the default is the symbol appearing in the buffer at
+point. For example, in C mode this looks for the symbol in the C
+Library Manual. The command only works if the appropriate manual's
+Info files are installed.
The major mode determines where to look for documentation for the
symbol---which Info files to look in, and which indices to search.
You can also use @kbd{M-x info-lookup-file} to look for documentation
for a file name.
- This feature currently supports the modes AWK, Autoconf, Bison, C,
-Emacs Lisp, LaTeX, M4, Makefile, Octave, Perl, Scheme, and Texinfo,
-provided you have installed the relevant Info files, which are
-typically available with the appropriate GNU package.
+ If you use @kbd{C-h S} in a major mode that does not support it,
+it asks you to specify the ``symbol help mode''. You should enter
+a command such as @code{c-mode} that would select a major
+mode which @kbd{C-h S} does support.
@node Man Page
@subsection Man Page Lookup
@cindex manual page
On Unix, the main form of on-line documentation was the @dfn{manual
-page} or @dfn{man page}. In the GNU operating system, we hope to
+page} or @dfn{man page}. In the GNU operating system, we aim to
replace man pages with better-organized manuals that you can browse
with Info (@pxref{Misc Help}). This process is not finished, so it is
still useful to read manual pages.
when @kbd{M-x manual-entry} prompts for the topic. For example, to
read the man page for the C library function @code{chmod} (as opposed
to a command of the same name), type @kbd{M-x manual-entry @key{RET}
-chmod(2) @key{RET}} (@code{chmod} is a system call, so it is in
-section @samp{2}).
+chmod(2) @key{RET}}. (@code{chmod} is a system call, so it is in
+section @samp{2}.)
@vindex Man-switches
If you do not specify a section, the results depend on how the
pops up a window with possible candidates asking you to choose one of
them.
-@vindex woman-manpath
- By default, @kbd{M-x woman} looks for manual pages in the
-directories specified in the @code{MANPATH} environment variable. (If
-@code{MANPATH} is not set, @code{woman} uses a suitable default value,
-which can be customized.) More precisely, @code{woman} looks for
-subdirectories that match the shell wildcard pattern @file{man*} in each one
-of these directories, and tries to find the manual pages in those
-subdirectories. When first invoked, @kbd{M-x woman} converts the
-value of @code{MANPATH} to a list of directory names and stores that
-list in the @code{woman-manpath} variable. Changing the value of this
-variable is another way to control the list of directories used.
-
-@vindex woman-path
- You can also augment the list of directories searched by
-@code{woman} by setting the value of the @code{woman-path} variable.
-This variable should hold a list of specific directories which
-@code{woman} should search, in addition to those in
-@code{woman-manpath}. Unlike @code{woman-manpath}, the directories in
-@code{woman-path} are searched for the manual pages, not for
-@file{man*} subdirectories.
-
-@findex woman-find-file
- Occasionally, you might need to display manual pages that are not in
-any of the directories listed by @code{woman-manpath} and
-@code{woman-path}. The @kbd{M-x woman-find-file} command prompts for a
-name of a manual page file, with completion, and then formats and
-displays that file like @kbd{M-x woman} does.
-
-@vindex woman-dired-keys
- The first time you invoke @kbd{M-x woman}, it defines the Dired
-@kbd{W} key to run the @code{woman-find-file} command on the current
-line's file. You can disable this by setting the variable
-@code{woman-dired-keys} to @code{nil}. @xref{Dired}. In addition,
-the Tar-mode @kbd{w} key is define to invoke @code{woman-find-file} on
-the current line's archive member.
-
For more information about setting up and using @kbd{M-x woman}, see
@ref{Top, WoMan, Browse UN*X Manual Pages WithOut Man, woman, The WoMan
Manual}.
function being called at point. (In other words, it finds the
function call that point is contained in, and displays the argument
list of that function.) If point is over a documented variable, it
-shows the variable's docstring. Eldoc mode applies in Emacs Lisp and
-Lisp Interaction modes only. Use the command @kbd{M-x eldoc-mode} to
-enable or disable this feature.
+shows the first line of the variable's docstring. Eldoc mode applies
+in Emacs Lisp and Lisp Interaction modes, and perhaps a few others
+that provide special support for looking up doc strings. Use the
+command @kbd{M-x eldoc-mode} to enable or disable this feature.
@node Hideshow
@section Hideshow minor mode
Non-@code{nil} says that @kbd{hs-hide-all} should hide comments too.
@item hs-isearch-open
-Specifies what kind of hidden blocks to open in Isearch mode.
-The value should be one of these four symbols:
+Specifies what kind of hidden blocks incremental search should make
+visible. The value should be one of these four symbols:
@table @code
@item code
Move point to the end of the innermost C statement or sentence; like
@kbd{M-a} except that it moves in the other direction
(@code{c-end-of-statement}).
-
-@item M-x c-backward-into-nomenclature
-@findex c-backward-into-nomenclature
-Move point backward to beginning of a C++ nomenclature section or word.
-With prefix argument @var{n}, move @var{n} times. If @var{n} is
-negative, move forward. C++ nomenclature means a symbol name in the
-style of NamingSymbolsWithMixedCaseAndNoUnderlines; each capital letter
-begins a section or word.
-
-In the GNU project, we recommend using underscores to separate words
-within an identifier in C or C++, rather than using case distinctions.
-
-@item M-x c-forward-into-nomenclature
-@findex c-forward-into-nomenclature
-Move point forward to end of a C++ nomenclature section or word.
-With prefix argument @var{n}, move @var{n} times.
@end table
@node Electric C
@subsection Electric C Characters
In C mode and related modes, certain printing characters are
-``electric''---in addition to inserting themselves, they also reindent
-the current line, and optionally also insert newlines. The
+@dfn{electric}---in addition to inserting themselves, they also
+reindent the current line, and optionally also insert newlines. The
``electric'' characters are @kbd{@{}, @kbd{@}}, @kbd{:}, @kbd{#},
@kbd{;}, @kbd{,}, @kbd{<}, @kbd{>}, @kbd{/}, @kbd{*}, @kbd{(}, and
@kbd{)}.
- Electric characters insert newlines only when the @dfn{auto-newline}
-feature is enabled (indicated by @samp{/a} in the mode line after the
-mode name). This feature is controlled by the variable
-@code{c-auto-newline}. You can turn this feature on or off with the
-command @kbd{C-c C-a}:
+ You might find electric indentation inconvenient if you are editing
+chaotically indented code. If you are new to CC Mode, you might find
+it disconcerting. You can toggle electric action with the command
+@kbd{C-c C-l}; when it is enabled, @samp{/l} appears in the mode line
+after the mode name:
@table @kbd
-@item C-c C-a
-@kindex C-c C-a @r{(C mode)}
-@findex c-toggle-auto-state
-Toggle the auto-newline feature (@code{c-toggle-auto-state}). With a
-prefix argument, this command turns the auto-newline feature on if the
-argument is positive, and off if it is negative.
+@item C-c C-l
+@kindex C-c C-l @r{(C mode)}
+@findex c-toggle-electric-state
+Toggle electric action (@code{c-toggle-electric-state}). With a
+prefix argument, this command enables electric action if the argument
+is positive, disables it if it is negative.
@end table
- The colon character is electric because that is appropriate for a
-single colon. But when you want to insert a double colon in C++, the
-electric behavior of colon is inconvenient. You can insert a double
-colon with no reindentation or newlines by typing @kbd{C-c :}:
+ Electric characters insert newlines only when, in addition to the
+electric state, the @dfn{auto-newline} feature is enabled (indicated
+by @samp{/la} in the mode line after the mode name). You can turn
+this feature on or off with the command @kbd{C-c C-a}:
@table @kbd
-@item C-c :
-@ifinfo
-@c This uses ``colon'' instead of a literal `:' because Info cannot
-@c cope with a `:' in a menu
-@kindex C-c @key{colon} @r{(C mode)}
-@end ifinfo
-@ifnotinfo
-@kindex C-c : @r{(C mode)}
-@end ifnotinfo
-@findex c-scope-operator
-Insert a double colon scope operator at point, without reindenting the
-line or adding any newlines (@code{c-scope-operator}).
+@item C-c C-a
+@kindex C-c C-a @r{(C mode)}
+@findex c-toggle-auto-newline
+Toggle the auto-newline feature (@code{c-toggle-auto-newline}). With a
+prefix argument, this command turns the auto-newline feature on if the
+argument is positive, and off if it is negative.
@end table
-@vindex c-electric-pound-behavior
- The electric @kbd{#} key reindents the line if it appears to be the
-beginning of a preprocessor directive. This happens when the value of
-@code{c-electric-pound-behavior} is @code{(alignleft)}. You can turn
-this feature off by setting @code{c-electric-pound-behavior} to
-@code{nil}.
-
-@vindex c-hanging-braces-alist
- The variable @code{c-hanging-braces-alist} controls the insertion of
-newlines before and after inserted braces. It is an association list
-with elements of the following form: @code{(@var{syntactic-symbol}
-. @var{nl-list})}. Most of the syntactic symbols that appear in
-@code{c-offsets-alist} are meaningful here as well.
-
- The list @var{nl-list} may contain either of the symbols
-@code{before} or @code{after}, or both; or it may be @code{nil}. When a
-brace is inserted, the syntactic context it defines is looked up in
-@code{c-hanging-braces-alist}; if it is found, the @var{nl-list} is used
-to determine where newlines are inserted: either before the brace,
-after, or both. If not found, the default is to insert a newline both
-before and after braces.
-
-@vindex c-hanging-colons-alist
- The variable @code{c-hanging-colons-alist} controls the insertion of
-newlines before and after inserted colons. It is an association list
-with elements of the following form: @code{(@var{syntactic-symbol}
-. @var{nl-list})}. The list @var{nl-list} may contain either of the
-symbols @code{before} or @code{after}, or both; or it may be @code{nil}.
-
- When a colon is inserted, the syntactic symbol it defines is looked
-up in this list, and if found, the @var{nl-list} is used to determine
-where newlines are inserted: either before the brace, after, or both.
-If the syntactic symbol is not found in this list, no newlines are
-inserted.
-
-@vindex c-cleanup-list
- Electric characters can also delete newlines automatically when the
-auto-newline feature is enabled. This feature makes auto-newline more
-acceptable, by deleting the newlines in the most common cases where you
-do not want them. Emacs can recognize several cases in which deleting a
-newline might be desirable; by setting the variable
-@code{c-cleanup-list}, you can specify @emph{which} of these cases that
-should happen. The variable's value is a list of symbols, each
-describing one case for possible deletion of a newline. Here are the
-meaningful symbols, and their meanings:
-
-@table @code
-@item brace-catch-brace
-Clean up @samp{@} catch (@var{condition}) @{} constructs by placing the
-entire construct on a single line. The clean-up occurs when you type
-the @samp{@{}, if there is nothing between the braces aside from
-@code{catch} and @var{condition}.
-
-@item brace-else-brace
-Clean up @samp{@} else @{} constructs by placing the entire construct on
-a single line. The clean-up occurs when you type the @samp{@{} after
-the @code{else}, but only if there is nothing but white space between
-the braces and the @code{else}.
-
-@item brace-elseif-brace
-Clean up @samp{@} else if (@dots{}) @{} constructs by placing the entire
-construct on a single line. The clean-up occurs when you type the
-@samp{@{}, if there is nothing but white space between the @samp{@}} and
-@samp{@{} aside from the keywords and the @code{if}-condition.
-
-@item empty-defun-braces
-Clean up empty defun braces by placing the braces on the same
-line. Clean-up occurs when you type the closing brace.
-
-@item defun-close-semi
-Clean up the semicolon after a @code{struct} or similar type
-declaration, by placing the semicolon on the same line as the closing
-brace. Clean-up occurs when you type the semicolon.
-
-@item list-close-comma
-Clean up commas following braces in array and aggregate
-initializers. Clean-up occurs when you type the comma.
-
-@item scope-operator
-Clean up double colons which may designate a C++ scope operator, by
-placing the colons together. Clean-up occurs when you type the second
-colon, but only when the two colons are separated by nothing but
-whitespace.
-@end table
+ Usually the CC Mode style configures the exact circumstances in
+which Emacs inserts auto-newlines. You can also configure this
+directly. @xref{Custom Auto-newlines,,, ccmode, The CC Mode Manual}.
@node Hungry Delete
@subsection Hungry Delete Feature in C
@cindex hungry deletion (C Mode)
- When the @dfn{hungry-delete} feature is enabled (indicated by
-@samp{/h} or @samp{/ah} in the mode line after the mode name), a single
-@key{DEL} command deletes all preceding whitespace, not just one space.
-To turn this feature on or off, use @kbd{C-c C-d}:
+ If you want to delete an entire block of whitespace at point, you
+can use @dfn{hungry deletion}. This deletes all the contiguous
+whitespace either before point or after point in a single operation.
+@dfn{Whitespace} here includes tabs and newlines, but not comments or
+preprocessor commands.
@table @kbd
+@item C-c C-@key{BS}
+@itemx C-c @key{BS}
+@findex c-hungry-backspace
+@kindex C-c C-@key{BS} (C Mode)
+@kindex C-c @key{BS} (C Mode)
+@code{c-hungry-backspace}---Delete the entire block of whitespace
+preceding point.
+
@item C-c C-d
-@kindex C-c C-d @r{(C mode)}
-@findex c-toggle-hungry-state
-Toggle the hungry-delete feature (@code{c-toggle-hungry-state}). With a
-prefix argument, this command turns the hungry-delete feature on if the
-argument is positive, and off if it is negative.
+@itemx C-c C-@key{DEL}
+@itemx C-c @key{DEL}
+@findex c-hungry-delete-forward
+@kindex C-c C-d (C Mode)
+@kindex C-c C-@key{DEL} (C Mode)
+@kindex C-c @key{DEL} (C Mode)
+@code{c-hungry-delete-forward}---Delete the entire block of whitespace
+following point.
+@end table
-@item C-c C-t
-@kindex C-c C-t @r{(C mode)}
-@findex c-toggle-auto-hungry-state
-Toggle the auto-newline and hungry-delete features, both at once
-(@code{c-toggle-auto-hungry-state}).
+ As an alternative to the above commands, you can enable @dfn{hungry
+delete mode}. When this feature is enabled (indicated by @samp{/h} in
+the mode line after the mode name), a single @key{BS} command deletes
+all preceding whitespace, not just one space, and a single @kbd{C-c
+C-d} (but @emph{not} @key{DELETE}) deletes all following whitespace.
+
+@table @kbd
+@item M-x c-toggle-hungry-state
+@findex c-toggle-hungry-state
+Toggle the hungry-delete feature
+(@code{c-toggle-hungry-state})@footnote{This command had the binding
+@kbd{C-c C-d} in earlier versions of Emacs. @kbd{C-c C-d} is now
+bound to @code{c-hungry-delete-forward}.}. With a prefix argument,
+this command turns the hungry-delete feature on if the argument is
+positive, and off if it is negative.
@end table
@vindex c-hungry-delete-key
@subsection Other Commands for C Mode
@table @kbd
+@item C-c C-w
+@itemx M-x c-subword-mode
+@findex c-subword-mode
+Enable (or disable) @dfn{subword mode}. In subword mode, Emacs's word
+commands then recognize upper case letters in
+@samp{StudlyCapsIdentifiers} as word boundaries. This is indicated by
+the flag @samp{/w} on the mode line after the mode name
+(e.g. @samp{C/law}). You can even use @kbd{M-x c-subword-mode} in
+non-CC Mode buffers.
+
+In the GNU project, we recommend using underscores to separate words
+within an identifier in C or C++, rather than using case distinctions.
+
@item M-x c-context-line-break
@findex c-context-line-break
This command inserts a line break and indents the new line in a manner
@code{c-context-line-break} isn't bound to a key by default, but it
needs a binding to be useful. The following code will bind it to
-@kbd{C-j}.
+@kbd{C-j}. We use @code{c-initialization-hook} here to make sure
+the keymap is loaded before we try to change it.
+
@example
-(define-key c-mode-base-map "\C-j" 'c-context-line-break)
+(defun my-bind-clb ()
+ (define-key c-mode-base-map "\C-j" 'c-context-line-break))
+(add-hook 'c-initialization-hook 'my-bind-clb)
@end example
@item C-M-h
In addition to the normal commands for moving by and operating on
``defuns'' (Fortran subprograms---functions and subroutines, as well as
modules for F90 mode), Fortran mode provides special commands to move by
-statements.
+statements and other program units.
@table @kbd
@kindex C-c C-n @r{(Fortran mode)}
(@code{f90-previous-block}). This is like @code{f90-next-block}, but
moves backwards.
-@kindex C-M-n @r{(F90 mode)}
+@kindex C-M-n @r{(Fortran mode)}
+@findex fortran-end-of-block
@findex f90-end-of-block
@item C-M-n
-Move to the end of the current code block (@code{f90-end-of-block}).
-This is for F90 mode only. With a numeric agument, move forward that
-number of blocks. This command checks for consistency of block types
-and labels (if present), but it does not check the outermost block
-since that may be incomplete. The mark is set before moving point.
-
-@kindex C-M-p @r{(F90 mode)}
+Move to the end of the current code block
+(@code{fortran-end-of-block}/@code{f90-end-of-block}). With a numeric
+agument, move forward that number of blocks. The mark is set before
+moving point. The F90 mode version of this command checks for
+consistency of block types and labels (if present), but it does not
+check the outermost block since that may be incomplete.
+
+@kindex C-M-p @r{(Fortran mode)}
+@findex fortran-beginning-of-block
@findex f90-beginning-of-block
@item C-M-p
Move to the start of the current code block
-(@code{f90-beginning-of-block}). This is like @code{f90-end-of-block},
-but moves backwards.
+(@code{fortran-beginning-of-block}/@code{f90-beginning-of-block}). This
+is like @code{fortran-end-of-block}, but moves backwards.
@end table
@node Fortran Indent
@vindex indent-tabs-mode @r{(Fortran mode)}
@vindex fortran-analyze-depth
@vindex fortran-tab-mode-default
-@vindex fortran-tab-mode-string
Fortran mode can use either style of continuation line. When you
enter Fortran mode, it tries to deduce the proper continuation style
automatically from the buffer contents. It does this by scanning up to
spaces determines the choice. If the scan fails (for example, if the
buffer is new and therefore empty), the value of
@code{fortran-tab-mode-default} (@code{nil} for fixed format, and
-non-@code{nil} for tab format) is used. You can tell which style is
-presently in effect by the presence or absence of the string specified
-by @code{fortran-tab-mode-string} (default @samp{/t}) in the mode line.
+non-@code{nil} for tab format) is used. @samp{/t} in the mode line
+indicates tab format is selected. Fortran mode sets the value of
+@code{indent-tabs-mode} accordingly (@pxref{Just Spaces}).
-@vindex fortran-continuation-string
If the text on a line starts with the Fortran continuation marker
-specified by @code{fortran-continuation-string} (conventionally
-@samp{$}), or if it begins with any non-whitespace character in column
+@samp{$}, or if it begins with any non-whitespace character in column
5, Fortran mode treats it as a continuation line. When you indent a
continuation line with @key{TAB}, it converts the line to the current
continuation style. When you split a Fortran statement with
Simply inserting a line number is enough to indent it according to
these rules. As each digit is inserted, the indentation is recomputed.
To turn off this feature, set the variable
-@code{fortran-electric-line-number} to @code{nil}.
+@code{fortran-electric-line-number} to @code{nil}.
@node ForIndent Conv
Extra indentation within each level of @samp{do} statement (default 3).
@item fortran-if-indent
-Extra indentation within each level of @samp{if} statement (default 3).
+Extra indentation within each level of @samp{if}, @samp{select case}, or
+@samp{where} statements (default 3).
@item fortran-structure-indent
Extra indentation within each level of @samp{structure}, @samp{union},
@end table
The variables controlling the indentation of comments are described in
-a separate section (@pxref{Fortran Comments}).
-
+the following section.
@node Fortran Comments
@subsection Fortran Comments
@vindex fortran-break-before-delimiters
Auto Fill breaks lines at spaces or delimiters when the lines get
longer than the desired width (the value of @code{fill-column}). The
-delimiters (besides whitespace) that Auto Fill may break at are
+delimiters (besides whitespace) that Auto Fill can break at are
@samp{+}, @samp{-}, @samp{/}, @samp{*}, @samp{=}, @samp{<}, @samp{>},
-and @samp{,}. The line break comes after the delimiter if the variable
-@code{fortran-break-before-delimiters} is @code{nil}. Otherwise (and by
-default), the break comes before the delimiter.
+and @samp{,}. The line break comes after the delimiter if the
+variable @code{fortran-break-before-delimiters} is @code{nil}.
+Otherwise (and by default), the break comes before the delimiter.
To enable Auto Fill in all Fortran buffers, add
@code{turn-on-auto-fill} to @code{fortran-mode-hook}. @xref{Hooks}.