@c This is part of the Emacs manual.
@c Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1997, 1999, 2000,
-@c 2001, 2002, 2003, 2004, 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
* Misc for Programs:: Other Emacs features useful for editing programs.
* C Modes:: Special commands of C, C++, Objective-C,
Java, and Pike modes.
-* Fortran:: Fortran mode and its special features.
* Asm Mode:: Asm mode and its special features.
+@ifnottex
+* Fortran:: Fortran mode and its special features.
+@end ifnottex
@end menu
@node Program Modes
Separate manuals are available for the modes for Ada (@pxref{Top, , Ada
Mode, ada-mode, Ada Mode}), C/C++/Objective C/Java/Corba IDL/Pike/AWK
(@pxref{Top, , CC Mode, ccmode, CC Mode}) and the IDLWAVE modes
-(@pxref{Top, , IDLWAVE, idlwave, IDLWAVE User Manual}).
+(@pxref{Top, , IDLWAVE, idlwave, IDLWAVE User Manual}). For Fortran
+mode, see
+@iftex
+@ref{Fortran,,, emacs-xtra, Specialized Emacs Features}.
+@end iftex
+@ifnottex
+@ref{Fortran}.
+@end ifnottex
+
@cindex mode hook
@vindex c-mode-hook
something like a function, is called a @dfn{defun}. The name comes
from Lisp, but in Emacs we use it for all languages.
- 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 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.
-
@menu
* Left Margin Paren:: An open-paren or similar opening delimiter
starts a defun if it is at the left margin.
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
The basic indentation commands indent a single line according to the
usual conventions of the language you are editing.
+@need 1000
@table @kbd
@item @key{TAB}
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}.
+Insert a newline, then adjust indentation of following line
+(@code{newline-and-indent}).
@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
-blank line and then gives it the appropriate indentation.
+(@code{newline-and-indent}), which inserts a newline and then adjusts
+indentation after it. (It also deletes any trailing whitespace which
+remains before the new newline.) Thus, @kbd{C-j} at the end of a line
+creates a blank line with appropriate indentation. In programming
+language modes, it is equivalent to @key{RET} @key{TAB}.
@key{TAB} indents a line that starts within a parenthetical grouping
under the preceding line within the grouping, or the text after the
result of @key{TAB} because you find it unaesthetic for a particular
line.
- By default, an open-parenthesis, open-brace or other opening
+ 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
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
@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 already in the buffer. To reindent the whole buffer in the
the mark at the beginning of the previous balanced expression. The
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 region by one sexp each time.
+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
(@pxref{Spelling}).
@menu
-* Comment Commands:: Inserting, killing, and indenting comments.
+* Comment Commands:: Inserting, killing, and aligning comments.
* Multi-Line Comments:: Commands for adding and editing multi-line comments.
* Options for Comments::Customizing the comment features.
@end menu
@node Comment Commands
@subsection Comment Commands
@cindex indentation for comments
+@cindex alignment for comments
The comment commands in this table insert, kill and align comments.
They are described in this section and following sections.
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 aligns 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
+already contains the comment-start string, @kbd{M-;} realigns it to
the conventional alignment and moves point after it. (Exception:
comments starting in column 0 are not moved.) Even when an existing
comment is properly aligned, @kbd{M-;} is still useful for moving
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.
- Some major modes have special rules for indenting certain kinds of
+ Some major modes have special rules for aligning certain kinds of
comments in certain contexts. For example, in Lisp code, comments which
start with two semicolons are indented as if they were lines of code,
instead of at the comment column. Comments which start with three
-semicolons are supposed to start at the left margin. Emacs understands
+semicolons are supposed to start at the left margin and are often used
+for sectioning purposes. Emacs understands
these conventions by indenting a double-semicolon comment using @key{TAB},
and by not changing the indentation of a triple-semicolon comment at all.
@example
-;; This function is just an example
+;; This function is just an example.
;;; Here either two or three semicolons are appropriate.
(defun foo (x)
-;;; And now, the first part of the function:
+;;; And now, the first part of the function:
;; The following line adds one.
(1+ x)) ; This line adds one.
@end example
- For C-like buffers, you can configure the exact effect of @kbd{M-;}
-more flexibly than for most buffers by setting the user options
+ 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
@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 (or type @kbd{C-c C-c} in C-like buffers). It
+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
-how many copies of the character to insert. Thus, in Lisp mode,
-@kbd{C-u 2 M-x comment-region} adds @samp{;;} to each line. Duplicating
-the comment delimiter is a way of calling attention to the comment. It
-can also affect how the comment is indented. In Lisp, for proper
-indentation, you should use an argument of two or three, if between defuns;
-if within a defun, it must be three.
+character of the comment start sequence it adds; the argument
+specifies how many copies of the character to insert. Thus, in Lisp
+mode, @kbd{C-u 2 M-x comment-region} adds @samp{;;} to each line.
+Duplicating the comment delimiter is a way of calling attention to the
+comment. It can also affect how the comment is aligned or indented.
+In Lisp, for proper 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
@vindex comment-indent-function
The variable @code{comment-indent-function} should contain a function
-that will be called to compute the indentation for a newly inserted
+that will be called to compute the alignment for a newly inserted
comment or for aligning an existing comment. It is set differently by
various major modes. The function is called with no arguments, but with
point at the beginning of the comment, or at the end of a line if a new
@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}.
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. Rather than this command, you might
-well prefer the newer ``Subword Mode'', which does the same thing
-better. @xref{Other C Commands}.
-
-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
preprocessor commands.
@table @kbd
-@item C-c C-@key{BS}
-@itemx C-c @key{BS}
+@item C-c C-@key{DEL}
+@itemx C-c @key{DEL}
@findex c-hungry-backspace
-@kindex C-c C-@key{BS} (C Mode)
-@kindex C-c @key{BS} (C Mode)
+@kindex C-c C-@key{DEL} (C Mode)
+@kindex C-c @key{DEL} (C Mode)
@code{c-hungry-backspace}---Delete the entire block of whitespace
preceding point.
@item C-c C-d
-@itemx C-c C-@key{DEL}
-@itemx C-c @key{DEL}
+@itemx C-c C-@key{DELETE}
+@itemx C-c @key{DELETE}
@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)
+@kindex C-c C-@key{DELETE} (C Mode)
+@kindex C-c @key{DELETE} (C Mode)
@code{c-hungry-delete-forward}---Delete the entire block of whitespace
following point.
@end table
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.
+the mode line after the mode name), a single @key{DEL} deletes all
+preceding whitespace, not just one space, and a single @kbd{C-c C-d}
+(but @emph{not} plain @key{DELETE}) deletes all following whitespace.
@table @kbd
@item M-x c-toggle-hungry-state
@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
+commands 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
@kbd{C-j}. We use @code{c-initialization-hook} here to make sure
the keymap is loaded before we try to change it.
-@example
+@smallexample
(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
+@end smallexample
@item C-M-h
Put mark at the end of a function definition, and put point at the
names.
@end table
-@node Fortran
-@section Fortran Mode
-@cindex Fortran mode
-@cindex mode, Fortran
-
- Fortran mode provides special motion commands for Fortran statements
-and subprograms, and indentation commands that understand Fortran
-conventions of nesting, line numbers and continuation statements.
-Fortran mode has support for Auto Fill mode that breaks long lines into
-proper Fortran continuation lines.
-
- Special commands for comments are provided because Fortran comments
-are unlike those of other languages. Built-in abbrevs optionally save
-typing when you insert Fortran keywords.
-
- Use @kbd{M-x fortran-mode} to switch to this major mode. This command
-runs the hook @code{fortran-mode-hook} (@pxref{Hooks}).
-
-@cindex Fortran77 and Fortran90
-@findex f90-mode
-@findex fortran-mode
- Fortran mode is meant for editing Fortran77 ``fixed format'' (and also
-``tab format'') source code. For editing the modern Fortran90 or
-Fortran95 ``free format'' source code, use F90 mode (@code{f90-mode}).
-Emacs normally uses Fortran mode for files with extension @samp{.f},
-@samp{.F} or @samp{.for}, and F90 mode for the extension @samp{.f90} and
-@samp{.f95}. GNU Fortran supports both kinds of format.
-
-@menu
-* Motion: Fortran Motion. Moving point by statements or subprograms.
-* Indent: Fortran Indent. Indentation commands for Fortran.
-* Comments: Fortran Comments. Inserting and aligning comments.
-* Autofill: Fortran Autofill. Auto fill support for Fortran.
-* Columns: Fortran Columns. Measuring columns for valid Fortran.
-* Abbrev: Fortran Abbrev. Built-in abbrevs for Fortran keywords.
-@end menu
-
-@node Fortran Motion
-@subsection Motion Commands
-
- 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 and other program units.
-
-@table @kbd
-@kindex C-c C-n @r{(Fortran mode)}
-@findex fortran-next-statement
-@findex f90-next-statement
-@item C-c C-n
-Move to the beginning of the next statement
-(@code{fortran-next-statement}/@code{f90-next-statement}).
-
-@kindex C-c C-p @r{(Fortran mode)}
-@findex fortran-previous-statement
-@findex f90-previous-statement
-@item C-c C-p
-Move to the beginning of the previous statement
-(@code{fortran-previous-statement}/@code{f90-previous-statement}).
-If there is no previous statement (i.e. if called from the first
-statement in the buffer), move to the start of the buffer.
-
-@kindex C-c C-e @r{(F90 mode)}
-@findex f90-next-block
-@item C-c C-e
-Move point forward to the start of the next code block
-(@code{f90-next-block}). A code block is a subroutine,
-@code{if}--@code{endif} statement, and so forth. This command exists
-for F90 mode only, not Fortran mode. With a numeric argument, this
-moves forward that many blocks.
-
-@kindex C-c C-a @r{(F90 mode)}
-@findex f90-previous-block
-@item C-c C-a
-Move point backward to the previous code block
-(@code{f90-previous-block}). This is like @code{f90-next-block}, but
-moves backwards.
-
-@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{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{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
-@subsection Fortran Indentation
-
- Special commands and features are needed for indenting Fortran code in
-order to make sure various syntactic entities (line numbers, comment line
-indicators and continuation line flags) appear in the columns that are
-required for standard, fixed (or tab) format Fortran.
-
-@menu
-* Commands: ForIndent Commands. Commands for indenting and filling Fortran.
-* Contline: ForIndent Cont. How continuation lines indent.
-* Numbers: ForIndent Num. How line numbers auto-indent.
-* Conv: ForIndent Conv. Conventions you must obey to avoid trouble.
-* Vars: ForIndent Vars. Variables controlling Fortran indent style.
-@end menu
-
-@node ForIndent Commands
-@subsubsection Fortran Indentation and Filling Commands
-
-@table @kbd
-@item C-M-j
-Break the current line at point and set up a continuation line
-(@code{fortran-split-line}).
-@item M-^
-Join this line to the previous line (@code{fortran-join-line}).
-@item C-M-q
-Indent all the lines of the subprogram point is in
-(@code{fortran-indent-subprogram}).
-@item M-q
-Fill a comment block or statement.
-@end table
-
-@kindex C-M-q @r{(Fortran mode)}
-@findex fortran-indent-subprogram
- The key @kbd{C-M-q} runs @code{fortran-indent-subprogram}, a command
-to reindent all the lines of the Fortran subprogram (function or
-subroutine) containing point.
-
-@kindex C-M-j @r{(Fortran mode)}
-@findex fortran-split-line
- The key @kbd{C-M-j} runs @code{fortran-split-line}, which splits
-a line in the appropriate fashion for Fortran. In a non-comment line,
-the second half becomes a continuation line and is indented
-accordingly. In a comment line, both halves become separate comment
-lines.
-
-@kindex M-^ @r{(Fortran mode)}
-@kindex C-c C-d @r{(Fortran mode)}
-@findex fortran-join-line
- @kbd{M-^} or @kbd{C-c C-d} runs the command @code{fortran-join-line},
-which joins a continuation line back to the previous line, roughly as
-the inverse of @code{fortran-split-line}. The point must be on a
-continuation line when this command is invoked.
-
-@kindex M-q @r{(Fortran mode)}
-@kbd{M-q} in Fortran mode fills the comment block or statement that
-point is in. This removes any excess statement continuations.
-
-@node ForIndent Cont
-@subsubsection Continuation Lines
-@cindex Fortran continuation lines
-
-@vindex fortran-continuation-string
- Most Fortran77 compilers allow two ways of writing continuation lines.
-If the first non-space character on a line is in column 5, then that
-line is a continuation of the previous line. We call this @dfn{fixed
-format}. (In GNU Emacs we always count columns from 0; but note that
-the Fortran standard counts from 1.) The variable
-@code{fortran-continuation-string} specifies what character to put in
-column 5. A line that starts with a tab character followed by any digit
-except @samp{0} is also a continuation line. We call this style of
-continuation @dfn{tab format}. (Fortran90 introduced ``free format'',
-with another style of continuation lines).
-
-@vindex indent-tabs-mode @r{(Fortran mode)}
-@vindex fortran-analyze-depth
-@vindex fortran-tab-mode-default
- 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
-@code{fortran-analyze-depth} (default 100) lines from the start of the
-buffer. The first line that begins with either a tab character or six
-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. @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}).
-
- If the text on a line starts with the Fortran continuation marker
-@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
-@kbd{C-M-j}, the continuation marker on the newline is created according
-to the continuation style.
-
- The setting of continuation style affects several other aspects of
-editing in Fortran mode. In fixed format mode, the minimum column
-number for the body of a statement is 6. Lines inside of Fortran
-blocks that are indented to larger column numbers always use only the
-space character for whitespace. In tab format mode, the minimum
-column number for the statement body is 8, and the whitespace before
-column 8 must always consist of one tab character.
-
-@node ForIndent Num
-@subsubsection Line Numbers
-
- If a number is the first non-whitespace in the line, Fortran
-indentation assumes it is a line number and moves it to columns 0
-through 4. (Columns always count from 0 in GNU Emacs.)
-
-@vindex fortran-line-number-indent
- Line numbers of four digits or less are normally indented one space.
-The variable @code{fortran-line-number-indent} controls this; it
-specifies the maximum indentation a line number can have. The default
-value of the variable is 1. Fortran mode tries to prevent line number
-digits passing column 4, reducing the indentation below the specified
-maximum if necessary. If @code{fortran-line-number-indent} has the
-value 5, line numbers are right-justified to end in column 4.
-
-@vindex fortran-electric-line-number
- 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}.
-
-
-@node ForIndent Conv
-@subsubsection Syntactic Conventions
-
- Fortran mode assumes that you follow certain conventions that simplify
-the task of understanding a Fortran program well enough to indent it
-properly:
-
-@itemize @bullet
-@item
-Two nested @samp{do} loops never share a @samp{continue} statement.
-
-@item
-Fortran keywords such as @samp{if}, @samp{else}, @samp{then}, @samp{do}
-and others are written without embedded whitespace or line breaks.
-
-Fortran compilers generally ignore whitespace outside of string
-constants, but Fortran mode does not recognize these keywords if they
-are not contiguous. Constructs such as @samp{else if} or @samp{end do}
-are acceptable, but the second word should be on the same line as the
-first and not on a continuation line.
-@end itemize
-
-@noindent
-If you fail to follow these conventions, the indentation commands may
-indent some lines unaesthetically. However, a correct Fortran program
-retains its meaning when reindented even if the conventions are not
-followed.
-
-@node ForIndent Vars
-@subsubsection Variables for Fortran Indentation
-
-@vindex fortran-do-indent
-@vindex fortran-if-indent
-@vindex fortran-structure-indent
-@vindex fortran-continuation-indent
-@vindex fortran-check-all-num@dots{}
-@vindex fortran-minimum-statement-indent@dots{}
- Several additional variables control how Fortran indentation works:
-
-@table @code
-@item fortran-do-indent
-Extra indentation within each level of @samp{do} statement (default 3).
-
-@item fortran-if-indent
-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},
-@samp{map}, or @samp{interface} statements (default 3).
-
-@item fortran-continuation-indent
-Extra indentation for bodies of continuation lines (default 5).
-
-@item fortran-check-all-num-for-matching-do
-In Fortran77, a numbered @samp{do} statement is ended by any statement
-with a matching line number. It is common (but not compulsory) to use a
-@samp{continue} statement for this purpose. If this variable has a
-non-@code{nil} value, indenting any numbered statement must check for a
-@samp{do} that ends there. If you always end @samp{do} statements with
-a @samp{continue} line (or if you use the more modern @samp{enddo}),
-then you can speed up indentation by setting this variable to
-@code{nil}. The default is @code{nil}.
-
-@item fortran-blink-matching-if
-If this is @code{t}, indenting an @samp{endif} (or @samp{enddo}
-statement moves the cursor momentarily to the matching @samp{if} (or
-@samp{do}) statement to show where it is. The default is @code{nil}.
-
-@item fortran-minimum-statement-indent-fixed
-Minimum indentation for Fortran statements when using fixed format
-continuation line style. Statement bodies are never indented less than
-this much. The default is 6.
-
-@item fortran-minimum-statement-indent-tab
-Minimum indentation for Fortran statements for tab format continuation line
-style. Statement bodies are never indented less than this much. The
-default is 8.
-@end table
-
-The variables controlling the indentation of comments are described in
-the following section.
-
-@node Fortran Comments
-@subsection Fortran Comments
-
- The usual Emacs comment commands assume that a comment can follow a
-line of code. In Fortran77, the standard comment syntax requires an
-entire line to be just a comment. Therefore, Fortran mode replaces the
-standard Emacs comment commands and defines some new variables.
-
-@vindex fortran-comment-line-start
- Fortran mode can also handle the Fortran90 comment syntax where comments
-start with @samp{!} and can follow other text. Because only some Fortran77
-compilers accept this syntax, Fortran mode will not insert such comments
-unless you have said in advance to do so. To do this, set the variable
-@code{fortran-comment-line-start} to @samp{"!"}.
-
-@table @kbd
-@item M-;
-Align comment or insert new comment (@code{fortran-indent-comment}).
-
-@item C-x ;
-Applies to nonstandard @samp{!} comments only.
-
-@item C-c ;
-Turn all lines of the region into comments, or (with argument) turn them back
-into real code (@code{fortran-comment-region}).
-@end table
-
-@findex fortran-indent-comment
- @kbd{M-;} in Fortran mode is redefined as the command
-@code{fortran-indent-comment}. Like the usual @kbd{M-;} command, this
-recognizes any kind of existing comment and aligns its text appropriately;
-if there is no existing comment, a comment is inserted and aligned. But
-inserting and aligning comments are not the same in Fortran mode as in
-other modes.
-
- When a new comment must be inserted, if the current line is blank, a
-full-line comment is inserted. On a non-blank line, a nonstandard @samp{!}
-comment is inserted if you have said you want to use them. Otherwise a
-full-line comment is inserted on a new line before the current line.
-
- Nonstandard @samp{!} comments are aligned like comments in other
-languages, but full-line comments are different. In a standard full-line
-comment, the comment delimiter itself must always appear in column zero.
-What can be aligned is the text within the comment. You can choose from
-three styles of alignment by setting the variable
-@code{fortran-comment-indent-style} to one of these values:
-
-@vindex fortran-comment-indent-style
-@vindex fortran-comment-line-extra-indent
-@table @code
-@item fixed
-Align the text at a fixed column, which is the sum of
-@code{fortran-comment-line-extra-indent} and the minimum statement
-indentation. This is the default.
-
-The minimum statement indentation is
-@code{fortran-minimum-statement-indent-fixed} for fixed format
-continuation line style and @code{fortran-minimum-statement-indent-tab}
-for tab format style.
-
-@item relative
-Align the text as if it were a line of code, but with an additional
-@code{fortran-comment-line-extra-indent} columns of indentation.
-
-@item nil
-Don't move text in full-line comments automatically.
-@end table
-
-@vindex fortran-comment-indent-char
- In addition, you can specify the character to be used to indent within
-full-line comments by setting the variable
-@code{fortran-comment-indent-char} to the single-character string you want
-to use.
-
-@vindex fortran-directive-re
- Compiler directive lines, or preprocessor lines, have much the same
-appearance as comment lines. It is important, though, that such lines
-never be indented at all, no matter what the value of
-@code{fortran-comment-indent-style}. The variable
-@code{fortran-directive-re} is a regular expression that specifies which
-lines are directives. Matching lines are never indented, and receive
-distinctive font-locking.
-
- The normal Emacs comment command @kbd{C-x ;} has not been redefined. If
-you use @samp{!} comments, this command can be used with them. Otherwise
-it is useless in Fortran mode.
-
-@kindex C-c ; @r{(Fortran mode)}
-@findex fortran-comment-region
-@vindex fortran-comment-region
- The command @kbd{C-c ;} (@code{fortran-comment-region}) turns all the
-lines of the region into comments by inserting the string @samp{C$$$} at
-the front of each one. With a numeric argument, it turns the region
-back into live code by deleting @samp{C$$$} from the front of each line
-in it. The string used for these comments can be controlled by setting
-the variable @code{fortran-comment-region}. Note that here we have an
-example of a command and a variable with the same name; these two uses
-of the name never conflict because in Lisp and in Emacs it is always
-clear from the context which one is meant.
-
-@node Fortran Autofill
-@subsection Auto Fill in Fortran Mode
-
- Fortran mode has specialized support for Auto Fill mode, which is a
-minor mode that automatically splits statements as you insert them when
-they become too wide. Splitting a statement involves making
-continuation lines using @code{fortran-continuation-string}
-(@pxref{ForIndent Cont}). This splitting happens when you type
-@key{SPC}, @key{RET}, or @key{TAB}, and also in the Fortran indentation
-commands. You activate Auto Fill in Fortran mode in the normal way
-(@pxref{Auto Fill}).
-
-@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 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.
-
- To enable Auto Fill in all Fortran buffers, add
-@code{turn-on-auto-fill} to @code{fortran-mode-hook}. @xref{Hooks}.
-
-@node Fortran Columns
-@subsection Checking Columns in Fortran
-
-@table @kbd
-@item C-c C-r
-Display a ``column ruler'' momentarily above the current line
-(@code{fortran-column-ruler}).
-@item C-c C-w
-Split the current window horizontally temporarily so that it is 72
-columns wide (@code{fortran-window-create-momentarily}). This may
-help you avoid making lines longer than the 72-character limit that
-some Fortran compilers impose.
-@item C-u C-c C-w
-Split the current window horizontally so that it is 72 columns wide
-(@code{fortran-window-create}). You can then continue editing.
-@item M-x fortran-strip-sequence-nos
-Delete all text in column 72 and beyond.
-@end table
-
-@kindex C-c C-r @r{(Fortran mode)}
-@findex fortran-column-ruler
- The command @kbd{C-c C-r} (@code{fortran-column-ruler}) shows a column
-ruler momentarily above the current line. The comment ruler is two lines
-of text that show you the locations of columns with special significance in
-Fortran programs. Square brackets show the limits of the columns for line
-numbers, and curly brackets show the limits of the columns for the
-statement body. Column numbers appear above them.
-
- Note that the column numbers count from zero, as always in GNU Emacs.
-As a result, the numbers may be one less than those you are familiar
-with; but the positions they indicate in the line are standard for
-Fortran.
-
-@vindex fortran-column-ruler-fixed
-@vindex fortran-column-ruler-tabs
- The text used to display the column ruler depends on the value of the
-variable @code{indent-tabs-mode}. If @code{indent-tabs-mode} is
-@code{nil}, then the value of the variable
-@code{fortran-column-ruler-fixed} is used as the column ruler.
-Otherwise, the value of the variable @code{fortran-column-ruler-tab} is
-displayed. By changing these variables, you can change the column ruler
-display.
-
-@kindex C-c C-w @r{(Fortran mode)}
-@findex fortran-window-create-momentarily
- @kbd{C-c C-w} (@code{fortran-window-create-momentarily}) temporarily
-splits the current window horizontally, making a window 72 columns
-wide, so you can see any lines that are too long. Type a space to
-restore the normal width.
-
-@kindex C-u C-c C-w @r{(Fortran mode)}
-@findex fortran-window-create
- You can also split the window horizontally and continue editing with
-the split in place. To do this, use @kbd{C-u C-c C-w} (@code{M-x
-fortran-window-create}). By editing in this window you can
-immediately see when you make a line too wide to be correct Fortran.
-
-@findex fortran-strip-sequence-nos
- The command @kbd{M-x fortran-strip-sequence-nos} deletes all text in
-column 72 and beyond, on all lines in the current buffer. This is the
-easiest way to get rid of old sequence numbers.
-
-@node Fortran Abbrev
-@subsection Fortran Keyword Abbrevs
-
- Fortran mode provides many built-in abbrevs for common keywords and
-declarations. These are the same sort of abbrev that you can define
-yourself. To use them, you must turn on Abbrev mode. @xref{Abbrevs}.
-
- The built-in abbrevs are unusual in one way: they all start with a
-semicolon. You cannot normally use semicolon in an abbrev, but Fortran
-mode makes this possible by changing the syntax of semicolon to ``word
-constituent.''
-
- For example, one built-in Fortran abbrev is @samp{;c} for
-@samp{continue}. If you insert @samp{;c} and then insert a punctuation
-character such as a space or a newline, the @samp{;c} expands automatically
-to @samp{continue}, provided Abbrev mode is enabled.@refill
-
- Type @samp{;?} or @samp{;C-h} to display a list of all the built-in
-Fortran abbrevs and what they stand for.
-
@node Asm Mode
@section Asm Mode
The variable @code{asm-comment-char} specifies which character
starts comments in assembler syntax.
+@ifnottex
+@include fortran-xtra.texi
+@end ifnottex
+
@ignore
arch-tag: c7ee7409-40a4-45c7-bfb7-ae7f2c74d0c0
@end ignore