Commands for Human Languages
****************************

This chapter describes Emacs commands that act on text, by which we mean sequences of characters in a human language (as opposed to, say, a computer programming language).  These commands act in ways that take into account the syntactic and stylistic conventions of human languages: conventions involving words, sentences, paragraphs, and capital letters.  There are also commands for filling, which means rearranging the lines of a paragraph to be approximately equal in length.  These commands, while intended primarily for editing text, are also often useful for editing programs.

Emacs has several major modes for editing human-language text.  If the file contains ordinary text, use Text mode, which customizes Emacs in small ways for the syntactic conventions of text.  Outline mode provides special commands for operating on text with an outline structure.

Emacs has other major modes for text which contains ``embedded'' commands, such as TeX and LaTeX (see TeX Mode); HTML, SGML, and XML (see HTML Mode); and Groff and Nroff (see Nroff Mode). In addition, you can edit formatted text in WYSIWYG style (``what you see is what you get''), using Enriched mode (see Formatted Text).

If you need to edit pictures made out of text characters (commonly referred to as ``ASCII art''), use Picture mode, a special major mode for editing such pictures. See Picture Mode.

The ``automatic typing'' features may be useful when writing text. See autotype.

Words
=====

Emacs has commands for moving over or operating on words.  By convention, the keys for them are all Meta characters.

M-f
     Move forward over a word (forward-word).

M-b
     Move backward over a word (backward-word).

M-d
     Kill up to the end of a word (kill-word).

M-DEL
     Kill back to the beginning of a word (backward-kill-word).

M-@
     Mark the end of the next word (mark-word).

M-t
     Transpose two words or drag a word across others (transpose-words).

Notice how these keys form a series that parallels the character-based C-f, C-b, C-d, DEL and C-t.  M-@ is cognate to C-@, which is an alias for C-SPC.

The commands M-f (forward-word) and M-b (backward-word) move forward and backward over words.  These Meta-based key sequences are analogous to the key sequences C-f and C-b, which move over single characters.  The analogy extends to numeric arguments, which serve as repeat counts. M-f with a negative argument moves backward, and M-b with a negative argument moves forward.  Forward motion stops right after the last letter of the word, while backward motion stops right before the first letter.

M-d (kill-word) kills the word after point.  To be precise, it kills everything from point to the place M-f would move to.  Thus, if point is in the middle of a word, M-d kills just the part after point.  If some punctuation comes between point and the next word, it is killed along with the word.  (If you wish to kill only the next word but not the punctuation before it, simply do M-f to get the end, and kill the word backwards with M-DEL.)  M-d takes arguments just like M-f.

M-DEL (backward-kill-word) kills the word before point.  It kills everything from point back to where M-b would move to.  For instance, if point is after the space in FOO, BAR, it kills FOO, .  If you wish to kill just FOO, and not the comma and the space, use M-b M-d instead of M-DEL.

M-t (transpose-words) exchanges the word before or containing point with the following word.  The delimiter characters between the words do not move.  For example, FOO, BAR transposes into BAR, FOO rather than BAR FOO,.  See Transpose, for more on transposition.

To operate on the next N words with an operation which acts on the region, use the command M-@ (mark-word).  This command does not move point, but sets the mark where M-f would move to.  Once the mark is active, each additional M-@ advances the mark by one additional word.  M-@ also accepts a numeric argument that says how many words to scan for the place to put the mark.

The word commands' understanding of word boundaries is controlled by the syntax table.  Any character can, for example, be declared to be a word delimiter.  See Syntax.

Sentences
=========

The Emacs commands for manipulating sentences and paragraphs are mostly on Meta keys, so as to be like the word-handling commands.

M-a
     Move back to the beginning of the sentence (backward-sentence).

M-e
     Move forward to the end of the sentence (forward-sentence).

M-k
     Kill forward to the end of the sentence (kill-sentence).

C-x DEL
     Kill back to the beginning of the sentence (backward-kill-sentence).

The commands M-a and M-e (backward-sentence and forward-sentence) move to the beginning and end of the current sentence, respectively.  They were chosen to resemble C-a and C-e, which move to the beginning and end of a line.  Unlike them, M-a and M-e move over successive sentences if repeated.

Moving backward over a sentence places point just before the first character of the sentence; moving forward places point right after the punctuation that ends the sentence.  Neither one moves over the whitespace at the sentence boundary.

Just as C-a and C-e have a kill command, C-k, to go with them, M-a and M-e have a corresponding kill command: M-k (kill-sentence) kills from point to the end of the sentence.  With a positive numeric argument N, it kills the next N sentences; with a negative argument -N, it kills back to the beginning of the Nth preceding sentence.

The C-x DEL (backward-kill-sentence) kills back to the beginning of a sentence.

The sentence commands assume that you follow the American typist's convention of putting two spaces at the end of a sentence; they consider a sentence to end wherever there is a ., ? or ! followed by the end of a line or two spaces, with any number of ), ], ', or " characters allowed in between. A sentence also begins or ends wherever a paragraph begins or ends. It is useful to follow this convention, because it makes a distinction between periods that end a sentence and periods that indicate abbreviations; that enables the Emacs sentence commands to distinguish, too.  These commands do not stop for periods that indicate abbreviations.

If you want to use just one space between sentences, you can set the variable sentence-end-double-space to nil to make the sentence commands stop for single spaces.  However, this has a drawback: there is no way to distinguish between periods that end sentences and those that indicate abbreviations.  For convenient and reliable editing, we therefore recommend you follow the two-space convention.  The variable sentence-end-double-space also affects filling (see Fill Commands) in related ways.

The variable sentence-end controls how to recognize the end of a sentence.  If non-nil, its value should be a regular expression, which is used to match the last few characters of a sentence, together with the whitespace following the sentence (see Regexps).  If the value is nil, the default, then Emacs computes sentence ends according to various criteria such as the value of sentence-end-double-space.

Some languages do not use periods to indicate the end of a sentence. For example, sentences in Thai end with a double space but without a period.  Set the variable sentence-end-without-period to t in such cases.

Paragraphs
==========

The Emacs commands for manipulating paragraphs are also on Meta keys.

M-{
     Move back to previous paragraph beginning (backward-paragraph).

M-}
     Move forward to next paragraph end (forward-paragraph).

M-h
     Put point and mark around this or next paragraph (mark-paragraph).

M-{ moves to the beginning of the current or previous paragraph, while M-} moves to the end of the current or next paragraph.  Blank lines and text-formatter command lines separate paragraphs and are not considered part of any paragraph.  If there is a blank line before the paragraph, M-{ moves to the blank line, because that is convenient in practice.

In Text mode, an indented line is not a paragraph break.  If you want indented lines to have this effect, use Paragraph-Indent Text mode instead.  See Text Mode.

In major modes for programs, paragraphs begin and end only at blank lines.  This makes the paragraph commands useful, even though there are no paragraphs as such in a program.

When you have set a fill prefix, then paragraphs are delimited by all lines which don't start with the fill prefix.  See Filling.

When you wish to operate on a paragraph, type M-h (mark-paragraph) to set the region around it.  For example, M-h C-w kills the paragraph around or after point.  M-h puts point at the beginning and mark at the end of the paragraph point was in.  If point is between paragraphs (in a run of blank lines, or at a boundary), the paragraph following point is surrounded by point and mark.  If there are blank lines preceding the first line of the paragraph, one of these blank lines is included in the region.  If the region is already active, the command sets the mark without changing point; furthermore, each subsequent M-h further advances the mark by one paragraph.

The precise definition of a paragraph boundary is controlled by the variables paragraph-separate and paragraph-start.  The value of paragraph-start is a regexp that should match any line that either starts or separates paragraphs.  The value of paragraph-separate is another regexp that should match only lines that separate paragraphs without being part of any paragraph (for example, blank lines).  Lines that start a new paragraph and are contained in it must match only paragraph-start, not paragraph-separate.  Each regular expression must match at the left margin.  For example, in Fundamental mode, paragraph-start is "\f\\|[ \t]*$", and paragraph-separate is "[ \t\f]*$".

Normally it is desirable for page boundaries to separate paragraphs. The default values of these variables recognize the usual separator for pages.

Pages
=====

Within some text files, text is divided into pages, which are delimited by the formfeed character (ASCII code 12, sometimes denoted as control-L).  When you print hardcopy for a file, the formfeed character forces a page break: each page of the file goes on a separate page on paper.  Most Emacs commands treat the formfeed character just like any other character: you can insert it with C-q C-l, and delete it with DEL.  However, since pages are often meaningful divisions of the file, Emacs provides commands to move over them and operate on them.

C-x [
     Move point to previous page boundary (backward-page).

C-x ]
     Move point to next page boundary (forward-page).

C-x C-p
     Put point and mark around this page (or another page) (mark-page).

C-x l
     Count the lines in this page (count-lines-page).

The C-x [ (backward-page) command moves point to immediately after the previous page delimiter.  If point is already right after a page delimiter, it skips that one and stops at the previous one.  A numeric argument serves as a repeat count.  The C-x ] (forward-page) command moves forward past the next page delimiter.

The C-x C-p command (mark-page) puts point at the beginning of the current page and the mark at the end.  The page delimiter at the end is included (the mark follows it).  The page delimiter at the front is excluded (point follows it).

C-x C-p C-w is a handy way to kill a page to move it elsewhere.  If you move to another page delimiter with C-x [ and C-x ], then yank the killed page, all the pages will be properly delimited once again.  The reason C-x C-p includes only the following page delimiter in the region is to ensure that.

A numeric argument to C-x C-p specifies which page to go to, relative to the current one.  Zero means the current page.  One means the next page, and -1 means the previous one.

The C-x l command (count-lines-page) is good for deciding where to break a page in two.  It displays in the echo area the total number of lines in the current page, and then divides it up into those preceding the current line and those following, as in

     Page has 96 (72+25) lines

Notice that the sum is off by one; this is correct if point is not at the beginning of a line.

The variable page-delimiter controls where pages begin.  Its value is a regular expression that matches the beginning of a line that separates pages (see Regexps).  The normal value of this variable is "^\f", which matches a formfeed character at the beginning of a line.

Filling Text
============

Filling text means breaking it up into lines that fit a specified width.  Emacs does filling in two ways.  In Auto Fill mode, inserting text with self-inserting characters also automatically fills it.  There are also explicit fill commands that you can use when editing text leaves it unfilled.  When you edit formatted text, you can specify a style of filling for each portion of the text (see Formatted Text).

Auto Fill Mode
--------------

Auto Fill mode is a minor mode in which lines are broken automatically when they become too wide.  Breaking happens only when you type a SPC or RET.

M-x auto-fill-mode
     Enable or disable Auto Fill mode.

SPC
RET
     In Auto Fill mode, break lines when appropriate.

M-x auto-fill-mode turns Auto Fill mode on if it was off, or off if it was on.  With a positive numeric argument it always turns Auto Fill mode on, and with a negative argument always turns it off.  You can see when Auto Fill mode is in effect by the presence of the word Fill in the mode line, inside the parentheses.  Auto Fill mode is a minor mode which is enabled or disabled for each buffer individually. See Minor Modes.

In Auto Fill mode, lines are broken automatically at spaces when they get longer than the desired width.  Line breaking and rearrangement takes place only when you type SPC or RET.  If you wish to insert a space or newline without permitting line-breaking, type C-q SPC or C-q C-j (recall that a newline is really a control-J).  Also, C-o inserts a newline without line breaking.

Auto Fill mode works well with programming-language modes, because it indents new lines with TAB.  If a line ending in a comment gets too long, the text of the comment is split into two comment lines. Optionally, new comment delimiters are inserted at the end of the first line and the beginning of the second so that each line is a separate comment; the variable comment-multi-line controls the choice (see Comments).

Adaptive filling (see Adaptive Fill) works for Auto Filling as well as for explicit fill commands.  It takes a fill prefix automatically from the second or first line of a paragraph.

Auto Fill mode does not refill entire paragraphs; it can break lines but cannot merge lines.  So editing in the middle of a paragraph can result in a paragraph that is not correctly filled.  The easiest way to make the paragraph properly filled again is usually with the explicit fill commands. See Fill Commands.

Many users like Auto Fill mode and want to use it in all text files. The section on init files says how to arrange this permanently for yourself. See Init File.

Explicit Fill Commands
----------------------

M-q
     Fill current paragraph (fill-paragraph).

C-x f
     Set the fill column (set-fill-column).

M-x fill-region
     Fill each paragraph in the region (fill-region).

M-x fill-region-as-paragraph
     Fill the region, considering it as one paragraph.

M-o M-s
     Center a line.

To refill a paragraph, use the command M-q (fill-paragraph).  This operates on the paragraph that point is inside, or the one after point if point is between paragraphs. Refilling works by removing all the line-breaks, then inserting new ones where necessary.  When there is an active region, this command operates on the text within the region like fill-region.

To refill many paragraphs, use M-x fill-region, which finds the paragraphs in the region and fills each of them.

M-q and fill-region use the same criteria as M-h for finding paragraph boundaries (see Paragraphs).  For more control, you can use M-x fill-region-as-paragraph, which refills everything between point and mark as a single paragraph.  This command deletes any blank lines within the region, so separate blocks of text end up combined into one block.

A numeric argument to M-q tells it to justify the text as well as filling it.  This means that extra spaces are inserted to make the right margin line up exactly at the fill column.  To remove the extra spaces, use M-q with no argument.  (Likewise for fill-region.)  Another way to control justification, and choose other styles of filling, is with the justification text property; see Format Justification.

The command M-o M-s (center-line) centers the current line within the current fill column.  With an argument N, it centers N lines individually and moves past them.  This binding is made by Text mode and is available only in that and related modes (see Text Mode).

The maximum line width for filling is in the variable fill-column.  Altering the value of fill-column makes it local to the current buffer; until that time, the default value is in effect.  The default is initially 70.  See Locals.  The easiest way to set fill-column is to use the command C-x f (set-fill-column).  With a numeric argument, it uses that as the new fill column.  With just C-u as argument, it sets fill-column to the current horizontal position of point.

Emacs commands normally consider a period followed by two spaces or by a newline as the end of a sentence; a period followed by just one space indicates an abbreviation and not the end of a sentence.  To preserve the distinction between these two ways of using a period, the fill commands do not break a line after a period followed by just one space.

If the variable sentence-end-double-space is nil, the fill commands expect and leave just one space at the end of a sentence. Ordinarily this variable is t, so the fill commands insist on two spaces for the end of a sentence, as explained above.  See Sentences.

If the variable colon-double-space is non-nil, the fill commands put two spaces after a colon.

The variable fill-nobreak-predicate is a hook (an abnormal hook, see Hooks) specifying additional conditions where line-breaking is not allowed.  Each function is called with no arguments, with point at a place where Emacs is considering breaking the line.  If a function returns a non-nil value, then that's a bad place to break the line.  Two standard functions you can use are fill-single-word-nobreak-p (don't break after the first word of a sentence or before the last) and fill-french-nobreak-p (don't break after ( or before ), : or ?).

The Fill Prefix
---------------

To fill a paragraph in which each line starts with a special marker (which might be a few spaces, giving an indented paragraph), you can use the fill prefix feature.  The fill prefix is a string that Emacs expects every line to start with, and which is not included in filling. You can specify a fill prefix explicitly; Emacs can also deduce the fill prefix automatically (see Adaptive Fill).

C-x .
     Set the fill prefix (set-fill-prefix).

M-q
     Fill a paragraph using current fill prefix (fill-paragraph).

M-x fill-individual-paragraphs
     Fill the region, considering each change of indentation as starting a new paragraph.

M-x fill-nonuniform-paragraphs
     Fill the region, considering only paragraph-separator lines as starting a new paragraph.

To specify a fill prefix for the current buffer, move to a line that starts with the desired prefix, put point at the end of the prefix, and type C-x . (set-fill-prefix).  (That's a period after the C-x.)  To turn off the fill prefix, specify an empty prefix: type C-x . with point at the beginning of a line.

When a fill prefix is in effect, the fill commands remove the fill prefix from each line of the paragraph before filling and insert it on each line after filling.  (The beginning of the first line of the paragraph is left unchanged, since often that is intentionally different.)  Auto Fill mode also inserts the fill prefix automatically when it makes a new line.  The C-o command inserts the fill prefix on new lines it creates, when you use it at the beginning of a line (see Blank Lines).  Conversely, the command M-^ deletes the prefix (if it occurs) after the newline that it deletes (see Indentation).

For example, if fill-column is 40 and you set the fill prefix to ;; , then M-q in the following text

     ;; This is an
     ;; example of a paragraph
     ;; inside a Lisp-style comment.

produces this:

     ;; This is an example of a paragraph
     ;; inside a Lisp-style comment.

Lines that do not start with the fill prefix are considered to start paragraphs, both in M-q and the paragraph commands; this gives good results for paragraphs with hanging indentation (every line indented except the first one).  Lines which are blank or indented once the prefix is removed also separate or start paragraphs; this is what you want if you are writing multi-paragraph comments with a comment delimiter on each line.

You can use M-x fill-individual-paragraphs to set the fill prefix for each paragraph automatically.  This command divides the region into paragraphs, treating every change in the amount of indentation as the start of a new paragraph, and fills each of these paragraphs.  Thus, all the lines in one ``paragraph'' have the same amount of indentation.  That indentation serves as the fill prefix for that paragraph.

M-x fill-nonuniform-paragraphs is a similar command that divides the region into paragraphs in a different way.  It considers only paragraph-separating lines (as defined by paragraph-separate) as starting a new paragraph.  Since this means that the lines of one paragraph may have different amounts of indentation, the fill prefix used is the smallest amount of indentation of any of the lines of the paragraph.  This gives good results with styles that indent a paragraph's first line more or less that the rest of the paragraph.

The fill prefix is stored in the variable fill-prefix.  Its value is a string, or nil when there is no fill prefix.  This is a per-buffer variable; altering the variable affects only the current buffer, but there is a default value which you can change as well.  See Locals.

The indentation text property provides another way to control the amount of indentation paragraphs receive.  See Format Indentation.

Adaptive Filling
----------------

The fill commands can deduce the proper fill prefix for a paragraph automatically in certain cases: either whitespace or certain punctuation characters at the beginning of a line are propagated to all lines of the paragraph.

If the paragraph has two or more lines, the fill prefix is taken from the paragraph's second line, but only if it appears on the first line as well.

If a paragraph has just one line, fill commands may take a prefix from that line.  The decision is complicated because there are three reasonable things to do in such a case:

  * Use the first line's prefix on all the lines of the paragraph.

  * Indent subsequent lines with whitespace, so that they line up under the text that follows the prefix on the first line, but don't actually copy the prefix from the first line.

  * Don't do anything special with the second and following lines.

All three of these styles of formatting are commonly used.  So the fill commands try to determine what you would like, based on the prefix that appears and on the major mode.  Here is how.

If the prefix found on the first line matches adaptive-fill-first-line-regexp, or if it appears to be a comment-starting sequence (this depends on the major mode), then the prefix found is used for filling the paragraph, provided it would not act as a paragraph starter on subsequent lines.

Otherwise, the prefix found is converted to an equivalent number of spaces, and those spaces are used as the fill prefix for the rest of the lines, provided they would not act as a paragraph starter on subsequent lines.

In Text mode, and other modes where only blank lines and page delimiters separate paragraphs, the prefix chosen by adaptive filling never acts as a paragraph starter, so it can always be used for filling.

The variable adaptive-fill-regexp determines what kinds of line beginnings can serve as a fill prefix: any characters at the start of the line that match this regular expression are used.  If you set the variable adaptive-fill-mode to nil, the fill prefix is never chosen automatically.

You can specify more complex ways of choosing a fill prefix automatically by setting the variable adaptive-fill-function to a function.  This function is called with point after the left margin of a line, and it should return the appropriate fill prefix based on that line.  If it returns nil, adaptive-fill-regexp gets a chance to find a prefix.

Refill Mode
-----------

Refill minor mode provides support for keeping paragraphs filled as you type or modify them in other ways.  It provides an effect similar to typical word processor behavior.  This works by running a paragraph-filling command at suitable times.

To toggle the use of Refill mode in the current buffer, type M-x refill-mode.  When you are typing text, only characters which normally trigger auto filling, like the space character, will trigger refilling.  This is to avoid making it too slow.  Apart from self-inserting characters, other commands which modify the text cause refilling.

The current implementation is preliminary and not robust.  You can get better ``line wrapping'' behavior using Longlines mode. See Longlines.  However, Longlines mode has an important side-effect: the newlines that it inserts for you are not saved to disk, so the files that you make with Longlines mode will appear to be completely unfilled if you edit them without Longlines mode.

Long Lines Mode
---------------

Sometimes, you may come across ``unfilled'' text files, which Emacs normally displays as a bunch of extremely long lines.  Comfortably reading and editing such files normally requires ``word wrap'', a feature that breaks up each long text line into multiple screen lines in a readable manner---by putting the breaks at word boundaries.  Many text editors, such as those built into many web browsers, perform word wrapping by default.

There are two different minor modes in Emacs that perform word wrapping.  The first is Visual Line mode, which does it by altering the behavior of screen line continuation.  See Visual Line Mode, for information about Visual Line mode.

Instead of using Visual Line mode, you can use a minor mode called Long Lines mode.  Long Lines mode wraps lines by inserting or deleting soft newlines as you type (see Hard and Soft Newlines). These soft newlines won't show up when you save the buffer into a file, or when you copy the text into the kill ring, clipboard, or a register.  Unlike Visual Line mode, Lone Lines mode breaks long lines at the fill column (see Fill Commands), rather than the right window edge.  To enable Long Lines mode, type M-x longlines-mode.  If the text is full of long lines, this also immediately ``wraps'' them all.

The word wrap performed by Long Lines mode is not the same as ordinary filling (see Fill Commands).  It does not contract multiple spaces into a single space, recognize fill prefixes (see Fill Prefix), or perform adaptive filling (see Adaptive Fill).  The reason for this is that a wrapped line is still, conceptually, a single line.  Each soft newline is equivalent to exactly one space in that long line, and vice versa.  However, you can still call filling functions such as M-q, and these will work as expected, inserting soft newlines that won't show up on disk or when the text is copied.  You can even rely entirely on the normal fill commands by turning off automatic line wrapping, with C-u M-x longlines-auto-wrap.  To turn automatic line wrapping back on, type M-x longlines-auto-wrap.

Type RET to insert a hard newline, one which automatic refilling will not remove.  If you want to see where all the hard newlines are, type M-x longlines-show-hard-newlines.  This will mark each hard newline with a special symbol.  The same command with a prefix argument turns this display off.

Long Lines mode does not change normal text files that are already filled, since the existing newlines are considered hard newlines. Before Long Lines can do anything, you need to transform each paragraph into a long line.  One way is to set fill-column to a large number (e.g., C-u 9999 C-x f), re-fill all the paragraphs, and then set fill-column back to its original value.

Case Conversion Commands
========================

Emacs has commands for converting either a single word or any arbitrary range of text to upper case or to lower case.

M-l
     Convert following word to lower case (downcase-word).

M-u
     Convert following word to upper case (upcase-word).

M-c
     Capitalize the following word (capitalize-word).

C-x C-l
     Convert region to lower case (downcase-region).

C-x C-u
     Convert region to upper case (upcase-region).

The word conversion commands are the most useful.  M-l (downcase-word) converts the word after point to lower case, moving past it.  Thus, repeating M-l converts successive words. M-u (upcase-word) converts to all capitals instead, while M-c (capitalize-word) puts the first letter of the word into upper case and the rest into lower case.  All these commands convert several words at once if given an argument.  They are especially convenient for converting a large amount of text from all upper case to mixed case, because you can move through the text using M-l, M-u or M-c on each word as appropriate, occasionally using M-f instead to skip a word.

When given a negative argument, the word case conversion commands apply to the appropriate number of words before point, but do not move point. This is convenient when you have just typed a word in the wrong case: you can give the case conversion command and continue typing.

If a word case conversion command is given in the middle of a word, it applies only to the part of the word which follows point.  (This is comparable to what M-d (kill-word) does.)  With a negative argument, case conversion applies only to the part of the word before point.

The other case conversion commands are C-x C-u (upcase-region) and C-x C-l (downcase-region), which convert everything between point and mark to the specified case.  Point and mark do not move.

The region case conversion commands upcase-region and downcase-region are normally disabled.  This means that they ask for confirmation if you try to use them.  When you confirm, you may enable the command, which means it will not ask for confirmation again. See Disabling.

Text Mode
=========

When you edit files of text in a human language, it's more convenient to use Text mode rather than Fundamental mode.  To enter Text mode, type M-x text-mode.

In Text mode, only blank lines and page delimiters separate paragraphs.  As a result, paragraphs can be indented, and adaptive filling determines what indentation to use when filling a paragraph. See Adaptive Fill.

Text mode defines TAB to run indent-relative (see Indentation), so that you can conveniently indent a line like the previous line.

Text mode turns off the features concerned with comments except when you explicitly invoke them.  It changes the syntax table so that single-quotes are considered part of words.  However, if a word starts with single-quotes, these are treated as a prefix for purposes such as capitalization.  That is, M-c will convert 'hello' into 'Hello', as expected.

If you indent the first lines of paragraphs, then you should use Paragraph-Indent Text mode rather than Text mode.  In this mode, you do not need to have blank lines between paragraphs, because the first-line indentation is sufficient to start a paragraph; however paragraphs in which every line is indented are not supported.  Use M-x paragraph-indent-text-mode to enter this mode.  Use M-x paragraph-indent-minor-mode to enable an equivalent minor mode in situations where you can't change the major mode---in mail composition, for instance.

Text mode, and all the modes based on it, define M-TAB as the command ispell-complete-word, which performs completion of the partial word in the buffer before point, using the spelling dictionary as the space of possible words.  See Spelling.  If your window manager defines M-TAB to switch windows, you can type ESC TAB or C-M-i.

Entering Text mode runs the hook text-mode-hook.  Other major modes related to Text mode also run this hook, followed by hooks of their own; this includes Paragraph-Indent Text mode, Nroff mode, TeX mode, Outline mode, and Mail mode.  Hook functions on text-mode-hook can look at the value of major-mode to see which of these modes is actually being entered.  See Hooks.

Outline Mode
============

Outline mode is a major mode much like Text mode but intended for editing outlines.  It allows you to make parts of the text temporarily invisible so that you can see the outline structure.  Type M-x outline-mode to switch to Outline mode as the major mode of the current buffer.

When Outline mode makes a line invisible, the line does not appear on the screen.  The screen appears exactly as if the invisible line were deleted, except that an ellipsis (three periods in a row) appears at the end of the previous visible line.  (Multiple consecutive invisible lines produce just one ellipsis.)

Editing commands that operate on lines, such as C-n and C-p, treat the text of the invisible line as part of the previous visible line.  Killing the ellipsis at the end of a visible line really kills all the following invisible lines.

Outline minor mode provides the same commands as the major mode, Outline mode, but you can use it in conjunction with other major modes. Type M-x outline-minor-mode to enable the Outline minor mode in the current buffer.  You can also specify this in the text of a file, with a file local variable of the form mode: outline-minor (see File Variables).

The major mode, Outline mode, provides special key bindings on the C-c prefix.  Outline minor mode provides similar bindings with C-c @ as the prefix; this is to reduce the conflicts with the major mode's special commands.  (The variable outline-minor-mode-prefix controls the prefix used.)

Entering Outline mode runs the hook text-mode-hook followed by the hook outline-mode-hook (see Hooks).

Format of Outlines
------------------

Outline mode assumes that the lines in the buffer are of two types: heading lines and body lines.  A heading line represents a topic in the outline.  Heading lines start with one or more stars; the number of stars determines the depth of the heading in the outline structure.  Thus, a heading line with one star is a major topic; all the heading lines with two stars between it and the next one-star heading are its subtopics; and so on.  Any line that is not a heading line is a body line.  Body lines belong with the preceding heading line.  Here is an example:

     * Food
     This is the body,
     which says something about the topic of food.

     ** Delicious Food
     This is the body of the second-level header.

     ** Distasteful Food
     This could have
     a body too, with
     several lines.

     *** Dormitory Food

     * Shelter
     Another first-level topic with its header line.

A heading line together with all following body lines is called collectively an entry.  A heading line together with all following deeper heading lines and their body lines is called a subtree.

You can customize the criterion for distinguishing heading lines by setting the variable outline-regexp.  (The recommended ways to do this are in a major mode function or with a file local variable.) Any line whose beginning has a match for this regexp is considered a heading line.  Matches that start within a line (not at the left margin) do not count.

The length of the matching text determines the level of the heading; longer matches make a more deeply nested level.  Thus, for example, if a text formatter has commands @chapter, @section and @subsection to divide the document into chapters and sections, you could make those lines count as heading lines by setting outline-regexp to "@chap\\|@\\(sub\\)*section".  Note the trick: the two words chapter and section are equally long, but by defining the regexp to match only chap we ensure that the length of the text matched on a chapter heading is shorter, so that Outline mode will know that sections are contained in chapters.  This works as long as no other command starts with @chap.

You can explicitly specify a rule for calculating the level of a heading line by setting the variable outline-level.  The value of outline-level should be a function that takes no arguments and returns the level of the current heading.  The recommended ways to set this variable are in a major mode command or with a file local variable.

Outline Motion Commands
-----------------------

Outline mode provides special motion commands that move backward and forward to heading lines.

C-c C-n
     Move point to the next visible heading line (outline-next-visible-heading).

C-c C-p
     Move point to the previous visible heading line (outline-previous-visible-heading).

C-c C-f
     Move point to the next visible heading line at the same level as the one point is on (outline-forward-same-level).

C-c C-b
     Move point to the previous visible heading line at the same level (outline-backward-same-level).

C-c C-u
     Move point up to a lower-level (more inclusive) visible heading line (outline-up-heading).

C-c C-n (outline-next-visible-heading) moves down to the next heading line.  C-c C-p (outline-previous-visible-heading) moves similarly backward.  Both accept numeric arguments as repeat counts.  The names emphasize that invisible headings are skipped, but this is not really a special feature.  All editing commands that look for lines ignore the invisible lines automatically.

More powerful motion commands understand the level structure of headings. C-c C-f (outline-forward-same-level) and C-c C-b (outline-backward-same-level) move from one heading line to another visible heading at the same depth in the outline.  C-c C-u (outline-up-heading) moves backward to another heading that is less deeply nested.

Outline Visibility Commands
---------------------------

The other special commands of outline mode are used to make lines visible or invisible.  Their names all start with hide or show. Most of them fall into pairs of opposites.  They are not undoable; instead, you can undo right past them.  Making lines visible or invisible is simply not recorded by the undo mechanism.

Many of these commands act on the ``current'' heading line.  If point is on a heading line, that is the current heading line; if point is on a body line, the current heading line is the nearest preceding header line.

C-c C-c
     Make the current heading line's body invisible (hide-entry).

C-c C-e
     Make the current heading line's body visible (show-entry).

C-c C-d
     Make everything under the current heading invisible, not including the heading itself (hide-subtree).

C-c C-s
     Make everything under the current heading visible, including body, subheadings, and their bodies (show-subtree).

C-c C-l
     Make the body of the current heading line, and of all its subheadings, invisible (hide-leaves).

C-c C-k
     Make all subheadings of the current heading line, at all levels, visible (show-branches).

C-c C-i
     Make immediate subheadings (one level down) of the current heading line visible (show-children).

C-c C-t
     Make all body lines in the buffer invisible (hide-body).

C-c C-a
     Make all lines in the buffer visible (show-all).

C-c C-q
     Hide everything except the top N levels of heading lines (hide-sublevels).

C-c C-o
     Hide everything except for the heading or body that point is in, plus the headings leading up from there to the top level of the outline (hide-other).

Two commands that are exact opposites are C-c C-c (hide-entry) and C-c C-e (show-entry).  They apply to the body lines directly following the current heading line. Subheadings and their bodies are not affected.

Two more powerful opposites are C-c C-d (hide-subtree) and C-c C-s (show-subtree).  Both apply to the current heading line's subtree: its body, all its subheadings, both direct and indirect, and all of their bodies.  In other words, the subtree contains everything following the current heading line, up to and not including the next heading of the same or higher rank.

Intermediate between a visible subtree and an invisible one is having all the subheadings visible but none of the body.  There are two commands for doing this, depending on whether you want to hide the bodies or make the subheadings visible.  They are C-c C-l (hide-leaves) and C-c C-k (show-branches).

A little weaker than show-branches is C-c C-i (show-children).  It makes just the direct subheadings visible---those one level down.  Deeper subheadings remain invisible, if they were invisible.

Two commands have a blanket effect on the whole file.  C-c C-t (hide-body) makes all body lines invisible, so that you see just the outline structure (as a special exception, it will not hide lines at the top of the file, preceding the first header line, even though these are technically body lines).  C-c C-a (show-all) makes all lines visible.  These commands can be thought of as a pair of opposites even though C-c C-a applies to more than just body lines.

The command C-c C-q (hide-sublevels) hides all but the top level headings.  With a numeric argument N, it hides everything except the top N levels of heading lines.

The command C-c C-o (hide-other) hides everything except the heading and body text that point is in, plus its parents (the headers leading up from there to top level in the outline) and the top level headings.

When incremental search finds text that is hidden by Outline mode, it makes that part of the buffer visible.  If you exit the search at that position, the text remains visible.  You can also automatically make text visible as you navigate in it by using M-x reveal-mode.

Viewing One Outline in Multiple Views
-------------------------------------

You can display two views of a single outline at the same time, in different windows.  To do this, you must create an indirect buffer using M-x make-indirect-buffer.  The first argument of this command is the existing outline buffer name, and its second argument is the name to use for the new indirect buffer.  See Indirect Buffers.

Once the indirect buffer exists, you can display it in a window in the normal fashion, with C-x 4 b or other Emacs commands.  The Outline mode commands to show and hide parts of the text operate on each buffer independently; as a result, each buffer can have its own view.  If you want more than two views on the same outline, create additional indirect buffers.

Folding Editing
---------------

The Foldout package extends Outline mode and Outline minor mode with ``folding'' commands.  The idea of folding is that you zoom in on a nested portion of the outline, while hiding its relatives at higher levels.

Consider an Outline mode buffer with all the text and subheadings under level-1 headings hidden.  To look at what is hidden under one of these headings, you could use C-c C-e (M-x show-entry) to expose the body, or C-c C-i to expose the child (level-2) headings.

With Foldout, you use C-c C-z (M-x foldout-zoom-subtree). This exposes the body and child subheadings, and narrows the buffer so that only the level-1 heading, the body and the level-2 headings are visible.  Now to look under one of the level-2 headings, position the cursor on it and use C-c C-z again.  This exposes the level-2 body and its level-3 child subheadings and narrows the buffer again.  Zooming in on successive subheadings can be done as much as you like.  A string in the mode line shows how deep you've gone.

When zooming in on a heading, to see only the child subheadings specify a numeric argument: C-u C-c C-z.  The number of levels of children can be specified too (compare M-x show-children), e.g. M-2 C-c C-z exposes two levels of child subheadings.  Alternatively, the body can be specified with a negative argument: M-- C-c C-z.  The whole subtree can be expanded, similarly to C-c C-s (M-x show-subtree), by specifying a zero argument: M-0 C-c C-z.

While you're zoomed in, you can still use Outline mode's exposure and hiding functions without disturbing Foldout.  Also, since the buffer is narrowed, ``global'' editing actions will only affect text under the zoomed-in heading.  This is useful for restricting changes to a particular chapter or section of your document.

To unzoom (exit) a fold, use C-c C-x (M-x foldout-exit-fold). This hides all the text and subheadings under the top-level heading and returns you to the previous view of the buffer.  Specifying a numeric argument exits that many levels of folds.  Specifying a zero argument exits all folds.

To cancel the narrowing of a fold without hiding the text and subheadings, specify a negative argument.  For example, M--2 C-c C-x exits two folds and leaves the text and subheadings exposed.

Foldout mode also provides mouse commands for entering and exiting folds, and for showing and hiding text:

C-M-Mouse-1 zooms in on the heading clicked on

       single click: expose body.

       double click: expose subheadings.

       triple click: expose body and subheadings.

       quad click: expose entire subtree.

C-M-Mouse-2 exposes text under the heading clicked on

       single click: expose body.

       double click: expose subheadings.

       triple click: expose body and subheadings.

       quad click: expose entire subtree.

C-M-Mouse-3 hides text under the heading clicked on or exits fold

       single click: hide subtree.

       double click: exit fold and hide text.

       triple click: exit fold without hiding text.

       quad click: exit all folds and hide text.

You can specify different modifier keys (instead of Control-Meta-) by setting foldout-mouse-modifiers; but if you have already loaded the foldout.el library, you must reload it in order for this to take effect.

To use the Foldout package, you can type M-x load-library RET foldout RET; or you can arrange for to do that automatically by putting this in your .emacs file:

     (eval-after-load "outline" '(require 'foldout))

TeX Mode
========

Emacs provides special major modes for editing files written in TeX and its related formats.  TeX is a powerful text formatter written by Donald Knuth; like GNU Emacs, it is free software. LaTeX is a simplified input format for TeX, implemented using TeX macros.  DocTeX is a special file format in which the LaTeX sources are written, combining sources with documentation. SliTeX is an obsolete special form of LaTeX. (It has been replaced by the slides document class, which comes with LaTeX.)

TeX mode has four variants: Plain TeX mode, LaTeX mode, DocTeX mode, and SliTeX mode.  These distinct major modes differ only slightly, and are designed for editing the four different formats.  Emacs selects the appropriate mode by looking at the contents of the buffer.  (This is done by the tex-mode command, which is normally called automatically when you visit a TeX-like file.  See Choosing Modes.)  If the contents are insufficient to determine this, Emacs chooses the mode specified by the variable tex-default-mode; its default value is latex-mode.  If Emacs does not guess right, you can select the correct variant of TeX mode using the command M-x plain-tex-mode, M-x latex-mode, M-x slitex-mode, or doctex-mode.

Emacs also provides BibTeX mode, a major mode for editing BibTeX files.  BibTeX is a tool for storing and formatting bibliographic references, which is commonly used together with LaTeX.  In addition, the RefTeX package provides a minor mode which can be used in conjunction with LaTeX mode to manage bibliographic references.  See reftex.

TeX Editing Commands
--------------------

"
     Insert, according to context, either `` or " or '' (tex-insert-quote).

C-j
     Insert a paragraph break (two newlines) and check the previous paragraph for unbalanced braces or dollar signs (tex-terminate-paragraph).

M-x tex-validate-region
     Check each paragraph in the region for unbalanced braces or dollar signs.

C-c {
     Insert {} and position point between them (tex-insert-braces).

C-c }
     Move forward past the next unmatched close brace (up-list).

In TeX, the character " is not normally used; instead, quotations begin with `` and end with ''.  For convenience, TeX mode overrides the normal meaning of the key " with a command that inserts a pair of single-quotes or backquotes (tex-insert-quote).  To be precise, it inserts `` after whitespace or an open brace, " after a backslash, and '' after any other character.

As a special exception, if you type " when the text before point is either `` or '', Emacs replaces that preceding text with a single " character.  You can therefore type "" to insert ", should you ever need to do so.  (You can also use C-q " to insert this character.)

To disable the " expansion feature, eliminate that binding in the local map (see Key Bindings).

In TeX mode, $ has a special syntax code which attempts to understand the way TeX math mode delimiters match.  When you insert a $ that is meant to exit math mode, the position of the matching $ that entered math mode is displayed for a second.  This is the same feature that displays the open brace that matches a close brace that is inserted.  However, there is no way to tell whether a $ enters math mode or leaves it; so when you insert a $ that enters math mode, the previous $ position is shown as if it were a match, even though they are actually unrelated.

TeX uses braces as delimiters that must match.  Some users prefer to keep braces balanced at all times, rather than inserting them singly.  Use C-c { (tex-insert-braces) to insert a pair of braces.  It leaves point between the two braces so you can insert the text that belongs inside.  Afterward, use the command C-c } (up-list) to move forward past the close brace.

There are two commands for checking the matching of braces.  C-j (tex-terminate-paragraph) checks the paragraph before point, and inserts two newlines to start a new paragraph.  It outputs a message in the echo area if any mismatch is found.  M-x tex-validate-region checks a region, paragraph by paragraph.  The errors are listed in the *Occur* buffer, and you can use C-c C-c or Mouse-2 in that buffer to go to a particular mismatch.

Note that Emacs commands count square brackets and parentheses in TeX mode, not just braces.  This is not strictly correct for the purpose of checking TeX syntax.  However, parentheses and square brackets are likely to be used in text as matching delimiters, and it is useful for the various motion commands and automatic match display to work with them.

LaTeX Editing Commands
----------------------

LaTeX mode (and its obsolete variant, SliTeX mode) provide a few extra features not applicable to plain TeX:

C-c C-o
     Insert \begin and \end for LaTeX block and position point on a line between them (tex-latex-block).

C-c C-e
     Close the innermost LaTeX block not yet closed (tex-close-latex-block).

In LaTeX input, \begin and \end commands are used to group blocks of text.  To insert a \begin and a matching \end (on a new line following the \begin), use C-c C-o (tex-latex-block).  A blank line is inserted between the two, and point is left there.  You can use completion when you enter the block type; to specify additional block type names beyond the standard list, set the variable latex-block-names.  For example, here's how to add theorem, corollary, and proof:

     (setq latex-block-names '("theorem" "corollary" "proof"))

In LaTeX input, \begin and \end commands must balance.  You can use C-c C-e (tex-close-latex-block) to insert automatically a matching \end to match the last unmatched \begin.  It indents the \end to match the corresponding \begin.  It inserts a newline after \end if point is at the beginning of a line.

TeX Printing Commands
---------------------

You can invoke TeX as an inferior of Emacs on either the entire contents of the buffer or just a region at a time.  Running TeX in this way on just one chapter is a good way to see what your changes look like without taking the time to format the entire file.

C-c C-r
     Invoke TeX on the current region, together with the buffer's header (tex-region).

C-c C-b
     Invoke TeX on the entire current buffer (tex-buffer).

C-c TAB
     Invoke BibTeX on the current file (tex-bibtex-file).

C-c C-f
     Invoke TeX on the current file (tex-file).

C-c C-l
     Recenter the window showing output from the inferior TeX so that the last line can be seen (tex-recenter-output-buffer).

C-c C-k
     Kill the TeX subprocess (tex-kill-job).

C-c C-p
     Print the output from the last C-c C-r, C-c C-b, or C-c C-f command (tex-print).

C-c C-v
     Preview the output from the last C-c C-r, C-c C-b, or C-c C-f command (tex-view).

C-c C-q
     Show the printer queue (tex-show-print-queue).

C-c C-c
     Invoke some other compilation command on the entire current buffer (tex-compile).

You can pass the current buffer through an inferior TeX by means of C-c C-b (tex-buffer).  The formatted output appears in a temporary file; to print it, type C-c C-p (tex-print). Afterward, you can use C-c C-q (tex-show-print-queue) to view the progress of your output towards being printed.  If your terminal has the ability to display TeX output files, you can preview the output on the terminal with C-c C-v (tex-view).

You can specify the directory to use for running TeX by setting the variable tex-directory.  "." is the default value.  If your environment variable TEXINPUTS contains relative directory names, or if your files contains \input commands with relative file names, then tex-directory must be "." or you will get the wrong results.  Otherwise, it is safe to specify some other directory, such as "/tmp".

If you want to specify which shell commands are used in the inferior TeX, you can do so by setting the values of the variables tex-run-command, latex-run-command, slitex-run-command, tex-dvi-print-command, tex-dvi-view-command, and tex-show-queue-command.  The default values may (or may not) be appropriate for your system.

Normally, the file name given to these commands comes at the end of the command string; for example, latex FILENAME.  In some cases, however, the file name needs to be embedded in the command; an example is when you need to provide the file name as an argument to one command whose output is piped to another.  You can specify where to put the file name with * in the command string.  For example,

     (setq tex-dvi-print-command "dvips -f * | lpr")

The terminal output from TeX, including any error messages, appears in a buffer called *tex-shell*.  If TeX gets an error, you can switch to this buffer and feed it input (this works as in Shell mode; see Interactive Shell).  Without switching to this buffer you can scroll it so that its last line is visible by typing C-c C-l.

Type C-c C-k (tex-kill-job) to kill the TeX process if you see that its output is no longer useful.  Using C-c C-b or C-c C-r also kills any TeX process still running.

You can also pass an arbitrary region through an inferior TeX by typing C-c C-r (tex-region).  This is tricky, however, because most files of TeX input contain commands at the beginning to set parameters and define macros, without which no later part of the file will format correctly.  To solve this problem, C-c C-r allows you to designate a part of the file as containing essential commands; it is included before the specified region as part of the input to TeX.  The designated part of the file is called the header.

To indicate the bounds of the header in Plain TeX mode, you insert two special strings in the file.  Insert %**start of header before the header, and %**end of header after it.  Each string must appear entirely on one line, but there may be other text on the line before or after.  The lines containing the two strings are included in the header. If %**start of header does not appear within the first 100 lines of the buffer, C-c C-r assumes that there is no header.

In LaTeX mode, the header begins with \documentclass or \documentstyle and ends with \begin{document}.  These are commands that LaTeX requires you to use in any case, so nothing special needs to be done to identify the header.

The commands (tex-buffer) and (tex-region) do all of their work in a temporary directory, and do not have available any of the auxiliary files needed by TeX for cross-references; these commands are generally not suitable for running the final copy in which all of the cross-references need to be correct.

When you want the auxiliary files for cross references, use C-c C-f (tex-file) which runs TeX on the current buffer's file, in that file's directory.  Before running TeX, it offers to save any modified buffers.  Generally, you need to use (tex-file) twice to get the cross-references right.

The value of the variable tex-start-options specifies options for the TeX run.

The value of the variable tex-start-commands specifies TeX commands for starting TeX.  The default value causes TeX to run in nonstop mode.  To run TeX interactively, set the variable to "".

Large TeX documents are often split into several files---one main file, plus subfiles.  Running TeX on a subfile typically does not work; you have to run it on the main file.  In order to make tex-file useful when you are editing a subfile, you can set the variable tex-main-file to the name of the main file.  Then tex-file runs TeX on that file.

The most convenient way to use tex-main-file is to specify it in a local variable list in each of the subfiles.  See File Variables.

For LaTeX files, you can use BibTeX to process the auxiliary file for the current buffer's file.  BibTeX looks up bibliographic citations in a data base and prepares the cited references for the bibliography section.  The command C-c TAB (tex-bibtex-file) runs the shell command (tex-bibtex-command) to produce a .bbl file for the current buffer's file.  Generally, you need to do C-c C-f (tex-file) once to generate the .aux file, then do C-c TAB (tex-bibtex-file), and then repeat C-c C-f (tex-file) twice more to get the cross-references correct.

To invoke some other compilation program on the current TeX buffer, type C-c C-c (tex-compile).  This command knows how to pass arguments to many common programs, including pdflatex, yap, xdvi, and dvips.  You can select your desired compilation program using the standard completion keys (see Completion).

TeX Mode Miscellany
-------------------

Entering any variant of TeX mode runs the hooks text-mode-hook and tex-mode-hook.  Then it runs either plain-tex-mode-hook, latex-mode-hook, or slitex-mode-hook, whichever is appropriate.  Starting the TeX shell runs the hook tex-shell-hook.  See Hooks.

The commands M-x iso-iso2tex, M-x iso-tex2iso, M-x iso-iso2gtex and M-x iso-gtex2iso can be used to convert between Latin-1 encoded files and TeX-encoded equivalents.

For managing all kinds of references for LaTeX, you can use RefTeX.  See reftex.

SGML, XML, and HTML Modes
=========================

The major modes for SGML, XML, and HTML provide indentation support and commands for operating on tags.  XML mode is actually identical to SGML mode (to be precise, xml-mode is an alias for sgml-mode), because XML is a strict subset of SGML.  HTML mode is a slightly customized variant of SGML mode.

In XML, every opening tag must have an explicit closing tag.  When the variable sgml-xml-mode is non-nil, the tag insertion commands described below always insert explicit closing tags as well. When you visit a file, Emacs determines whether it is XML by examining the file contents, and sets sgml-xml-mode accordingly.

C-c C-n
     Interactively specify a special character and insert the SGML &-command for that character.

C-c C-t
     Interactively specify a tag and its attributes (sgml-tag). This command asks you for a tag name and for the attribute values, then inserts both the opening tag and the closing tag, leaving point between them.

     With a prefix argument N, the command puts the tag around the N words already present in the buffer after point.  Whenever a region is active, it puts the tag around the region (when Transient Mark mode is off, it does this when a numeric argument of -1 is supplied.)

C-c C-a
     Interactively insert attribute values for the current tag (sgml-attributes).

C-c C-f
     Skip across a balanced tag group (which extends from an opening tag through its corresponding closing tag) (sgml-skip-tag-forward). A numeric argument acts as a repeat count.

C-c C-b
     Skip backward across a balanced tag group (which extends from an opening tag through its corresponding closing tag) (sgml-skip-tag-forward).  A numeric argument acts as a repeat count.

C-c C-d
     Delete the tag at or after point, and delete the matching tag too (sgml-delete-tag).  If the tag at or after point is an opening tag, delete the closing tag too; if it is a closing tag, delete the opening tag too.

C-c ? TAG RET
     Display a description of the meaning of tag TAG (sgml-tag-help).  If the argument TAG is empty, describe the tag at point.

C-c /
     Insert a close tag for the innermost unterminated tag (sgml-close-tag).  If called from within a tag or a comment, close this element instead of inserting a close tag.

C-c 8
     Toggle a minor mode in which Latin-1 characters insert the corresponding SGML commands that stand for them, instead of the characters themselves (sgml-name-8bit-mode).

C-c C-v
     Run a shell command (which you must specify) to validate the current buffer as SGML (sgml-validate).

C-c TAB
     Toggle the visibility of existing tags in the buffer.  This can be used as a cheap preview.

Emacs also provides a more advanced mode for editing XML documents, called nXML mode (nxml-mode).  nXML mode is aware of many existing XML schema, and uses them to provide completion of XML elements via C-RET or M-TAB, as well as ``on-the-fly'' validation of XML, with errors highlighted via Font Lock (see Font Lock).  It is described in its own manual. See nXML Mode.

Nroff Mode
==========

Nroff mode is a mode like Text mode but modified to handle nroff commands present in the text.  Invoke M-x nroff-mode to enter this mode.  It differs from Text mode in only a few ways.  All nroff command lines are considered paragraph separators, so that filling will never garble the nroff commands.  Pages are separated by .bp commands.  Comments start with backslash-doublequote.  Also, three special commands are provided that are not in Text mode:

M-n
     Move to the beginning of the next line that isn't an nroff command (forward-text-line).  An argument is a repeat count.

M-p
     Like M-n but move up (backward-text-line).

M-?
     Displays in the echo area the number of text lines (lines that are not nroff commands) in the region (count-text-lines).

The other feature of Nroff mode is that you can turn on Electric Nroff mode.  This is a minor mode that you can turn on or off with M-x electric-nroff-mode (see Minor Modes).  When the mode is on, each time you use RET to end a line that contains an nroff command that opens a kind of grouping, the matching nroff command to close that grouping is automatically inserted on the following line.  For example, if you are at the beginning of a line and type . ( b RET, this inserts the matching command .)b on a new line following point.

If you use Outline minor mode with Nroff mode (see Outline Mode), heading lines are lines of the form .H followed by a number (the header level).

Entering Nroff mode runs the hook text-mode-hook, followed by the hook nroff-mode-hook (see Hooks).

Editing Formatted Text
======================

Enriched mode is a minor mode for editing files that contain formatted text in WYSIWYG fashion, as in a word processor.  Currently, formatted text in Enriched mode can specify fonts, colors, underlining, margins, and types of filling and justification.  In the future, we plan to implement other formatting features as well.

Enriched mode is a minor mode (see Minor Modes).  It is typically used in conjunction with Text mode (see Text Mode), but you can also use it with other major modes such as Outline mode and Paragraph-Indent Text mode.

Potentially, Emacs can store formatted text files in various file formats.  Currently, only one format is implemented: text/enriched format, which is defined by the MIME protocol.  See Format Conversion (the Emacs Lisp Reference Manual), for details of how Emacs recognizes and converts file formats.

The Emacs distribution contains a formatted text file that can serve as an example.  Its name is etc/enriched.doc.  It contains samples illustrating all the features described in this section.  It also contains a list of ideas for future enhancements.

Requesting to Edit Formatted Text
---------------------------------

Whenever you visit a file that Emacs saved in the text/enriched format, Emacs automatically converts the formatting information in the file into Emacs's own internal format (known as text properties), and turns on Enriched mode.

To create a new file of formatted text, first visit the nonexistent file, then type M-x enriched-mode before you start inserting text. This command turns on Enriched mode.  Do this before you begin inserting text, to ensure that the text you insert is handled properly.

More generally, the command enriched-mode turns Enriched mode on if it was off, and off if it was on.  With a prefix argument, this command turns Enriched mode on if the argument is positive, and turns the mode off otherwise.

When you save a buffer while Enriched mode is enabled in it, Emacs automatically converts the text to text/enriched format while writing it into the file.  When you visit the file again, Emacs will automatically recognize the format, reconvert the text, and turn on Enriched mode again.

You can add annotations for saving additional text properties, which Emacs normally does not save, by adding to enriched-translations. Note that the text/enriched standard requires any non-standard annotations to have names starting with x-, as in x-read-only.  This ensures that they will not conflict with standard annotations that may be added later.

See Text Properties (the Emacs Lisp Reference Manual), for more information about text properties.

Hard and Soft Newlines
----------------------

In formatted text, Emacs distinguishes between two different kinds of newlines, hard newlines and soft newlines.  (You can enable or disable this feature separately in any  buffer with the command use-hard-newlines.)

Hard newlines are used to separate paragraphs, or items in a list, or anywhere that there should always be a line break regardless of the margins.  The RET command (newline) and C-o (open-line) insert hard newlines.

Soft newlines are used to make text fit between the margins.  All the fill commands, including Auto Fill, insert soft newlines---and they delete only soft newlines.

Although hard and soft newlines look the same, it is important to bear the difference in mind.  Do not use RET to break lines in the middle of filled paragraphs, or else you will get hard newlines that are barriers to further filling.  Instead, let Auto Fill mode break lines, so that if the text or the margins change, Emacs can refill the lines properly.  See Auto Fill.

On the other hand, in tables and lists, where the lines should always remain as you type them, you can use RET to end lines.  For these lines, you may also want to set the justification style to unfilled.  See Format Justification.

Editing Format Information
--------------------------

There are two ways to alter the formatting information for a formatted text file: with keyboard commands, and with the mouse.

The easiest way to add properties to your document is with the Text Properties menu.  You can get to this menu in two ways: from the Edit menu in the menu bar (use F10 e t if you have no mouse), or with C-Mouse-2 (hold the CTRL key and press the middle mouse button).  There are also keyboard commands described in the following section.

These items in the Text Properties menu run commands directly:

Remove Face Properties
     Delete from the region all face and color text properties (facemenu-remove-face-props).

Remove Text Properties
     Delete all text properties from the region (facemenu-remove-all).

Describe Properties
     List all the text properties, widgets, buttons, and overlays of the character following point (describe-text-properties).

Display Faces
     Display a list of all the defined faces (list-faces-display).

Display Colors
     Display a list of all the defined colors (list-colors-display).

Other items in the Text Properties menu lead to submenus:

Faces in Formatted Text
-----------------------

The Faces submenu under Text Properties lists various Emacs faces including bold, italic, and underline (see Faces).  These menu items operate on the region if it is active and nonempty.  Otherwise, they specify to use that face for an immediately following self-inserting character.  There is also an item Other with which you can enter a face name through the minibuffer (see Standard Faces).

Instead of the Faces submenu, you can use these keyboard commands:

M-o d
     Remove all face properties from the region (which includes specified colors), or force the following inserted character to have no face property (facemenu-set-default).

M-o b
     Add the face bold to the region or to the following inserted character (facemenu-set-bold).

M-o i
     Add the face italic to the region or to the following inserted character (facemenu-set-italic).

M-o l
     Add the face bold-italic to the region or to the following inserted character (facemenu-set-bold-italic).

M-o u
     Add the face underline to the region or to the following inserted character (facemenu-set-underline).

M-o o FACE RET
     Add the face FACE to the region or to the following inserted character (facemenu-set-face).

With a prefix argument, all these commands apply to an immediately following self-inserting character, disregarding the region.

A self-inserting character normally inherits the face property (and most other text properties) from the preceding character in the buffer.  If you use the above commands to specify face for the next self-inserting character, or the next section's commands to specify a foreground or background color for it, then it does not inherit the face property from the preceding character; instead it uses whatever you specified.  It will still inherit other text properties, though.

Strictly speaking, these commands apply only to the first following self-inserting character that you type.  But if you insert additional characters after it, they will inherit from the first one.  So it appears that these commands apply to all of them.

Enriched mode defines two additional faces: excerpt and fixed.  These correspond to codes used in the text/enriched file format.

The excerpt face is intended for quotations.  This face is the same as italic unless you customize it (see Face Customization).

The fixed face means, ``Use a fixed-width font for this part of the text.''  Applying the fixed face to a part of the text will cause that part of the text to appear in a fixed-width font, even if the default font is variable-width.  This applies to Emacs and to other systems that display text/enriched format.  So if you specifically want a certain part of the text to use a fixed-width font, you should specify the fixed face for that part.

By default, the fixed face looks the same as bold. This is an attempt to distinguish it from default.  You may wish to customize fixed to some other fixed-width medium font. See Face Customization.

If your terminal cannot display different faces, you will not be able to see them, but you can still edit documents containing faces, and even add faces and colors to documents.  The faces you specify will be visible when the file is viewed on a terminal that can display them.

Colors in Formatted Text
------------------------

You can specify foreground and background colors for portions of the text.  Under Text Properties, there is a submenu for specifying the foreground color, and a submenu for specifying the background color. Each one lists all the colors that you have used in Enriched mode in the current Emacs session.

If the region is active, the command applies to the text in the region; otherwise, it applies to any immediately following self-inserting input.  When Transient Mark mode is off (see Persistent Mark), it always applies to the region unless a prefix argument is given, in which case it applies to the following input.

Each of the two color submenus contains one additional item: Other.  You can use this item to specify a color that is not listed in the menu; it reads the color name with the minibuffer.  To display a list of available colors and their names, use the Display Colors menu item in the Text Properties menu (see Editing Format Info).

Any color that you specify in this way, or that is mentioned in a formatted text file that you read in, is added to the corresponding color menu for the duration of the Emacs session.

There are no predefined key bindings for specifying colors, but you can do so with the extended commands M-x facemenu-set-foreground and M-x facemenu-set-background.  Both of these commands read the name of the color with the minibuffer.

Indentation in Formatted Text
-----------------------------

When editing formatted text, you can specify different amounts of indentation for the right or left margin of an entire paragraph or a part of a paragraph.  The margins you specify automatically affect the Emacs fill commands (see Filling) and line-breaking commands.

The Indentation submenu of Text Properties provides a convenient interface for specifying these properties.  The submenu contains four items:

Indent More
     Indent the region by 4 columns (increase-left-margin).  In Enriched mode, this command is also available on C-x TAB; if you supply a numeric argument, that says how many columns to add to the margin (a negative argument reduces the number of columns).

Indent Less
     Remove 4 columns of indentation from the region.

Indent Right More
     Make the text narrower by indenting 4 columns at the right margin.

Indent Right Less
     Remove 4 columns of indentation from the right margin.

You can use these commands repeatedly to increase or decrease the indentation.

The most common way to use them is to change the indentation of an entire paragraph.  For other uses, the effects of refilling can be hard to predict, except in some special cases like the one described next.

The most common other use is to format paragraphs with hanging indents, which means that the first line is indented less than subsequent lines.  To set up a hanging indent, increase the indentation of the region starting after the first word of the paragraph and running until the end of the paragraph.

Indenting the first line of a paragraph is easier.  Set the margin for the whole paragraph where you want it to be for the body of the paragraph, then indent the first line by inserting extra spaces or tabs.

The variable standard-indent specifies how many columns these commands should add to or subtract from the indentation.  The default value is 4.  The overall default right margin for Enriched mode is controlled by the variable fill-column, as usual.

There are also two commands for setting the left or right margin of the region absolutely: set-left-margin and set-right-margin.  Enriched mode binds these commands to C-c [ and C-c ], respectively.  You can specify the margin width either with a numeric argument or in the minibuffer.

Sometimes, as a result of editing, the filling of a paragraph becomes messed up---parts of the paragraph may extend past the left or right margins.  When this happens, use M-q (fill-paragraph) to refill the paragraph.

The fill prefix, if any, works in addition to the specified paragraph indentation: C-x . does not include the specified indentation's whitespace in the new value for the fill prefix, and the fill commands look for the fill prefix after the indentation on each line.  See Fill Prefix.

Justification in Formatted Text
-------------------------------

When editing formatted text, you can specify various styles of justification for a paragraph.  The style you specify automatically affects the Emacs fill commands.

The Justification submenu of Text Properties provides a convenient interface for specifying the style.  The submenu contains five items:

Left
     This is the most common style of justification (at least for English). Lines are aligned at the left margin but left uneven at the right.

Right
     This aligns each line with the right margin.  Spaces and tabs are added on the left, if necessary, to make lines line up on the right.

Full
     This justifies the text, aligning both edges of each line.  Justified text looks very nice in a printed book, where the spaces can all be adjusted equally, but it does not look as nice with a fixed-width font on the screen.  Perhaps a future version of Emacs will be able to adjust the width of spaces in a line to achieve elegant justification.

Center
     This centers every line between the current margins.

Unfilled
     This turns off filling entirely.  Each line will remain as you wrote it; the fill and auto-fill functions will have no effect on text which has this setting.  You can, however, still indent the left margin.  In unfilled regions, all newlines are treated as hard newlines (see Hard and Soft Newlines) .

In Enriched mode, you can also specify justification from the keyboard using the M-j prefix character:

M-j l
     Make the region left-filled (set-justification-left).

M-j r
     Make the region right-filled (set-justification-right).

M-j b
     Make the region fully justified (set-justification-full).

M-j c
M-S
     Make the region centered (set-justification-center).

M-j u
     Make the region unfilled (set-justification-none).

Justification styles apply to entire paragraphs.  All the justification-changing commands operate on the paragraph containing point, or, if the region is active, on all paragraphs which overlap the region.

The default justification style is specified by the variable default-justification.  Its value should be one of the symbols left, right, full, center, or none. This is a per-buffer variable.  Setting the variable directly affects only the current buffer.  However, customizing it in a Custom buffer sets (as always) the default value for buffers that do not override it. See Locals, and Easy Customization.

Setting Other Text Properties
-----------------------------

The Special Properties submenu of Text Properties can add or remove three other useful text properties: read-only, invisible and intangible.  The intangible property disallows moving point within the text, the invisible text property hides text from display, and the read-only property disallows alteration of the text.

Each of these special properties has a menu item to add it to the region.  The last menu item, Remove Special, removes all of these special properties from the text in the region.

Currently, the invisible and intangible properties are not saved in the text/enriched format.  The read-only property is saved, but it is not a standard part of the text/enriched format, so other editors may not respect it.

Forcing Enriched Mode
---------------------

Normally, Emacs knows when you are editing formatted text because it recognizes the special annotations used in the file that you visited. However, sometimes you must take special actions to convert file contents or turn on Enriched mode:

  * When you visit a file that was created with some other editor, Emacs may not recognize the file as being in the text/enriched format.  In this case, when you visit the file you will see the formatting commands rather than the formatted text.  Type M-x format-decode-buffer to translate it.  This also automatically turns on Enriched mode.

  * When you insert a file into a buffer, rather than visiting it, Emacs does the necessary conversions on the text which you insert, but it does not enable Enriched mode.  If you wish to do that, type M-x enriched-mode.

The command format-decode-buffer translates text in various formats into Emacs's internal format.  It asks you to specify the format to translate from; however, normally you can type just RET, which tells Emacs to guess the format.

If you wish to look at a text/enriched file in its raw form, as a sequence of characters rather than as formatted text, use the M-x find-file-literally command.  This visits a file, like find-file, but does not do format conversion.  It also inhibits character code conversion (see Coding Systems) and automatic uncompression (see Compressed Files).  To disable format conversion but allow character code conversion and/or automatic uncompression if appropriate, use format-find-file with suitable arguments.

Editing Text-based Tables
=========================

Table mode provides an easy and intuitive way to create and edit WYSIWYG text-based tables.  Here is an example of such a table:

     +-----------------+--------------------------------+-----------------+
     |     Command     |          Description           |   Key Binding   |
     +-----------------+--------------------------------+-----------------+
     |  forward-char   |Move point right N characters   |       C-f       |
     |                 |(left if N is negative).        |                 |
     |                 |                                |                 |
     |                 |On reaching end of buffer, stop |                 |
     |                 |and signal error.               |                 |
     +-----------------+--------------------------------+-----------------+
     |  backward-char  |Move point left N characters    |       C-b       |
     |                 |(right if N is negative).       |                 |
     |                 |                                |                 |
     |                 |On attempt to pass beginning or |                 |
     |                 |end of buffer, stop and signal  |                 |
     |                 |error.                          |                 |
     +-----------------+--------------------------------+-----------------+

Table mode allows the contents of the table such as this one to be easily manipulated by inserting or deleting characters inside a cell. A cell is effectively a localized rectangular edit region and edits to a cell do not affect the contents of the surrounding cells.  If the contents do not fit into a cell, then the cell is automatically expanded in the vertical and/or horizontal directions and the rest of the table is restructured and reformatted in accordance with the growth of the cell.

What is a Text-based Table?
---------------------------

Keep the following examples of valid tables in mind as a reference while you read this section:

                   +--+----+---+     +-+     +--+-----+
                   |  |    |   |     | |     |  |     |
                   +--+----+---+     +-+     |  +--+--+
                   |  |    |   |             |  |  |  |
                   +--+----+---+             +--+--+  |
                                             |     |  |
                                             +-----+--+

A table consists of a rectangular frame whose inside is divided into cells.  Each cell must be at least one character wide and one character high, not counting its border lines.  A cell can be subdivided into multiple rectangular cells, but cells cannot overlap.

The table frame and cell border lines are made of three special characters.  These variables specify those characters:

table-cell-vertical-char
     Holds the character used for vertical lines.  The default value is |.

table-cell-horizontal-chars
     Holds the characters used for horizontal lines.  The default value is "-=".

table-cell-intersection-char
     Holds the character used at where horizontal line and vertical line meet.  The default value is +.

Based on this definition, the following five tables are examples of invalid tables:

        +-----+    +-----+       +--+    +-++--+    ++
        |     |    |     |       |  |    | ||  |    ++
        | +-+ |    |     |       |  |    | ||  |
        | | | |    +--+  |    +--+--+    +-++--+
        | +-+ |    |  |  |    |  |  |    +-++--+
        |     |    |  |  |    |  |  |    | ||  |
        +-----+    +--+--+    +--+--+    +-++--+
          a           b          c          d        e

From left to right:

 a. Overlapped cells or non-rectangular cells are not allowed.

 b. Same as a.

 c. The border must be rectangular.

 d. Cells must have a minimum width/height of one character.

 e. Same as d.

How to Create a Table?
----------------------

The command to create a table is table-insert.  When called interactively, it asks for the number of columns, number of rows, cell width and cell height.  The number of columns is the number of cells horizontally side by side.  The number of rows is the number of cells vertically within the table's height.  The cell width is a number of characters that each cell holds, left to right.  The cell height is a number of lines each cell holds.  The cell width and the cell height can be either an integer (when the value is constant across the table) or a series of integer, separated by spaces or commas, where each number corresponds to the next cell within a row from left to right, or the next cell within a column from top to bottom.

Table Recognition
-----------------

Table mode maintains special text properties in the buffer to allow editing in a convenient fashion.  When a buffer with tables is saved to its file, these text properties are lost, so when you visit this file again later, Emacs does not see a table, but just formatted text. To resurrect the table text properties, issue the M-x table-recognize command.  It scans the current buffer, recognizes valid table cells, and attaches appropriate text properties to allow for table editing.  The converse command, table-unrecognize, is used to remove the special text properties and convert the buffer back to plain text.

Special commands exist to enable or disable tables within a region, enable or disable individual tables, and enable/disable individual cells.  These commands are:

M-x table-recognize-region
     Recognize tables within the current region and activate them.

M-x table-unrecognize-region
     Deactivate tables within the current region.

M-x table-recognize-table
     Recognize the table under point and activate it.

M-x table-unrecognize-table
     Deactivate the table under point.

M-x table-recognize-cell
     Recognize the cell under point and activate it.

M-x table-unrecognize-cell
     Deactivate the cell under point.

For another way of converting text into tables, see Table Conversion.

Commands for Table Cells
------------------------

The commands table-forward-cell and table-backward-cell move point from the current cell to an adjacent cell forward and backward respectively.  The order of the cells is cyclic: when point is in the last cell of a table, typing M-x table-forward-cell moves to the first cell in the table. Likewise M-x table-backward-cell from the first cell in a table moves to the last cell.

The command table-span-cell merges the current cell with the adjacent cell in a specified direction---right, left, above or below. You specify the direction with the minibuffer.  It does not allow merges which don't result in a legitimate cell layout.

The command table-split-cell splits the current cell vertically or horizontally.  This command is a wrapper to the direction specific commands table-split-cell-vertically and table-split-cell-horizontally.  You specify the direction with a minibuffer argument.

The command table-split-cell-vertically splits the current cell vertically and creates a pair of cells above and below where point is located.  The content in the original cell is split as well.

The command table-split-cell-horizontally splits the current cell horizontally and creates a pair of cells right and left of where point is located.  If the cell being split is not empty, this asks you how to handle the cell contents.  The three options are: split, left, or right.  split splits the contents at point literally, while the left and right options move the entire contents into the left or right cell respectively.

The next four commands enlarge or shrink a cell.  They use numeric arguments (see Arguments) to specify how many columns or rows to enlarge or shrink a particular table.

M-x table-heighten-cell
     Enlarge the current cell vertically.

M-x table-shorten-cell
     Shrink the current cell vertically.

M-x table-widen-cell
     Enlarge the current cell horizontally.

M-x table-narrow-cell
     Shrink the current cell horizontally.

Cell Justification
------------------

You can specify text justification for each cell.  The justification is remembered independently for each cell and the subsequent editing of cell contents is subject to the specified justification.

The command table-justify ask you to specify what to justify: a cell, a column, or a row.  If you select cell justification, this command sets the justification only for the current cell.  Selecting column or row justification sets the justification for all the cells within a column or row respectively.  The command then ask you which kind of justification to apply: left, center, right, top, middle, bottom, or none.  Horizontal justification and vertical justification are specified independently.  The options left, center, and right specify horizontal justification while the options top, middle, bottom, and none specify vertical justification.  The vertical justification none effectively removes vertical justification.  Horizontal justification must be one of left, center, or right.

Justification information is stored in the buffer as a part of text property.  Therefore, this information is ephemeral and does not survive through the loss of the buffer (closing the buffer and revisiting the buffer erase any previous text properties).  To countermand for this, the command table-recognize and other recognition commands (see Table Recognition) are equipped with a convenience feature (turned on by default).  During table recognition, the contents of a cell are examined to determine which justification was originally applied to the cell and then applies this justification to the cell.  This is a speculative algorithm and is therefore not perfect, however, the justification is deduced correctly most of the time.  To disable this feature, customize the variable table-detect-cell-alignment and set it to nil.

Commands for Table Rows
-----------------------

The command table-insert-row inserts a row of cells before the current row in a table.  The current row where point is located is pushed down after the newly inserted row.  A numeric prefix argument specifies the number of rows to insert.  Note that in order to insert rows after the last row at the bottom of a table, you must place point below the table---that is, outside the table---prior to invoking this command.

The command table-delete-row deletes a row of cells at point. A numeric prefix argument specifies the number of rows to delete.

Commands for Table Columns
--------------------------

The command table-insert-column inserts a column of cells to the left of the current row in a table.  This pushes the current column to the right.  To insert a column to the right side of the rightmost column, place point to the right of the rightmost column, which is outside of the table, prior to invoking this command.  A numeric prefix argument specifies the number of columns to insert.

A command table-delete-column deletes a column of cells at point.  A numeric prefix argument specifies the number of columns to delete.

Fix Width of Cells
------------------

The command table-fixed-width-mode toggles fixed width mode on and off.  When fixed width mode is turned on, editing inside a cell never changes the cell width; when it is off, the cell width expands automatically in order to prevent a word from being folded into multiple lines.  By default, fixed width mode is disabled.

Conversion Between Plain Text and Tables
----------------------------------------

The command table-capture captures plain text in a region and turns it into a table.  Unlike table-recognize (see Table Recognition), the original text does not have a table appearance but may hold a logical table structure.  For example, some elements separated by known patterns form a two dimensional structure which can be turned into a table.

Here's an example of data that table-capture can operate on. The numbers are horizontally separated by a comma and vertically separated by a newline character.

     1, 2, 3, 4
     5, 6, 7, 8
     , 9, 10

Invoking M-x table-capture on that text produces this table:

     +-----+-----+-----+-----+
     |1    |2    |3    |4    |
     +-----+-----+-----+-----+
     |5    |6    |7    |8    |
     +-----+-----+-----+-----+
     |     |9    |10   |     |
     +-----+-----+-----+-----+

The conversion uses , for the column delimiter and newline for a row delimiter, cells are left justified, and minimum cell width is 5.

The command table-release does the opposite of table-capture.  It releases a table by removing the table frame and cell borders.  This leaves the table contents as plain text.  One of the useful applications of table-capture and table-release is to edit a text in layout.  Look at the following three paragraphs (the latter two are indented with header lines):

     table-capture is a powerful command, but mastering its
     power requires some practice.  Here are some things it can do:

     Parse Cell Items      By using column delimiter regular
                           expression and raw delimiter regular
                           expression, it parses the specified text
                           area and extracts cell items from
                           non-table text and then forms a table out
                           of them.

     Capture Text Area     When no delimiters are specified it
                           creates a single cell table.  The text in
                           the specified region is placed in that
                           cell.

Applying table-capture to a region containing the above three paragraphs, with empty strings for column delimiter regexp and row delimiter regexp, creates a table with a single cell like the following one.

     +-----------------------------------------------------------------+
     |table-capture is a powerful command, but mastering its         |
     |power requires some practice.  Here are some things it can do:   |
     |                                                                 |
     |Parse Cell Items      By using column delimiter regular          |
     |                      expression and raw delimiter regular       |
     |                      expression, it parses the specified text   |
     |                      area and extracts cell items from          |
     |                      non-table text and then forms a table out  |
     |                      of them.                                   |
     |                                                                 |
     |Capture Text Area     When no delimiters are specified it        |
     |                      creates a single cell table.  The text in  |
     |                      the specified region is placed in that     |
     |                      cell.                                      |
     +-----------------------------------------------------------------+

By splitting the cell appropriately we now have a table consisting of paragraphs occupying its own cell.  Each cell can now be edited independently without affecting the layout of other cells.

     +-----------------------------------------------------------------+
     |table-capture is a powerful command, but mastering its         |
     |power requires some practice.  Here are some things it can do:   |
     +---------------------+-------------------------------------------+
     |Parse Cell Items     |By using column delimiter regular          |
     |                     |expression and raw delimiter regular       |
     |                     |expression, it parses the specified text   |
     |                     |area and extracts cell items from          |
     |                     |non-table text and then forms a table out  |
     |                     |of them.                                   |
     +---------------------+-------------------------------------------+
     |Capture Text Area    |When no delimiters are specified it        |
     |                     |creates a single cell table.  The text in  |
     |                     |the specified region is placed in that     |
     |                     |cell.                                      |
     +---------------------+-------------------------------------------+

By applying table-release, which does the opposite process, the contents become once again plain text.  table-release works as a companion command to table-capture.

Analyzing Table Dimensions
--------------------------

The command table-query-dimension analyzes a table structure and reports information regarding its dimensions.  In case of the above example table, the table-query-dimension command displays in echo area:

     Cell: (21w, 6h), Table: (67w, 16h), Dim: (2c, 3r), Total Cells: 5

This indicates that the current cell is 21 character wide and 6 lines high, the entire table is 67 characters wide and 16 lines high.  The table has 2 columns and 3 rows.  It has a total of 5 cells, since the first row has a spanned cell.

Table Miscellany
----------------

The command table-insert-sequence inserts a string into each cell.  Each string is a part of a sequence i.e. a series of increasing integer numbers.

The command table-generate-source generates a table formatted for a specific markup language.  It asks for a language (which must be one of html, latex, or cals), a destination buffer where to put the result, and the table caption (a string), and then inserts the generated table in the proper syntax into the destination buffer.  The default destination buffer is table.LANG, where LANG is the language you specified.