simplify a few accesses to fields of structs, using auxiliary pointer

[mandoc.git] / tbl.7

diff --git a/tbl.7 b/tbl.7
index d1623f3d111eb31625a390fd9487e96694b4d85b..4ecc354c4ea357a467bd0fe883d256b09e847fb3 100644 (file)
--- a/tbl.7
+++ b/tbl.7
@@ -1,6 +1,7 @@
-.\"    $Id: tbl.7,v 1.12 2011/02/07 00:05:40 schwarze Exp $
+.\"    $Id: tbl.7,v 1.37 2021/09/18 12:34:27 schwarze Exp $

 .\"
 .\" Copyright (c) 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 .\"
 .\" Copyright (c) 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>

+.\" Copyright (c) 2014,2015,2017,2018,2019 Ingo Schwarze <schwarze@openbsd.org>

 .\"
 .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above
 .\"
 .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above


@@ -14,7 +15,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"

-.Dd $Mdocdate: February 7 2011 $
+.Dd $Mdocdate: September 18 2021 $

 .Dt TBL 7
 .Os
 .Sh NAME
 .Dt TBL 7
 .Os
 .Sh NAME


@@ -23,286 +24,391 @@
 .Sh DESCRIPTION
 The
 .Nm tbl
 .Sh DESCRIPTION
 The
 .Nm tbl

-language is a table-formatting language.
+language formats tables.

 It is used within
 .Xr mdoc 7
 and
 .Xr man 7
 It is used within
 .Xr mdoc 7
 and
 .Xr man 7

-.Ux
-manual pages.
+pages.

 This manual describes the subset of the
 .Nm
 language accepted by the
 .Xr mandoc 1
 utility.
 .Pp
 This manual describes the subset of the
 .Nm
 language accepted by the
 .Xr mandoc 1
 utility.
 .Pp

-Tables within
-.Xr mdoc 7
-or
-.Xr man 7
-are enclosed by the
-.Sq TS
-and
-.Sq TE
-macro tags, whose precise syntax is documented in
-.Xr roff 7 .
-Tables consist of a series of options on a single line, followed by the
-table layout, followed by data.
-.Pp
-For example, the following creates a boxed table with digits centered in
-the cells.
-.Bd -literal -offset indent
-\&.TS
-tab(:) box;
-c5 c5 c5.
-1:2:3
-4:5:6
-\&.TE
-.Ed
-.Pp
-When formatted, the following output is produced:
-.Bd -filled -offset indent -compact
-.TS
-tab(:) box;
-c5 c5 c5.
-1:2:3
-4:5:6
-.TE
-.Ed
-.Sh TABLE STRUCTURE
-Tables are enclosed by the
-.Sq TS
-and
-.Sq TE
+Each table is started with a

 .Xr roff 7
 .Xr roff 7

-macros.
-A table consists of an optional single line of table
-.Sx Options
-terminated by a semicolon, followed by one or more lines of
+.Ic \&TS
+macro, consist of at most one line of
+.Sx Options ,
+one or more

 .Sx Layout
 .Sx Layout

-specifications terminated by a period, then
-.Sx Data .
+lines, one or more
+.Sx Data
+lines, and ends with a
+.Ic \&TE
+macro.

 All input must be 7-bit ASCII.
 All input must be 7-bit ASCII.

-Example:
-.Bd -literal -offset indent
-\&.TS
-box tab(:);
-c | c
-| c | c.
-1:2
-3:4
-\&.TE
-.Ed
-.Pp
-Table data is
-.Em pre-processed ,
-that is, data rows are parsed then inserted into the underlying stream
-of input data.
-This allows data rows to be interspersed by arbitrary
-.Xr roff 7 ,
-.Xr mdoc 7 ,
-and
-.Xr man 7
-macros such as
-.Bd -literal -offset indent
-\&.TS
-tab(:);
-c c c.
-1:2:3
-\&.Ao
-3:2:1
-\&.Ac
-\&.TE
-.Ed
-.Pp
-in the case of
-.Xr mdoc 7
-or
-.Bd -literal -offset indent
-\&.TS
-tab(:);
-c c c.
-\&.ds ab 2
-1:\e*(ab:3
-\&.I
-3:2:1
-\&.TE
-.Ed
-.Pp
-in the case of
-.Xr man 7 .

 .Ss Options
 .Ss Options

-The first line of a table consists of space-separated option keys and
-modifiers terminated by a semicolon.
-If the first line does not have a terminating semicolon, it is assumed
-that no options are specified and instead a
+If the first input line of a table ends with a semicolon, it contains
+case-insensitive options separated by spaces, tabs, or commas.
+Otherwise, it is interpreted as the first

 .Sx Layout
 .Sx Layout

-is processed.
-Some options accept arguments enclosed by parenthesis.
-The following case-insensitive options are available:
+line.
+.Pp
+The following options are available.
+Some of them require arguments enclosed in parentheses:

 .Bl -tag -width Ds
 .Bl -tag -width Ds

-.It Cm center
-This option is not supported by
-.Xr mandoc 1 .
-This may also be invoked with
-.Cm centre .
-.It Cm delim
-Accepts a two-character argument.
-This option is not supported by
-.Xr mandoc 1 .
-.It Cm expand
-This option is not supported by
-.Xr mandoc 1 .
+.It Cm allbox
+Draw a single-line box around each table cell.

 .It Cm box
 Draw a single-line box around the table.
 .It Cm box
 Draw a single-line box around the table.

-This may also be invoked with
+For GNU compatibility, this may also be invoked with

 .Cm frame .
 .Cm frame .

+.It Cm center
+Center the table instead of left-adjusting it.
+For GNU compatibility, this may also be invoked with
+.Cm centre .
+.It Cm decimalpoint
+Use the single-character argument as the decimal point with the
+.Cm n
+layout key.
+This is a GNU extension.
+.It Cm delim
+Use the two characters of the argument as
+.Xr eqn 7
+delimiters.
+Currently unsupported.

 .It Cm doublebox
 Draw a double-line box around the table.
 .It Cm doublebox
 Draw a double-line box around the table.

-This may also be invoked with
+For GNU compatibility, this may also be invoked with

 .Cm doubleframe .
 .Cm doubleframe .

-.It Cm allbox
-This option is not supported by
-.Xr mandoc 1 .
-.It Cm tab
-Accepts a single-character argument.
-This character is used as a delimiter between data cells, which otherwise
-defaults to the tab character.
+.It Cm expand
+Increase the width of the table to the current line length.
+Currently ignored.

 .It Cm linesize
 .It Cm linesize

-Accepts a natural number (all digits).
-This option is not supported by
-.Xr mandoc 1 .
+Draw lines with the point size given by the unsigned integer argument.
+Currently ignored.

 .It Cm nokeep
 .It Cm nokeep

-This option is not supported by
-.Xr mandoc 1 .
-.It Cm decimalpoint
-Accepts a single-character argument.
-This character will be used as the decimal point with the
-.Cm n
-layout key.
+Allow page breaks within the table.
+This is a GNU extension and currently ignored.

 .It Cm nospaces
 .It Cm nospaces

-This option is not supported by
-.Xr mandoc 1 .
+Ignore leading and trailing spaces in data cells.
+This is a GNU extension.
+.It Cm nowarn
+Suppress warnings about tables exceeding the current line length.
+This is a GNU extension and currently ignored.
+.It Cm tab
+Use the single-character argument as a delimiter between data cells.
+By default, the horizontal tabulator character is used.

 .El
 .Ss Layout
 .El
 .Ss Layout

-The table layout follows
+The table layout follows an

 .Sx Options
 .Sx Options

-or a
-.Sq \&T&
-macro invocation.
-Layout specifies how data rows are displayed on output.
-Each layout line corresponds to a line of data; the last layout line
-applies to all remaining data lines.
-Layout lines may also be separated by a comma.
-Each layout cell consists of one of the following case-insensitive keys:
-.Bl -tag -width Ds
+line or a
+.Xr roff 7
+.Ic \&TS
+or
+.Ic \&T&
+macro.
+Each layout line specifies how one line of
+.Sx Data
+is formatted.
+The last layout line ends with a full stop.
+It also applies to all remaining data lines.
+Multiple layout lines can be joined by commas on a single physical
+input line.
+.Pp
+Each layout line consists of one or more layout cell specifications,
+optionally separated by whitespace.
+The following case-insensitive key characters start a new cell
+specification:
+.Bl -tag -width 2n

 .It Cm c
 .It Cm c

-Centre a literal string within its column.
+Center the string in this cell.

 .It Cm r
 .It Cm r

-Right-justify a literal string within its column.
+Right-justify the string in this cell.

 .It Cm l
 .It Cm l

-Left-justify a literal string within its column.
+Left-justify the string in this cell.

 .It Cm n
 Justify a number around its last decimal point.
 .It Cm n
 Justify a number around its last decimal point.

-If the decimal point is not found on the number, it's assumed to trail
-the number.
+If no decimal point is found in the number,
+it is assumed to trail the number.

 .It Cm s
 Horizontally span columns from the last
 .It Cm s
 Horizontally span columns from the last

-.No non- Ns Cm s
-data cell.
-It is an error if spanning columns follow a
-.Cm \-
+.Pf non- Cm s
+layout cell.
+It is an error if a column span follows a
+.Cm _

 or
 or

-.Cm \(ba
-cell, or come first.
-This option is not supported by
-.Xr mandoc 1 .
+.Cm =
+cell, or comes first on a layout line.
+The combined cell as a whole consumes only one cell
+of the corresponding data line.

 .It Cm a
 .It Cm a

-Left-justify a literal string and pad with one space.
-.It Cm ^
+Left-justify a string and pad with one space.
+.It Cm \(ha

 Vertically span rows from the last
 Vertically span rows from the last

-.No non- Ns Cm ^
-data cell.
-It is an error to invoke a vertical span on the first layout row.
-Unlike a horizontal spanner, you must specify an empty cell (if it not
-empty, the data is discarded) in the corresponding data cell.
-.It Cm \-
-Replace the data cell (its contents will be lost) with a single
-horizontal line.
-This may also be invoked with
-.Cm _ .
+.Pf non- Cm \(ha
+layout cell.
+It is an error to invoke a vertical span on the first layout line.
+Unlike a horizontal span, a vertical span consumes a data cell
+and discards the content.
+.It Cm _
+Draw a single horizontal line in this cell.
+This consumes a data cell and discards the content.
+It may also be invoked with
+.Cm \- .

 .It Cm =
 .It Cm =

-Replace the data cell (its contents will be lost) with a double
-horizontal line.
-.It Cm \(ba
-Emit a vertical bar instead of data.
-.It Cm \(ba\(ba
-Emit a double-vertical bar instead of data.
+Draw a double horizontal line in this cell.
+This consumes a data cell and discards the content.

 .El
 .Pp
 .El
 .Pp

-Keys may be followed by a set of modifiers.
-A modifier is either a modifier key or a natural number for specifying
-the minimum width of a column.
-The following case-insensitive modifier keys are available:
-.Cm z ,
-.Cm u ,
-.Cm e ,
-.Cm t ,
-.Cm d ,
-.Cm f ,
-.Cm b ,
-.Cm i ,
-.Cm b ,
-and
-.Cm i .
-All of these are ignored by
-.Xr mandoc 1 .
-.Pp
-For example, the following layout specifies a centre-justified column of
-minimum width 10, followed by vertical bar, followed by a left-justified
-column of minimum width 10, another vertical bar, then a column
-justified about the decimal point in numbers:
+Each cell key may be followed by zero or more of the following
+case-insensitive modifiers:
+.Bl -tag -width 2n
+.It Cm b
+Use a bold font for the contents of this cell.
+.It Cm d
+Move content down to the last row of this vertical span.
+Currently ignored.
+.It Cm e
+Make this column wider to match the maximum width
+of any other column also having the
+.Cm e
+modifier.
+.It Cm f
+The next one or two characters select the font to use for this cell.
+One-character font names must be followed by a blank or period.
+See the
+.Xr roff 7
+manual for supported font names.
+.It Cm i
+Use an italic font for the contents of this cell.
+.It Cm m
+Specify a cell start macro.
+This is a GNU extension and currently unsupported.
+.It Cm p
+Set the point size to the following unsigned argument,
+or change it by the following signed argument.
+Currently ignored.
+.It Cm v
+Set the vertical line spacing to the following unsigned argument,
+or change it by the following signed argument.
+Currently ignored.
+.It Cm t
+Do not vertically center content in this vertical span,
+leave it in the top row.
+Currently ignored.
+.It Cm u
+Move cell content up by half a table row.
+Currently ignored.
+.It Cm w
+Specify a minimum column width.
+.It Cm x
+After determining the width of all other columns, distribute the
+rest of the line length among all columns having the
+.Cm x
+modifier.
+.It Cm z
+Do not use this cell for determining the width of this column.
+.It Cm \&|
+Draw a single vertical line to the right of this cell.
+.It Cm ||
+Draw a double vertical line to the right of this cell.
+.El

 .Pp
 .Pp

-.Dl c10 | l10 | n
+If a modifier consists of decimal digits,
+it specifies a minimum spacing in units of
+.Cm n
+between this column and the next column to the right.
+The default is 3.
+If there is a vertical line, it is drawn inside the spacing.

 .Ss Data
 .Ss Data

-The data section follows the last layout row.
-By default, cells in a data section are delimited by a tab.
-This behaviour may be changed with the
+The data section follows the last
+.Sx Layout
+line.
+Each data line consists of one or more data cells, delimited by

 .Cm tab
 .Cm tab

-option.
-If
-.Cm _
+characters.
+.Pp
+If a data cell contains only the two bytes
+.Ql \e\(ha ,
+the cell above spans to this row, as if the layout specification
+of this cell were
+.Cm \(ha .
+.Pp
+If a data cell contains only the single character
+.Ql _

 or
 or

-.Cm =
-is specified, a single or double line, respectively, is drawn across the
-data field.
-If
-.Cm \e-
+.Ql = ,
+a single or double horizontal line is drawn across the cell,
+joining its neighbours.
+If a data cell contains only the two character sequence
+.Ql \e_

 or
 or

-.Cm \e=
-is specified, a line is drawn within the data field (i.e. terminating
-within the cell and not draw to the border).
-If the last cell of a line is
-.Cm T{ ,
-all subsequent lines are included as part of the cell until
-.Cm T}
-is specified as its own data cell.
-It may then be followed by a tab
-.Pq or as designated by Cm tab
-or an end-of-line to terminate the row.
-.Sh COMPATIBILITY
-This section documents compatibility between mandoc and other
-.Nm
-implementations, at this time limited to GNU tbl.
+.Ql \e= ,
+a single or double horizontal line is drawn inside the cell,
+not joining its neighbours.
+If a data line contains nothing but the single character
+.Ql _
+or
+.Ql = ,
+a horizontal line across the whole table is inserted
+without consuming a layout row.

 .Pp
 .Pp

-.Bl -dash -compact
-.It
-In GNU tbl, comments and macros are disallowed prior to the data block
-of a table.
+In place of any data cell, a text block can be used.
+It starts with
+.Ic \&T{
+at the end of a physical input line.
+Input line breaks inside the text block
+neither end the text block nor its data cell.
+It only ends if
+.Ic \&T}
+occurs at the beginning of a physical input line and is followed
+by an end-of-cell indicator.
+If the
+.Ic \&T}
+is followed by the end of the physical input line, the text block,
+the data cell, and the data line ends at this point.
+If the
+.Ic \&T}
+is followed by the
+.Cm tab
+character, only the text block and the data cell end,
+but the data line continues with the data cell following the
+.Cm tab
+character.
+If
+.Ic \&T}
+is followed by any other character, it does not end the text block,
+which instead continues to the following physical input line.
+.Sh EXAMPLES
+String justification and font selection:
+.Bd -literal -offset indent
+\&.TS
+rb c  lb
+r  ci l.
+r      center  l
+ri     ce      le
+right  c       left
+\&.TE
+.Ed
+.Bd -filled -offset indent
+.TS
+rb c  lb
+r  ci l.
+r      center  l
+ri     ce      le
+right  c       left
+.TE
+.Ed
+.Pp
+Some ports in
+.Ox 6.1
+to show number alignment and line drawing:
+.Bd -literal -offset indent
+\&.TS
+box tab(:);
+r| l
+r  n.
+software:version
+_
+AFL:2.39b
+Mutt:1.8.0
+Ruby:1.8.7.374
+TeX Live:2015
+\&.TE
+.Ed
+.Bd -filled -offset indent
+.TS
+box tab(:);
+r| l
+r  n.
+software:version
+_
+AFL:2.39b
+Mutt:1.8.0
+Ruby:1.8.7.374
+TeX Live:2015
+.TE
+.Ed
+.sp 2v
+Spans and skipping width calculations:
+.Bd -literal -offset indent
+\&.TS
+box tab(:);
+lz  s | rt
+lt| cb| \(ha
+\(ha | rz  s.
+left:r
+l:center:
+:right
+\&.TE
+.Ed
+.Bd -filled -offset indent
+.TS
+box tab(:);
+lz  s | rt
+lt| cb| ^
+^ | rz  s.
+left:r
+l:center:
+:right
+.TE
+.Ed
+.sp 2v
+Text blocks, specifying spacings and specifying and equalizing
+column widths, putting lines into individual cells, and overriding
+.Cm allbox :
+.Bd -literal -offset indent
+\&.TS
+allbox tab(:);
+le le||7 lw10.
+The fourth line:_:line 1
+of this column:=:line 2
+determines:\_:line 3
+the column width.:T{
+This text is too wide to fit into a column of width 17.
+T}:line 4
+T{
+No break here.
+T}::line 5
+\&.TE
+.Ed
+.Bd -filled -offset indent
+.TS
+allbox tab(:);
+le le||7 lw10.
+The fourth line:_:line 1
+of this column:=:line 2
+determines:\_:line 3
+the column width.:T{
+This text is too wide to fit into a column of width 17.
+T}:line 4
+T{
+No break here.
+T}::line 5
+.TE
+.Ed
+.sp 2v
+These examples were constructed to demonstrate many
+.Nm
+features in a compact way.
+In real manual pages, keep tables as simple as possible.
+They usually look better, are less fragile, and are more portable.
+.Sh COMPATIBILITY

 The
 .Xr mandoc 1
 The
 .Xr mandoc 1

-implementation allows them.
-.El
+implementation of
+.Nm
+doesn't support
+.Xr mdoc 7
+and
+.Xr man 7
+macros and
+.Xr eqn 7
+equations inside tables.

 .Sh SEE ALSO
 .Xr mandoc 1 ,
 .Xr man 7 ,
 .Sh SEE ALSO
 .Xr mandoc 1 ,
 .Xr man 7 ,


@@ -311,7 +417,7 @@ implementation allows them.
 .Xr roff 7
 .Rs
 .%A M. E. Lesk
 .Xr roff 7
 .Rs
 .%A M. E. Lesk

-.%T Tbl\(emA Program to Format Tables
+.%T Tbl \(em A Program to Format Tables

 .%D June 11, 1976
 .Re
 .Sh HISTORY
 .%D June 11, 1976
 .Re
 .Sh HISTORY


@@ -321,11 +427,29 @@ The GNU reimplementation of tbl, part of the groff package, was released
 in 1990 by James Clark.
 A standalone tbl implementation was written by Kristaps Dzonsons in
 2010.
 in 1990 by James Clark.
 A standalone tbl implementation was written by Kristaps Dzonsons in
 2010.

-This formed the basis of the implementation that is part of the
+This formed the basis of the implementation that first appeared in
+.Ox 4.9
+as a part of the

 .Xr mandoc 1
 utility.
 .Sh AUTHORS
 .Xr mandoc 1
 utility.
 .Sh AUTHORS

-This partial
+This

 .Nm
 reference was written by
 .Nm
 reference was written by

-.An Kristaps Dzonsons Aq kristaps@bsd.lv .
+.An Kristaps Dzonsons Aq Mt kristaps@bsd.lv
+and
+.An Ingo Schwarze Aq Mt schwarze@openbsd.org .
+.Sh BUGS
+In
+.Fl T
+.Cm utf8
+output mode, heavy lines are drawn instead of double lines.
+This cannot be improved because the Unicode standard only provides
+an incomplete set of box drawing characters with double lines,
+whereas it provides a full set of box drawing characters
+with heavy lines.
+It is unlikely this can be improved in the future because the box
+drawing characters are already marked in Unicode as characters
+intended only for backward compatibility with legacy systems,
+and their use is not encouraged.
+So it seems unlikely that the missing ones might get added in the future.