.\"	Id: tbl.3,v 1.6 2018/12/14 06:33:14 schwarze Exp 
.\"
.\" Copyright (c) 2013, 2015, 2018 Ingo Schwarze <schwarze@openbsd.org>
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.Dd December 14, 2018
.Dt TBL 3
.Os
.Sh NAME
.Nm tbl_alloc ,
.Nm tbl_read ,
.Nm tbl_restart ,
.Nm tbl_span ,
.Nm tbl_end ,
.Nm tbl_free
.Nd roff table parser library for mandoc
.Sh SYNOPSIS
.In sys/types.h
.In tbl.h
.In tbl_parse.h
.Ft struct tbl_node *
.Fo tbl_alloc
.Fa "int pos"
.Fa "int line"
.Fc
.Ft void
.Fo tbl_read
.Fa "struct tbl_node *tbl"
.Fa "int ln"
.Fa "const char *p"
.Fa "int offs"
.Fc
.Ft void
.Fo tbl_restart
.Fa "int line"
.Fa "int pos"
.Fa "struct tbl_node *tbl"
.Fc
.Ft const struct tbl_span *
.Fo tbl_span
.Fa "struct tbl_node *tbl"
.Fc
.Ft void
.Fo tbl_end
.Fa "struct tbl_node **tblp"
.Fc
.Ft void
.Fo tbl_free
.Fa "struct tbl_node *tbl"
.Fc
.Sh DESCRIPTION
This library is tightly integrated into the
.Xr mandoc 1
utility and not designed for stand-alone use.
The present manual is intended as a reference for developers working on
.Xr mandoc 1 .
.Ss Data structures
Unless otherwise noted, all of the following data structures are declared in
.In tbl.h
and are deleted in
.Fn tbl_free .
.Bl -tag -width Ds
.It Vt struct tbl_node
This structure describes a complete table.
It is declared in
.In tbl_int.h ,
created in
.Fn tbl_alloc ,
and stored in the members
.Fa first_tbl ,
.Fa last_tbl ,
and
.Fa tbl
of
.Vt struct roff Bq Pa roff.c .
.Pp
The
.Fa first_span ,
.Fa current_span ,
.Fa last_span ,
and
.Fa next
members may be
.Dv NULL .
The
.Fa first_row
and
.Fa last_row
members may be
.Dv NULL ,
but if there is a span, the function
.Fn tbl_layout
guarantees that these pointers are not
.Dv NULL .
.It Vt struct tbl_opts
This structure describes the options of one table.
It is used as a substructure of
.Vt struct tbl_node
and thus created and deleted together with it.
It is filled in
.Fn tbl_options .
.It Vt struct tbl_row
This structure describes one layout line in a table
by maintaining a list of all the cells in that line.
It is allocated and filled in
.Fn row Bq Pa tbl_layout.c
and referenced from the
.Fa layout
member of
.Vt struct tbl_node .
.Pp
The
.Fa next
member may be
.Dv NULL .
The function
.Fn tbl_layout
guarantees that the
.Fa first
and
.Fa last
members are not NULL.
.It Vt struct tbl_cell
This structure describes one layout cell in a table,
in particular its alignment, membership in spans, and
usage for lines.
It is allocated and filled in
.Fn cell_alloc Bq Pa tbl_layout.c
and referenced from the
.Fa first
and
.Fa last
members of
.Vt struct tbl_row .
.Pp
The
.Fa next
member may be
.Dv NULL .
.It Vt struct tbl_span
This structure describes one data line in a table
by maintaining a list of all data cells in that line
or by specifying that it is a horizontal line.
It is allocated and filled in
.Fn newspan Bq Pa tbl_data.c
which is called from
.Fn tbl_data
and referenced from the
.Fa first_span ,
.Fa current_span ,
and
.Fa last_span
members of
.Vt struct tbl_node ,
and from the
.Fa span
members of
.Vt struct man_node
and
.Vt struct mdoc_node
from
.In man.h
and
.In mdoc.h .
.Pp
The
.Fa first ,
.Fa last ,
.Fa prev ,
and
.Fa next
members may be
.Dv NULL .
The function
.Fn newspan Bq Pa tbl_data.c
guarantees that the
.Fa opts
and
.Fa layout
members are not
.Dv NULL .
.It Vt struct tbl_dat
This structure describes one data cell in a table by specifying
whether it contains a line or data, whether it spans additional
layout cells, and by storing the data.
It is allocated and filled in
.Fn tbl_data
and referenced from the
.Fa first
and
.Fa last
members of
.Vt struct tbl_span .
.Pp
The
.Fa string
and
.Fa next
members may be
.Dv NULL .
The function
.Fn getdata
guarantees that the
.Fa layout
member is not
.Dv NULL .
.El
.Ss Interface functions
The following functions are implemented in
.Pa tbl.c ,
and all callers are in
.Pa roff.c .
.Bl -tag -width Ds
.It Fn tbl_alloc
Allocates, initializes, and returns a new
.Vt struct tbl_node .
Called from
.Fn roff_TS .
.It Fn tbl_read
Dispatches to
.Fn tbl_option ,
.Fn tbl_layout ,
.Fn tbl_cdata ,
and
.Fn tbl_data ,
see below.
Called from
.Fn roff_parseln .
.It Fn tbl_restart
Resets the
.Fa part
member of
.Vt struct tbl_node
to
.Dv TBL_PART_LAYOUT .
Called from
.Fn roff_T_ .
.It Fn tbl_span
On the first call, return the first
.Vt struct tbl_span ;
for later calls, return the next one or
.Dv NULL .
Called from
.Fn roff_span .
.It Fn tbl_end
Flags the last span as
.Dv TBL_SPAN_LAST
and clears the pointer passed as an argment.
Called from
.Fn roff_TE
and
.Fn roff_endparse .
.It Fn tbl_free
Frees the specified
.Vt struct tbl_node
and all the tbl_row, tbl_cell, tbl_span, and tbl_dat structures
referenced from it.
Called from
.Fn roff_free
and
.Fn roff_reset .
.El
.Ss Private functions
The following functions are declared in
.In tbl_int.h .
.Bl -tag -width Ds
.It Ft int Fn tbl_options "struct tbl_node *tbl" "int ln" "const char *p"
Parses the options line into
.Vt struct tbl_opts .
Implemented in
.Pa tbl_opts.c ,
called from
.Fn tbl_read .
.It Ft int Fn tbl_layout "struct tbl_node *tbl" "int ln" "const char *p"
Allocates and fills one
.Vt struct tbl_row
for each layout line and one
.Vt struct tbl_cell
for each layout cell.
Implemented in
.Pa tbl_layout.c ,
called from
.Fn tbl_read .
.It Ft int Fn tbl_data "struct tbl_node *tbl" "int ln" "const char *p"
Allocates one
.Vt struct tbl_span
for each data line and calls
.Fn getdata
for each data cell.
Implemented in
.Pa tbl_data.c ,
called from
.Fn tbl_read .
.It Ft int Fn tbl_cdata "struct tbl_node *tbl" "int ln" "const char *p"
Continues parsing a data line:
When finding
.Sq T} ,
switches back to
.Dv TBL_PART_DATA
mode and calls
.Fn getdata
if there are more data cells on the line.
Otherwise, appends the data to the current data cell.
Implemented in
.Pa tbl_data.c ,
called from
.Fn tbl_read .
.It Xo
.Ft int
.Fo getdata
.Fa "struct tbl_node *tbl"
.Fa "struct tbl_span *dp"
.Fa "int ln"
.Fa "const char *p"
.Fa "int *pos"
.Fc
.Xc
Parses one data cell into one
.Vt struct tbl_dat .
Implemented in
.Pa tbl_data.c ,
called from
.Fn tbl_data
and
.Fn tbl_cdata .
.El
.Sh SEE ALSO
.Xr mandoc 1 ,
.Xr mandoc 3 ,
.Xr tbl 7
.Sh AUTHORS
.An -nosplit
The
.Nm tbl
library was written by
.An Kristaps Dzonsons Aq Mt kristaps@bsd.lv
with contributions from
.An Ingo Schwarze Aq Mt schwarze@openbsd.org .