-.\" $Id: mdoc.3,v 1.42 2010/06/26 15:36:37 kristaps Exp $
+.\" $Id: mdoc.3,v 1.51 2010/12/17 11:41:45 kristaps Exp $
.\"
-.\" Copyright (c) 2009-2010 Kristaps Dzonsons <kristaps@bsd.lv>
+.\" Copyright (c) 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
+.\" Copyright (c) 2010 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
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
-.Dd $Mdocdate: June 26 2010 $
+.Dd $Mdocdate: December 17 2010 $
.Dt MDOC 3
.Os
.Sh NAME
.Nd mdoc macro compiler library
.Sh SYNOPSIS
.In mandoc.h
-.In regs.h
.In mdoc.h
.Vt extern const char * const * mdoc_macronames;
.Vt extern const char * const * mdoc_argnames;
.Ft "struct mdoc *"
-.Fn mdoc_alloc "void *data" "int pflags" "mandocmsg msgs"
+.Fo mdoc_alloc
+.Fa "struct regset *regs"
+.Fa "void *data"
+.Fa "mandocmsg msgs"
+.Fc
.Ft int
.Fn mdoc_endparse "struct mdoc *mdoc"
.Ft void
.Ft int
.Fo mdoc_parseln
.Fa "struct mdoc *mdoc"
-.Fa "const struct regset *regs"
.Fa "int line"
.Fa "char *buf"
.Fc
.Fn mdoc_reset
function may be used in order to reset the parser for another input
sequence.
-See the
-.Sx EXAMPLES
-section for a simple example.
-.Pp
-This section further defines the
-.Sx Types ,
-.Sx Functions
-and
-.Sx Variables
-available to programmers.
-Following that, the
-.Sx Abstract Syntax Tree
-section documents the output tree.
.Ss Types
-Both functions (see
-.Sx Functions )
-and variables (see
-.Sx Variables )
-may use the following types:
.Bl -ohang
.It Vt struct mdoc
-An opaque type defined in
-.Pa mdoc.c .
+An opaque type.
Its values are only used privately within the library.
.It Vt struct mdoc_node
A parsed node.
-Defined in
-.Pa mdoc.h .
See
.Sx Abstract Syntax Tree
for details.
-.It Vt mandocmsg
-A function callback type defined in
-.Pa mandoc.h .
.El
.Ss Functions
-Function descriptions follow:
.Bl -ohang
.It Fn mdoc_alloc
Allocates a parsing structure.
.Fa data
pointer is passed to
.Fa msgs .
-The
-.Fa pflags
-arguments are defined in
-.Pa mdoc.h .
Returns NULL on failure.
If non-NULL, the pointer must be freed with
.Fn mdoc_free .
return 0, the data will be incomplete.
.El
.Ss Variables
-The following variables are also defined:
.Bl -ohang
.It Va mdoc_macronames
An array of string-ified token names.
fields), its position in the tree (the
.Va parent ,
.Va child ,
+.Va nchild ,
.Va next
and
.Va prev
-fields) and some type-specific data.
+fields) and some type-specific data, in particular, for nodes generated
+from macros, the generating macro in the
+.Va tok
+field.
.Pp
The tree itself is arranged according to the following normal form,
where capitalised non-terminals represent nodes.
.It ELEMENT
\(<- TEXT*
.It HEAD
-\(<- mnode+
+\(<- mnode*
.It BODY
-\(<- mnode+
+\(<- mnode* [ENDBODY mnode*]
.It TAIL
-\(<- mnode+
+\(<- mnode*
.It TEXT
\(<- [[:printable:],0x1e]*
.El
Multiple body parts are only found in invocations of
.Sq \&Bl \-column ,
where a new body introduces a new phrase.
+.Ss Badly-nested Blocks
+The ENDBODY node is available to end the formatting associated
+with a given block before the physical end of that block.
+It has a non-null
+.Va end
+field, is of the BODY
+.Va type ,
+has the same
+.Va tok
+as the BLOCK it is ending, and has a
+.Va pending
+field pointing to that BLOCK's BODY node.
+It is an indirect child of that BODY node
+and has no children of its own.
+.Pp
+An ENDBODY node is generated when a block ends while one of its child
+blocks is still open, like in the following example:
+.Bd -literal -offset indent
+\&.Ao ao
+\&.Bo bo ac
+\&.Ac bc
+\&.Bc end
+.Ed
+.Pp
+This example results in the following block structure:
+.Bd -literal -offset indent
+BLOCK Ao
+ HEAD Ao
+ BODY Ao
+ TEXT ao
+ BLOCK Bo, pending -> Ao
+ HEAD Bo
+ BODY Bo
+ TEXT bo
+ TEXT ac
+ ENDBODY Ao, pending -> Ao
+ TEXT bc
+TEXT end
+.Ed
+.Pp
+Here, the formatting of the
+.Sq \&Ao
+block extends from TEXT ao to TEXT ac,
+while the formatting of the
+.Sq \&Bo
+block extends from TEXT bo to TEXT bc.
+It renders as follows in
+.Fl T Ns Cm ascii
+mode:
+.Pp
+.Dl <ao [bo ac> bc] end
+.Pp
+Support for badly-nested blocks is only provided for backward
+compatibility with some older
+.Xr mdoc 7
+implementations.
+Using badly-nested blocks is
+.Em strongly discouraged :
+the
+.Fl T Ns Cm html
+and
+.Fl T Ns Cm xhtml
+front-ends are unable to render them in any meaningful way.
+Furthermore, behaviour when encountering badly-nested blocks is not
+consistent across troff implementations, especially when using multiple
+levels of badly-nested blocks.
.Sh EXAMPLES
The following example reads lines from stdin and parses them, operating
on the finished parse tree with
.Fn parsed .
This example does not error-check nor free memory upon failure.
.Bd -literal -offset indent
+struct regset regs;
struct mdoc *mdoc;
const struct mdoc_node *node;
char *buf;
size_t len;
int line;
+bzero(®s, sizeof(struct regset));
line = 1;
-mdoc = mdoc_alloc(NULL, 0, NULL);
+mdoc = mdoc_alloc(®s, NULL, NULL);
buf = NULL;
alloc_len = 0;
mdoc_free(mdoc);
.Ed
.Pp
-Please see
+To compile this, execute
+.Pp
+.Dl % cc main.c libmdoc.a libmandoc.a
+.Pp
+where
.Pa main.c
-in the source archive for a rigorous reference.
+is the example file.
.Sh SEE ALSO
.Xr mandoc 1 ,
.Xr mdoc 7
git.ckatri.com / mandoc.git / blobdiff