Annotation of mandoc/mdoc.3, Revision 1.44
1.44 ! kristaps 1: .\" $Id: mdoc.3,v 1.43 2010/06/27 15:52:41 kristaps Exp $
1.6 kristaps 2: .\"
1.37 kristaps 3: .\" Copyright (c) 2009-2010 Kristaps Dzonsons <kristaps@bsd.lv>
1.6 kristaps 4: .\"
5: .\" Permission to use, copy, modify, and distribute this software for any
1.28 kristaps 6: .\" purpose with or without fee is hereby granted, provided that the above
7: .\" copyright notice and this permission notice appear in all copies.
1.6 kristaps 8: .\"
1.28 kristaps 9: .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10: .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11: .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12: .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13: .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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1.33 kristaps 16: .\"
1.44 ! kristaps 17: .Dd $Mdocdate: June 27 2010 $
1.27 kristaps 18: .Dt MDOC 3
1.1 kristaps 19: .Os
20: .Sh NAME
1.39 kristaps 21: .Nm mdoc ,
1.1 kristaps 22: .Nm mdoc_alloc ,
23: .Nm mdoc_endparse ,
1.38 kristaps 24: .Nm mdoc_free ,
25: .Nm mdoc_meta ,
1.4 kristaps 26: .Nm mdoc_node ,
1.38 kristaps 27: .Nm mdoc_parseln ,
1.20 kristaps 28: .Nm mdoc_reset
1.2 kristaps 29: .Nd mdoc macro compiler library
1.1 kristaps 30: .Sh SYNOPSIS
1.38 kristaps 31: .In mandoc.h
1.42 kristaps 32: .In regs.h
1.35 kristaps 33: .In mdoc.h
1.4 kristaps 34: .Vt extern const char * const * mdoc_macronames;
35: .Vt extern const char * const * mdoc_argnames;
1.1 kristaps 36: .Ft "struct mdoc *"
1.43 kristaps 37: .Fo mdoc_alloc
1.44 ! kristaps 38: .Fa "struct regset *regs"
1.43 kristaps 39: .Fa "void *data"
40: .Fa "int pflags"
41: .Fa "mandocmsg msgs"
42: .Fc
1.26 kristaps 43: .Ft int
1.38 kristaps 44: .Fn mdoc_endparse "struct mdoc *mdoc"
1.1 kristaps 45: .Ft void
1.2 kristaps 46: .Fn mdoc_free "struct mdoc *mdoc"
1.38 kristaps 47: .Ft "const struct mdoc_meta *"
48: .Fn mdoc_meta "const struct mdoc *mdoc"
49: .Ft "const struct mdoc_node *"
50: .Fn mdoc_node "const struct mdoc *mdoc"
1.1 kristaps 51: .Ft int
1.42 kristaps 52: .Fo mdoc_parseln
53: .Fa "struct mdoc *mdoc"
54: .Fa "int line"
55: .Fa "char *buf"
56: .Fc
1.1 kristaps 57: .Ft int
1.38 kristaps 58: .Fn mdoc_reset "struct mdoc *mdoc"
1.1 kristaps 59: .Sh DESCRIPTION
60: The
61: .Nm mdoc
1.33 kristaps 62: library parses lines of
1.17 kristaps 63: .Xr mdoc 7
1.38 kristaps 64: input
65: into an abstract syntax tree (AST).
1.6 kristaps 66: .Pp
1.1 kristaps 67: In general, applications initiate a parsing sequence with
68: .Fn mdoc_alloc ,
1.33 kristaps 69: parse each line in a document with
1.1 kristaps 70: .Fn mdoc_parseln ,
71: close the parsing session with
72: .Fn mdoc_endparse ,
73: operate over the syntax tree returned by
1.33 kristaps 74: .Fn mdoc_node
1.4 kristaps 75: and
76: .Fn mdoc_meta ,
1.1 kristaps 77: then free all allocated memory with
78: .Fn mdoc_free .
1.20 kristaps 79: The
80: .Fn mdoc_reset
81: function may be used in order to reset the parser for another input
1.38 kristaps 82: sequence.
83: See the
1.1 kristaps 84: .Sx EXAMPLES
1.38 kristaps 85: section for a simple example.
1.2 kristaps 86: .Pp
1.33 kristaps 87: This section further defines the
1.6 kristaps 88: .Sx Types ,
1.33 kristaps 89: .Sx Functions
1.6 kristaps 90: and
91: .Sx Variables
1.38 kristaps 92: available to programmers.
93: Following that, the
1.33 kristaps 94: .Sx Abstract Syntax Tree
1.17 kristaps 95: section documents the output tree.
1.6 kristaps 96: .Ss Types
97: Both functions (see
98: .Sx Functions )
99: and variables (see
100: .Sx Variables )
101: may use the following types:
1.37 kristaps 102: .Bl -ohang
1.6 kristaps 103: .It Vt struct mdoc
104: An opaque type defined in
105: .Pa mdoc.c .
106: Its values are only used privately within the library.
107: .It Vt struct mdoc_node
1.38 kristaps 108: A parsed node.
109: Defined in
1.6 kristaps 110: .Pa mdoc.h .
1.33 kristaps 111: See
1.6 kristaps 112: .Sx Abstract Syntax Tree
113: for details.
1.38 kristaps 114: .It Vt mandocmsg
115: A function callback type defined in
116: .Pa mandoc.h .
1.6 kristaps 117: .El
118: .Ss Functions
1.2 kristaps 119: Function descriptions follow:
1.37 kristaps 120: .Bl -ohang
1.2 kristaps 121: .It Fn mdoc_alloc
1.38 kristaps 122: Allocates a parsing structure.
123: The
1.2 kristaps 124: .Fa data
1.40 kristaps 125: pointer is passed to
126: .Fa msgs .
1.20 kristaps 127: The
128: .Fa pflags
129: arguments are defined in
130: .Pa mdoc.h .
1.38 kristaps 131: Returns NULL on failure.
132: If non-NULL, the pointer must be freed with
1.2 kristaps 133: .Fn mdoc_free .
1.20 kristaps 134: .It Fn mdoc_reset
1.38 kristaps 135: Reset the parser for another parse routine.
136: After its use,
1.20 kristaps 137: .Fn mdoc_parseln
1.38 kristaps 138: behaves as if invoked for the first time.
139: If it returns 0, memory could not be allocated.
1.2 kristaps 140: .It Fn mdoc_free
1.38 kristaps 141: Free all resources of a parser.
142: The pointer is no longer valid after invocation.
1.2 kristaps 143: .It Fn mdoc_parseln
1.38 kristaps 144: Parse a nil-terminated line of input.
145: This line should not contain the trailing newline.
146: Returns 0 on failure, 1 on success.
147: The input buffer
1.2 kristaps 148: .Fa buf
149: is modified by this function.
150: .It Fn mdoc_endparse
1.38 kristaps 151: Signals that the parse is complete.
152: Note that if
1.2 kristaps 153: .Fn mdoc_endparse
154: is called subsequent to
1.4 kristaps 155: .Fn mdoc_node ,
1.38 kristaps 156: the resulting tree is incomplete.
157: Returns 0 on failure, 1 on success.
1.4 kristaps 158: .It Fn mdoc_node
1.38 kristaps 159: Returns the first node of the parse.
160: Note that if
1.2 kristaps 161: .Fn mdoc_parseln
162: or
163: .Fn mdoc_endparse
164: return 0, the tree will be incomplete.
1.4 kristaps 165: .It Fn mdoc_meta
1.38 kristaps 166: Returns the document's parsed meta-data.
167: If this information has not yet been supplied or
1.4 kristaps 168: .Fn mdoc_parseln
169: or
170: .Fn mdoc_endparse
171: return 0, the data will be incomplete.
172: .El
1.6 kristaps 173: .Ss Variables
1.4 kristaps 174: The following variables are also defined:
1.37 kristaps 175: .Bl -ohang
1.4 kristaps 176: .It Va mdoc_macronames
177: An array of string-ified token names.
178: .It Va mdoc_argnames
179: An array of string-ified token argument names.
1.2 kristaps 180: .El
1.6 kristaps 181: .Ss Abstract Syntax Tree
1.33 kristaps 182: The
1.6 kristaps 183: .Nm
1.17 kristaps 184: functions produce an abstract syntax tree (AST) describing input in a
1.38 kristaps 185: regular form.
186: It may be reviewed at any time with
1.6 kristaps 187: .Fn mdoc_nodes ;
188: however, if called before
189: .Fn mdoc_endparse ,
190: or after
1.33 kristaps 191: .Fn mdoc_endparse
1.6 kristaps 192: or
193: .Fn mdoc_parseln
1.33 kristaps 194: fail, it may be incomplete.
1.18 kristaps 195: .Pp
196: This AST is governed by the ontological
1.17 kristaps 197: rules dictated in
198: .Xr mdoc 7
1.33 kristaps 199: and derives its terminology accordingly.
1.17 kristaps 200: .Qq In-line
201: elements described in
202: .Xr mdoc 7
1.33 kristaps 203: are described simply as
1.17 kristaps 204: .Qq elements .
1.6 kristaps 205: .Pp
1.33 kristaps 206: The AST is composed of
1.6 kristaps 207: .Vt struct mdoc_node
208: nodes with block, head, body, element, root and text types as declared
209: by the
210: .Va type
1.38 kristaps 211: field.
212: Each node also provides its parse point (the
1.6 kristaps 213: .Va line ,
214: .Va sec ,
215: and
216: .Va pos
217: fields), its position in the tree (the
218: .Va parent ,
219: .Va child ,
1.33 kristaps 220: .Va next
1.6 kristaps 221: and
1.33 kristaps 222: .Va prev
1.25 kristaps 223: fields) and some type-specific data.
1.6 kristaps 224: .Pp
225: The tree itself is arranged according to the following normal form,
226: where capitalised non-terminals represent nodes.
227: .Pp
1.37 kristaps 228: .Bl -tag -width "ELEMENTXX" -compact
1.6 kristaps 229: .It ROOT
230: \(<- mnode+
231: .It mnode
232: \(<- BLOCK | ELEMENT | TEXT
233: .It BLOCK
1.41 kristaps 234: \(<- HEAD [TEXT] (BODY [TEXT])+ [TAIL [TEXT]]
1.6 kristaps 235: .It ELEMENT
236: \(<- TEXT*
237: .It HEAD
238: \(<- mnode+
239: .It BODY
240: \(<- mnode+
241: .It TAIL
242: \(<- mnode+
243: .It TEXT
1.38 kristaps 244: \(<- [[:printable:],0x1e]*
1.6 kristaps 245: .El
1.2 kristaps 246: .Pp
1.6 kristaps 247: Of note are the TEXT nodes following the HEAD, BODY and TAIL nodes of
1.41 kristaps 248: the BLOCK production: these refer to punctuation marks.
1.38 kristaps 249: Furthermore, although a TEXT node will generally have a non-zero-length
250: string, in the specific case of
1.8 kristaps 251: .Sq \&.Bd \-literal ,
1.6 kristaps 252: an empty line will produce a zero-length string.
1.41 kristaps 253: Multiple body parts are only found in invocations of
254: .Sq \&Bl \-column ,
255: where a new body introduces a new phrase.
1.2 kristaps 256: .Sh EXAMPLES
257: The following example reads lines from stdin and parses them, operating
1.33 kristaps 258: on the finished parse tree with
1.2 kristaps 259: .Fn parsed .
1.37 kristaps 260: This example does not error-check nor free memory upon failure.
261: .Bd -literal -offset indent
1.44 ! kristaps 262: struct regset regs;
1.2 kristaps 263: struct mdoc *mdoc;
1.31 kristaps 264: const struct mdoc_node *node;
1.2 kristaps 265: char *buf;
266: size_t len;
267: int line;
268:
1.44 ! kristaps 269: bzero(®s, sizeof(struct regset));
1.2 kristaps 270: line = 1;
1.44 ! kristaps 271: mdoc = mdoc_alloc(®s, NULL, 0, NULL);
1.37 kristaps 272: buf = NULL;
273: alloc_len = 0;
1.2 kristaps 274:
1.37 kristaps 275: while ((len = getline(&buf, &alloc_len, stdin)) >= 0) {
276: if (len && buflen[len - 1] = '\en')
277: buf[len - 1] = '\e0';
278: if ( ! mdoc_parseln(mdoc, line, buf))
279: errx(1, "mdoc_parseln");
280: line++;
1.2 kristaps 281: }
282:
283: if ( ! mdoc_endparse(mdoc))
1.37 kristaps 284: errx(1, "mdoc_endparse");
1.4 kristaps 285: if (NULL == (node = mdoc_node(mdoc)))
1.37 kristaps 286: errx(1, "mdoc_node");
1.2 kristaps 287:
288: parsed(mdoc, node);
289: mdoc_free(mdoc);
290: .Ed
1.38 kristaps 291: .Pp
292: Please see
293: .Pa main.c
294: in the source archive for a rigorous reference.
1.17 kristaps 295: .Sh SEE ALSO
1.20 kristaps 296: .Xr mandoc 1 ,
1.14 kristaps 297: .Xr mdoc 7
1.2 kristaps 298: .Sh AUTHORS
299: The
300: .Nm
1.38 kristaps 301: library was written by
1.37 kristaps 302: .An Kristaps Dzonsons Aq kristaps@bsd.lv .
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