xref: /freebsd/contrib/mandoc/mdoc_markdown.c (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71)
1 /*	$Id: mdoc_markdown.c,v 1.31 2019/07/01 22:56:24 schwarze Exp $ */
2 /*
3  * Copyright (c) 2017, 2018 Ingo Schwarze <schwarze@openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS 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
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 #include <sys/types.h>
18 
19 #include <assert.h>
20 #include <ctype.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 
25 #include "mandoc_aux.h"
26 #include "mandoc.h"
27 #include "roff.h"
28 #include "mdoc.h"
29 #include "main.h"
30 
31 struct	md_act {
32 	int		(*cond)(struct roff_node *n);
33 	int		(*pre)(struct roff_node *n);
34 	void		(*post)(struct roff_node *n);
35 	const char	 *prefix; /* pre-node string constant */
36 	const char	 *suffix; /* post-node string constant */
37 };
38 
39 static	void	 md_nodelist(struct roff_node *);
40 static	void	 md_node(struct roff_node *);
41 static	const char *md_stack(char c);
42 static	void	 md_preword(void);
43 static	void	 md_rawword(const char *);
44 static	void	 md_word(const char *);
45 static	void	 md_named(const char *);
46 static	void	 md_char(unsigned char);
47 static	void	 md_uri(const char *);
48 
49 static	int	 md_cond_head(struct roff_node *);
50 static	int	 md_cond_body(struct roff_node *);
51 
52 static	int	 md_pre_abort(struct roff_node *);
53 static	int	 md_pre_raw(struct roff_node *);
54 static	int	 md_pre_word(struct roff_node *);
55 static	int	 md_pre_skip(struct roff_node *);
56 static	void	 md_pre_syn(struct roff_node *);
57 static	int	 md_pre_An(struct roff_node *);
58 static	int	 md_pre_Ap(struct roff_node *);
59 static	int	 md_pre_Bd(struct roff_node *);
60 static	int	 md_pre_Bk(struct roff_node *);
61 static	int	 md_pre_Bl(struct roff_node *);
62 static	int	 md_pre_D1(struct roff_node *);
63 static	int	 md_pre_Dl(struct roff_node *);
64 static	int	 md_pre_En(struct roff_node *);
65 static	int	 md_pre_Eo(struct roff_node *);
66 static	int	 md_pre_Fa(struct roff_node *);
67 static	int	 md_pre_Fd(struct roff_node *);
68 static	int	 md_pre_Fn(struct roff_node *);
69 static	int	 md_pre_Fo(struct roff_node *);
70 static	int	 md_pre_In(struct roff_node *);
71 static	int	 md_pre_It(struct roff_node *);
72 static	int	 md_pre_Lk(struct roff_node *);
73 static	int	 md_pre_Mt(struct roff_node *);
74 static	int	 md_pre_Nd(struct roff_node *);
75 static	int	 md_pre_Nm(struct roff_node *);
76 static	int	 md_pre_No(struct roff_node *);
77 static	int	 md_pre_Ns(struct roff_node *);
78 static	int	 md_pre_Pp(struct roff_node *);
79 static	int	 md_pre_Rs(struct roff_node *);
80 static	int	 md_pre_Sh(struct roff_node *);
81 static	int	 md_pre_Sm(struct roff_node *);
82 static	int	 md_pre_Vt(struct roff_node *);
83 static	int	 md_pre_Xr(struct roff_node *);
84 static	int	 md_pre__T(struct roff_node *);
85 static	int	 md_pre_br(struct roff_node *);
86 
87 static	void	 md_post_raw(struct roff_node *);
88 static	void	 md_post_word(struct roff_node *);
89 static	void	 md_post_pc(struct roff_node *);
90 static	void	 md_post_Bk(struct roff_node *);
91 static	void	 md_post_Bl(struct roff_node *);
92 static	void	 md_post_D1(struct roff_node *);
93 static	void	 md_post_En(struct roff_node *);
94 static	void	 md_post_Eo(struct roff_node *);
95 static	void	 md_post_Fa(struct roff_node *);
96 static	void	 md_post_Fd(struct roff_node *);
97 static	void	 md_post_Fl(struct roff_node *);
98 static	void	 md_post_Fn(struct roff_node *);
99 static	void	 md_post_Fo(struct roff_node *);
100 static	void	 md_post_In(struct roff_node *);
101 static	void	 md_post_It(struct roff_node *);
102 static	void	 md_post_Lb(struct roff_node *);
103 static	void	 md_post_Nm(struct roff_node *);
104 static	void	 md_post_Pf(struct roff_node *);
105 static	void	 md_post_Vt(struct roff_node *);
106 static	void	 md_post__T(struct roff_node *);
107 
108 static	const struct md_act md_acts[MDOC_MAX - MDOC_Dd] = {
109 	{ NULL, NULL, NULL, NULL, NULL }, /* Dd */
110 	{ NULL, NULL, NULL, NULL, NULL }, /* Dt */
111 	{ NULL, NULL, NULL, NULL, NULL }, /* Os */
112 	{ NULL, md_pre_Sh, NULL, NULL, NULL }, /* Sh */
113 	{ NULL, md_pre_Sh, NULL, NULL, NULL }, /* Ss */
114 	{ NULL, md_pre_Pp, NULL, NULL, NULL }, /* Pp */
115 	{ md_cond_body, md_pre_D1, md_post_D1, NULL, NULL }, /* D1 */
116 	{ md_cond_body, md_pre_Dl, md_post_D1, NULL, NULL }, /* Dl */
117 	{ md_cond_body, md_pre_Bd, md_post_D1, NULL, NULL }, /* Bd */
118 	{ NULL, NULL, NULL, NULL, NULL }, /* Ed */
119 	{ md_cond_body, md_pre_Bl, md_post_Bl, NULL, NULL }, /* Bl */
120 	{ NULL, NULL, NULL, NULL, NULL }, /* El */
121 	{ NULL, md_pre_It, md_post_It, NULL, NULL }, /* It */
122 	{ NULL, md_pre_raw, md_post_raw, "*", "*" }, /* Ad */
123 	{ NULL, md_pre_An, NULL, NULL, NULL }, /* An */
124 	{ NULL, md_pre_Ap, NULL, NULL, NULL }, /* Ap */
125 	{ NULL, md_pre_raw, md_post_raw, "*", "*" }, /* Ar */
126 	{ NULL, md_pre_raw, md_post_raw, "**", "**" }, /* Cd */
127 	{ NULL, md_pre_raw, md_post_raw, "**", "**" }, /* Cm */
128 	{ NULL, md_pre_raw, md_post_raw, "`", "`" }, /* Dv */
129 	{ NULL, md_pre_raw, md_post_raw, "`", "`" }, /* Er */
130 	{ NULL, md_pre_raw, md_post_raw, "`", "`" }, /* Ev */
131 	{ NULL, NULL, NULL, NULL, NULL }, /* Ex */
132 	{ NULL, md_pre_Fa, md_post_Fa, NULL, NULL }, /* Fa */
133 	{ NULL, md_pre_Fd, md_post_Fd, "**", "**" }, /* Fd */
134 	{ NULL, md_pre_raw, md_post_Fl, "**-", "**" }, /* Fl */
135 	{ NULL, md_pre_Fn, md_post_Fn, NULL, NULL }, /* Fn */
136 	{ NULL, md_pre_Fd, md_post_raw, "*", "*" }, /* Ft */
137 	{ NULL, md_pre_raw, md_post_raw, "**", "**" }, /* Ic */
138 	{ NULL, md_pre_In, md_post_In, NULL, NULL }, /* In */
139 	{ NULL, md_pre_raw, md_post_raw, "`", "`" }, /* Li */
140 	{ md_cond_head, md_pre_Nd, NULL, NULL, NULL }, /* Nd */
141 	{ NULL, md_pre_Nm, md_post_Nm, "**", "**" }, /* Nm */
142 	{ md_cond_body, md_pre_word, md_post_word, "[", "]" }, /* Op */
143 	{ NULL, md_pre_abort, NULL, NULL, NULL }, /* Ot */
144 	{ NULL, md_pre_raw, md_post_raw, "*", "*" }, /* Pa */
145 	{ NULL, NULL, NULL, NULL, NULL }, /* Rv */
146 	{ NULL, NULL, NULL, NULL, NULL }, /* St */
147 	{ NULL, md_pre_raw, md_post_raw, "*", "*" }, /* Va */
148 	{ NULL, md_pre_Vt, md_post_Vt, "*", "*" }, /* Vt */
149 	{ NULL, md_pre_Xr, NULL, NULL, NULL }, /* Xr */
150 	{ NULL, NULL, md_post_pc, NULL, NULL }, /* %A */
151 	{ NULL, md_pre_raw, md_post_pc, "*", "*" }, /* %B */
152 	{ NULL, NULL, md_post_pc, NULL, NULL }, /* %D */
153 	{ NULL, md_pre_raw, md_post_pc, "*", "*" }, /* %I */
154 	{ NULL, md_pre_raw, md_post_pc, "*", "*" }, /* %J */
155 	{ NULL, NULL, md_post_pc, NULL, NULL }, /* %N */
156 	{ NULL, NULL, md_post_pc, NULL, NULL }, /* %O */
157 	{ NULL, NULL, md_post_pc, NULL, NULL }, /* %P */
158 	{ NULL, NULL, md_post_pc, NULL, NULL }, /* %R */
159 	{ NULL, md_pre__T, md_post__T, NULL, NULL }, /* %T */
160 	{ NULL, NULL, md_post_pc, NULL, NULL }, /* %V */
161 	{ NULL, NULL, NULL, NULL, NULL }, /* Ac */
162 	{ md_cond_body, md_pre_word, md_post_word, "<", ">" }, /* Ao */
163 	{ md_cond_body, md_pre_word, md_post_word, "<", ">" }, /* Aq */
164 	{ NULL, NULL, NULL, NULL, NULL }, /* At */
165 	{ NULL, NULL, NULL, NULL, NULL }, /* Bc */
166 	{ NULL, NULL, NULL, NULL, NULL }, /* Bf XXX not implemented */
167 	{ md_cond_body, md_pre_word, md_post_word, "[", "]" }, /* Bo */
168 	{ md_cond_body, md_pre_word, md_post_word, "[", "]" }, /* Bq */
169 	{ NULL, NULL, NULL, NULL, NULL }, /* Bsx */
170 	{ NULL, NULL, NULL, NULL, NULL }, /* Bx */
171 	{ NULL, NULL, NULL, NULL, NULL }, /* Db */
172 	{ NULL, NULL, NULL, NULL, NULL }, /* Dc */
173 	{ md_cond_body, md_pre_word, md_post_word, "\"", "\"" }, /* Do */
174 	{ md_cond_body, md_pre_word, md_post_word, "\"", "\"" }, /* Dq */
175 	{ NULL, NULL, NULL, NULL, NULL }, /* Ec */
176 	{ NULL, NULL, NULL, NULL, NULL }, /* Ef */
177 	{ NULL, md_pre_raw, md_post_raw, "*", "*" }, /* Em */
178 	{ md_cond_body, md_pre_Eo, md_post_Eo, NULL, NULL }, /* Eo */
179 	{ NULL, NULL, NULL, NULL, NULL }, /* Fx */
180 	{ NULL, md_pre_raw, md_post_raw, "**", "**" }, /* Ms */
181 	{ NULL, md_pre_No, NULL, NULL, NULL }, /* No */
182 	{ NULL, md_pre_Ns, NULL, NULL, NULL }, /* Ns */
183 	{ NULL, NULL, NULL, NULL, NULL }, /* Nx */
184 	{ NULL, NULL, NULL, NULL, NULL }, /* Ox */
185 	{ NULL, NULL, NULL, NULL, NULL }, /* Pc */
186 	{ NULL, NULL, md_post_Pf, NULL, NULL }, /* Pf */
187 	{ md_cond_body, md_pre_word, md_post_word, "(", ")" }, /* Po */
188 	{ md_cond_body, md_pre_word, md_post_word, "(", ")" }, /* Pq */
189 	{ NULL, NULL, NULL, NULL, NULL }, /* Qc */
190 	{ md_cond_body, md_pre_raw, md_post_raw, "'`", "`'" }, /* Ql */
191 	{ md_cond_body, md_pre_word, md_post_word, "\"", "\"" }, /* Qo */
192 	{ md_cond_body, md_pre_word, md_post_word, "\"", "\"" }, /* Qq */
193 	{ NULL, NULL, NULL, NULL, NULL }, /* Re */
194 	{ md_cond_body, md_pre_Rs, NULL, NULL, NULL }, /* Rs */
195 	{ NULL, NULL, NULL, NULL, NULL }, /* Sc */
196 	{ md_cond_body, md_pre_word, md_post_word, "'", "'" }, /* So */
197 	{ md_cond_body, md_pre_word, md_post_word, "'", "'" }, /* Sq */
198 	{ NULL, md_pre_Sm, NULL, NULL, NULL }, /* Sm */
199 	{ NULL, md_pre_raw, md_post_raw, "*", "*" }, /* Sx */
200 	{ NULL, md_pre_raw, md_post_raw, "**", "**" }, /* Sy */
201 	{ NULL, md_pre_raw, md_post_raw, "`", "`" }, /* Tn */
202 	{ NULL, NULL, NULL, NULL, NULL }, /* Ux */
203 	{ NULL, NULL, NULL, NULL, NULL }, /* Xc */
204 	{ NULL, NULL, NULL, NULL, NULL }, /* Xo */
205 	{ NULL, md_pre_Fo, md_post_Fo, "**", "**" }, /* Fo */
206 	{ NULL, NULL, NULL, NULL, NULL }, /* Fc */
207 	{ md_cond_body, md_pre_word, md_post_word, "[", "]" }, /* Oo */
208 	{ NULL, NULL, NULL, NULL, NULL }, /* Oc */
209 	{ NULL, md_pre_Bk, md_post_Bk, NULL, NULL }, /* Bk */
210 	{ NULL, NULL, NULL, NULL, NULL }, /* Ek */
211 	{ NULL, NULL, NULL, NULL, NULL }, /* Bt */
212 	{ NULL, NULL, NULL, NULL, NULL }, /* Hf */
213 	{ NULL, md_pre_raw, md_post_raw, "*", "*" }, /* Fr */
214 	{ NULL, NULL, NULL, NULL, NULL }, /* Ud */
215 	{ NULL, NULL, md_post_Lb, NULL, NULL }, /* Lb */
216 	{ NULL, md_pre_abort, NULL, NULL, NULL }, /* Lp */
217 	{ NULL, md_pre_Lk, NULL, NULL, NULL }, /* Lk */
218 	{ NULL, md_pre_Mt, NULL, NULL, NULL }, /* Mt */
219 	{ md_cond_body, md_pre_word, md_post_word, "{", "}" }, /* Brq */
220 	{ md_cond_body, md_pre_word, md_post_word, "{", "}" }, /* Bro */
221 	{ NULL, NULL, NULL, NULL, NULL }, /* Brc */
222 	{ NULL, NULL, md_post_pc, NULL, NULL }, /* %C */
223 	{ NULL, md_pre_skip, NULL, NULL, NULL }, /* Es */
224 	{ md_cond_body, md_pre_En, md_post_En, NULL, NULL }, /* En */
225 	{ NULL, NULL, NULL, NULL, NULL }, /* Dx */
226 	{ NULL, NULL, md_post_pc, NULL, NULL }, /* %Q */
227 	{ NULL, md_pre_Lk, md_post_pc, NULL, NULL }, /* %U */
228 	{ NULL, NULL, NULL, NULL, NULL }, /* Ta */
229 };
230 static const struct md_act *md_act(enum roff_tok);
231 
232 static	int	 outflags;
233 #define	MD_spc		 (1 << 0)  /* Blank character before next word. */
234 #define	MD_spc_force	 (1 << 1)  /* Even before trailing punctuation. */
235 #define	MD_nonl		 (1 << 2)  /* Prevent linebreak in markdown code. */
236 #define	MD_nl		 (1 << 3)  /* Break markdown code line. */
237 #define	MD_br		 (1 << 4)  /* Insert an output line break. */
238 #define	MD_sp		 (1 << 5)  /* Insert a paragraph break. */
239 #define	MD_Sm		 (1 << 6)  /* Horizontal spacing mode. */
240 #define	MD_Bk		 (1 << 7)  /* Word keep mode. */
241 #define	MD_An_split	 (1 << 8)  /* Author mode is "split". */
242 #define	MD_An_nosplit	 (1 << 9)  /* Author mode is "nosplit". */
243 
244 static	int	 escflags; /* Escape in generated markdown code: */
245 #define	ESC_BOL	 (1 << 0)  /* "#*+-" near the beginning of a line. */
246 #define	ESC_NUM	 (1 << 1)  /* "." after a leading number. */
247 #define	ESC_HYP	 (1 << 2)  /* "(" immediately after "]". */
248 #define	ESC_SQU	 (1 << 4)  /* "]" when "[" is open. */
249 #define	ESC_FON	 (1 << 5)  /* "*" immediately after unrelated "*". */
250 #define	ESC_EOL	 (1 << 6)  /* " " at the and of a line. */
251 
252 static	int	 code_blocks, quote_blocks, list_blocks;
253 static	int	 outcount;
254 
255 
256 static const struct md_act *
257 md_act(enum roff_tok tok)
258 {
259 	assert(tok >= MDOC_Dd && tok <= MDOC_MAX);
260 	return md_acts + (tok - MDOC_Dd);
261 }
262 
263 void
264 markdown_mdoc(void *arg, const struct roff_meta *mdoc)
265 {
266 	outflags = MD_Sm;
267 	md_word(mdoc->title);
268 	if (mdoc->msec != NULL) {
269 		outflags &= ~MD_spc;
270 		md_word("(");
271 		md_word(mdoc->msec);
272 		md_word(")");
273 	}
274 	md_word("-");
275 	md_word(mdoc->vol);
276 	if (mdoc->arch != NULL) {
277 		md_word("(");
278 		md_word(mdoc->arch);
279 		md_word(")");
280 	}
281 	outflags |= MD_sp;
282 
283 	md_nodelist(mdoc->first->child);
284 
285 	outflags |= MD_sp;
286 	md_word(mdoc->os);
287 	md_word("-");
288 	md_word(mdoc->date);
289 	putchar('\n');
290 }
291 
292 static void
293 md_nodelist(struct roff_node *n)
294 {
295 	while (n != NULL) {
296 		md_node(n);
297 		n = n->next;
298 	}
299 }
300 
301 static void
302 md_node(struct roff_node *n)
303 {
304 	const struct md_act	*act;
305 	int			 cond, process_children;
306 
307 	if (n->type == ROFFT_COMMENT || n->flags & NODE_NOPRT)
308 		return;
309 
310 	if (outflags & MD_nonl)
311 		outflags &= ~(MD_nl | MD_sp);
312 	else if (outflags & MD_spc && n->flags & NODE_LINE)
313 		outflags |= MD_nl;
314 
315 	act = NULL;
316 	cond = 0;
317 	process_children = 1;
318 	n->flags &= ~NODE_ENDED;
319 
320 	if (n->type == ROFFT_TEXT) {
321 		if (n->flags & NODE_DELIMC)
322 			outflags &= ~(MD_spc | MD_spc_force);
323 		else if (outflags & MD_Sm)
324 			outflags |= MD_spc_force;
325 		md_word(n->string);
326 		if (n->flags & NODE_DELIMO)
327 			outflags &= ~(MD_spc | MD_spc_force);
328 		else if (outflags & MD_Sm)
329 			outflags |= MD_spc;
330 	} else if (n->tok < ROFF_MAX) {
331 		switch (n->tok) {
332 		case ROFF_br:
333 			process_children = md_pre_br(n);
334 			break;
335 		case ROFF_sp:
336 			process_children = md_pre_Pp(n);
337 			break;
338 		default:
339 			process_children = 0;
340 			break;
341 		}
342 	} else {
343 		act = md_act(n->tok);
344 		cond = act->cond == NULL || (*act->cond)(n);
345 		if (cond && act->pre != NULL &&
346 		    (n->end == ENDBODY_NOT || n->child != NULL))
347 			process_children = (*act->pre)(n);
348 	}
349 
350 	if (process_children && n->child != NULL)
351 		md_nodelist(n->child);
352 
353 	if (n->flags & NODE_ENDED)
354 		return;
355 
356 	if (cond && act->post != NULL)
357 		(*act->post)(n);
358 
359 	if (n->end != ENDBODY_NOT)
360 		n->body->flags |= NODE_ENDED;
361 }
362 
363 static const char *
364 md_stack(char c)
365 {
366 	static char	*stack;
367 	static size_t	 sz;
368 	static size_t	 cur;
369 
370 	switch (c) {
371 	case '\0':
372 		break;
373 	case (char)-1:
374 		assert(cur);
375 		stack[--cur] = '\0';
376 		break;
377 	default:
378 		if (cur + 1 >= sz) {
379 			sz += 8;
380 			stack = mandoc_realloc(stack, sz);
381 		}
382 		stack[cur] = c;
383 		stack[++cur] = '\0';
384 		break;
385 	}
386 	return stack == NULL ? "" : stack;
387 }
388 
389 /*
390  * Handle vertical and horizontal spacing.
391  */
392 static void
393 md_preword(void)
394 {
395 	const char	*cp;
396 
397 	/*
398 	 * If a list block is nested inside a code block or a blockquote,
399 	 * blank lines for paragraph breaks no longer work; instead,
400 	 * they terminate the list.  Work around this markdown issue
401 	 * by using mere line breaks instead.
402 	 */
403 
404 	if (list_blocks && outflags & MD_sp) {
405 		outflags &= ~MD_sp;
406 		outflags |= MD_br;
407 	}
408 
409 	/*
410 	 * End the old line if requested.
411 	 * Escape whitespace at the end of the markdown line
412 	 * such that it won't look like an output line break.
413 	 */
414 
415 	if (outflags & MD_sp)
416 		putchar('\n');
417 	else if (outflags & MD_br) {
418 		putchar(' ');
419 		putchar(' ');
420 	} else if (outflags & MD_nl && escflags & ESC_EOL)
421 		md_named("zwnj");
422 
423 	/* Start a new line if necessary. */
424 
425 	if (outflags & (MD_nl | MD_br | MD_sp)) {
426 		putchar('\n');
427 		for (cp = md_stack('\0'); *cp != '\0'; cp++) {
428 			putchar(*cp);
429 			if (*cp == '>')
430 				putchar(' ');
431 		}
432 		outflags &= ~(MD_nl | MD_br | MD_sp);
433 		escflags = ESC_BOL;
434 		outcount = 0;
435 
436 	/* Handle horizontal spacing. */
437 
438 	} else if (outflags & MD_spc) {
439 		if (outflags & MD_Bk)
440 			fputs("&nbsp;", stdout);
441 		else
442 			putchar(' ');
443 		escflags &= ~ESC_FON;
444 		outcount++;
445 	}
446 
447 	outflags &= ~(MD_spc_force | MD_nonl);
448 	if (outflags & MD_Sm)
449 		outflags |= MD_spc;
450 	else
451 		outflags &= ~MD_spc;
452 }
453 
454 /*
455  * Print markdown syntax elements.
456  * Can also be used for constant strings when neither escaping
457  * nor delimiter handling is required.
458  */
459 static void
460 md_rawword(const char *s)
461 {
462 	md_preword();
463 
464 	if (*s == '\0')
465 		return;
466 
467 	if (escflags & ESC_FON) {
468 		escflags &= ~ESC_FON;
469 		if (*s == '*' && !code_blocks)
470 			fputs("&zwnj;", stdout);
471 	}
472 
473 	while (*s != '\0') {
474 		switch(*s) {
475 		case '*':
476 			if (s[1] == '\0')
477 				escflags |= ESC_FON;
478 			break;
479 		case '[':
480 			escflags |= ESC_SQU;
481 			break;
482 		case ']':
483 			escflags |= ESC_HYP;
484 			escflags &= ~ESC_SQU;
485 			break;
486 		default:
487 			break;
488 		}
489 		md_char(*s++);
490 	}
491 	if (s[-1] == ' ')
492 		escflags |= ESC_EOL;
493 	else
494 		escflags &= ~ESC_EOL;
495 }
496 
497 /*
498  * Print text and mdoc(7) syntax elements.
499  */
500 static void
501 md_word(const char *s)
502 {
503 	const char	*seq, *prevfont, *currfont, *nextfont;
504 	char		 c;
505 	int		 bs, sz, uc, breakline;
506 
507 	/* No spacing before closing delimiters. */
508 	if (s[0] != '\0' && s[1] == '\0' &&
509 	    strchr("!),.:;?]", s[0]) != NULL &&
510 	    (outflags & MD_spc_force) == 0)
511 		outflags &= ~MD_spc;
512 
513 	md_preword();
514 
515 	if (*s == '\0')
516 		return;
517 
518 	/* No spacing after opening delimiters. */
519 	if ((s[0] == '(' || s[0] == '[') && s[1] == '\0')
520 		outflags &= ~MD_spc;
521 
522 	breakline = 0;
523 	prevfont = currfont = "";
524 	while ((c = *s++) != '\0') {
525 		bs = 0;
526 		switch(c) {
527 		case ASCII_NBRSP:
528 			if (code_blocks)
529 				c = ' ';
530 			else {
531 				md_named("nbsp");
532 				c = '\0';
533 			}
534 			break;
535 		case ASCII_HYPH:
536 			bs = escflags & ESC_BOL && !code_blocks;
537 			c = '-';
538 			break;
539 		case ASCII_BREAK:
540 			continue;
541 		case '#':
542 		case '+':
543 		case '-':
544 			bs = escflags & ESC_BOL && !code_blocks;
545 			break;
546 		case '(':
547 			bs = escflags & ESC_HYP && !code_blocks;
548 			break;
549 		case ')':
550 			bs = escflags & ESC_NUM && !code_blocks;
551 			break;
552 		case '*':
553 		case '[':
554 		case '_':
555 		case '`':
556 			bs = !code_blocks;
557 			break;
558 		case '.':
559 			bs = escflags & ESC_NUM && !code_blocks;
560 			break;
561 		case '<':
562 			if (code_blocks == 0) {
563 				md_named("lt");
564 				c = '\0';
565 			}
566 			break;
567 		case '=':
568 			if (escflags & ESC_BOL && !code_blocks) {
569 				md_named("equals");
570 				c = '\0';
571 			}
572 			break;
573 		case '>':
574 			if (code_blocks == 0) {
575 				md_named("gt");
576 				c = '\0';
577 			}
578 			break;
579 		case '\\':
580 			uc = 0;
581 			nextfont = NULL;
582 			switch (mandoc_escape(&s, &seq, &sz)) {
583 			case ESCAPE_UNICODE:
584 				uc = mchars_num2uc(seq + 1, sz - 1);
585 				break;
586 			case ESCAPE_NUMBERED:
587 				uc = mchars_num2char(seq, sz);
588 				break;
589 			case ESCAPE_SPECIAL:
590 				uc = mchars_spec2cp(seq, sz);
591 				break;
592 			case ESCAPE_UNDEF:
593 				uc = *seq;
594 				break;
595 			case ESCAPE_DEVICE:
596 				md_rawword("markdown");
597 				continue;
598 			case ESCAPE_FONTBOLD:
599 				nextfont = "**";
600 				break;
601 			case ESCAPE_FONTITALIC:
602 				nextfont = "*";
603 				break;
604 			case ESCAPE_FONTBI:
605 				nextfont = "***";
606 				break;
607 			case ESCAPE_FONT:
608 			case ESCAPE_FONTCW:
609 			case ESCAPE_FONTROMAN:
610 				nextfont = "";
611 				break;
612 			case ESCAPE_FONTPREV:
613 				nextfont = prevfont;
614 				break;
615 			case ESCAPE_BREAK:
616 				breakline = 1;
617 				break;
618 			case ESCAPE_NOSPACE:
619 			case ESCAPE_SKIPCHAR:
620 			case ESCAPE_OVERSTRIKE:
621 				/* XXX not implemented */
622 				/* FALLTHROUGH */
623 			case ESCAPE_ERROR:
624 			default:
625 				break;
626 			}
627 			if (nextfont != NULL && !code_blocks) {
628 				if (*currfont != '\0') {
629 					outflags &= ~MD_spc;
630 					md_rawword(currfont);
631 				}
632 				prevfont = currfont;
633 				currfont = nextfont;
634 				if (*currfont != '\0') {
635 					outflags &= ~MD_spc;
636 					md_rawword(currfont);
637 				}
638 			}
639 			if (uc) {
640 				if ((uc < 0x20 && uc != 0x09) ||
641 				    (uc > 0x7E && uc < 0xA0))
642 					uc = 0xFFFD;
643 				if (code_blocks) {
644 					seq = mchars_uc2str(uc);
645 					fputs(seq, stdout);
646 					outcount += strlen(seq);
647 				} else {
648 					printf("&#%d;", uc);
649 					outcount++;
650 				}
651 				escflags &= ~ESC_FON;
652 			}
653 			c = '\0';
654 			break;
655 		case ']':
656 			bs = escflags & ESC_SQU && !code_blocks;
657 			escflags |= ESC_HYP;
658 			break;
659 		default:
660 			break;
661 		}
662 		if (bs)
663 			putchar('\\');
664 		md_char(c);
665 		if (breakline &&
666 		    (*s == '\0' || *s == ' ' || *s == ASCII_NBRSP)) {
667 			printf("  \n");
668 			breakline = 0;
669 			while (*s == ' ' || *s == ASCII_NBRSP)
670 				s++;
671 		}
672 	}
673 	if (*currfont != '\0') {
674 		outflags &= ~MD_spc;
675 		md_rawword(currfont);
676 	} else if (s[-2] == ' ')
677 		escflags |= ESC_EOL;
678 	else
679 		escflags &= ~ESC_EOL;
680 }
681 
682 /*
683  * Print a single HTML named character reference.
684  */
685 static void
686 md_named(const char *s)
687 {
688 	printf("&%s;", s);
689 	escflags &= ~(ESC_FON | ESC_EOL);
690 	outcount++;
691 }
692 
693 /*
694  * Print a single raw character and maintain certain escape flags.
695  */
696 static void
697 md_char(unsigned char c)
698 {
699 	if (c != '\0') {
700 		putchar(c);
701 		if (c == '*')
702 			escflags |= ESC_FON;
703 		else
704 			escflags &= ~ESC_FON;
705 		outcount++;
706 	}
707 	if (c != ']')
708 		escflags &= ~ESC_HYP;
709 	if (c == ' ' || c == '\t' || c == '>')
710 		return;
711 	if (isdigit(c) == 0)
712 		escflags &= ~ESC_NUM;
713 	else if (escflags & ESC_BOL)
714 		escflags |= ESC_NUM;
715 	escflags &= ~ESC_BOL;
716 }
717 
718 static int
719 md_cond_head(struct roff_node *n)
720 {
721 	return n->type == ROFFT_HEAD;
722 }
723 
724 static int
725 md_cond_body(struct roff_node *n)
726 {
727 	return n->type == ROFFT_BODY;
728 }
729 
730 static int
731 md_pre_abort(struct roff_node *n)
732 {
733 	abort();
734 }
735 
736 static int
737 md_pre_raw(struct roff_node *n)
738 {
739 	const char	*prefix;
740 
741 	if ((prefix = md_act(n->tok)->prefix) != NULL) {
742 		md_rawword(prefix);
743 		outflags &= ~MD_spc;
744 		if (*prefix == '`')
745 			code_blocks++;
746 	}
747 	return 1;
748 }
749 
750 static void
751 md_post_raw(struct roff_node *n)
752 {
753 	const char	*suffix;
754 
755 	if ((suffix = md_act(n->tok)->suffix) != NULL) {
756 		outflags &= ~(MD_spc | MD_nl);
757 		md_rawword(suffix);
758 		if (*suffix == '`')
759 			code_blocks--;
760 	}
761 }
762 
763 static int
764 md_pre_word(struct roff_node *n)
765 {
766 	const char	*prefix;
767 
768 	if ((prefix = md_act(n->tok)->prefix) != NULL) {
769 		md_word(prefix);
770 		outflags &= ~MD_spc;
771 	}
772 	return 1;
773 }
774 
775 static void
776 md_post_word(struct roff_node *n)
777 {
778 	const char	*suffix;
779 
780 	if ((suffix = md_act(n->tok)->suffix) != NULL) {
781 		outflags &= ~(MD_spc | MD_nl);
782 		md_word(suffix);
783 	}
784 }
785 
786 static void
787 md_post_pc(struct roff_node *n)
788 {
789 	md_post_raw(n);
790 	if (n->parent->tok != MDOC_Rs)
791 		return;
792 	if (n->next != NULL) {
793 		md_word(",");
794 		if (n->prev != NULL &&
795 		    n->prev->tok == n->tok &&
796 		    n->next->tok == n->tok)
797 			md_word("and");
798 	} else {
799 		md_word(".");
800 		outflags |= MD_nl;
801 	}
802 }
803 
804 static int
805 md_pre_skip(struct roff_node *n)
806 {
807 	return 0;
808 }
809 
810 static void
811 md_pre_syn(struct roff_node *n)
812 {
813 	if (n->prev == NULL || ! (n->flags & NODE_SYNPRETTY))
814 		return;
815 
816 	if (n->prev->tok == n->tok &&
817 	    n->tok != MDOC_Ft &&
818 	    n->tok != MDOC_Fo &&
819 	    n->tok != MDOC_Fn) {
820 		outflags |= MD_br;
821 		return;
822 	}
823 
824 	switch (n->prev->tok) {
825 	case MDOC_Fd:
826 	case MDOC_Fn:
827 	case MDOC_Fo:
828 	case MDOC_In:
829 	case MDOC_Vt:
830 		outflags |= MD_sp;
831 		break;
832 	case MDOC_Ft:
833 		if (n->tok != MDOC_Fn && n->tok != MDOC_Fo) {
834 			outflags |= MD_sp;
835 			break;
836 		}
837 		/* FALLTHROUGH */
838 	default:
839 		outflags |= MD_br;
840 		break;
841 	}
842 }
843 
844 static int
845 md_pre_An(struct roff_node *n)
846 {
847 	switch (n->norm->An.auth) {
848 	case AUTH_split:
849 		outflags &= ~MD_An_nosplit;
850 		outflags |= MD_An_split;
851 		return 0;
852 	case AUTH_nosplit:
853 		outflags &= ~MD_An_split;
854 		outflags |= MD_An_nosplit;
855 		return 0;
856 	default:
857 		if (outflags & MD_An_split)
858 			outflags |= MD_br;
859 		else if (n->sec == SEC_AUTHORS &&
860 		    ! (outflags & MD_An_nosplit))
861 			outflags |= MD_An_split;
862 		return 1;
863 	}
864 }
865 
866 static int
867 md_pre_Ap(struct roff_node *n)
868 {
869 	outflags &= ~MD_spc;
870 	md_word("'");
871 	outflags &= ~MD_spc;
872 	return 0;
873 }
874 
875 static int
876 md_pre_Bd(struct roff_node *n)
877 {
878 	switch (n->norm->Bd.type) {
879 	case DISP_unfilled:
880 	case DISP_literal:
881 		return md_pre_Dl(n);
882 	default:
883 		return md_pre_D1(n);
884 	}
885 }
886 
887 static int
888 md_pre_Bk(struct roff_node *n)
889 {
890 	switch (n->type) {
891 	case ROFFT_BLOCK:
892 		return 1;
893 	case ROFFT_BODY:
894 		outflags |= MD_Bk;
895 		return 1;
896 	default:
897 		return 0;
898 	}
899 }
900 
901 static void
902 md_post_Bk(struct roff_node *n)
903 {
904 	if (n->type == ROFFT_BODY)
905 		outflags &= ~MD_Bk;
906 }
907 
908 static int
909 md_pre_Bl(struct roff_node *n)
910 {
911 	n->norm->Bl.count = 0;
912 	if (n->norm->Bl.type == LIST_column)
913 		md_pre_Dl(n);
914 	outflags |= MD_sp;
915 	return 1;
916 }
917 
918 static void
919 md_post_Bl(struct roff_node *n)
920 {
921 	n->norm->Bl.count = 0;
922 	if (n->norm->Bl.type == LIST_column)
923 		md_post_D1(n);
924 	outflags |= MD_sp;
925 }
926 
927 static int
928 md_pre_D1(struct roff_node *n)
929 {
930 	/*
931 	 * Markdown blockquote syntax does not work inside code blocks.
932 	 * The best we can do is fall back to another nested code block.
933 	 */
934 	if (code_blocks) {
935 		md_stack('\t');
936 		code_blocks++;
937 	} else {
938 		md_stack('>');
939 		quote_blocks++;
940 	}
941 	outflags |= MD_sp;
942 	return 1;
943 }
944 
945 static void
946 md_post_D1(struct roff_node *n)
947 {
948 	md_stack((char)-1);
949 	if (code_blocks)
950 		code_blocks--;
951 	else
952 		quote_blocks--;
953 	outflags |= MD_sp;
954 }
955 
956 static int
957 md_pre_Dl(struct roff_node *n)
958 {
959 	/*
960 	 * Markdown code block syntax does not work inside blockquotes.
961 	 * The best we can do is fall back to another nested blockquote.
962 	 */
963 	if (quote_blocks) {
964 		md_stack('>');
965 		quote_blocks++;
966 	} else {
967 		md_stack('\t');
968 		code_blocks++;
969 	}
970 	outflags |= MD_sp;
971 	return 1;
972 }
973 
974 static int
975 md_pre_En(struct roff_node *n)
976 {
977 	if (n->norm->Es == NULL ||
978 	    n->norm->Es->child == NULL)
979 		return 1;
980 
981 	md_word(n->norm->Es->child->string);
982 	outflags &= ~MD_spc;
983 	return 1;
984 }
985 
986 static void
987 md_post_En(struct roff_node *n)
988 {
989 	if (n->norm->Es == NULL ||
990 	    n->norm->Es->child == NULL ||
991 	    n->norm->Es->child->next == NULL)
992 		return;
993 
994 	outflags &= ~MD_spc;
995 	md_word(n->norm->Es->child->next->string);
996 }
997 
998 static int
999 md_pre_Eo(struct roff_node *n)
1000 {
1001 	if (n->end == ENDBODY_NOT &&
1002 	    n->parent->head->child == NULL &&
1003 	    n->child != NULL &&
1004 	    n->child->end != ENDBODY_NOT)
1005 		md_preword();
1006 	else if (n->end != ENDBODY_NOT ? n->child != NULL :
1007 	    n->parent->head->child != NULL && (n->child != NULL ||
1008 	    (n->parent->tail != NULL && n->parent->tail->child != NULL)))
1009 		outflags &= ~(MD_spc | MD_nl);
1010 	return 1;
1011 }
1012 
1013 static void
1014 md_post_Eo(struct roff_node *n)
1015 {
1016 	if (n->end != ENDBODY_NOT) {
1017 		outflags |= MD_spc;
1018 		return;
1019 	}
1020 
1021 	if (n->child == NULL && n->parent->head->child == NULL)
1022 		return;
1023 
1024 	if (n->parent->tail != NULL && n->parent->tail->child != NULL)
1025 		outflags &= ~MD_spc;
1026         else
1027 		outflags |= MD_spc;
1028 }
1029 
1030 static int
1031 md_pre_Fa(struct roff_node *n)
1032 {
1033 	int	 am_Fa;
1034 
1035 	am_Fa = n->tok == MDOC_Fa;
1036 
1037 	if (am_Fa)
1038 		n = n->child;
1039 
1040 	while (n != NULL) {
1041 		md_rawword("*");
1042 		outflags &= ~MD_spc;
1043 		md_node(n);
1044 		outflags &= ~MD_spc;
1045 		md_rawword("*");
1046 		if ((n = n->next) != NULL)
1047 			md_word(",");
1048 	}
1049 	return 0;
1050 }
1051 
1052 static void
1053 md_post_Fa(struct roff_node *n)
1054 {
1055 	if (n->next != NULL && n->next->tok == MDOC_Fa)
1056 		md_word(",");
1057 }
1058 
1059 static int
1060 md_pre_Fd(struct roff_node *n)
1061 {
1062 	md_pre_syn(n);
1063 	md_pre_raw(n);
1064 	return 1;
1065 }
1066 
1067 static void
1068 md_post_Fd(struct roff_node *n)
1069 {
1070 	md_post_raw(n);
1071 	outflags |= MD_br;
1072 }
1073 
1074 static void
1075 md_post_Fl(struct roff_node *n)
1076 {
1077 	md_post_raw(n);
1078 	if (n->child == NULL && n->next != NULL &&
1079 	    n->next->type != ROFFT_TEXT && !(n->next->flags & NODE_LINE))
1080 		outflags &= ~MD_spc;
1081 }
1082 
1083 static int
1084 md_pre_Fn(struct roff_node *n)
1085 {
1086 	md_pre_syn(n);
1087 
1088 	if ((n = n->child) == NULL)
1089 		return 0;
1090 
1091 	md_rawword("**");
1092 	outflags &= ~MD_spc;
1093 	md_node(n);
1094 	outflags &= ~MD_spc;
1095 	md_rawword("**");
1096 	outflags &= ~MD_spc;
1097 	md_word("(");
1098 
1099 	if ((n = n->next) != NULL)
1100 		md_pre_Fa(n);
1101 	return 0;
1102 }
1103 
1104 static void
1105 md_post_Fn(struct roff_node *n)
1106 {
1107 	md_word(")");
1108 	if (n->flags & NODE_SYNPRETTY) {
1109 		md_word(";");
1110 		outflags |= MD_sp;
1111 	}
1112 }
1113 
1114 static int
1115 md_pre_Fo(struct roff_node *n)
1116 {
1117 	switch (n->type) {
1118 	case ROFFT_BLOCK:
1119 		md_pre_syn(n);
1120 		break;
1121 	case ROFFT_HEAD:
1122 		if (n->child == NULL)
1123 			return 0;
1124 		md_pre_raw(n);
1125 		break;
1126 	case ROFFT_BODY:
1127 		outflags &= ~(MD_spc | MD_nl);
1128 		md_word("(");
1129 		break;
1130 	default:
1131 		break;
1132 	}
1133 	return 1;
1134 }
1135 
1136 static void
1137 md_post_Fo(struct roff_node *n)
1138 {
1139 	switch (n->type) {
1140 	case ROFFT_HEAD:
1141 		if (n->child != NULL)
1142 			md_post_raw(n);
1143 		break;
1144 	case ROFFT_BODY:
1145 		md_post_Fn(n);
1146 		break;
1147 	default:
1148 		break;
1149 	}
1150 }
1151 
1152 static int
1153 md_pre_In(struct roff_node *n)
1154 {
1155 	if (n->flags & NODE_SYNPRETTY) {
1156 		md_pre_syn(n);
1157 		md_rawword("**");
1158 		outflags &= ~MD_spc;
1159 		md_word("#include <");
1160 	} else {
1161 		md_word("<");
1162 		outflags &= ~MD_spc;
1163 		md_rawword("*");
1164 	}
1165 	outflags &= ~MD_spc;
1166 	return 1;
1167 }
1168 
1169 static void
1170 md_post_In(struct roff_node *n)
1171 {
1172 	if (n->flags & NODE_SYNPRETTY) {
1173 		outflags &= ~MD_spc;
1174 		md_rawword(">**");
1175 		outflags |= MD_nl;
1176 	} else {
1177 		outflags &= ~MD_spc;
1178 		md_rawword("*>");
1179 	}
1180 }
1181 
1182 static int
1183 md_pre_It(struct roff_node *n)
1184 {
1185 	struct roff_node	*bln;
1186 
1187 	switch (n->type) {
1188 	case ROFFT_BLOCK:
1189 		return 1;
1190 
1191 	case ROFFT_HEAD:
1192 		bln = n->parent->parent;
1193 		if (bln->norm->Bl.comp == 0 &&
1194 		    bln->norm->Bl.type != LIST_column)
1195 			outflags |= MD_sp;
1196 		outflags |= MD_nl;
1197 
1198 		switch (bln->norm->Bl.type) {
1199 		case LIST_item:
1200 			outflags |= MD_br;
1201 			return 0;
1202 		case LIST_inset:
1203 		case LIST_diag:
1204 		case LIST_ohang:
1205 			outflags |= MD_br;
1206 			return 1;
1207 		case LIST_tag:
1208 		case LIST_hang:
1209 			outflags |= MD_sp;
1210 			return 1;
1211 		case LIST_bullet:
1212 			md_rawword("*\t");
1213 			break;
1214 		case LIST_dash:
1215 		case LIST_hyphen:
1216 			md_rawword("-\t");
1217 			break;
1218 		case LIST_enum:
1219 			md_preword();
1220 			if (bln->norm->Bl.count < 99)
1221 				bln->norm->Bl.count++;
1222 			printf("%d.\t", bln->norm->Bl.count);
1223 			escflags &= ~ESC_FON;
1224 			break;
1225 		case LIST_column:
1226 			outflags |= MD_br;
1227 			return 0;
1228 		default:
1229 			return 0;
1230 		}
1231 		outflags &= ~MD_spc;
1232 		outflags |= MD_nonl;
1233 		outcount = 0;
1234 		md_stack('\t');
1235 		if (code_blocks || quote_blocks)
1236 			list_blocks++;
1237 		return 0;
1238 
1239 	case ROFFT_BODY:
1240 		bln = n->parent->parent;
1241 		switch (bln->norm->Bl.type) {
1242 		case LIST_ohang:
1243 			outflags |= MD_br;
1244 			break;
1245 		case LIST_tag:
1246 		case LIST_hang:
1247 			md_pre_D1(n);
1248 			break;
1249 		default:
1250 			break;
1251 		}
1252 		return 1;
1253 
1254 	default:
1255 		return 0;
1256 	}
1257 }
1258 
1259 static void
1260 md_post_It(struct roff_node *n)
1261 {
1262 	struct roff_node	*bln;
1263 	int			 i, nc;
1264 
1265 	if (n->type != ROFFT_BODY)
1266 		return;
1267 
1268 	bln = n->parent->parent;
1269 	switch (bln->norm->Bl.type) {
1270 	case LIST_bullet:
1271 	case LIST_dash:
1272 	case LIST_hyphen:
1273 	case LIST_enum:
1274 		md_stack((char)-1);
1275 		if (code_blocks || quote_blocks)
1276 			list_blocks--;
1277 		break;
1278 	case LIST_tag:
1279 	case LIST_hang:
1280 		md_post_D1(n);
1281 		break;
1282 
1283 	case LIST_column:
1284 		if (n->next == NULL)
1285 			break;
1286 
1287 		/* Calculate the array index of the current column. */
1288 
1289 		i = 0;
1290 		while ((n = n->prev) != NULL && n->type != ROFFT_HEAD)
1291 			i++;
1292 
1293 		/*
1294 		 * If a width was specified for this column,
1295 		 * subtract what printed, and
1296 		 * add the same spacing as in mdoc_term.c.
1297 		 */
1298 
1299 		nc = bln->norm->Bl.ncols;
1300 		i = i < nc ? strlen(bln->norm->Bl.cols[i]) - outcount +
1301 		    (nc < 5 ? 4 : nc == 5 ? 3 : 1) : 1;
1302 		if (i < 1)
1303 			i = 1;
1304 		while (i-- > 0)
1305 			putchar(' ');
1306 
1307 		outflags &= ~MD_spc;
1308 		escflags &= ~ESC_FON;
1309 		outcount = 0;
1310 		break;
1311 
1312 	default:
1313 		break;
1314 	}
1315 }
1316 
1317 static void
1318 md_post_Lb(struct roff_node *n)
1319 {
1320 	if (n->sec == SEC_LIBRARY)
1321 		outflags |= MD_br;
1322 }
1323 
1324 static void
1325 md_uri(const char *s)
1326 {
1327 	while (*s != '\0') {
1328 		if (strchr("%()<>", *s) != NULL) {
1329 			printf("%%%2.2hhX", *s);
1330 			outcount += 3;
1331 		} else {
1332 			putchar(*s);
1333 			outcount++;
1334 		}
1335 		s++;
1336 	}
1337 }
1338 
1339 static int
1340 md_pre_Lk(struct roff_node *n)
1341 {
1342 	const struct roff_node *link, *descr, *punct;
1343 
1344 	if ((link = n->child) == NULL)
1345 		return 0;
1346 
1347 	/* Find beginning of trailing punctuation. */
1348 	punct = n->last;
1349 	while (punct != link && punct->flags & NODE_DELIMC)
1350 		punct = punct->prev;
1351 	punct = punct->next;
1352 
1353 	/* Link text. */
1354 	descr = link->next;
1355 	if (descr == punct)
1356 		descr = link;  /* no text */
1357 	md_rawword("[");
1358 	outflags &= ~MD_spc;
1359 	do {
1360 		md_word(descr->string);
1361 		descr = descr->next;
1362 	} while (descr != punct);
1363 	outflags &= ~MD_spc;
1364 
1365 	/* Link target. */
1366 	md_rawword("](");
1367 	md_uri(link->string);
1368 	outflags &= ~MD_spc;
1369 	md_rawword(")");
1370 
1371 	/* Trailing punctuation. */
1372 	while (punct != NULL) {
1373 		md_word(punct->string);
1374 		punct = punct->next;
1375 	}
1376 	return 0;
1377 }
1378 
1379 static int
1380 md_pre_Mt(struct roff_node *n)
1381 {
1382 	const struct roff_node *nch;
1383 
1384 	md_rawword("[");
1385 	outflags &= ~MD_spc;
1386 	for (nch = n->child; nch != NULL; nch = nch->next)
1387 		md_word(nch->string);
1388 	outflags &= ~MD_spc;
1389 	md_rawword("](mailto:");
1390 	for (nch = n->child; nch != NULL; nch = nch->next) {
1391 		md_uri(nch->string);
1392 		if (nch->next != NULL) {
1393 			putchar(' ');
1394 			outcount++;
1395 		}
1396 	}
1397 	outflags &= ~MD_spc;
1398 	md_rawword(")");
1399 	return 0;
1400 }
1401 
1402 static int
1403 md_pre_Nd(struct roff_node *n)
1404 {
1405 	outflags &= ~MD_nl;
1406 	outflags |= MD_spc;
1407 	md_word("-");
1408 	return 1;
1409 }
1410 
1411 static int
1412 md_pre_Nm(struct roff_node *n)
1413 {
1414 	switch (n->type) {
1415 	case ROFFT_BLOCK:
1416 		outflags |= MD_Bk;
1417 		md_pre_syn(n);
1418 		break;
1419 	case ROFFT_HEAD:
1420 	case ROFFT_ELEM:
1421 		md_pre_raw(n);
1422 		break;
1423 	default:
1424 		break;
1425 	}
1426 	return 1;
1427 }
1428 
1429 static void
1430 md_post_Nm(struct roff_node *n)
1431 {
1432 	switch (n->type) {
1433 	case ROFFT_BLOCK:
1434 		outflags &= ~MD_Bk;
1435 		break;
1436 	case ROFFT_HEAD:
1437 	case ROFFT_ELEM:
1438 		md_post_raw(n);
1439 		break;
1440 	default:
1441 		break;
1442 	}
1443 }
1444 
1445 static int
1446 md_pre_No(struct roff_node *n)
1447 {
1448 	outflags |= MD_spc_force;
1449 	return 1;
1450 }
1451 
1452 static int
1453 md_pre_Ns(struct roff_node *n)
1454 {
1455 	outflags &= ~MD_spc;
1456 	return 0;
1457 }
1458 
1459 static void
1460 md_post_Pf(struct roff_node *n)
1461 {
1462 	if (n->next != NULL && (n->next->flags & NODE_LINE) == 0)
1463 		outflags &= ~MD_spc;
1464 }
1465 
1466 static int
1467 md_pre_Pp(struct roff_node *n)
1468 {
1469 	outflags |= MD_sp;
1470 	return 0;
1471 }
1472 
1473 static int
1474 md_pre_Rs(struct roff_node *n)
1475 {
1476 	if (n->sec == SEC_SEE_ALSO)
1477 		outflags |= MD_sp;
1478 	return 1;
1479 }
1480 
1481 static int
1482 md_pre_Sh(struct roff_node *n)
1483 {
1484 	switch (n->type) {
1485 	case ROFFT_BLOCK:
1486 		if (n->sec == SEC_AUTHORS)
1487 			outflags &= ~(MD_An_split | MD_An_nosplit);
1488 		break;
1489 	case ROFFT_HEAD:
1490 		outflags |= MD_sp;
1491 		md_rawword(n->tok == MDOC_Sh ? "#" : "##");
1492 		break;
1493 	case ROFFT_BODY:
1494 		outflags |= MD_sp;
1495 		break;
1496 	default:
1497 		break;
1498 	}
1499 	return 1;
1500 }
1501 
1502 static int
1503 md_pre_Sm(struct roff_node *n)
1504 {
1505 	if (n->child == NULL)
1506 		outflags ^= MD_Sm;
1507 	else if (strcmp("on", n->child->string) == 0)
1508 		outflags |= MD_Sm;
1509 	else
1510 		outflags &= ~MD_Sm;
1511 
1512 	if (outflags & MD_Sm)
1513 		outflags |= MD_spc;
1514 
1515 	return 0;
1516 }
1517 
1518 static int
1519 md_pre_Vt(struct roff_node *n)
1520 {
1521 	switch (n->type) {
1522 	case ROFFT_BLOCK:
1523 		md_pre_syn(n);
1524 		return 1;
1525 	case ROFFT_BODY:
1526 	case ROFFT_ELEM:
1527 		md_pre_raw(n);
1528 		return 1;
1529 	default:
1530 		return 0;
1531 	}
1532 }
1533 
1534 static void
1535 md_post_Vt(struct roff_node *n)
1536 {
1537 	switch (n->type) {
1538 	case ROFFT_BODY:
1539 	case ROFFT_ELEM:
1540 		md_post_raw(n);
1541 		break;
1542 	default:
1543 		break;
1544 	}
1545 }
1546 
1547 static int
1548 md_pre_Xr(struct roff_node *n)
1549 {
1550 	n = n->child;
1551 	if (n == NULL)
1552 		return 0;
1553 	md_node(n);
1554 	n = n->next;
1555 	if (n == NULL)
1556 		return 0;
1557 	outflags &= ~MD_spc;
1558 	md_word("(");
1559 	md_node(n);
1560 	md_word(")");
1561 	return 0;
1562 }
1563 
1564 static int
1565 md_pre__T(struct roff_node *n)
1566 {
1567 	if (n->parent->tok == MDOC_Rs && n->parent->norm->Rs.quote_T)
1568 		md_word("\"");
1569 	else
1570 		md_rawword("*");
1571 	outflags &= ~MD_spc;
1572 	return 1;
1573 }
1574 
1575 static void
1576 md_post__T(struct roff_node *n)
1577 {
1578 	outflags &= ~MD_spc;
1579 	if (n->parent->tok == MDOC_Rs && n->parent->norm->Rs.quote_T)
1580 		md_word("\"");
1581 	else
1582 		md_rawword("*");
1583 	md_post_pc(n);
1584 }
1585 
1586 static int
1587 md_pre_br(struct roff_node *n)
1588 {
1589 	outflags |= MD_br;
1590 	return 0;
1591 }
1592