1/*-
2 * Copyright (c) 1992, 1993, 1994
3 *	The Regents of the University of California.  All rights reserved.
4 * Copyright (c) 1992, 1993, 1994, 1995, 1996
5 *	Keith Bostic.  All rights reserved.
6 *
7 * See the LICENSE file for redistribution information.
8 */
9
10#include "config.h"
11
12#ifndef lint
13static const char sccsid[] = "@(#)v_paragraph.c	10.7 (Berkeley) 3/6/96";
14#endif /* not lint */
15
16#include <sys/types.h>
17#include <sys/queue.h>
18#include <sys/time.h>
19
20#include <bitstring.h>
21#include <errno.h>
22#include <limits.h>
23#include <stdio.h>
24#include <stdlib.h>
25#include <string.h>
26
27#include "../common/common.h"
28#include "vi.h"
29
30#define	INTEXT_CHECK {							\
31	if (len == 0 || v_isempty(p, len)) {				\
32		if (!--cnt)						\
33			goto found;					\
34		pstate = P_INBLANK;					\
35	}								\
36	/*								\
37	 * !!!								\
38	 * Historic documentation (USD:15-11, 4.2) said that formfeed	\
39	 * characters (^L) in the first column delimited paragraphs.	\
40	 * The historic vi code mentions formfeed characters, but never	\
41	 * implements them.  It seems reasonable, do it.		\
42	 */								\
43	if (p[0] == '\014') {						\
44		if (!--cnt)						\
45			goto found;					\
46		continue;						\
47	}								\
48	if (p[0] != '.' || len < 2)					\
49		continue;						\
50	for (lp = VIP(sp)->ps; *lp != '\0'; lp += 2)			\
51		if (lp[0] == p[1] &&					\
52		    (lp[1] == ' ' && len == 2 || lp[1] == p[2]) &&	\
53		    !--cnt)						\
54			goto found;					\
55}
56
57/*
58 * v_paragraphf -- [count]}
59 *	Move forward count paragraphs.
60 *
61 * Paragraphs are empty lines after text, formfeed characters, or values
62 * from the paragraph or section options.
63 *
64 * PUBLIC: int v_paragraphf __P((SCR *, VICMD *));
65 */
66int
67v_paragraphf(sp, vp)
68	SCR *sp;
69	VICMD *vp;
70{
71	enum { P_INTEXT, P_INBLANK } pstate;
72	size_t lastlen, len;
73	recno_t cnt, lastlno, lno;
74	int isempty;
75	char *p, *lp;
76
77	/*
78	 * !!!
79	 * If the starting cursor position is at or before any non-blank
80	 * characters in the line, i.e. the movement is cutting all of the
81	 * line's text, the buffer is in line mode.  It's a lot easier to
82	 * check here, because we know that the end is going to be the start
83	 * or end of a line.
84	 *
85	 * This was historical practice in vi, with a single exception.  If
86	 * the paragraph movement was from the start of the last line to EOF,
87	 * then all the characters were deleted from the last line, but the
88	 * line itself remained.  If somebody complains, don't pause, don't
89	 * hesitate, just hit them.
90	 */
91	if (ISMOTION(vp))
92		if (vp->m_start.cno == 0)
93			F_SET(vp, VM_LMODE);
94		else {
95			vp->m_stop = vp->m_start;
96			vp->m_stop.cno = 0;
97			if (nonblank(sp, vp->m_stop.lno, &vp->m_stop.cno))
98				return (1);
99			if (vp->m_start.cno <= vp->m_stop.cno)
100				F_SET(vp, VM_LMODE);
101		}
102
103	/* Figure out what state we're currently in. */
104	lno = vp->m_start.lno;
105	if (db_get(sp, lno, 0, &p, &len))
106		goto eof;
107
108	/*
109	 * If we start in text, we want to switch states
110	 * (2 * N - 1) times, in non-text, (2 * N) times.
111	 */
112	cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
113	cnt *= 2;
114	if (len == 0 || v_isempty(p, len))
115		pstate = P_INBLANK;
116	else {
117		--cnt;
118		pstate = P_INTEXT;
119	}
120
121	for (;;) {
122		lastlno = lno;
123		lastlen = len;
124		if (db_get(sp, ++lno, 0, &p, &len))
125			goto eof;
126		switch (pstate) {
127		case P_INTEXT:
128			INTEXT_CHECK;
129			break;
130		case P_INBLANK:
131			if (len == 0 || v_isempty(p, len))
132				break;
133			if (--cnt) {
134				pstate = P_INTEXT;
135				break;
136			}
137			/*
138			 * !!!
139			 * Non-motion commands move to the end of the range,
140			 * delete and yank stay at the start.  Ignore others.
141			 * Adjust the end of the range for motion commands;
142			 * historically, a motion component was to the end of
143			 * the previous line, whereas the movement command was
144			 * to the start of the new "paragraph".
145			 */
146found:			if (ISMOTION(vp)) {
147				vp->m_stop.lno = lastlno;
148				vp->m_stop.cno = lastlen ? lastlen - 1 : 0;
149				vp->m_final = vp->m_start;
150			} else {
151				vp->m_stop.lno = lno;
152				vp->m_stop.cno = 0;
153				vp->m_final = vp->m_stop;
154			}
155			return (0);
156		default:
157			abort();
158		}
159	}
160
161	/*
162	 * !!!
163	 * Adjust end of the range for motion commands; EOF is a movement
164	 * sink.  The } command historically moved to the end of the last
165	 * line, not the beginning, from any position before the end of the
166	 * last line.  It also historically worked on empty files, so we
167	 * have to make it okay.
168	 */
169eof:	if (vp->m_start.lno == lno || vp->m_start.lno == lno - 1) {
170		if (db_eget(sp, vp->m_start.lno, &p, &len, &isempty)) {
171			if (!isempty)
172				return (1);
173			vp->m_start.cno = 0;
174			return (0);
175		}
176		if (vp->m_start.cno == (len ? len - 1 : 0)) {
177			v_eof(sp, NULL);
178			return (1);
179		}
180	}
181	/*
182	 * !!!
183	 * Non-motion commands move to the end of the range, delete
184	 * and yank stay at the start.  Ignore others.
185	 *
186	 * If deleting the line (which happens if deleting to EOF), then
187	 * cursor movement is to the first nonblank.
188	 */
189	if (ISMOTION(vp) && ISCMD(vp->rkp, 'd')) {
190		F_CLR(vp, VM_RCM_MASK);
191		F_SET(vp, VM_RCM_SETFNB);
192	}
193	vp->m_stop.lno = lno - 1;
194	vp->m_stop.cno = len ? len - 1 : 0;
195	vp->m_final = ISMOTION(vp) ? vp->m_start : vp->m_stop;
196	return (0);
197}
198
199/*
200 * v_paragraphb -- [count]{
201 *	Move backward count paragraphs.
202 *
203 * PUBLIC: int v_paragraphb __P((SCR *, VICMD *));
204 */
205int
206v_paragraphb(sp, vp)
207	SCR *sp;
208	VICMD *vp;
209{
210	enum { P_INTEXT, P_INBLANK } pstate;
211	size_t len;
212	recno_t cnt, lno;
213	char *p, *lp;
214
215	/*
216	 * !!!
217	 * Check for SOF.  The historic vi didn't complain if users hit SOF
218	 * repeatedly, unless it was part of a motion command.  There is no
219	 * question but that Emerson's editor of choice was vi.
220	 *
221	 * The { command historically moved to the beginning of the first
222	 * line if invoked on the first line.
223	 *
224	 * !!!
225	 * If the starting cursor position is in the first column (backward
226	 * paragraph movements did NOT historically pay attention to non-blank
227	 * characters) i.e. the movement is cutting the entire line, the buffer
228	 * is in line mode.  Cuts from the beginning of the line also did not
229	 * cut the current line, but started at the previous EOL.
230	 *
231	 * Correct for a left motion component while we're thinking about it.
232	 */
233	lno = vp->m_start.lno;
234
235	if (ISMOTION(vp))
236		if (vp->m_start.cno == 0) {
237			if (vp->m_start.lno == 1) {
238				v_sof(sp, &vp->m_start);
239				return (1);
240			} else
241				--vp->m_start.lno;
242			F_SET(vp, VM_LMODE);
243		} else
244			--vp->m_start.cno;
245
246	if (vp->m_start.lno <= 1)
247		goto sof;
248
249	/* Figure out what state we're currently in. */
250	if (db_get(sp, lno, 0, &p, &len))
251		goto sof;
252
253	/*
254	 * If we start in text, we want to switch states
255	 * (2 * N - 1) times, in non-text, (2 * N) times.
256	 */
257	cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
258	cnt *= 2;
259	if (len == 0 || v_isempty(p, len))
260		pstate = P_INBLANK;
261	else {
262		--cnt;
263		pstate = P_INTEXT;
264
265		/*
266		 * !!!
267		 * If the starting cursor is past the first column,
268		 * the current line is checked for a paragraph.
269		 */
270		if (vp->m_start.cno > 0)
271			++lno;
272	}
273
274	for (;;) {
275		if (db_get(sp, --lno, 0, &p, &len))
276			goto sof;
277		switch (pstate) {
278		case P_INTEXT:
279			INTEXT_CHECK;
280			break;
281		case P_INBLANK:
282			if (len != 0 && !v_isempty(p, len)) {
283				if (!--cnt)
284					goto found;
285				pstate = P_INTEXT;
286			}
287			break;
288		default:
289			abort();
290		}
291	}
292
293	/* SOF is a movement sink. */
294sof:	lno = 1;
295
296found:	vp->m_stop.lno = lno;
297	vp->m_stop.cno = 0;
298
299	/*
300	 * All commands move to the end of the range.  (We already
301	 * adjusted the start of the range for motion commands).
302	 */
303	vp->m_final = vp->m_stop;
304	return (0);
305}
306
307/*
308 * v_buildps --
309 *	Build the paragraph command search pattern.
310 *
311 * PUBLIC: int v_buildps __P((SCR *, char *, char *));
312 */
313int
314v_buildps(sp, p_p, s_p)
315	SCR *sp;
316	char *p_p, *s_p;
317{
318	VI_PRIVATE *vip;
319	size_t p_len, s_len;
320	char *p;
321
322	/*
323	 * The vi paragraph command searches for either a paragraph or
324	 * section option macro.
325	 */
326	p_len = p_p == NULL ? 0 : strlen(p_p);
327	s_len = s_p == NULL ? 0 : strlen(s_p);
328
329	if (p_len == 0 && s_len == 0)
330		return (0);
331
332	MALLOC_RET(sp, p, char *, p_len + s_len + 1);
333
334	vip = VIP(sp);
335	if (vip->ps != NULL)
336		free(vip->ps);
337
338	if (p_p != NULL)
339		memmove(p, p_p, p_len + 1);
340	if (s_p != NULL)
341		memmove(p + p_len, s_p, s_len + 1);
342	vip->ps = p;
343	return (0);
344}
345