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[] = "$Id: v_paragraph.c,v 10.10 2001/06/25 15:19:32 skimo Exp $";
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(SCR *, VICMD *);
65 */
66int
67v_paragraphf(SCR *sp, VICMD *vp)
68{
69	enum { P_INTEXT, P_INBLANK } pstate;
70	size_t lastlen, len;
71	recno_t cnt, lastlno, lno;
72	int isempty;
73	CHAR_T *p;
74	char *lp;
75
76	/*
77	 * !!!
78	 * If the starting cursor position is at or before any non-blank
79	 * characters in the line, i.e. the movement is cutting all of the
80	 * line's text, the buffer is in line mode.  It's a lot easier to
81	 * check here, because we know that the end is going to be the start
82	 * or end of a line.
83	 *
84	 * This was historical practice in vi, with a single exception.  If
85	 * the paragraph movement was from the start of the last line to EOF,
86	 * then all the characters were deleted from the last line, but the
87	 * line itself remained.  If somebody complains, don't pause, don't
88	 * hesitate, just hit them.
89	 */
90	if (ISMOTION(vp))
91		if (vp->m_start.cno == 0)
92			F_SET(vp, VM_LMODE);
93		else {
94			vp->m_stop = vp->m_start;
95			vp->m_stop.cno = 0;
96			if (nonblank(sp, vp->m_stop.lno, &vp->m_stop.cno))
97				return (1);
98			if (vp->m_start.cno <= vp->m_stop.cno)
99				F_SET(vp, VM_LMODE);
100		}
101
102	/* Figure out what state we're currently in. */
103	lno = vp->m_start.lno;
104	if (db_get(sp, lno, 0, &p, &len))
105		goto eof;
106
107	/*
108	 * If we start in text, we want to switch states
109	 * (2 * N - 1) times, in non-text, (2 * N) times.
110	 */
111	cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
112	cnt *= 2;
113	if (len == 0 || v_isempty(p, len))
114		pstate = P_INBLANK;
115	else {
116		--cnt;
117		pstate = P_INTEXT;
118	}
119
120	for (;;) {
121		lastlno = lno;
122		lastlen = len;
123		if (db_get(sp, ++lno, 0, &p, &len))
124			goto eof;
125		switch (pstate) {
126		case P_INTEXT:
127			INTEXT_CHECK;
128			break;
129		case P_INBLANK:
130			if (len == 0 || v_isempty(p, len))
131				break;
132			if (--cnt) {
133				pstate = P_INTEXT;
134				break;
135			}
136			/*
137			 * !!!
138			 * Non-motion commands move to the end of the range,
139			 * delete and yank stay at the start.  Ignore others.
140			 * Adjust the end of the range for motion commands;
141			 * historically, a motion component was to the end of
142			 * the previous line, whereas the movement command was
143			 * to the start of the new "paragraph".
144			 */
145found:			if (ISMOTION(vp)) {
146				vp->m_stop.lno = lastlno;
147				vp->m_stop.cno = lastlen ? lastlen - 1 : 0;
148				vp->m_final = vp->m_start;
149			} else {
150				vp->m_stop.lno = lno;
151				vp->m_stop.cno = 0;
152				vp->m_final = vp->m_stop;
153			}
154			return (0);
155		default:
156			abort();
157		}
158	}
159
160	/*
161	 * !!!
162	 * Adjust end of the range for motion commands; EOF is a movement
163	 * sink.  The } command historically moved to the end of the last
164	 * line, not the beginning, from any position before the end of the
165	 * last line.  It also historically worked on empty files, so we
166	 * have to make it okay.
167	 */
168eof:	if (vp->m_start.lno == lno || vp->m_start.lno == lno - 1) {
169		if (db_eget(sp, vp->m_start.lno, &p, &len, &isempty)) {
170			if (!isempty)
171				return (1);
172			vp->m_start.cno = 0;
173			return (0);
174		}
175		if (vp->m_start.cno == (len ? len - 1 : 0)) {
176			v_eof(sp, NULL);
177			return (1);
178		}
179	}
180	/*
181	 * !!!
182	 * Non-motion commands move to the end of the range, delete
183	 * and yank stay at the start.  Ignore others.
184	 *
185	 * If deleting the line (which happens if deleting to EOF), then
186	 * cursor movement is to the first nonblank.
187	 */
188	if (ISMOTION(vp) && ISCMD(vp->rkp, 'd')) {
189		F_CLR(vp, VM_RCM_MASK);
190		F_SET(vp, VM_RCM_SETFNB);
191	}
192	vp->m_stop.lno = lno - 1;
193	vp->m_stop.cno = len ? len - 1 : 0;
194	vp->m_final = ISMOTION(vp) ? vp->m_start : vp->m_stop;
195	return (0);
196}
197
198/*
199 * v_paragraphb -- [count]{
200 *	Move backward count paragraphs.
201 *
202 * PUBLIC: int v_paragraphb(SCR *, VICMD *);
203 */
204int
205v_paragraphb(SCR *sp, VICMD *vp)
206{
207	enum { P_INTEXT, P_INBLANK } pstate;
208	size_t len;
209	recno_t cnt, lno;
210	CHAR_T *p;
211	char *lp;
212
213	/*
214	 * !!!
215	 * Check for SOF.  The historic vi didn't complain if users hit SOF
216	 * repeatedly, unless it was part of a motion command.  There is no
217	 * question but that Emerson's editor of choice was vi.
218	 *
219	 * The { command historically moved to the beginning of the first
220	 * line if invoked on the first line.
221	 *
222	 * !!!
223	 * If the starting cursor position is in the first column (backward
224	 * paragraph movements did NOT historically pay attention to non-blank
225	 * characters) i.e. the movement is cutting the entire line, the buffer
226	 * is in line mode.  Cuts from the beginning of the line also did not
227	 * cut the current line, but started at the previous EOL.
228	 *
229	 * Correct for a left motion component while we're thinking about it.
230	 */
231	lno = vp->m_start.lno;
232
233	if (ISMOTION(vp))
234		if (vp->m_start.cno == 0) {
235			if (vp->m_start.lno == 1) {
236				v_sof(sp, &vp->m_start);
237				return (1);
238			} else
239				--vp->m_start.lno;
240			F_SET(vp, VM_LMODE);
241		} else
242			--vp->m_start.cno;
243
244	if (vp->m_start.lno <= 1)
245		goto sof;
246
247	/* Figure out what state we're currently in. */
248	if (db_get(sp, lno, 0, &p, &len))
249		goto sof;
250
251	/*
252	 * If we start in text, we want to switch states
253	 * (2 * N - 1) times, in non-text, (2 * N) times.
254	 */
255	cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
256	cnt *= 2;
257	if (len == 0 || v_isempty(p, len))
258		pstate = P_INBLANK;
259	else {
260		--cnt;
261		pstate = P_INTEXT;
262
263		/*
264		 * !!!
265		 * If the starting cursor is past the first column,
266		 * the current line is checked for a paragraph.
267		 */
268		if (vp->m_start.cno > 0)
269			++lno;
270	}
271
272	for (;;) {
273		if (db_get(sp, --lno, 0, &p, &len))
274			goto sof;
275		switch (pstate) {
276		case P_INTEXT:
277			INTEXT_CHECK;
278			break;
279		case P_INBLANK:
280			if (len != 0 && !v_isempty(p, len)) {
281				if (!--cnt)
282					goto found;
283				pstate = P_INTEXT;
284			}
285			break;
286		default:
287			abort();
288		}
289	}
290
291	/* SOF is a movement sink. */
292sof:	lno = 1;
293
294found:	vp->m_stop.lno = lno;
295	vp->m_stop.cno = 0;
296
297	/*
298	 * All commands move to the end of the range.  (We already
299	 * adjusted the start of the range for motion commands).
300	 */
301	vp->m_final = vp->m_stop;
302	return (0);
303}
304
305/*
306 * v_buildps --
307 *	Build the paragraph command search pattern.
308 *
309 * PUBLIC: int v_buildps(SCR *, char *, char *);
310 */
311int
312v_buildps(SCR *sp, char *p_p, char *s_p)
313{
314	VI_PRIVATE *vip;
315	size_t p_len, s_len;
316	char *p;
317
318	/*
319	 * The vi paragraph command searches for either a paragraph or
320	 * section option macro.
321	 */
322	p_len = p_p == NULL ? 0 : strlen(p_p);
323	s_len = s_p == NULL ? 0 : strlen(s_p);
324
325	if (p_len == 0 && s_len == 0)
326		return (0);
327
328	MALLOC_RET(sp, p, char *, p_len + s_len + 1);
329
330	vip = VIP(sp);
331	if (vip->ps != NULL)
332		free(vip->ps);
333
334	if (p_p != NULL)
335		memmove(p, p_p, p_len + 1);
336	if (s_p != NULL)
337		memmove(p + p_len, s_p, s_len + 1);
338	vip->ps = p;
339	return (0);
340}
341