xref: /freebsd/contrib/nvi/vi/v_paragraph.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
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
13 static 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  */
66 int
67 v_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 			 */
146 found:			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 	 */
169 eof:	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  */
205 int
206 v_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. */
294 sof:	lno = 1;
295 
296 found:	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  */
313 int
314 v_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