xref: /freebsd/contrib/nvi/vi/v_paragraph.c (revision cab6a39d7b343596a5823e65c0f7b426551ec22d)
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 #include <sys/types.h>
13 #include <sys/queue.h>
14 #include <sys/time.h>
15 
16 #include <bitstring.h>
17 #include <errno.h>
18 #include <limits.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 
23 #include "../common/common.h"
24 #include "vi.h"
25 
26 #define	INTEXT_CHECK do {						\
27 	if (len == 0 || v_isempty(p, len)) {				\
28 		if (!--cnt)						\
29 			goto found;					\
30 		pstate = P_INBLANK;					\
31 	}								\
32 	/*								\
33 	 * !!!								\
34 	 * Historic documentation (USD:15-11, 4.2) said that formfeed	\
35 	 * characters (^L) in the first column delimited paragraphs.	\
36 	 * The historic vi code mentions formfeed characters, but never	\
37 	 * implements them.  It seems reasonable, do it.		\
38 	 */								\
39 	if (p[0] == '\014') {						\
40 		if (!--cnt)						\
41 			goto found;					\
42 		continue;						\
43 	}								\
44 	if (p[0] != '.' || len < 2)					\
45 		continue;						\
46 	for (lp = VIP(sp)->ps; *lp != '\0'; lp += 2)			\
47 		if (lp[0] == p[1] &&					\
48 		    (lp[1] == ' ' && len == 2 || lp[1] == p[2]) &&	\
49 		    !--cnt)						\
50 			goto found;					\
51 } while (0)
52 
53 /*
54  * v_paragraphf -- [count]}
55  *	Move forward count paragraphs.
56  *
57  * Paragraphs are empty lines after text, formfeed characters, or values
58  * from the paragraph or section options.
59  *
60  * PUBLIC: int v_paragraphf(SCR *, VICMD *);
61  */
62 int
63 v_paragraphf(SCR *sp, VICMD *vp)
64 {
65 	enum { P_INTEXT, P_INBLANK } pstate;
66 	size_t lastlen, len;
67 	recno_t cnt, lastlno, lno;
68 	int isempty;
69 	CHAR_T *p;
70 	char *lp;
71 
72 	/*
73 	 * !!!
74 	 * If the starting cursor position is at or before any non-blank
75 	 * characters in the line, i.e. the movement is cutting all of the
76 	 * line's text, the buffer is in line mode.  It's a lot easier to
77 	 * check here, because we know that the end is going to be the start
78 	 * or end of a line.
79 	 *
80 	 * This was historical practice in vi, with a single exception.  If
81 	 * the paragraph movement was from the start of the last line to EOF,
82 	 * then all the characters were deleted from the last line, but the
83 	 * line itself remained.  If somebody complains, don't pause, don't
84 	 * hesitate, just hit them.
85 	 */
86 	if (ISMOTION(vp)) {
87 		if (vp->m_start.cno == 0)
88 			F_SET(vp, VM_LMODE);
89 		else {
90 			vp->m_stop = vp->m_start;
91 			vp->m_stop.cno = 0;
92 			if (nonblank(sp, vp->m_stop.lno, &vp->m_stop.cno))
93 				return (1);
94 			if (vp->m_start.cno <= vp->m_stop.cno)
95 				F_SET(vp, VM_LMODE);
96 		}
97 	}
98 
99 	/* Figure out what state we're currently in. */
100 	lno = vp->m_start.lno;
101 	if (db_get(sp, lno, 0, &p, &len))
102 		goto eof;
103 
104 	/*
105 	 * If we start in text, we want to switch states
106 	 * (2 * N - 1) times, in non-text, (2 * N) times.
107 	 */
108 	cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
109 	cnt *= 2;
110 	if (len == 0 || v_isempty(p, len))
111 		pstate = P_INBLANK;
112 	else {
113 		--cnt;
114 		pstate = P_INTEXT;
115 	}
116 
117 	for (;;) {
118 		lastlno = lno;
119 		lastlen = len;
120 		if (db_get(sp, ++lno, 0, &p, &len))
121 			goto eof;
122 		switch (pstate) {
123 		case P_INTEXT:
124 			INTEXT_CHECK;
125 			break;
126 		case P_INBLANK:
127 			if (len == 0 || v_isempty(p, len))
128 				break;
129 			if (--cnt) {
130 				pstate = P_INTEXT;
131 				break;
132 			}
133 			/*
134 			 * !!!
135 			 * Non-motion commands move to the end of the range,
136 			 * delete and yank stay at the start.  Ignore others.
137 			 * Adjust the end of the range for motion commands;
138 			 * historically, a motion component was to the end of
139 			 * the previous line, whereas the movement command was
140 			 * to the start of the new "paragraph".
141 			 */
142 found:			if (ISMOTION(vp)) {
143 				vp->m_stop.lno = lastlno;
144 				vp->m_stop.cno = lastlen ? lastlen - 1 : 0;
145 				vp->m_final = vp->m_start;
146 			} else {
147 				vp->m_stop.lno = lno;
148 				vp->m_stop.cno = 0;
149 				vp->m_final = vp->m_stop;
150 			}
151 			return (0);
152 		default:
153 			abort();
154 		}
155 	}
156 
157 	/*
158 	 * !!!
159 	 * Adjust end of the range for motion commands; EOF is a movement
160 	 * sink.  The } command historically moved to the end of the last
161 	 * line, not the beginning, from any position before the end of the
162 	 * last line.  It also historically worked on empty files, so we
163 	 * have to make it okay.
164 	 */
165 eof:	if (vp->m_start.lno == lno || vp->m_start.lno == lno - 1) {
166 		if (db_eget(sp, vp->m_start.lno, &p, &len, &isempty)) {
167 			if (!isempty)
168 				return (1);
169 			vp->m_start.cno = 0;
170 			return (0);
171 		}
172 		if (vp->m_start.cno == (len ? len - 1 : 0)) {
173 			v_eof(sp, NULL);
174 			return (1);
175 		}
176 	}
177 	/*
178 	 * !!!
179 	 * Non-motion commands move to the end of the range, delete
180 	 * and yank stay at the start.  Ignore others.
181 	 *
182 	 * If deleting the line (which happens if deleting to EOF), then
183 	 * cursor movement is to the first nonblank.
184 	 */
185 	if (ISMOTION(vp) && ISCMD(vp->rkp, 'd')) {
186 		F_CLR(vp, VM_RCM_MASK);
187 		F_SET(vp, VM_RCM_SETFNB);
188 	}
189 	vp->m_stop.lno = lno - 1;
190 	vp->m_stop.cno = len ? len - 1 : 0;
191 	vp->m_final = ISMOTION(vp) ? vp->m_start : vp->m_stop;
192 	return (0);
193 }
194 
195 /*
196  * v_paragraphb -- [count]{
197  *	Move backward count paragraphs.
198  *
199  * PUBLIC: int v_paragraphb(SCR *, VICMD *);
200  */
201 int
202 v_paragraphb(SCR *sp, VICMD *vp)
203 {
204 	enum { P_INTEXT, P_INBLANK } pstate;
205 	size_t len;
206 	recno_t cnt, lno;
207 	CHAR_T *p;
208 	char *lp;
209 
210 	/*
211 	 * !!!
212 	 * Check for SOF.  The historic vi didn't complain if users hit SOF
213 	 * repeatedly, unless it was part of a motion command.  There is no
214 	 * question but that Emerson's editor of choice was vi.
215 	 *
216 	 * The { command historically moved to the beginning of the first
217 	 * line if invoked on the first line.
218 	 *
219 	 * !!!
220 	 * If the starting cursor position is in the first column (backward
221 	 * paragraph movements did NOT historically pay attention to non-blank
222 	 * characters) i.e. the movement is cutting the entire line, the buffer
223 	 * is in line mode.  Cuts from the beginning of the line also did not
224 	 * cut the current line, but started at the previous EOL.
225 	 *
226 	 * Correct for a left motion component while we're thinking about it.
227 	 */
228 	lno = vp->m_start.lno;
229 
230 	if (ISMOTION(vp)) {
231 		if (vp->m_start.cno == 0) {
232 			if (vp->m_start.lno == 1) {
233 				v_sof(sp, &vp->m_start);
234 				return (1);
235 			} else
236 				--vp->m_start.lno;
237 			F_SET(vp, VM_LMODE);
238 		} else
239 			--vp->m_start.cno;
240 	}
241 
242 	if (vp->m_start.lno <= 1)
243 		goto sof;
244 
245 	/* Figure out what state we're currently in. */
246 	if (db_get(sp, lno, 0, &p, &len))
247 		goto sof;
248 
249 	/*
250 	 * If we start in text, we want to switch states
251 	 * (2 * N - 1) times, in non-text, (2 * N) times.
252 	 */
253 	cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
254 	cnt *= 2;
255 	if (len == 0 || v_isempty(p, len))
256 		pstate = P_INBLANK;
257 	else {
258 		--cnt;
259 		pstate = P_INTEXT;
260 
261 		/*
262 		 * !!!
263 		 * If the starting cursor is past the first column,
264 		 * the current line is checked for a paragraph.
265 		 */
266 		if (vp->m_start.cno > 0)
267 			++lno;
268 	}
269 
270 	for (;;) {
271 		if (db_get(sp, --lno, 0, &p, &len))
272 			goto sof;
273 		switch (pstate) {
274 		case P_INTEXT:
275 			INTEXT_CHECK;
276 			break;
277 		case P_INBLANK:
278 			if (len != 0 && !v_isempty(p, len)) {
279 				if (!--cnt)
280 					goto found;
281 				pstate = P_INTEXT;
282 			}
283 			break;
284 		default:
285 			abort();
286 		}
287 	}
288 
289 	/* SOF is a movement sink. */
290 sof:	lno = 1;
291 
292 found:	vp->m_stop.lno = lno;
293 	vp->m_stop.cno = 0;
294 
295 	/*
296 	 * All commands move to the end of the range.  (We already
297 	 * adjusted the start of the range for motion commands).
298 	 */
299 	vp->m_final = vp->m_stop;
300 	return (0);
301 }
302 
303 /*
304  * v_buildps --
305  *	Build the paragraph command search pattern.
306  *
307  * PUBLIC: int v_buildps(SCR *, char *, char *);
308  */
309 int
310 v_buildps(SCR *sp, char *p_p, char *s_p)
311 {
312 	VI_PRIVATE *vip;
313 	size_t p_len, s_len;
314 	char *p;
315 
316 	/*
317 	 * The vi paragraph command searches for either a paragraph or
318 	 * section option macro.
319 	 */
320 	p_len = p_p == NULL ? 0 : strlen(p_p);
321 	s_len = s_p == NULL ? 0 : strlen(s_p);
322 
323 	if (p_len == 0 && s_len == 0)
324 		return (0);
325 
326 	MALLOC_RET(sp, p, p_len + s_len + 1);
327 
328 	vip = VIP(sp);
329 	free(vip->ps);
330 
331 	if (p_p != NULL)
332 		memmove(p, p_p, p_len + 1);
333 	if (s_p != NULL)
334 		memmove(p + p_len, s_p, s_len + 1);
335 	vip->ps = p;
336 	return (0);
337 }
338