xref: /freebsd/contrib/nvi/vi/v_paragraph.c (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
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[] = "$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  */
66 int
67 v_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 			 */
145 found:			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 	 */
168 eof:	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  */
204 int
205 v_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. */
292 sof:	lno = 1;
293 
294 found:	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  */
311 int
312 v_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