xref: /freebsd/contrib/nvi/vi/v_section.c (revision 4f29da19bd44f0e99f021510460a81bf754c21d2)
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_section.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 <limits.h>
22 #include <stdio.h>
23 #include <string.h>
24 
25 #include "../common/common.h"
26 #include "vi.h"
27 
28 /*
29  * !!!
30  * In historic vi, the section commands ignored empty lines, unlike the
31  * paragraph commands, which was probably okay.  However, they also moved
32  * to the start of the last line when there where no more sections instead
33  * of the end of the last line like the paragraph commands.  I've changed
34  * the latter behavior to match the paragraph commands.
35  *
36  * In historic vi, a section was defined as the first character(s) of the
37  * line matching, which could be followed by anything.  This implementation
38  * follows that historic practice.
39  *
40  * !!!
41  * The historic vi documentation (USD:15-10) claimed:
42  *	The section commands interpret a preceding count as a different
43  *	window size in which to redraw the screen at the new location,
44  *	and this window size is the base size for newly drawn windows
45  *	until another size is specified.  This is very useful if you are
46  *	on a slow terminal ...
47  *
48  * I can't get the 4BSD vi to do this, it just beeps at me.  For now, a
49  * count to the section commands simply repeats the command.
50  */
51 
52 /*
53  * v_sectionf -- [count]]]
54  *	Move forward count sections/functions.
55  *
56  * !!!
57  * Using ]] as a motion command was a bit special, historically.  It could
58  * match } as well as the usual { and section values.  If it matched a { or
59  * a section, it did NOT include the matched line.  If it matched a }, it
60  * did include the line.  No clue why.
61  *
62  * PUBLIC: int v_sectionf __P((SCR *, VICMD *));
63  */
64 int
65 v_sectionf(sp, vp)
66 	SCR *sp;
67 	VICMD *vp;
68 {
69 	recno_t cnt, lno;
70 	size_t len;
71 	char *p, *list, *lp;
72 
73 	/* Get the macro list. */
74 	if ((list = O_STR(sp, O_SECTIONS)) == NULL)
75 		return (1);
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 	if (ISMOTION(vp))
86 		if (vp->m_start.cno == 0)
87 			F_SET(vp, VM_LMODE);
88 		else {
89 			vp->m_stop = vp->m_start;
90 			vp->m_stop.cno = 0;
91 			if (nonblank(sp, vp->m_stop.lno, &vp->m_stop.cno))
92 				return (1);
93 			if (vp->m_start.cno <= vp->m_stop.cno)
94 				F_SET(vp, VM_LMODE);
95 		}
96 
97 	cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
98 	for (lno = vp->m_start.lno; !db_get(sp, ++lno, 0, &p, &len);) {
99 		if (len == 0)
100 			continue;
101 		if (p[0] == '{' || ISMOTION(vp) && p[0] == '}') {
102 			if (!--cnt) {
103 				if (p[0] == '{')
104 					goto adjust1;
105 				goto adjust2;
106 			}
107 			continue;
108 		}
109 		/*
110 		 * !!!
111 		 * Historic documentation (USD:15-11, 4.2) said that formfeed
112 		 * characters (^L) in the first column delimited sections.
113 		 * The historic code mentions formfeed characters, but never
114 		 * implements them.  Seems reasonable, do it.
115 		 */
116 		if (p[0] == '\014') {
117 			if (!--cnt)
118 				goto adjust1;
119 			continue;
120 		}
121 		if (p[0] != '.' || len < 2)
122 			continue;
123 		for (lp = list; *lp != '\0'; lp += 2 * sizeof(*lp))
124 			if (lp[0] == p[1] &&
125 			    (lp[1] == ' ' && len == 2 || lp[1] == p[2]) &&
126 			    !--cnt) {
127 				/*
128 				 * !!!
129 				 * If not cutting this line, adjust to the end
130 				 * of the previous one.  Otherwise, position to
131 				 * column 0.
132 				 */
133 adjust1:			if (ISMOTION(vp))
134 					goto ret1;
135 
136 adjust2:			vp->m_stop.lno = lno;
137 				vp->m_stop.cno = 0;
138 				goto ret2;
139 			}
140 	}
141 
142 	/* If moving forward, reached EOF, check to see if we started there. */
143 	if (vp->m_start.lno == lno - 1) {
144 		v_eof(sp, NULL);
145 		return (1);
146 	}
147 
148 ret1:	if (db_get(sp, --lno, DBG_FATAL, NULL, &len))
149 		return (1);
150 	vp->m_stop.lno = lno;
151 	vp->m_stop.cno = len ? len - 1 : 0;
152 
153 	/*
154 	 * Non-motion commands go to the end of the range.  Delete and
155 	 * yank stay at the start of the range.  Ignore others.
156 	 */
157 ret2:	if (ISMOTION(vp)) {
158 		vp->m_final = vp->m_start;
159 		if (F_ISSET(vp, VM_LMODE))
160 			vp->m_final.cno = 0;
161 	} else
162 		vp->m_final = vp->m_stop;
163 	return (0);
164 }
165 
166 /*
167  * v_sectionb -- [count][[
168  *	Move backward count sections/functions.
169  *
170  * PUBLIC: int v_sectionb __P((SCR *, VICMD *));
171  */
172 int
173 v_sectionb(sp, vp)
174 	SCR *sp;
175 	VICMD *vp;
176 {
177 	size_t len;
178 	recno_t cnt, lno;
179 	char *p, *list, *lp;
180 
181 	/* An empty file or starting from line 1 is always illegal. */
182 	if (vp->m_start.lno <= 1) {
183 		v_sof(sp, NULL);
184 		return (1);
185 	}
186 
187 	/* Get the macro list. */
188 	if ((list = O_STR(sp, O_SECTIONS)) == NULL)
189 		return (1);
190 
191 	cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
192 	for (lno = vp->m_start.lno; !db_get(sp, --lno, 0, &p, &len);) {
193 		if (len == 0)
194 			continue;
195 		if (p[0] == '{') {
196 			if (!--cnt)
197 				goto adjust1;
198 			continue;
199 		}
200 		/*
201 		 * !!!
202 		 * Historic documentation (USD:15-11, 4.2) said that formfeed
203 		 * characters (^L) in the first column delimited sections.
204 		 * The historic code mentions formfeed characters, but never
205 		 * implements them.  Seems reasonable, do it.
206 		 */
207 		if (p[0] == '\014') {
208 			if (!--cnt)
209 				goto adjust1;
210 			continue;
211 		}
212 		if (p[0] != '.' || len < 2)
213 			continue;
214 		for (lp = list; *lp != '\0'; lp += 2 * sizeof(*lp))
215 			if (lp[0] == p[1] &&
216 			    (lp[1] == ' ' && len == 2 || lp[1] == p[2]) &&
217 			    !--cnt) {
218 adjust1:			vp->m_stop.lno = lno;
219 				vp->m_stop.cno = 0;
220 				goto ret1;
221 			}
222 	}
223 
224 	/*
225 	 * If moving backward, reached SOF, which is a movement sink.
226 	 * We already checked for starting there.
227 	 */
228 	vp->m_stop.lno = 1;
229 	vp->m_stop.cno = 0;
230 
231 	/*
232 	 * All commands move to the end of the range.
233 	 *
234 	 * !!!
235 	 * Historic practice is the section cut was in line mode if it started
236 	 * from column 0 and was in the backward direction.  Otherwise, left
237 	 * motion commands adjust the starting point to the character before
238 	 * the current one.  What makes this worse is that if it cut to line
239 	 * mode it also went to the first non-<blank>.
240 	 */
241 ret1:	if (vp->m_start.cno == 0) {
242 		F_CLR(vp, VM_RCM_MASK);
243 		F_SET(vp, VM_RCM_SETFNB);
244 
245 		--vp->m_start.lno;
246 		F_SET(vp, VM_LMODE);
247 	} else
248 		--vp->m_start.cno;
249 
250 	vp->m_final = vp->m_stop;
251 	return (0);
252 }
253