xref: /freebsd/contrib/nvi/vi/v_section.c (revision fcb560670601b2a4d87bb31d7531c8dcc37ee71b)
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_section.c,v 10.10 2001/06/25 15:19:35 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 <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(SCR *sp, VICMD *vp)
66 {
67 	recno_t cnt, lno;
68 	size_t len;
69 	CHAR_T *p;
70 	char *list, *lp;
71 
72 	/* Get the macro list. */
73 	if ((list = O_STR(sp, O_SECTIONS)) == NULL)
74 		return (1);
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 	if (ISMOTION(vp))
85 		if (vp->m_start.cno == 0)
86 			F_SET(vp, VM_LMODE);
87 		else {
88 			vp->m_stop = vp->m_start;
89 			vp->m_stop.cno = 0;
90 			if (nonblank(sp, vp->m_stop.lno, &vp->m_stop.cno))
91 				return (1);
92 			if (vp->m_start.cno <= vp->m_stop.cno)
93 				F_SET(vp, VM_LMODE);
94 		}
95 
96 	cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
97 	for (lno = vp->m_start.lno; !db_get(sp, ++lno, 0, &p, &len);) {
98 		if (len == 0)
99 			continue;
100 		if (p[0] == '{' || (ISMOTION(vp) && p[0] == '}')) {
101 			if (!--cnt) {
102 				if (p[0] == '{')
103 					goto adjust1;
104 				goto adjust2;
105 			}
106 			continue;
107 		}
108 		/*
109 		 * !!!
110 		 * Historic documentation (USD:15-11, 4.2) said that formfeed
111 		 * characters (^L) in the first column delimited sections.
112 		 * The historic code mentions formfeed characters, but never
113 		 * implements them.  Seems reasonable, do it.
114 		 */
115 		if (p[0] == '\014') {
116 			if (!--cnt)
117 				goto adjust1;
118 			continue;
119 		}
120 		if (p[0] != '.' || len < 2)
121 			continue;
122 		for (lp = list; *lp != '\0'; lp += 2 * sizeof(*lp))
123 			if (lp[0] == p[1] &&
124 			    ((lp[1] == ' ' && len == 2) || lp[1] == p[2]) &&
125 			    !--cnt) {
126 				/*
127 				 * !!!
128 				 * If not cutting this line, adjust to the end
129 				 * of the previous one.  Otherwise, position to
130 				 * column 0.
131 				 */
132 adjust1:			if (ISMOTION(vp))
133 					goto ret1;
134 
135 adjust2:			vp->m_stop.lno = lno;
136 				vp->m_stop.cno = 0;
137 				goto ret2;
138 			}
139 	}
140 
141 	/* If moving forward, reached EOF, check to see if we started there. */
142 	if (vp->m_start.lno == lno - 1) {
143 		v_eof(sp, NULL);
144 		return (1);
145 	}
146 
147 ret1:	if (db_get(sp, --lno, DBG_FATAL, NULL, &len))
148 		return (1);
149 	vp->m_stop.lno = lno;
150 	vp->m_stop.cno = len ? len - 1 : 0;
151 
152 	/*
153 	 * Non-motion commands go to the end of the range.  Delete and
154 	 * yank stay at the start of the range.  Ignore others.
155 	 */
156 ret2:	if (ISMOTION(vp)) {
157 		vp->m_final = vp->m_start;
158 		if (F_ISSET(vp, VM_LMODE))
159 			vp->m_final.cno = 0;
160 	} else
161 		vp->m_final = vp->m_stop;
162 	return (0);
163 }
164 
165 /*
166  * v_sectionb -- [count][[
167  *	Move backward count sections/functions.
168  *
169  * PUBLIC: int v_sectionb __P((SCR *, VICMD *));
170  */
171 int
172 v_sectionb(SCR *sp, VICMD *vp)
173 {
174 	size_t len;
175 	recno_t cnt, lno;
176 	CHAR_T *p;
177 	char *list, *lp;
178 
179 	/* An empty file or starting from line 1 is always illegal. */
180 	if (vp->m_start.lno <= 1) {
181 		v_sof(sp, NULL);
182 		return (1);
183 	}
184 
185 	/* Get the macro list. */
186 	if ((list = O_STR(sp, O_SECTIONS)) == NULL)
187 		return (1);
188 
189 	cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
190 	for (lno = vp->m_start.lno; !db_get(sp, --lno, 0, &p, &len);) {
191 		if (len == 0)
192 			continue;
193 		if (p[0] == '{') {
194 			if (!--cnt)
195 				goto adjust1;
196 			continue;
197 		}
198 		/*
199 		 * !!!
200 		 * Historic documentation (USD:15-11, 4.2) said that formfeed
201 		 * characters (^L) in the first column delimited sections.
202 		 * The historic code mentions formfeed characters, but never
203 		 * implements them.  Seems reasonable, do it.
204 		 */
205 		if (p[0] == '\014') {
206 			if (!--cnt)
207 				goto adjust1;
208 			continue;
209 		}
210 		if (p[0] != '.' || len < 2)
211 			continue;
212 		for (lp = list; *lp != '\0'; lp += 2 * sizeof(*lp))
213 			if (lp[0] == p[1] &&
214 			    ((lp[1] == ' ' && len == 2) || lp[1] == p[2]) &&
215 			    !--cnt) {
216 adjust1:			vp->m_stop.lno = lno;
217 				vp->m_stop.cno = 0;
218 				goto ret1;
219 			}
220 	}
221 
222 	/*
223 	 * If moving backward, reached SOF, which is a movement sink.
224 	 * We already checked for starting there.
225 	 */
226 	vp->m_stop.lno = 1;
227 	vp->m_stop.cno = 0;
228 
229 	/*
230 	 * All commands move to the end of the range.
231 	 *
232 	 * !!!
233 	 * Historic practice is the section cut was in line mode if it started
234 	 * from column 0 and was in the backward direction.  Otherwise, left
235 	 * motion commands adjust the starting point to the character before
236 	 * the current one.  What makes this worse is that if it cut to line
237 	 * mode it also went to the first non-<blank>.
238 	 */
239 ret1:	if (vp->m_start.cno == 0) {
240 		F_CLR(vp, VM_RCM_MASK);
241 		F_SET(vp, VM_RCM_SETFNB);
242 
243 		--vp->m_start.lno;
244 		F_SET(vp, VM_LMODE);
245 	} else
246 		--vp->m_start.cno;
247 
248 	vp->m_final = vp->m_stop;
249 	return (0);
250 }
251