xref: /freebsd/contrib/nvi/vi/v_section.c (revision 72143e89bb430c3b1406b399b810806904f6c882)
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 <limits.h>
18 #include <stdio.h>
19 #include <string.h>
20 
21 #include "../common/common.h"
22 #include "vi.h"
23 
24 /*
25  * !!!
26  * In historic vi, the section commands ignored empty lines, unlike the
27  * paragraph commands, which was probably okay.  However, they also moved
28  * to the start of the last line when there where no more sections instead
29  * of the end of the last line like the paragraph commands.  I've changed
30  * the latter behavior to match the paragraph commands.
31  *
32  * In historic vi, a section was defined as the first character(s) of the
33  * line matching, which could be followed by anything.  This implementation
34  * follows that historic practice.
35  *
36  * !!!
37  * The historic vi documentation (USD:15-10) claimed:
38  *	The section commands interpret a preceding count as a different
39  *	window size in which to redraw the screen at the new location,
40  *	and this window size is the base size for newly drawn windows
41  *	until another size is specified.  This is very useful if you are
42  *	on a slow terminal ...
43  *
44  * I can't get the 4BSD vi to do this, it just beeps at me.  For now, a
45  * count to the section commands simply repeats the command.
46  */
47 
48 /*
49  * v_sectionf -- [count]]]
50  *	Move forward count sections/functions.
51  *
52  * !!!
53  * Using ]] as a motion command was a bit special, historically.  It could
54  * match } as well as the usual { and section values.  If it matched a { or
55  * a section, it did NOT include the matched line.  If it matched a }, it
56  * did include the line.  No clue why.
57  *
58  * PUBLIC: int v_sectionf(SCR *, VICMD *);
59  */
60 int
61 v_sectionf(SCR *sp, VICMD *vp)
62 {
63 	recno_t cnt, lno;
64 	size_t len;
65 	CHAR_T *p;
66 	char *list, *lp;
67 
68 	/* Get the macro list. */
69 	if ((list = O_STR(sp, O_SECTIONS)) == NULL)
70 		return (1);
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 	if (ISMOTION(vp)) {
81 		if (vp->m_start.cno == 0)
82 			F_SET(vp, VM_LMODE);
83 		else {
84 			vp->m_stop = vp->m_start;
85 			vp->m_stop.cno = 0;
86 			if (nonblank(sp, vp->m_stop.lno, &vp->m_stop.cno))
87 				return (1);
88 			if (vp->m_start.cno <= vp->m_stop.cno)
89 				F_SET(vp, VM_LMODE);
90 		}
91 	}
92 
93 	cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
94 	for (lno = vp->m_start.lno; !db_get(sp, ++lno, 0, &p, &len);) {
95 		if (len == 0)
96 			continue;
97 		if (p[0] == '{' || (ISMOTION(vp) && p[0] == '}')) {
98 			if (!--cnt) {
99 				if (p[0] == '{')
100 					goto adjust1;
101 				goto adjust2;
102 			}
103 			continue;
104 		}
105 		/*
106 		 * !!!
107 		 * Historic documentation (USD:15-11, 4.2) said that formfeed
108 		 * characters (^L) in the first column delimited sections.
109 		 * The historic code mentions formfeed characters, but never
110 		 * implements them.  Seems reasonable, do it.
111 		 */
112 		if (p[0] == '\014') {
113 			if (!--cnt)
114 				goto adjust1;
115 			continue;
116 		}
117 		if (p[0] != '.' || len < 2)
118 			continue;
119 		for (lp = list; *lp != '\0'; lp += 2 * sizeof(*lp))
120 			if (lp[0] == p[1] &&
121 			    ((lp[1] == ' ' && len == 2) || lp[1] == p[2]) &&
122 			    !--cnt) {
123 				/*
124 				 * !!!
125 				 * If not cutting this line, adjust to the end
126 				 * of the previous one.  Otherwise, position to
127 				 * column 0.
128 				 */
129 adjust1:			if (ISMOTION(vp))
130 					goto ret1;
131 
132 adjust2:			vp->m_stop.lno = lno;
133 				vp->m_stop.cno = 0;
134 				goto ret2;
135 			}
136 	}
137 
138 	/* If moving forward, reached EOF, check to see if we started there. */
139 	if (vp->m_start.lno == lno - 1) {
140 		v_eof(sp, NULL);
141 		return (1);
142 	}
143 
144 ret1:	if (db_get(sp, --lno, DBG_FATAL, NULL, &len))
145 		return (1);
146 	vp->m_stop.lno = lno;
147 	vp->m_stop.cno = len ? len - 1 : 0;
148 
149 	/*
150 	 * Non-motion commands go to the end of the range.  Delete and
151 	 * yank stay at the start of the range.  Ignore others.
152 	 */
153 ret2:	if (ISMOTION(vp)) {
154 		vp->m_final = vp->m_start;
155 		if (F_ISSET(vp, VM_LMODE))
156 			vp->m_final.cno = 0;
157 	} else
158 		vp->m_final = vp->m_stop;
159 	return (0);
160 }
161 
162 /*
163  * v_sectionb -- [count][[
164  *	Move backward count sections/functions.
165  *
166  * PUBLIC: int v_sectionb(SCR *, VICMD *);
167  */
168 int
169 v_sectionb(SCR *sp, VICMD *vp)
170 {
171 	size_t len;
172 	recno_t cnt, lno;
173 	CHAR_T *p;
174 	char *list, *lp;
175 
176 	/* An empty file or starting from line 1 is always illegal. */
177 	if (vp->m_start.lno <= 1) {
178 		v_sof(sp, NULL);
179 		return (1);
180 	}
181 
182 	/* Get the macro list. */
183 	if ((list = O_STR(sp, O_SECTIONS)) == NULL)
184 		return (1);
185 
186 	cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
187 	for (lno = vp->m_start.lno; !db_get(sp, --lno, 0, &p, &len);) {
188 		if (len == 0)
189 			continue;
190 		if (p[0] == '{') {
191 			if (!--cnt)
192 				goto adjust1;
193 			continue;
194 		}
195 		/*
196 		 * !!!
197 		 * Historic documentation (USD:15-11, 4.2) said that formfeed
198 		 * characters (^L) in the first column delimited sections.
199 		 * The historic code mentions formfeed characters, but never
200 		 * implements them.  Seems reasonable, do it.
201 		 */
202 		if (p[0] == '\014') {
203 			if (!--cnt)
204 				goto adjust1;
205 			continue;
206 		}
207 		if (p[0] != '.' || len < 2)
208 			continue;
209 		for (lp = list; *lp != '\0'; lp += 2 * sizeof(*lp))
210 			if (lp[0] == p[1] &&
211 			    ((lp[1] == ' ' && len == 2) || lp[1] == p[2]) &&
212 			    !--cnt) {
213 adjust1:			vp->m_stop.lno = lno;
214 				vp->m_stop.cno = 0;
215 				goto ret1;
216 			}
217 	}
218 
219 	/*
220 	 * If moving backward, reached SOF, which is a movement sink.
221 	 * We already checked for starting there.
222 	 */
223 	vp->m_stop.lno = 1;
224 	vp->m_stop.cno = 0;
225 
226 	/*
227 	 * All commands move to the end of the range.
228 	 *
229 	 * !!!
230 	 * Historic practice is the section cut was in line mode if it started
231 	 * from column 0 and was in the backward direction.  Otherwise, left
232 	 * motion commands adjust the starting point to the character before
233 	 * the current one.  What makes this worse is that if it cut to line
234 	 * mode it also went to the first non-<blank>.
235 	 */
236 ret1:	if (vp->m_start.cno == 0) {
237 		F_CLR(vp, VM_RCM_MASK);
238 		F_SET(vp, VM_RCM_SETFNB);
239 
240 		--vp->m_start.lno;
241 		F_SET(vp, VM_LMODE);
242 	} else
243 		--vp->m_start.cno;
244 
245 	vp->m_final = vp->m_stop;
246 	return (0);
247 }
248