xref: /openbsd/usr.bin/vi/vi/v_section.c (revision 4cfece93)
1 /*	$OpenBSD: v_section.c,v 1.7 2014/11/12 04:28:41 bentley Exp $	*/
2 
3 /*-
4  * Copyright (c) 1992, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  * Copyright (c) 1992, 1993, 1994, 1995, 1996
7  *	Keith Bostic.  All rights reserved.
8  *
9  * See the LICENSE file for redistribution information.
10  */
11 
12 #include "config.h"
13 
14 #include <sys/types.h>
15 #include <sys/queue.h>
16 #include <sys/time.h>
17 
18 #include <bitstring.h>
19 #include <limits.h>
20 #include <stdio.h>
21 #include <string.h>
22 
23 #include "../common/common.h"
24 #include "vi.h"
25 
26 /*
27  * !!!
28  * In historic vi, the section commands ignored empty lines, unlike the
29  * paragraph commands, which was probably okay.  However, they also moved
30  * to the start of the last line when there where no more sections instead
31  * of the end of the last line like the paragraph commands.  I've changed
32  * the latter behavior to match the paragraph commands.
33  *
34  * In historic vi, a section was defined as the first character(s) of the
35  * line matching, which could be followed by anything.  This implementation
36  * follows that historic practice.
37  *
38  * !!!
39  * The historic vi documentation (USD:15-10) claimed:
40  *	The section commands interpret a preceding count as a different
41  *	window size in which to redraw the screen at the new location,
42  *	and this window size is the base size for newly drawn windows
43  *	until another size is specified.  This is very useful if you are
44  *	on a slow terminal ...
45  *
46  * I can't get the 4BSD vi to do this, it just beeps at me.  For now, a
47  * count to the section commands simply repeats the command.
48  */
49 
50 /*
51  * v_sectionf -- [count]]]
52  *	Move forward count sections/functions.
53  *
54  * !!!
55  * Using ]] as a motion command was a bit special, historically.  It could
56  * match } as well as the usual { and section values.  If it matched a { or
57  * a section, it did NOT include the matched line.  If it matched a }, it
58  * did include the line.  No clue why.
59  *
60  * PUBLIC: int v_sectionf(SCR *, VICMD *);
61  */
62 int
63 v_sectionf(SCR *sp, VICMD *vp)
64 {
65 	recno_t cnt, lno;
66 	size_t len;
67 	char *p, *list, *lp;
68 
69 	/* Get the macro list. */
70 	if ((list = O_STR(sp, O_SECTIONS)) == NULL)
71 		return (1);
72 
73 	/*
74 	 * !!!
75 	 * If the starting cursor position is at or before any non-blank
76 	 * characters in the line, i.e. the movement is cutting all of the
77 	 * line's text, the buffer is in line mode.  It's a lot easier to
78 	 * check here, because we know that the end is going to be the start
79 	 * or end of a line.
80 	 */
81 	if (ISMOTION(vp)) {
82 		if (vp->m_start.cno == 0)
83 			F_SET(vp, VM_LMODE);
84 		else {
85 			vp->m_stop = vp->m_start;
86 			vp->m_stop.cno = 0;
87 			if (nonblank(sp, vp->m_stop.lno, &vp->m_stop.cno))
88 				return (1);
89 			if (vp->m_start.cno <= vp->m_stop.cno)
90 				F_SET(vp, VM_LMODE);
91 		}
92 	}
93 
94 	cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
95 	for (lno = vp->m_start.lno; !db_get(sp, ++lno, 0, &p, &len);) {
96 		if (len == 0)
97 			continue;
98 		if (p[0] == '{' || (ISMOTION(vp) && p[0] == '}')) {
99 			if (!--cnt) {
100 				if (p[0] == '{')
101 					goto adjust1;
102 				goto adjust2;
103 			}
104 			continue;
105 		}
106 		/*
107 		 * !!!
108 		 * Historic documentation (USD:15-11, 4.2) said that formfeed
109 		 * characters (^L) in the first column delimited sections.
110 		 * The historic code mentions formfeed characters, but never
111 		 * implements them.  Seems reasonable, do it.
112 		 */
113 		if (p[0] == '\014') {
114 			if (!--cnt)
115 				goto adjust1;
116 			continue;
117 		}
118 		if (p[0] != '.' || len < 2)
119 			continue;
120 		for (lp = list; *lp != '\0'; lp += 2 * sizeof(*lp))
121 			if (lp[0] == p[1] &&
122 			    ((lp[1] == ' ' && len == 2) || lp[1] == p[2]) &&
123 			    !--cnt) {
124 				/*
125 				 * !!!
126 				 * If not cutting this line, adjust to the end
127 				 * of the previous one.  Otherwise, position to
128 				 * column 0.
129 				 */
130 adjust1:			if (ISMOTION(vp))
131 					goto ret1;
132 
133 adjust2:			vp->m_stop.lno = lno;
134 				vp->m_stop.cno = 0;
135 				goto ret2;
136 			}
137 	}
138 
139 	/* If moving forward, reached EOF, check to see if we started there. */
140 	if (vp->m_start.lno == lno - 1) {
141 		v_eof(sp, NULL);
142 		return (1);
143 	}
144 
145 ret1:	if (db_get(sp, --lno, DBG_FATAL, NULL, &len))
146 		return (1);
147 	vp->m_stop.lno = lno;
148 	vp->m_stop.cno = len ? len - 1 : 0;
149 
150 	/*
151 	 * Non-motion commands go to the end of the range.  Delete and
152 	 * yank stay at the start of the range.  Ignore others.
153 	 */
154 ret2:	if (ISMOTION(vp)) {
155 		vp->m_final = vp->m_start;
156 		if (F_ISSET(vp, VM_LMODE))
157 			vp->m_final.cno = 0;
158 	} else
159 		vp->m_final = vp->m_stop;
160 	return (0);
161 }
162 
163 /*
164  * v_sectionb -- [count][[
165  *	Move backward count sections/functions.
166  *
167  * PUBLIC: int v_sectionb(SCR *, VICMD *);
168  */
169 int
170 v_sectionb(SCR *sp, VICMD *vp)
171 {
172 	size_t len;
173 	recno_t cnt, lno;
174 	char *p, *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