xref: /openbsd/usr.bin/vi/vi/v_left.c (revision d9a51c35)
1 /*	$OpenBSD: v_left.c,v 1.7 2022/12/26 19:16:04 jmc 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 
22 #include "../common/common.h"
23 #include "vi.h"
24 
25 /*
26  * v_left -- [count]^H, [count]h
27  *	Move left by columns.
28  *
29  * PUBLIC: int v_left(SCR *, VICMD *);
30  */
31 int
v_left(SCR * sp,VICMD * vp)32 v_left(SCR *sp, VICMD *vp)
33 {
34 	recno_t cnt;
35 
36 	/*
37 	 * !!!
38 	 * The ^H and h commands always failed in the first column.
39 	 */
40 	if (vp->m_start.cno == 0) {
41 		v_sol(sp);
42 		return (1);
43 	}
44 
45 	/* Find the end of the range. */
46 	cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
47 	if (vp->m_start.cno > cnt)
48 		vp->m_stop.cno = vp->m_start.cno - cnt;
49 	else
50 		vp->m_stop.cno = 0;
51 
52 	/*
53 	 * All commands move to the end of the range.  Motion commands
54 	 * adjust the starting point to the character before the current
55 	 * one.
56 	 */
57 	if (ISMOTION(vp))
58 		--vp->m_start.cno;
59 	vp->m_final = vp->m_stop;
60 	return (0);
61 }
62 
63 /*
64  * v_cfirst -- [count]_
65  *	Move to the first non-blank character in a line.
66  *
67  * PUBLIC: int v_cfirst(SCR *, VICMD *);
68  */
69 int
v_cfirst(SCR * sp,VICMD * vp)70 v_cfirst(SCR *sp, VICMD *vp)
71 {
72 	recno_t cnt, lno;
73 
74 	/*
75 	 * !!!
76 	 * If the _ is a motion component, it makes the command a line motion
77 	 * e.g. "d_" deletes the line.  It also means that the cursor doesn't
78 	 * move.
79 	 *
80 	 * The _ command never failed in the first column.
81 	 */
82 	if (ISMOTION(vp))
83 		F_SET(vp, VM_LMODE);
84 	/*
85 	 * !!!
86 	 * Historically a specified count makes _ move down count - 1
87 	 * rows, so, "3_" is the same as "2j_".
88 	 */
89 	cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
90 	if (cnt != 1) {
91 		--vp->count;
92 		return (v_down(sp, vp));
93 	}
94 
95 	/*
96 	 * Move to the first non-blank.
97 	 *
98 	 * Can't just use RCM_SET_FNB, in case _ is used as the motion
99 	 * component of another command.
100 	 */
101 	vp->m_stop.cno = 0;
102 	if (nonblank(sp, vp->m_stop.lno, &vp->m_stop.cno))
103 		return (1);
104 
105 	/*
106 	 * !!!
107 	 * The _ command has to fail if the file is empty and we're doing
108 	 * a delete.  If deleting line 1, and 0 is the first nonblank,
109 	 * make the check.
110 	 */
111 	if (vp->m_stop.lno == 1 &&
112 	    vp->m_stop.cno == 0 && ISCMD(vp->rkp, 'd')) {
113 		if (db_last(sp, &lno))
114 			return (1);
115 		if (lno == 0) {
116 			v_sol(sp);
117 			return (1);
118 		}
119 	}
120 
121 	/*
122 	 * Delete and non-motion commands move to the end of the range,
123 	 * yank stays at the start.  Ignore others.
124 	 */
125 	vp->m_final =
126 	    ISMOTION(vp) && ISCMD(vp->rkp, 'y') ? vp->m_start : vp->m_stop;
127 	return (0);
128 }
129 
130 /*
131  * v_first -- ^
132  *	Move to the first non-blank character in this line.
133  *
134  * PUBLIC: int v_first(SCR *, VICMD *);
135  */
136 int
v_first(SCR * sp,VICMD * vp)137 v_first(SCR *sp, VICMD *vp)
138 {
139 	/*
140 	 * !!!
141 	 * Yielding to none in our quest for compatibility with every
142 	 * historical blemish of vi, no matter how strange it might be,
143 	 * we permit the user to enter a count and then ignore it.
144 	 */
145 
146 	/*
147 	 * Move to the first non-blank.
148 	 *
149 	 * Can't just use RCM_SET_FNB, in case ^ is used as the motion
150 	 * component of another command.
151 	 */
152 	vp->m_stop.cno = 0;
153 	if (nonblank(sp, vp->m_stop.lno, &vp->m_stop.cno))
154 		return (1);
155 
156 	/*
157 	 * !!!
158 	 * The ^ command succeeded if used as a command when the cursor was
159 	 * on the first non-blank in the line, but failed if used as a motion
160 	 * component in the same situation.
161 	 */
162 	if (ISMOTION(vp) && vp->m_start.cno == vp->m_stop.cno) {
163 		v_sol(sp);
164 		return (1);
165 	}
166 
167 	/*
168 	 * If moving right, non-motion commands move to the end of the range.
169 	 * Delete and yank stay at the start.  Motion commands adjust the
170 	 * ending point to the character before the current ending character.
171 	 *
172 	 * If moving left, all commands move to the end of the range.  Motion
173 	 * commands adjust the starting point to the character before the
174 	 * current starting character.
175 	 */
176 	if (vp->m_start.cno < vp->m_stop.cno)
177 		if (ISMOTION(vp)) {
178 			--vp->m_stop.cno;
179 			vp->m_final = vp->m_start;
180 		} else
181 			vp->m_final = vp->m_stop;
182 	else {
183 		if (ISMOTION(vp))
184 			--vp->m_start.cno;
185 		vp->m_final = vp->m_stop;
186 	}
187 	return (0);
188 }
189 
190 /*
191  * v_ncol -- [count]|
192  *	Move to column count or the first column on this line.  If the
193  *	requested column is past EOL, move to EOL.  The nasty part is
194  *	that we have to know character column widths to make this work.
195  *
196  * PUBLIC: int v_ncol(SCR *, VICMD *);
197  */
198 int
v_ncol(SCR * sp,VICMD * vp)199 v_ncol(SCR *sp, VICMD *vp)
200 {
201 	if (F_ISSET(vp, VC_C1SET) && vp->count > 1) {
202 		--vp->count;
203 		vp->m_stop.cno =
204 		    vs_colpos(sp, vp->m_start.lno, (size_t)vp->count);
205 		/*
206 		 * !!!
207 		 * The | command succeeded if used as a command and the cursor
208 		 * didn't move, but failed if used as a motion component in the
209 		 * same situation.
210 		 */
211 		if (ISMOTION(vp) && vp->m_stop.cno == vp->m_start.cno) {
212 			v_nomove(sp);
213 			return (1);
214 		}
215 	} else {
216 		/*
217 		 * !!!
218 		 * The | command succeeded if used as a command in column 0
219 		 * without a count, but failed if used as a motion component
220 		 * in the same situation.
221 		 */
222 		if (ISMOTION(vp) && vp->m_start.cno == 0) {
223 			v_sol(sp);
224 			return (1);
225 		}
226 		vp->m_stop.cno = 0;
227 	}
228 
229 	/*
230 	 * If moving right, non-motion commands move to the end of the range.
231 	 * Delete and yank stay at the start.  Motion commands adjust the
232 	 * ending point to the character before the current ending character.
233 	 *
234 	 * If moving left, all commands move to the end of the range.  Motion
235 	 * commands adjust the starting point to the character before the
236 	 * current starting character.
237 	 */
238 	if (vp->m_start.cno < vp->m_stop.cno)
239 		if (ISMOTION(vp)) {
240 			--vp->m_stop.cno;
241 			vp->m_final = vp->m_start;
242 		} else
243 			vp->m_final = vp->m_stop;
244 	else {
245 		if (ISMOTION(vp))
246 			--vp->m_start.cno;
247 		vp->m_final = vp->m_stop;
248 	}
249 	return (0);
250 }
251 
252 /*
253  * v_zero -- 0
254  *	Move to the first column on this line.
255  *
256  * PUBLIC: int v_zero(SCR *, VICMD *);
257  */
258 int
v_zero(SCR * sp,VICMD * vp)259 v_zero(SCR *sp, VICMD *vp)
260 {
261 	/*
262 	 * !!!
263 	 * The 0 command succeeded if used as a command in the first column
264 	 * but failed if used as a motion component in the same situation.
265 	 */
266 	if (ISMOTION(vp) && vp->m_start.cno == 0) {
267 		v_sol(sp);
268 		return (1);
269 	}
270 
271 	/*
272 	 * All commands move to the end of the range.  Motion commands
273 	 * adjust the starting point to the character before the current
274 	 * one.
275 	 */
276 	vp->m_stop.cno = 0;
277 	if (ISMOTION(vp))
278 		--vp->m_start.cno;
279 	vp->m_final = vp->m_stop;
280 	return (0);
281 }
282