vi/v_word.c

   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_word.c,v 10.6 2001/06/25 15:19:36 skimo Exp $ (Berkeley) $Date: 2001/06/25 15:19:36 $";
  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 <ctype.h>
  22 #include <limits.h>
  23 #include <stdio.h>
  24
  25 #include "../common/common.h"
  26 #include "vi.h"
  27
  28 /*
  29  * There are two types of "words".  Bigwords are easy -- groups of anything
  30  * delimited by whitespace.  Normal words are trickier.  They are either a
  31  * group of characters, numbers and underscores, or a group of anything but,
  32  * delimited by whitespace.  When for a word, if you're in whitespace, it's
  33  * easy, just remove the whitespace and go to the beginning or end of the
  34  * word.  Otherwise, figure out if the next character is in a different group.
  35  * If it is, go to the beginning or end of that group, otherwise, go to the
  36  * beginning or end of the current group.  The historic version of vi didn't
  37  * get this right, so, for example, there were cases where "4e" was not the
  38  * same as "eeee" -- in particular, single character words, and commands that
  39  * began in whitespace were almost always handled incorrectly.  To get it right
  40  * you have to resolve the cursor after each search so that the look-ahead to
  41  * figure out what type of "word" the cursor is in will be correct.
  42  *
  43  * Empty lines, and lines that consist of only white-space characters count
  44  * as a single word, and the beginning and end of the file counts as an
  45  * infinite number of words.
  46  *
  47  * Movements associated with commands are different than movement commands.
  48  * For example, in "abc  def", with the cursor on the 'a', "cw" is from
  49  * 'a' to 'c', while "w" is from 'a' to 'd'.  In general, trailing white
  50  * space is discarded from the change movement.  Another example is that,
  51  * in the same string, a "cw" on any white space character replaces that
  52  * single character, and nothing else.  Ain't nothin' in here that's easy.
  53  *
  54  * One historic note -- in the original vi, the 'w', 'W' and 'B' commands
  55  * would treat groups of empty lines as individual words, i.e. the command
  56  * would move the cursor to each new empty line.  The 'e' and 'E' commands
  57  * would treat groups of empty lines as a single word, i.e. the first use
  58  * would move past the group of lines.  The 'b' command would just beep at
  59  * you, or, if you did it from the start of the line as part of a motion
  60  * command, go absolutely nuts.  If the lines contained only white-space
  61  * characters, the 'w' and 'W' commands would just beep at you, and the 'B',
  62  * 'b', 'E' and 'e' commands would treat the group as a single word, and
  63  * the 'B' and 'b' commands will treat the lines as individual words.  This
  64  * implementation treats all of these cases as a single white-space word.
  65  */
  66
  67 enum which {BIGWORD, LITTLEWORD};
  68
  69 static int bword __P((SCR *, VICMD *, enum which));
  70 static int eword __P((SCR *, VICMD *, enum which));
  71 static int fword __P((SCR *, VICMD *, enum which));
  72
  73 /*
  74  * v_wordW -- [count]W
  75  *      Move forward a bigword at a time.
  76  *
  77  * PUBLIC: int v_wordW __P((SCR *, VICMD *));
  78  */
  79 int
  80 v_wordW(SCR *sp, VICMD *vp)
  81 {
  82         return (fword(sp, vp, BIGWORD));
  83 }
  84
  85 /*
  86  * v_wordw -- [count]w
  87  *      Move forward a word at a time.
  88  *
  89  * PUBLIC: int v_wordw __P((SCR *, VICMD *));
  90  */
  91 int
  92 v_wordw(SCR *sp, VICMD *vp)
  93 {
  94         return (fword(sp, vp, LITTLEWORD));
  95 }
  96
  97 /*
  98  * fword --
  99  *      Move forward by words.
 100  */
 101 static int
 102 fword(SCR *sp, VICMD *vp, enum which type)
 103 {
 104         enum { INWORD, NOTWORD } state;
 105         VCS cs;
 106         u_long cnt;
 107
 108         cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
 109         cs.cs_lno = vp->m_start.lno;
 110         cs.cs_cno = vp->m_start.cno;
 111         if (cs_init(sp, &cs))
 112                 return (1);
 113
 114         /*
 115          * If in white-space:
 116          *      If the count is 1, and it's a change command, we're done.
 117          *      Else, move to the first non-white-space character, which
 118          *      counts as a single word move.  If it's a motion command,
 119          *      don't move off the end of the line.
 120          */
 121         if (cs.cs_flags == CS_EMP || cs.cs_flags == 0 && isblank(cs.cs_ch)) {
 122                 if (ISMOTION(vp) && cs.cs_flags != CS_EMP && cnt == 1) {
 123                         if (ISCMD(vp->rkp, 'c'))
 124                                 return (0);
 125                         if (ISCMD(vp->rkp, 'd') || ISCMD(vp->rkp, 'y')) {
 126                                 if (cs_fspace(sp, &cs))
 127                                         return (1);
 128                                 goto ret;
 129                         }
 130                 }
 131                 if (cs_fblank(sp, &cs))
 132                         return (1);
 133                 --cnt;
 134         }
 135
 136         /*
 137          * Cyclically move to the next word -- this involves skipping
 138          * over word characters and then any trailing non-word characters.
 139          * Note, for the 'w' command, the definition of a word keeps
 140          * switching.
 141          */
 142         if (type == BIGWORD)
 143                 while (cnt--) {
 144                         for (;;) {
 145                                 if (cs_next(sp, &cs))
 146                                         return (1);
 147                                 if (cs.cs_flags == CS_EOF)
 148                                         goto ret;
 149                                 if (cs.cs_flags != 0 || isblank(cs.cs_ch))
 150                                         break;
 151                         }
 152                         /*
 153                          * If a motion command and we're at the end of the
 154                          * last word, we're done.  Delete and yank eat any
 155                          * trailing blanks, but we don't move off the end
 156                          * of the line regardless.
 157                          */
 158                         if (cnt == 0 && ISMOTION(vp)) {
 159                                 if ((ISCMD(vp->rkp, 'd') ||
 160                                     ISCMD(vp->rkp, 'y')) &&
 161                                     cs_fspace(sp, &cs))
 162                                         return (1);
 163                                 break;
 164                         }
 165
 166                         /* Eat whitespace characters. */
 167                         if (cs_fblank(sp, &cs))
 168                                 return (1);
 169                         if (cs.cs_flags == CS_EOF)
 170                                 goto ret;
 171                 }
 172         else
 173                 while (cnt--) {
 174                         state = cs.cs_flags == 0 &&
 175                             inword(cs.cs_ch) ? INWORD : NOTWORD;
 176                         for (;;) {
 177                                 if (cs_next(sp, &cs))
 178                                         return (1);
 179                                 if (cs.cs_flags == CS_EOF)
 180                                         goto ret;
 181                                 if (cs.cs_flags != 0 || isblank(cs.cs_ch))
 182                                         break;
 183                                 if (state == INWORD) {
 184                                         if (!inword(cs.cs_ch))
 185                                                 break;
 186                                 } else
 187                                         if (inword(cs.cs_ch))
 188                                                 break;
 189                         }
 190                         /* See comment above. */
 191                         if (cnt == 0 && ISMOTION(vp)) {
 192                                 if ((ISCMD(vp->rkp, 'd') ||
 193                                     ISCMD(vp->rkp, 'y')) &&
 194                                     cs_fspace(sp, &cs))
 195                                         return (1);
 196                                 break;
 197                         }
 198
 199                         /* Eat whitespace characters. */
 200                         if (cs.cs_flags != 0 || isblank(cs.cs_ch))
 201                                 if (cs_fblank(sp, &cs))
 202                                         return (1);
 203                         if (cs.cs_flags == CS_EOF)
 204                                 goto ret;
 205                 }
 206
 207         /*
 208          * If we didn't move, we must be at EOF.
 209          *
 210          * !!!
 211          * That's okay for motion commands, however.
 212          */
 213 ret:    if (!ISMOTION(vp) &&
 214             cs.cs_lno == vp->m_start.lno && cs.cs_cno == vp->m_start.cno) {
 215                 v_eof(sp, &vp->m_start);
 216                 return (1);
 217         }
 218
 219         /* Adjust the end of the range for motion commands. */
 220         vp->m_stop.lno = cs.cs_lno;
 221         vp->m_stop.cno = cs.cs_cno;
 222         if (ISMOTION(vp) && cs.cs_flags == 0)
 223                 --vp->m_stop.cno;
 224
 225         /*
 226          * Non-motion commands move to the end of the range.  Delete
 227          * and yank stay at the start, ignore others.
 228          */
 229         vp->m_final = ISMOTION(vp) ? vp->m_start : vp->m_stop;
 230         return (0);
 231 }
 232
 233 /*
 234  * v_wordE -- [count]E
 235  *      Move forward to the end of the bigword.
 236  *
 237  * PUBLIC: int v_wordE __P((SCR *, VICMD *));
 238  */
 239 int
 240 v_wordE(SCR *sp, VICMD *vp)
 241 {
 242         return (eword(sp, vp, BIGWORD));
 243 }
 244
 245 /*
 246  * v_worde -- [count]e
 247  *      Move forward to the end of the word.
 248  *
 249  * PUBLIC: int v_worde __P((SCR *, VICMD *));
 250  */
 251 int
 252 v_worde(SCR *sp, VICMD *vp)
 253 {
 254         return (eword(sp, vp, LITTLEWORD));
 255 }
 256
 257 /*
 258  * eword --
 259  *      Move forward to the end of the word.
 260  */
 261 static int
 262 eword(SCR *sp, VICMD *vp, enum which type)
 263 {
 264         enum { INWORD, NOTWORD } state;
 265         VCS cs;
 266         u_long cnt;
 267
 268         cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
 269         cs.cs_lno = vp->m_start.lno;
 270         cs.cs_cno = vp->m_start.cno;
 271         if (cs_init(sp, &cs))
 272                 return (1);
 273
 274         /*
 275          * !!!
 276          * If in whitespace, or the next character is whitespace, move past
 277          * it.  (This doesn't count as a word move.)  Stay at the character
 278          * past the current one, it sets word "state" for the 'e' command.
 279          */
 280         if (cs.cs_flags == 0 && !isblank(cs.cs_ch)) {
 281                 if (cs_next(sp, &cs))
 282                         return (1);
 283                 if (cs.cs_flags == 0 && !isblank(cs.cs_ch))
 284                         goto start;
 285         }
 286         if (cs_fblank(sp, &cs))
 287                 return (1);
 288
 289         /*
 290          * Cyclically move to the next word -- this involves skipping
 291          * over word characters and then any trailing non-word characters.
 292          * Note, for the 'e' command, the definition of a word keeps
 293          * switching.
 294          */
 295 start:  if (type == BIGWORD)
 296                 while (cnt--) {
 297                         for (;;) {
 298                                 if (cs_next(sp, &cs))
 299                                         return (1);
 300                                 if (cs.cs_flags == CS_EOF)
 301                                         goto ret;
 302                                 if (cs.cs_flags != 0 || isblank(cs.cs_ch))
 303                                         break;
 304                         }
 305                         /*
 306                          * When we reach the start of the word after the last
 307                          * word, we're done.  If we changed state, back up one
 308                          * to the end of the previous word.
 309                          */
 310                         if (cnt == 0) {
 311                                 if (cs.cs_flags == 0 && cs_prev(sp, &cs))
 312                                         return (1);
 313                                 break;
 314                         }
 315
 316                         /* Eat whitespace characters. */
 317                         if (cs_fblank(sp, &cs))
 318                                 return (1);
 319                         if (cs.cs_flags == CS_EOF)
 320                                 goto ret;
 321                 }
 322         else
 323                 while (cnt--) {
 324                         state = cs.cs_flags == 0 &&
 325                             inword(cs.cs_ch) ? INWORD : NOTWORD;
 326                         for (;;) {
 327                                 if (cs_next(sp, &cs))
 328                                         return (1);
 329                                 if (cs.cs_flags == CS_EOF)
 330                                         goto ret;
 331                                 if (cs.cs_flags != 0 || isblank(cs.cs_ch))
 332                                         break;
 333                                 if (state == INWORD) {
 334                                         if (!inword(cs.cs_ch))
 335                                                 break;
 336                                 } else
 337                                         if (inword(cs.cs_ch))
 338                                                 break;
 339                         }
 340                         /* See comment above. */
 341                         if (cnt == 0) {
 342                                 if (cs.cs_flags == 0 && cs_prev(sp, &cs))
 343                                         return (1);
 344                                 break;
 345                         }
 346
 347                         /* Eat whitespace characters. */
 348                         if (cs.cs_flags != 0 || isblank(cs.cs_ch))
 349                                 if (cs_fblank(sp, &cs))
 350                                         return (1);
 351                         if (cs.cs_flags == CS_EOF)
 352                                 goto ret;
 353                 }
 354
 355         /*
 356          * If we didn't move, we must be at EOF.
 357          *
 358          * !!!
 359          * That's okay for motion commands, however.
 360          */
 361 ret:    if (!ISMOTION(vp) &&
 362             cs.cs_lno == vp->m_start.lno && cs.cs_cno == vp->m_start.cno) {
 363                 v_eof(sp, &vp->m_start);
 364                 return (1);
 365         }
 366
 367         /* Set the end of the range for motion commands. */
 368         vp->m_stop.lno = cs.cs_lno;
 369         vp->m_stop.cno = cs.cs_cno;
 370
 371         /*
 372          * Non-motion commands move to the end of the range.
 373          * Delete and yank stay at the start, ignore others.
 374          */
 375         vp->m_final = ISMOTION(vp) ? vp->m_start : vp->m_stop;
 376         return (0);
 377 }
 378
 379 /*
 380  * v_WordB -- [count]B
 381  *      Move backward a bigword at a time.
 382  *
 383  * PUBLIC: int v_wordB __P((SCR *, VICMD *));
 384  */
 385 int
 386 v_wordB(SCR *sp, VICMD *vp)
 387 {
 388         return (bword(sp, vp, BIGWORD));
 389 }
 390
 391 /*
 392  * v_wordb -- [count]b
 393  *      Move backward a word at a time.
 394  *
 395  * PUBLIC: int v_wordb __P((SCR *, VICMD *));
 396  */
 397 int
 398 v_wordb(SCR *sp, VICMD *vp)
 399 {
 400         return (bword(sp, vp, LITTLEWORD));
 401 }
 402
 403 /*
 404  * bword --
 405  *      Move backward by words.
 406  */
 407 static int
 408 bword(SCR *sp, VICMD *vp, enum which type)
 409 {
 410         enum { INWORD, NOTWORD } state;
 411         VCS cs;
 412         u_long cnt;
 413
 414         cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
 415         cs.cs_lno = vp->m_start.lno;
 416         cs.cs_cno = vp->m_start.cno;
 417         if (cs_init(sp, &cs))
 418                 return (1);
 419
 420         /*
 421          * !!!
 422          * If in whitespace, or the previous character is whitespace, move
 423          * past it.  (This doesn't count as a word move.)  Stay at the
 424          * character before the current one, it sets word "state" for the
 425          * 'b' command.
 426          */
 427         if (cs.cs_flags == 0 && !isblank(cs.cs_ch)) {
 428                 if (cs_prev(sp, &cs))
 429                         return (1);
 430                 if (cs.cs_flags == 0 && !isblank(cs.cs_ch))
 431                         goto start;
 432         }
 433         if (cs_bblank(sp, &cs))
 434                 return (1);
 435
 436         /*
 437          * Cyclically move to the beginning of the previous word -- this
 438          * involves skipping over word characters and then any trailing
 439          * non-word characters.  Note, for the 'b' command, the definition
 440          * of a word keeps switching.
 441          */
 442 start:  if (type == BIGWORD)
 443                 while (cnt--) {
 444                         for (;;) {
 445                                 if (cs_prev(sp, &cs))
 446                                         return (1);
 447                                 if (cs.cs_flags == CS_SOF)
 448                                         goto ret;
 449                                 if (cs.cs_flags != 0 || isblank(cs.cs_ch))
 450                                         break;
 451                         }
 452                         /*
 453                          * When we reach the end of the word before the last
 454                          * word, we're done.  If we changed state, move forward
 455                          * one to the end of the next word.
 456                          */
 457                         if (cnt == 0) {
 458                                 if (cs.cs_flags == 0 && cs_next(sp, &cs))
 459                                         return (1);
 460                                 break;
 461                         }
 462
 463                         /* Eat whitespace characters. */
 464                         if (cs_bblank(sp, &cs))
 465                                 return (1);
 466                         if (cs.cs_flags == CS_SOF)
 467                                 goto ret;
 468                 }
 469         else
 470                 while (cnt--) {
 471                         state = cs.cs_flags == 0 &&
 472                             inword(cs.cs_ch) ? INWORD : NOTWORD;
 473                         for (;;) {
 474                                 if (cs_prev(sp, &cs))
 475                                         return (1);
 476                                 if (cs.cs_flags == CS_SOF)
 477                                         goto ret;
 478                                 if (cs.cs_flags != 0 || isblank(cs.cs_ch))
 479                                         break;
 480                                 if (state == INWORD) {
 481                                         if (!inword(cs.cs_ch))
 482                                                 break;
 483                                 } else
 484                                         if (inword(cs.cs_ch))
 485                                                 break;
 486                         }
 487                         /* See comment above. */
 488                         if (cnt == 0) {
 489                                 if (cs.cs_flags == 0 && cs_next(sp, &cs))
 490                                         return (1);
 491                                 break;
 492                         }
 493
 494                         /* Eat whitespace characters. */
 495                         if (cs.cs_flags != 0 || isblank(cs.cs_ch))
 496                                 if (cs_bblank(sp, &cs))
 497                                         return (1);
 498                         if (cs.cs_flags == CS_SOF)
 499                                 goto ret;
 500                 }
 501
 502         /* If we didn't move, we must be at SOF. */
 503 ret:    if (cs.cs_lno == vp->m_start.lno && cs.cs_cno == vp->m_start.cno) {
 504                 v_sof(sp, &vp->m_start);
 505                 return (1);
 506         }
 507
 508         /* Set the end of the range for motion commands. */
 509         vp->m_stop.lno = cs.cs_lno;
 510         vp->m_stop.cno = cs.cs_cno;
 511
 512         /*
 513          * All commands move to the end of the range.  Motion commands
 514          * adjust the starting point to the character before the current
 515          * one.
 516          *
 517          * !!!
 518          * The historic vi didn't get this right -- the `yb' command yanked
 519          * the right stuff and even updated the cursor value, but the cursor
 520          * was not actually updated on the screen.
 521          */
 522         vp->m_final = vp->m_stop;
 523         if (ISMOTION(vp))
 524                 --vp->m_start.cno;
 525         return (0);
 526 }