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 10.5 1996/03/06 19:54:48 bostic Exp $ (Berkeley) $Date: 1996/03/06 19:54:48 $";
  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(sp, vp)
  81         SCR *sp;
  82         VICMD *vp;
  83 {
  84         return (fword(sp, vp, BIGWORD));
  85 }
  86
  87 /*
  88  * v_wordw -- [count]w
  89  *      Move forward a word at a time.
  90  *
  91  * PUBLIC: int v_wordw __P((SCR *, VICMD *));
  92  */
  93 int
  94 v_wordw(sp, vp)
  95         SCR *sp;
  96         VICMD *vp;
  97 {
  98         return (fword(sp, vp, LITTLEWORD));
  99 }
 100
 101 /*
 102  * fword --
 103  *      Move forward by words.
 104  */
 105 static int
 106 fword(sp, vp, type)
 107         SCR *sp;
 108         VICMD *vp;
 109         enum which type;
 110 {
 111         enum { INWORD, NOTWORD } state;
 112         VCS cs;
 113         u_long cnt;
 114
 115         cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
 116         cs.cs_lno = vp->m_start.lno;
 117         cs.cs_cno = vp->m_start.cno;
 118         if (cs_init(sp, &cs))
 119                 return (1);
 120
 121         /*
 122          * If in white-space:
 123          *      If the count is 1, and it's a change command, we're done.
 124          *      Else, move to the first non-white-space character, which
 125          *      counts as a single word move.  If it's a motion command,
 126          *      don't move off the end of the line.
 127          */
 128         if (cs.cs_flags == CS_EMP || cs.cs_flags == 0 && isblank(cs.cs_ch)) {
 129                 if (ISMOTION(vp) && cs.cs_flags != CS_EMP && cnt == 1) {
 130                         if (ISCMD(vp->rkp, 'c'))
 131                                 return (0);
 132                         if (ISCMD(vp->rkp, 'd') || ISCMD(vp->rkp, 'y')) {
 133                                 if (cs_fspace(sp, &cs))
 134                                         return (1);
 135                                 goto ret;
 136                         }
 137                 }
 138                 if (cs_fblank(sp, &cs))
 139                         return (1);
 140                 --cnt;
 141         }
 142
 143         /*
 144          * Cyclically move to the next word -- this involves skipping
 145          * over word characters and then any trailing non-word characters.
 146          * Note, for the 'w' command, the definition of a word keeps
 147          * switching.
 148          */
 149         if (type == BIGWORD)
 150                 while (cnt--) {
 151                         for (;;) {
 152                                 if (cs_next(sp, &cs))
 153                                         return (1);
 154                                 if (cs.cs_flags == CS_EOF)
 155                                         goto ret;
 156                                 if (cs.cs_flags != 0 || isblank(cs.cs_ch))
 157                                         break;
 158                         }
 159                         /*
 160                          * If a motion command and we're at the end of the
 161                          * last word, we're done.  Delete and yank eat any
 162                          * trailing blanks, but we don't move off the end
 163                          * of the line regardless.
 164                          */
 165                         if (cnt == 0 && ISMOTION(vp)) {
 166                                 if ((ISCMD(vp->rkp, 'd') ||
 167                                     ISCMD(vp->rkp, 'y')) &&
 168                                     cs_fspace(sp, &cs))
 169                                         return (1);
 170                                 break;
 171                         }
 172
 173                         /* Eat whitespace characters. */
 174                         if (cs_fblank(sp, &cs))
 175                                 return (1);
 176                         if (cs.cs_flags == CS_EOF)
 177                                 goto ret;
 178                 }
 179         else
 180                 while (cnt--) {
 181                         state = cs.cs_flags == 0 &&
 182                             inword(cs.cs_ch) ? INWORD : NOTWORD;
 183                         for (;;) {
 184                                 if (cs_next(sp, &cs))
 185                                         return (1);
 186                                 if (cs.cs_flags == CS_EOF)
 187                                         goto ret;
 188                                 if (cs.cs_flags != 0 || isblank(cs.cs_ch))
 189                                         break;
 190                                 if (state == INWORD) {
 191                                         if (!inword(cs.cs_ch))
 192                                                 break;
 193                                 } else
 194                                         if (inword(cs.cs_ch))
 195                                                 break;
 196                         }
 197                         /* See comment above. */
 198                         if (cnt == 0 && ISMOTION(vp)) {
 199                                 if ((ISCMD(vp->rkp, 'd') ||
 200                                     ISCMD(vp->rkp, 'y')) &&
 201                                     cs_fspace(sp, &cs))
 202                                         return (1);
 203                                 break;
 204                         }
 205
 206                         /* Eat whitespace characters. */
 207                         if (cs.cs_flags != 0 || isblank(cs.cs_ch))
 208                                 if (cs_fblank(sp, &cs))
 209                                         return (1);
 210                         if (cs.cs_flags == CS_EOF)
 211                                 goto ret;
 212                 }
 213
 214         /*
 215          * If we didn't move, we must be at EOF.
 216          *
 217          * !!!
 218          * That's okay for motion commands, however.
 219          */
 220 ret:    if (!ISMOTION(vp) &&
 221             cs.cs_lno == vp->m_start.lno && cs.cs_cno == vp->m_start.cno) {
 222                 v_eof(sp, &vp->m_start);
 223                 return (1);
 224         }
 225
 226         /* Adjust the end of the range for motion commands. */
 227         vp->m_stop.lno = cs.cs_lno;
 228         vp->m_stop.cno = cs.cs_cno;
 229         if (ISMOTION(vp) && cs.cs_flags == 0)
 230                 --vp->m_stop.cno;
 231
 232         /*
 233          * Non-motion commands move to the end of the range.  Delete
 234          * and yank stay at the start, ignore others.
 235          */
 236         vp->m_final = ISMOTION(vp) ? vp->m_start : vp->m_stop;
 237         return (0);
 238 }
 239
 240 /*
 241  * v_wordE -- [count]E
 242  *      Move forward to the end of the bigword.
 243  *
 244  * PUBLIC: int v_wordE __P((SCR *, VICMD *));
 245  */
 246 int
 247 v_wordE(sp, vp)
 248         SCR *sp;
 249         VICMD *vp;
 250 {
 251         return (eword(sp, vp, BIGWORD));
 252 }
 253
 254 /*
 255  * v_worde -- [count]e
 256  *      Move forward to the end of the word.
 257  *
 258  * PUBLIC: int v_worde __P((SCR *, VICMD *));
 259  */
 260 int
 261 v_worde(sp, vp)
 262         SCR *sp;
 263         VICMD *vp;
 264 {
 265         return (eword(sp, vp, LITTLEWORD));
 266 }
 267
 268 /*
 269  * eword --
 270  *      Move forward to the end of the word.
 271  */
 272 static int
 273 eword(sp, vp, type)
 274         SCR *sp;
 275         VICMD *vp;
 276         enum which type;
 277 {
 278         enum { INWORD, NOTWORD } state;
 279         VCS cs;
 280         u_long cnt;
 281
 282         cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
 283         cs.cs_lno = vp->m_start.lno;
 284         cs.cs_cno = vp->m_start.cno;
 285         if (cs_init(sp, &cs))
 286                 return (1);
 287
 288         /*
 289          * !!!
 290          * If in whitespace, or the next character is whitespace, move past
 291          * it.  (This doesn't count as a word move.)  Stay at the character
 292          * past the current one, it sets word "state" for the 'e' command.
 293          */
 294         if (cs.cs_flags == 0 && !isblank(cs.cs_ch)) {
 295                 if (cs_next(sp, &cs))
 296                         return (1);
 297                 if (cs.cs_flags == 0 && !isblank(cs.cs_ch))
 298                         goto start;
 299         }
 300         if (cs_fblank(sp, &cs))
 301                 return (1);
 302
 303         /*
 304          * Cyclically move to the next word -- this involves skipping
 305          * over word characters and then any trailing non-word characters.
 306          * Note, for the 'e' command, the definition of a word keeps
 307          * switching.
 308          */
 309 start:  if (type == BIGWORD)
 310                 while (cnt--) {
 311                         for (;;) {
 312                                 if (cs_next(sp, &cs))
 313                                         return (1);
 314                                 if (cs.cs_flags == CS_EOF)
 315                                         goto ret;
 316                                 if (cs.cs_flags != 0 || isblank(cs.cs_ch))
 317                                         break;
 318                         }
 319                         /*
 320                          * When we reach the start of the word after the last
 321                          * word, we're done.  If we changed state, back up one
 322                          * to the end of the previous word.
 323                          */
 324                         if (cnt == 0) {
 325                                 if (cs.cs_flags == 0 && cs_prev(sp, &cs))
 326                                         return (1);
 327                                 break;
 328                         }
 329
 330                         /* Eat whitespace characters. */
 331                         if (cs_fblank(sp, &cs))
 332                                 return (1);
 333                         if (cs.cs_flags == CS_EOF)
 334                                 goto ret;
 335                 }
 336         else
 337                 while (cnt--) {
 338                         state = cs.cs_flags == 0 &&
 339                             inword(cs.cs_ch) ? INWORD : NOTWORD;
 340                         for (;;) {
 341                                 if (cs_next(sp, &cs))
 342                                         return (1);
 343                                 if (cs.cs_flags == CS_EOF)
 344                                         goto ret;
 345                                 if (cs.cs_flags != 0 || isblank(cs.cs_ch))
 346                                         break;
 347                                 if (state == INWORD) {
 348                                         if (!inword(cs.cs_ch))
 349                                                 break;
 350                                 } else
 351                                         if (inword(cs.cs_ch))
 352                                                 break;
 353                         }
 354                         /* See comment above. */
 355                         if (cnt == 0) {
 356                                 if (cs.cs_flags == 0 && cs_prev(sp, &cs))
 357                                         return (1);
 358                                 break;
 359                         }
 360
 361                         /* Eat whitespace characters. */
 362                         if (cs.cs_flags != 0 || isblank(cs.cs_ch))
 363                                 if (cs_fblank(sp, &cs))
 364                                         return (1);
 365                         if (cs.cs_flags == CS_EOF)
 366                                 goto ret;
 367                 }
 368
 369         /*
 370          * If we didn't move, we must be at EOF.
 371          *
 372          * !!!
 373          * That's okay for motion commands, however.
 374          */
 375 ret:    if (!ISMOTION(vp) &&
 376             cs.cs_lno == vp->m_start.lno && cs.cs_cno == vp->m_start.cno) {
 377                 v_eof(sp, &vp->m_start);
 378                 return (1);
 379         }
 380
 381         /* Set the end of the range for motion commands. */
 382         vp->m_stop.lno = cs.cs_lno;
 383         vp->m_stop.cno = cs.cs_cno;
 384
 385         /*
 386          * Non-motion commands move to the end of the range.
 387          * Delete and yank stay at the start, ignore others.
 388          */
 389         vp->m_final = ISMOTION(vp) ? vp->m_start : vp->m_stop;
 390         return (0);
 391 }
 392
 393 /*
 394  * v_WordB -- [count]B
 395  *      Move backward a bigword at a time.
 396  *
 397  * PUBLIC: int v_wordB __P((SCR *, VICMD *));
 398  */
 399 int
 400 v_wordB(sp, vp)
 401         SCR *sp;
 402         VICMD *vp;
 403 {
 404         return (bword(sp, vp, BIGWORD));
 405 }
 406
 407 /*
 408  * v_wordb -- [count]b
 409  *      Move backward a word at a time.
 410  *
 411  * PUBLIC: int v_wordb __P((SCR *, VICMD *));
 412  */
 413 int
 414 v_wordb(sp, vp)
 415         SCR *sp;
 416         VICMD *vp;
 417 {
 418         return (bword(sp, vp, LITTLEWORD));
 419 }
 420
 421 /*
 422  * bword --
 423  *      Move backward by words.
 424  */
 425 static int
 426 bword(sp, vp, type)
 427         SCR *sp;
 428         VICMD *vp;
 429         enum which type;
 430 {
 431         enum { INWORD, NOTWORD } state;
 432         VCS cs;
 433         u_long cnt;
 434
 435         cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
 436         cs.cs_lno = vp->m_start.lno;
 437         cs.cs_cno = vp->m_start.cno;
 438         if (cs_init(sp, &cs))
 439                 return (1);
 440
 441         /*
 442          * !!!
 443          * If in whitespace, or the previous character is whitespace, move
 444          * past it.  (This doesn't count as a word move.)  Stay at the
 445          * character before the current one, it sets word "state" for the
 446          * 'b' command.
 447          */
 448         if (cs.cs_flags == 0 && !isblank(cs.cs_ch)) {
 449                 if (cs_prev(sp, &cs))
 450                         return (1);
 451                 if (cs.cs_flags == 0 && !isblank(cs.cs_ch))
 452                         goto start;
 453         }
 454         if (cs_bblank(sp, &cs))
 455                 return (1);
 456
 457         /*
 458          * Cyclically move to the beginning of the previous word -- this
 459          * involves skipping over word characters and then any trailing
 460          * non-word characters.  Note, for the 'b' command, the definition
 461          * of a word keeps switching.
 462          */
 463 start:  if (type == BIGWORD)
 464                 while (cnt--) {
 465                         for (;;) {
 466                                 if (cs_prev(sp, &cs))
 467                                         return (1);
 468                                 if (cs.cs_flags == CS_SOF)
 469                                         goto ret;
 470                                 if (cs.cs_flags != 0 || isblank(cs.cs_ch))
 471                                         break;
 472                         }
 473                         /*
 474                          * When we reach the end of the word before the last
 475                          * word, we're done.  If we changed state, move forward
 476                          * one to the end of the next word.
 477                          */
 478                         if (cnt == 0) {
 479                                 if (cs.cs_flags == 0 && cs_next(sp, &cs))
 480                                         return (1);
 481                                 break;
 482                         }
 483
 484                         /* Eat whitespace characters. */
 485                         if (cs_bblank(sp, &cs))
 486                                 return (1);
 487                         if (cs.cs_flags == CS_SOF)
 488                                 goto ret;
 489                 }
 490         else
 491                 while (cnt--) {
 492                         state = cs.cs_flags == 0 &&
 493                             inword(cs.cs_ch) ? INWORD : NOTWORD;
 494                         for (;;) {
 495                                 if (cs_prev(sp, &cs))
 496                                         return (1);
 497                                 if (cs.cs_flags == CS_SOF)
 498                                         goto ret;
 499                                 if (cs.cs_flags != 0 || isblank(cs.cs_ch))
 500                                         break;
 501                                 if (state == INWORD) {
 502                                         if (!inword(cs.cs_ch))
 503                                                 break;
 504                                 } else
 505                                         if (inword(cs.cs_ch))
 506                                                 break;
 507                         }
 508                         /* See comment above. */
 509                         if (cnt == 0) {
 510                                 if (cs.cs_flags == 0 && cs_next(sp, &cs))
 511                                         return (1);
 512                                 break;
 513                         }
 514
 515                         /* Eat whitespace characters. */
 516                         if (cs.cs_flags != 0 || isblank(cs.cs_ch))
 517                                 if (cs_bblank(sp, &cs))
 518                                         return (1);
 519                         if (cs.cs_flags == CS_SOF)
 520                                 goto ret;
 521                 }
 522
 523         /* If we didn't move, we must be at SOF. */
 524 ret:    if (cs.cs_lno == vp->m_start.lno && cs.cs_cno == vp->m_start.cno) {
 525                 v_sof(sp, &vp->m_start);
 526                 return (1);
 527         }
 528
 529         /* Set the end of the range for motion commands. */
 530         vp->m_stop.lno = cs.cs_lno;
 531         vp->m_stop.cno = cs.cs_cno;
 532
 533         /*
 534          * All commands move to the end of the range.  Motion commands
 535          * adjust the starting point to the character before the current
 536          * one.
 537          *
 538          * !!!
 539          * The historic vi didn't get this right -- the `yb' command yanked
 540          * the right stuff and even updated the cursor value, but the cursor
 541          * was not actually updated on the screen.
 542          */
 543         vp->m_final = vp->m_stop;
 544         if (ISMOTION(vp))
 545                 --vp->m_start.cno;
 546         return (0);
 547 }