src/cmds.c

   1 /* Simple built-in editing commands.
   2
   3 Copyright (C) 1985, 1993-1998, 2001-2014 Free Software Foundation, Inc.
   4
   5 This file is part of GNU Emacs.
   6
   7 GNU Emacs is free software: you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation, either version 3 of the License, or
  10 (at your option) any later version.
  11
  12 GNU Emacs is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20
  21 #include <config.h>
  22
  23 #include "lisp.h"
  24 #include "commands.h"
  25 #include "character.h"
  26 #include "buffer.h"
  27 #include "syntax.h"
  28 #include "window.h"
  29 #include "keyboard.h"
  30 #include "keymap.h"
  31 #include "dispextern.h"
  32 #include "frame.h"
  33
  34 static Lisp_Object Qkill_forward_chars, Qkill_backward_chars;
  35
  36 /* A possible value for a buffer's overwrite-mode variable.  */
  37 static Lisp_Object Qoverwrite_mode_binary;
  38
  39 static int internal_self_insert (int, EMACS_INT);
  40 \f
  41 DEFUN ("forward-point", Fforward_point, Sforward_point, 1, 1, 0,
  42        doc: /* Return buffer position N characters after (before if N negative) point.  */)
  43   (Lisp_Object n)
  44 {
  45   CHECK_NUMBER (n);
  46
  47   return make_number (PT + XINT (n));
  48 }
  49
  50 /* Add N to point; or subtract N if FORWARD is false.  N defaults to 1.
  51    Validate the new location.  Return nil.  */
  52 static Lisp_Object
  53 move_point (Lisp_Object n, bool forward)
  54 {
  55   /* This used to just set point to point + XINT (n), and then check
  56      to see if it was within boundaries.  But now that SET_PT can
  57      potentially do a lot of stuff (calling entering and exiting
  58      hooks, etcetera), that's not a good approach.  So we validate the
  59      proposed position, then set point.  */
  60
  61   EMACS_INT new_point;
  62
  63   if (NILP (n))
  64     XSETFASTINT (n, 1);
  65   else
  66     CHECK_NUMBER (n);
  67
  68   new_point = PT + (forward ? XINT (n) : - XINT (n));
  69
  70   if (new_point < BEGV)
  71     {
  72       SET_PT (BEGV);
  73       xsignal0 (Qbeginning_of_buffer);
  74     }
  75   if (new_point > ZV)
  76     {
  77       SET_PT (ZV);
  78       xsignal0 (Qend_of_buffer);
  79     }
  80
  81   SET_PT (new_point);
  82   return Qnil;
  83 }
  84
  85 DEFUN ("forward-char", Fforward_char, Sforward_char, 0, 1, "^p",
  86        doc: /* Move point N characters forward (backward if N is negative).
  87 On reaching end or beginning of buffer, stop and signal error.
  88 Interactively, N is the numeric prefix argument.
  89 If N is omitted or nil, move point 1 character forward.
  90
  91 Depending on the bidirectional context, the movement may be to the
  92 right or to the left on the screen.  This is in contrast with
  93 \\[right-char], which see.  */)
  94   (Lisp_Object n)
  95 {
  96   return move_point (n, 1);
  97 }
  98
  99 DEFUN ("backward-char", Fbackward_char, Sbackward_char, 0, 1, "^p",
 100        doc: /* Move point N characters backward (forward if N is negative).
 101 On attempt to pass beginning or end of buffer, stop and signal error.
 102 Interactively, N is the numeric prefix argument.
 103 If N is omitted or nil, move point 1 character backward.
 104
 105 Depending on the bidirectional context, the movement may be to the
 106 right or to the left on the screen.  This is in contrast with
 107 \\[left-char], which see.  */)
 108   (Lisp_Object n)
 109 {
 110   return move_point (n, 0);
 111 }
 112
 113 DEFUN ("forward-line", Fforward_line, Sforward_line, 0, 1, "^p",
 114        doc: /* Move N lines forward (backward if N is negative).
 115 Precisely, if point is on line I, move to the start of line I + N
 116 \("start of line" in the logical order).
 117 If there isn't room, go as far as possible (no error).
 118 Returns the count of lines left to move.  If moving forward,
 119 that is N - number of lines moved; if backward, N + number moved.
 120 With positive N, a non-empty line at the end counts as one line
 121 successfully moved (for the return value).  */)
 122   (Lisp_Object n)
 123 {
 124   ptrdiff_t opoint = PT, pos, pos_byte, shortage, count;
 125
 126   if (NILP (n))
 127     count = 1;
 128   else
 129     {
 130       CHECK_NUMBER (n);
 131       count = XINT (n);
 132     }
 133
 134   shortage = scan_newline_from_point (count, &pos, &pos_byte);
 135
 136   SET_PT_BOTH (pos, pos_byte);
 137
 138   if (shortage > 0
 139       && (count <= 0
 140           || (ZV > BEGV
 141               && PT != opoint
 142               && (FETCH_BYTE (PT_BYTE - 1) != '\n'))))
 143     shortage--;
 144
 145   return make_number (count <= 0 ? - shortage : shortage);
 146 }
 147
 148 DEFUN ("beginning-of-line", Fbeginning_of_line, Sbeginning_of_line, 0, 1, "^p",
 149        doc: /* Move point to beginning of current line (in the logical order).
 150 With argument N not nil or 1, move forward N - 1 lines first.
 151 If point reaches the beginning or end of buffer, it stops there.
 152
 153 This function constrains point to the current field unless this moves
 154 point to a different line than the original, unconstrained result.
 155 If N is nil or 1, and a front-sticky field starts at point, the point
 156 does not move.  To ignore field boundaries bind
 157 `inhibit-field-text-motion' to t, or use the `forward-line' function
 158 instead.  For instance, `(forward-line 0)' does the same thing as
 159 `(beginning-of-line)', except that it ignores field boundaries.  */)
 160   (Lisp_Object n)
 161 {
 162   if (NILP (n))
 163     XSETFASTINT (n, 1);
 164   else
 165     CHECK_NUMBER (n);
 166
 167   SET_PT (XINT (Fline_beginning_position (n)));
 168
 169   return Qnil;
 170 }
 171
 172 DEFUN ("end-of-line", Fend_of_line, Send_of_line, 0, 1, "^p",
 173        doc: /* Move point to end of current line (in the logical order).
 174 With argument N not nil or 1, move forward N - 1 lines first.
 175 If point reaches the beginning or end of buffer, it stops there.
 176 To ignore intangibility, bind `inhibit-point-motion-hooks' to t.
 177
 178 This function constrains point to the current field unless this moves
 179 point to a different line than the original, unconstrained result.  If
 180 N is nil or 1, and a rear-sticky field ends at point, the point does
 181 not move.  To ignore field boundaries bind `inhibit-field-text-motion'
 182 to t.  */)
 183   (Lisp_Object n)
 184 {
 185   ptrdiff_t newpos;
 186
 187   if (NILP (n))
 188     XSETFASTINT (n, 1);
 189   else
 190     CHECK_NUMBER (n);
 191
 192   while (1)
 193     {
 194       newpos = XINT (Fline_end_position (n));
 195       SET_PT (newpos);
 196
 197       if (PT > newpos
 198           && FETCH_CHAR (PT - 1) == '\n')
 199         {
 200           /* If we skipped over a newline that follows
 201              an invisible intangible run,
 202              move back to the last tangible position
 203              within the line.  */
 204
 205           SET_PT (PT - 1);
 206           break;
 207         }
 208       else if (PT > newpos && PT < ZV
 209                && FETCH_CHAR (PT) != '\n')
 210         /* If we skipped something intangible
 211            and now we're not really at eol,
 212            keep going.  */
 213         n = make_number (1);
 214       else
 215         break;
 216     }
 217
 218   return Qnil;
 219 }
 220
 221 DEFUN ("delete-char", Fdelete_char, Sdelete_char, 1, 2, "p\nP",
 222        doc: /* Delete the following N characters (previous if N is negative).
 223 Optional second arg KILLFLAG non-nil means kill instead (save in kill ring).
 224 Interactively, N is the prefix arg, and KILLFLAG is set if
 225 N was explicitly specified.
 226
 227 The command `delete-forward-char' is preferable for interactive use, e.g.
 228 because it respects values of `delete-active-region' and `overwrite-mode'.  */)
 229   (Lisp_Object n, Lisp_Object killflag)
 230 {
 231   EMACS_INT pos;
 232
 233   CHECK_NUMBER (n);
 234
 235   pos = PT + XINT (n);
 236   if (NILP (killflag))
 237     {
 238       if (XINT (n) < 0)
 239         {
 240           if (pos < BEGV)
 241             xsignal0 (Qbeginning_of_buffer);
 242           else
 243             del_range (pos, PT);
 244         }
 245       else
 246         {
 247           if (pos > ZV)
 248             xsignal0 (Qend_of_buffer);
 249           else
 250             del_range (PT, pos);
 251         }
 252     }
 253   else
 254     {
 255       call1 (Qkill_forward_chars, n);
 256     }
 257   return Qnil;
 258 }
 259
 260 static int nonundocount;
 261
 262 /* Note that there's code in command_loop_1 which typically avoids
 263    calling this.  */
 264 DEFUN ("self-insert-command", Fself_insert_command, Sself_insert_command, 1, 1, "p",
 265        doc: /* Insert the character you type.
 266 Whichever character you type to run this command is inserted.
 267 The numeric prefix argument N says how many times to repeat the insertion.
 268 Before insertion, `expand-abbrev' is executed if the inserted character does
 269 not have word syntax and the previous character in the buffer does.
 270 After insertion, the value of `auto-fill-function' is called if the
 271 `auto-fill-chars' table has a non-nil value for the inserted character.
 272 At the end, it runs `post-self-insert-hook'.  */)
 273   (Lisp_Object n)
 274 {
 275   bool remove_boundary = 1;
 276   CHECK_NUMBER (n);
 277
 278   if (XFASTINT (n) < 0)
 279     error ("Negative repetition argument %"pI"d", XFASTINT (n));
 280
 281   if (!EQ (Vthis_command, KVAR (current_kboard, Vlast_command)))
 282     nonundocount = 0;
 283
 284   if (NILP (Vexecuting_kbd_macro)
 285       && !EQ (minibuf_window, selected_window))
 286     {
 287       if (nonundocount <= 0 || nonundocount >= 20)
 288         {
 289           remove_boundary = 0;
 290           nonundocount = 0;
 291         }
 292       nonundocount++;
 293     }
 294
 295   if (remove_boundary
 296       && CONSP (BVAR (current_buffer, undo_list))
 297       && NILP (XCAR (BVAR (current_buffer, undo_list)))
 298       /* Only remove auto-added boundaries, not boundaries
 299          added be explicit calls to undo-boundary.  */
 300       && EQ (BVAR (current_buffer, undo_list), last_undo_boundary))
 301     /* Remove the undo_boundary that was just pushed.  */
 302     bset_undo_list (current_buffer, XCDR (BVAR (current_buffer, undo_list)));
 303
 304   /* Barf if the key that invoked this was not a character.  */
 305   if (!CHARACTERP (last_command_event))
 306     bitch_at_user ();
 307   else {
 308     int character = translate_char (Vtranslation_table_for_input,
 309                                     XINT (last_command_event));
 310     int val = internal_self_insert (character, XFASTINT (n));
 311     if (val == 2)
 312       nonundocount = 0;
 313     frame_make_pointer_invisible (SELECTED_FRAME ());
 314   }
 315
 316   return Qnil;
 317 }
 318
 319 /* Insert N times character C
 320
 321    If this insertion is suitable for direct output (completely simple),
 322    return 0.  A value of 1 indicates this *might* not have been simple.
 323    A value of 2 means this did things that call for an undo boundary.  */
 324
 325 static Lisp_Object Qexpand_abbrev;
 326 static Lisp_Object Qpost_self_insert_hook;
 327
 328 static int
 329 internal_self_insert (int c, EMACS_INT n)
 330 {
 331   int hairy = 0;
 332   Lisp_Object tem;
 333   register enum syntaxcode synt;
 334   Lisp_Object overwrite;
 335   /* Length of multi-byte form of C.  */
 336   int len;
 337   /* Working buffer and pointer for multi-byte form of C.  */
 338   unsigned char str[MAX_MULTIBYTE_LENGTH];
 339   ptrdiff_t chars_to_delete = 0;
 340   ptrdiff_t spaces_to_insert = 0;
 341
 342   overwrite = BVAR (current_buffer, overwrite_mode);
 343   if (!NILP (Vbefore_change_functions) || !NILP (Vafter_change_functions))
 344     hairy = 1;
 345
 346   /* At first, get multi-byte form of C in STR.  */
 347   if (!NILP (BVAR (current_buffer, enable_multibyte_characters)))
 348     {
 349       len = CHAR_STRING (c, str);
 350       if (len == 1)
 351         /* If C has modifier bits, this makes C an appropriate
 352            one-byte char.  */
 353         c = *str;
 354     }
 355   else
 356     {
 357       str[0] = SINGLE_BYTE_CHAR_P (c) ? c : CHAR_TO_BYTE8 (c);
 358       len = 1;
 359     }
 360   if (!NILP (overwrite)
 361       && PT < ZV)
 362     {
 363       /* In overwrite-mode, we substitute a character at point (C2,
 364          hereafter) by C.  For that, we delete C2 in advance.  But,
 365          just substituting C2 by C may move a remaining text in the
 366          line to the right or to the left, which is not preferable.
 367          So we insert more spaces or delete more characters in the
 368          following cases: if C is narrower than C2, after deleting C2,
 369          we fill columns with spaces, if C is wider than C2, we delete
 370          C2 and several characters following C2.  */
 371
 372       /* This is the character after point.  */
 373       int c2 = FETCH_CHAR (PT_BYTE);
 374
 375       int cwidth;
 376
 377       /* Overwriting in binary-mode always replaces C2 by C.
 378          Overwriting in textual-mode doesn't always do that.
 379          It inserts newlines in the usual way,
 380          and inserts any character at end of line
 381          or before a tab if it doesn't use the whole width of the tab.  */
 382       if (EQ (overwrite, Qoverwrite_mode_binary))
 383         chars_to_delete = min (n, PTRDIFF_MAX);
 384       else if (c != '\n' && c2 != '\n'
 385                && (cwidth = XFASTINT (Fchar_width (make_number (c)))) != 0)
 386         {
 387           ptrdiff_t pos = PT;
 388           ptrdiff_t pos_byte = PT_BYTE;
 389           ptrdiff_t curcol = current_column ();
 390
 391           if (n <= (min (MOST_POSITIVE_FIXNUM, PTRDIFF_MAX) - curcol) / cwidth)
 392             {
 393               /* Column the cursor should be placed at after this insertion.
 394                  The value should be calculated only when necessary.  */
 395               ptrdiff_t target_clm = curcol + n * cwidth;
 396
 397               /* The actual cursor position after the trial of moving
 398                  to column TARGET_CLM.  It is greater than TARGET_CLM
 399                  if the TARGET_CLM is middle of multi-column
 400                  character.  In that case, the new point is set after
 401                  that character.  */
 402               ptrdiff_t actual_clm
 403                 = XFASTINT (Fmove_to_column (make_number (target_clm), Qnil));
 404
 405               chars_to_delete = PT - pos;
 406
 407               if (actual_clm > target_clm)
 408                 {
 409                   /* We will delete too many columns.  Let's fill columns
 410                      by spaces so that the remaining text won't move.  */
 411                   ptrdiff_t actual = PT_BYTE;
 412                   DEC_POS (actual);
 413                   if (FETCH_CHAR (actual) == '\t')
 414                     /* Rather than add spaces, let's just keep the tab. */
 415                     chars_to_delete--;
 416                   else
 417                     spaces_to_insert = actual_clm - target_clm;
 418                 }
 419
 420               SET_PT_BOTH (pos, pos_byte);
 421             }
 422         }
 423       hairy = 2;
 424     }
 425
 426   synt = SYNTAX (c);
 427
 428   if (!NILP (BVAR (current_buffer, abbrev_mode))
 429       && synt != Sword
 430       && NILP (BVAR (current_buffer, read_only))
 431       && PT > BEGV
 432       && (SYNTAX (!NILP (BVAR (current_buffer, enable_multibyte_characters))
 433                   ? XFASTINT (Fprevious_char ())
 434                   : UNIBYTE_TO_CHAR (XFASTINT (Fprevious_char ())))
 435           == Sword))
 436     {
 437       EMACS_INT modiff = MODIFF;
 438       Lisp_Object sym;
 439
 440       sym = call0 (Qexpand_abbrev);
 441
 442       /* If we expanded an abbrev which has a hook,
 443          and the hook has a non-nil `no-self-insert' property,
 444          return right away--don't really self-insert.  */
 445       if (SYMBOLP (sym) && ! NILP (sym)
 446           && ! NILP (XSYMBOL (sym)->function)
 447           && SYMBOLP (XSYMBOL (sym)->function))
 448         {
 449           Lisp_Object prop;
 450           prop = Fget (XSYMBOL (sym)->function, intern ("no-self-insert"));
 451           if (! NILP (prop))
 452             return 1;
 453         }
 454
 455       if (MODIFF != modiff)
 456         hairy = 2;
 457     }
 458
 459   if (chars_to_delete)
 460     {
 461       int mc = ((NILP (BVAR (current_buffer, enable_multibyte_characters))
 462                  && SINGLE_BYTE_CHAR_P (c))
 463                 ? UNIBYTE_TO_CHAR (c) : c);
 464       Lisp_Object string = Fmake_string (make_number (n), make_number (mc));
 465
 466       if (spaces_to_insert)
 467         {
 468           tem = Fmake_string (make_number (spaces_to_insert),
 469                               make_number (' '));
 470           string = concat2 (string, tem);
 471         }
 472
 473       replace_range (PT, PT + chars_to_delete, string, 1, 1, 1);
 474       Fforward_char (make_number (n + spaces_to_insert));
 475     }
 476   else if (n > 1)
 477     {
 478       USE_SAFE_ALLOCA;
 479       char *strn, *p;
 480       SAFE_NALLOCA (strn, len, n);
 481       for (p = strn; n > 0; n--, p += len)
 482         memcpy (p, str, len);
 483       insert_and_inherit (strn, p - strn);
 484       SAFE_FREE ();
 485     }
 486   else if (n > 0)
 487     insert_and_inherit ((char *) str, len);
 488
 489   if ((CHAR_TABLE_P (Vauto_fill_chars)
 490        ? !NILP (CHAR_TABLE_REF (Vauto_fill_chars, c))
 491        : (c == ' ' || c == '\n'))
 492       && !NILP (BVAR (current_buffer, auto_fill_function)))
 493     {
 494       Lisp_Object auto_fill_result;
 495
 496       if (c == '\n')
 497         /* After inserting a newline, move to previous line and fill
 498            that.  Must have the newline in place already so filling and
 499            justification, if any, know where the end is going to be.  */
 500         SET_PT_BOTH (PT - 1, PT_BYTE - 1);
 501       auto_fill_result = call0 (BVAR (current_buffer, auto_fill_function));
 502       /* Test PT < ZV in case the auto-fill-function is strange.  */
 503       if (c == '\n' && PT < ZV)
 504         SET_PT_BOTH (PT + 1, PT_BYTE + 1);
 505       if (!NILP (auto_fill_result))
 506         hairy = 2;
 507     }
 508
 509   /* Run hooks for electric keys.  */
 510   Frun_hooks (1, &Qpost_self_insert_hook);
 511
 512   return hairy;
 513 }
 514 \f
 515 /* module initialization */
 516
 517 void
 518 syms_of_cmds (void)
 519 {
 520   DEFSYM (Qkill_backward_chars, "kill-backward-chars");
 521   DEFSYM (Qkill_forward_chars, "kill-forward-chars");
 522   DEFSYM (Qoverwrite_mode_binary, "overwrite-mode-binary");
 523   DEFSYM (Qexpand_abbrev, "expand-abbrev");
 524   DEFSYM (Qpost_self_insert_hook, "post-self-insert-hook");
 525
 526   DEFVAR_LISP ("post-self-insert-hook", Vpost_self_insert_hook,
 527                doc: /* Hook run at the end of `self-insert-command'.
 528 This is run after inserting the character.  */);
 529   Vpost_self_insert_hook = Qnil;
 530
 531   defsubr (&Sforward_point);
 532   defsubr (&Sforward_char);
 533   defsubr (&Sbackward_char);
 534   defsubr (&Sforward_line);
 535   defsubr (&Sbeginning_of_line);
 536   defsubr (&Send_of_line);
 537
 538   defsubr (&Sdelete_char);
 539   defsubr (&Sself_insert_command);
 540 }
 541
 542 void
 543 keys_of_cmds (void)
 544 {
 545   int n;
 546
 547   nonundocount = 0;
 548   initial_define_key (global_map, Ctl ('I'), "self-insert-command");
 549   for (n = 040; n < 0177; n++)
 550     initial_define_key (global_map, n, "self-insert-command");
 551 #ifdef MSDOS
 552   for (n = 0200; n < 0240; n++)
 553     initial_define_key (global_map, n, "self-insert-command");
 554 #endif
 555   for (n = 0240; n < 0400; n++)
 556     initial_define_key (global_map, n, "self-insert-command");
 557
 558   initial_define_key (global_map, Ctl ('A'), "beginning-of-line");
 559   initial_define_key (global_map, Ctl ('B'), "backward-char");
 560   initial_define_key (global_map, Ctl ('E'), "end-of-line");
 561   initial_define_key (global_map, Ctl ('F'), "forward-char");
 562 }