src/cmds.c

   1 /* Simple built-in editing commands.
   2
   3 Copyright (C) 1985, 1993-1998, 2001-2013 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   if (count <= 0)
 135     pos = find_newline (PT, PT_BYTE, BEGV, BEGV_BYTE, count - 1,
 136                         &shortage, &pos_byte, 1);
 137   else
 138     pos = find_newline (PT, PT_BYTE, ZV, ZV_BYTE, count,
 139                         &shortage, &pos_byte, 1);
 140
 141   SET_PT_BOTH (pos, pos_byte);
 142
 143   if (shortage > 0
 144       && (count <= 0
 145           || (ZV > BEGV
 146               && PT != opoint
 147               && (FETCH_BYTE (PT_BYTE - 1) != '\n'))))
 148     shortage--;
 149
 150   return make_number (count <= 0 ? - shortage : shortage);
 151 }
 152
 153 DEFUN ("beginning-of-line", Fbeginning_of_line, Sbeginning_of_line, 0, 1, "^p",
 154        doc: /* Move point to beginning of current line (in the logical order).
 155 With argument N not nil or 1, move forward N - 1 lines first.
 156 If point reaches the beginning or end of buffer, it stops there.
 157
 158 This function constrains point to the current field unless this moves
 159 point to a different line than the original, unconstrained result.
 160 If N is nil or 1, and a front-sticky field starts at point, the point
 161 does not move.  To ignore field boundaries bind
 162 `inhibit-field-text-motion' to t, or use the `forward-line' function
 163 instead.  For instance, `(forward-line 0)' does the same thing as
 164 `(beginning-of-line)', except that it ignores field boundaries.  */)
 165   (Lisp_Object n)
 166 {
 167   if (NILP (n))
 168     XSETFASTINT (n, 1);
 169   else
 170     CHECK_NUMBER (n);
 171
 172   SET_PT (XINT (Fline_beginning_position (n)));
 173
 174   return Qnil;
 175 }
 176
 177 DEFUN ("end-of-line", Fend_of_line, Send_of_line, 0, 1, "^p",
 178        doc: /* Move point to end of current line (in the logical order).
 179 With argument N not nil or 1, move forward N - 1 lines first.
 180 If point reaches the beginning or end of buffer, it stops there.
 181 To ignore intangibility, bind `inhibit-point-motion-hooks' to t.
 182
 183 This function constrains point to the current field unless this moves
 184 point to a different line than the original, unconstrained result.  If
 185 N is nil or 1, and a rear-sticky field ends at point, the point does
 186 not move.  To ignore field boundaries bind `inhibit-field-text-motion'
 187 to t.  */)
 188   (Lisp_Object n)
 189 {
 190   ptrdiff_t newpos;
 191
 192   if (NILP (n))
 193     XSETFASTINT (n, 1);
 194   else
 195     CHECK_NUMBER (n);
 196
 197   while (1)
 198     {
 199       newpos = XINT (Fline_end_position (n));
 200       SET_PT (newpos);
 201
 202       if (PT > newpos
 203           && FETCH_CHAR (PT - 1) == '\n')
 204         {
 205           /* If we skipped over a newline that follows
 206              an invisible intangible run,
 207              move back to the last tangible position
 208              within the line.  */
 209
 210           SET_PT (PT - 1);
 211           break;
 212         }
 213       else if (PT > newpos && PT < ZV
 214                && FETCH_CHAR (PT) != '\n')
 215         /* If we skipped something intangible
 216            and now we're not really at eol,
 217            keep going.  */
 218         n = make_number (1);
 219       else
 220         break;
 221     }
 222
 223   return Qnil;
 224 }
 225
 226 DEFUN ("delete-char", Fdelete_char, Sdelete_char, 1, 2, "p\nP",
 227        doc: /* Delete the following N characters (previous if N is negative).
 228 Optional second arg KILLFLAG non-nil means kill instead (save in kill ring).
 229 Interactively, N is the prefix arg, and KILLFLAG is set if
 230 N was explicitly specified.
 231
 232 The command `delete-forward-char' is preferable for interactive use.  */)
 233   (Lisp_Object n, Lisp_Object killflag)
 234 {
 235   EMACS_INT pos;
 236
 237   CHECK_NUMBER (n);
 238
 239   pos = PT + XINT (n);
 240   if (NILP (killflag))
 241     {
 242       if (XINT (n) < 0)
 243         {
 244           if (pos < BEGV)
 245             xsignal0 (Qbeginning_of_buffer);
 246           else
 247             del_range (pos, PT);
 248         }
 249       else
 250         {
 251           if (pos > ZV)
 252             xsignal0 (Qend_of_buffer);
 253           else
 254             del_range (PT, pos);
 255         }
 256     }
 257   else
 258     {
 259       call1 (Qkill_forward_chars, n);
 260     }
 261   return Qnil;
 262 }
 263
 264 static int nonundocount;
 265
 266 /* Note that there's code in command_loop_1 which typically avoids
 267    calling this.  */
 268 DEFUN ("self-insert-command", Fself_insert_command, Sself_insert_command, 1, 1, "p",
 269        doc: /* Insert the character you type.
 270 Whichever character you type to run this command is inserted.
 271 Before insertion, `expand-abbrev' is executed if the inserted character does
 272 not have word syntax and the previous character in the buffer does.
 273 After insertion, the value of `auto-fill-function' is called if the
 274 `auto-fill-chars' table has a non-nil value for the inserted character.
 275 At the end, it runs `post-self-insert-hook'.  */)
 276   (Lisp_Object n)
 277 {
 278   bool remove_boundary = 1;
 279   CHECK_NATNUM (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 ();
 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)
 358                 ? c
 359                 : multibyte_char_to_unibyte (c));
 360       len = 1;
 361     }
 362   if (!NILP (overwrite)
 363       && PT < ZV)
 364     {
 365       /* In overwrite-mode, we substitute a character at point (C2,
 366          hereafter) by C.  For that, we delete C2 in advance.  But,
 367          just substituting C2 by C may move a remaining text in the
 368          line to the right or to the left, which is not preferable.
 369          So we insert more spaces or delete more characters in the
 370          following cases: if C is narrower than C2, after deleting C2,
 371          we fill columns with spaces, if C is wider than C2, we delete
 372          C2 and several characters following C2.  */
 373
 374       /* This is the character after point.  */
 375       int c2 = FETCH_CHAR (PT_BYTE);
 376
 377       int cwidth;
 378
 379       /* Overwriting in binary-mode always replaces C2 by C.
 380          Overwriting in textual-mode doesn't always do that.
 381          It inserts newlines in the usual way,
 382          and inserts any character at end of line
 383          or before a tab if it doesn't use the whole width of the tab.  */
 384       if (EQ (overwrite, Qoverwrite_mode_binary))
 385         chars_to_delete = min (n, PTRDIFF_MAX);
 386       else if (c != '\n' && c2 != '\n'
 387                && (cwidth = XFASTINT (Fchar_width (make_number (c)))) != 0)
 388         {
 389           ptrdiff_t pos = PT;
 390           ptrdiff_t pos_byte = PT_BYTE;
 391           ptrdiff_t curcol = current_column ();
 392
 393           if (n <= (min (MOST_POSITIVE_FIXNUM, PTRDIFF_MAX) - curcol) / cwidth)
 394             {
 395               /* Column the cursor should be placed at after this insertion.
 396                  The value should be calculated only when necessary.  */
 397               ptrdiff_t target_clm = curcol + n * cwidth;
 398
 399               /* The actual cursor position after the trial of moving
 400                  to column TARGET_CLM.  It is greater than TARGET_CLM
 401                  if the TARGET_CLM is middle of multi-column
 402                  character.  In that case, the new point is set after
 403                  that character.  */
 404               ptrdiff_t actual_clm
 405                 = XFASTINT (Fmove_to_column (make_number (target_clm), Qnil));
 406
 407               chars_to_delete = PT - pos;
 408
 409               if (actual_clm > target_clm)
 410                 {
 411                   /* We will delete too many columns.  Let's fill columns
 412                      by spaces so that the remaining text won't move.  */
 413                   ptrdiff_t actual = PT_BYTE;
 414                   DEC_POS (actual);
 415                   if (FETCH_CHAR (actual) == '\t')
 416                     /* Rather than add spaces, let's just keep the tab. */
 417                     chars_to_delete--;
 418                   else
 419                     spaces_to_insert = actual_clm - target_clm;
 420                 }
 421
 422               SET_PT_BOTH (pos, pos_byte);
 423             }
 424         }
 425       hairy = 2;
 426     }
 427
 428   synt = SYNTAX (c);
 429
 430   if (!NILP (BVAR (current_buffer, abbrev_mode))
 431       && synt != Sword
 432       && NILP (BVAR (current_buffer, read_only))
 433       && PT > BEGV
 434       && (SYNTAX (!NILP (BVAR (current_buffer, enable_multibyte_characters))
 435                   ? XFASTINT (Fprevious_char ())
 436                   : UNIBYTE_TO_CHAR (XFASTINT (Fprevious_char ())))
 437           == Sword))
 438     {
 439       EMACS_INT modiff = MODIFF;
 440       Lisp_Object sym;
 441
 442       sym = call0 (Qexpand_abbrev);
 443
 444       /* If we expanded an abbrev which has a hook,
 445          and the hook has a non-nil `no-self-insert' property,
 446          return right away--don't really self-insert.  */
 447       if (SYMBOLP (sym) && ! NILP (sym)
 448           && ! NILP (XSYMBOL (sym)->function)
 449           && SYMBOLP (XSYMBOL (sym)->function))
 450         {
 451           Lisp_Object prop;
 452           prop = Fget (XSYMBOL (sym)->function, intern ("no-self-insert"));
 453           if (! NILP (prop))
 454             return 1;
 455         }
 456
 457       if (MODIFF != modiff)
 458         hairy = 2;
 459     }
 460
 461   if (chars_to_delete)
 462     {
 463       int mc = ((NILP (BVAR (current_buffer, enable_multibyte_characters))
 464                  && SINGLE_BYTE_CHAR_P (c))
 465                 ? UNIBYTE_TO_CHAR (c) : c);
 466       Lisp_Object string = Fmake_string (make_number (n), make_number (mc));
 467
 468       if (spaces_to_insert)
 469         {
 470           tem = Fmake_string (make_number (spaces_to_insert),
 471                               make_number (' '));
 472           string = concat2 (string, tem);
 473         }
 474
 475       replace_range (PT, PT + chars_to_delete, string, 1, 1, 1);
 476       Fforward_char (make_number (n + spaces_to_insert));
 477     }
 478   else if (n > 1)
 479     {
 480       USE_SAFE_ALLOCA;
 481       char *strn, *p;
 482       SAFE_NALLOCA (strn, len, n);
 483       for (p = strn; n > 0; n--, p += len)
 484         memcpy (p, str, len);
 485       insert_and_inherit (strn, p - strn);
 486       SAFE_FREE ();
 487     }
 488   else if (n > 0)
 489     insert_and_inherit ((char *) str, len);
 490
 491   if ((CHAR_TABLE_P (Vauto_fill_chars)
 492        ? !NILP (CHAR_TABLE_REF (Vauto_fill_chars, c))
 493        : (c == ' ' || c == '\n'))
 494       && !NILP (BVAR (current_buffer, auto_fill_function)))
 495     {
 496       Lisp_Object auto_fill_result;
 497
 498       if (c == '\n')
 499         /* After inserting a newline, move to previous line and fill
 500            that.  Must have the newline in place already so filling and
 501            justification, if any, know where the end is going to be.  */
 502         SET_PT_BOTH (PT - 1, PT_BYTE - 1);
 503       auto_fill_result = call0 (BVAR (current_buffer, auto_fill_function));
 504       /* Test PT < ZV in case the auto-fill-function is strange.  */
 505       if (c == '\n' && PT < ZV)
 506         SET_PT_BOTH (PT + 1, PT_BYTE + 1);
 507       if (!NILP (auto_fill_result))
 508         hairy = 2;
 509     }
 510
 511   /* Run hooks for electric keys.  */
 512   Frun_hooks (1, &Qpost_self_insert_hook);
 513
 514   return hairy;
 515 }
 516 \f
 517 /* module initialization */
 518
 519 void
 520 syms_of_cmds (void)
 521 {
 522   DEFSYM (Qkill_backward_chars, "kill-backward-chars");
 523   DEFSYM (Qkill_forward_chars, "kill-forward-chars");
 524   DEFSYM (Qoverwrite_mode_binary, "overwrite-mode-binary");
 525   DEFSYM (Qexpand_abbrev, "expand-abbrev");
 526   DEFSYM (Qpost_self_insert_hook, "post-self-insert-hook");
 527
 528   DEFVAR_LISP ("post-self-insert-hook", Vpost_self_insert_hook,
 529                doc: /* Hook run at the end of `self-insert-command'.
 530 This is run after inserting the character.  */);
 531   Vpost_self_insert_hook = Qnil;
 532
 533   defsubr (&Sforward_point);
 534   defsubr (&Sforward_char);
 535   defsubr (&Sbackward_char);
 536   defsubr (&Sforward_line);
 537   defsubr (&Sbeginning_of_line);
 538   defsubr (&Send_of_line);
 539
 540   defsubr (&Sdelete_char);
 541   defsubr (&Sself_insert_command);
 542 }
 543
 544 void
 545 keys_of_cmds (void)
 546 {
 547   int n;
 548
 549   nonundocount = 0;
 550   initial_define_key (global_map, Ctl ('I'), "self-insert-command");
 551   for (n = 040; n < 0177; n++)
 552     initial_define_key (global_map, n, "self-insert-command");
 553 #ifdef MSDOS
 554   for (n = 0200; n < 0240; n++)
 555     initial_define_key (global_map, n, "self-insert-command");
 556 #endif
 557   for (n = 0240; n < 0400; n++)
 558     initial_define_key (global_map, n, "self-insert-command");
 559
 560   initial_define_key (global_map, Ctl ('A'), "beginning-of-line");
 561   initial_define_key (global_map, Ctl ('B'), "backward-char");
 562   initial_define_key (global_map, Ctl ('E'), "end-of-line");
 563   initial_define_key (global_map, Ctl ('F'), "forward-char");
 564 }