git.sur5r.net Git - i3/i3/blob - src/cmdparse.y

   1 %{
   2 /*
   3  * vim:ts=4:sw=4:expandtab
   4  *
   5  * i3 - an improved dynamic tiling window manager
   6  * © 2009-2011 Michael Stapelberg and contributors (see also: LICENSE)
   7  *
   8  * cmdparse.y: the parser for commands you send to i3 (or bind on keys)
   9  *
  10
  11  */
  12 #include <sys/types.h>
  13 #include <sys/stat.h>
  14 #include <unistd.h>
  15 #include <fcntl.h>
  16 #include <limits.h>
  17
  18 #include "all.h"
  19
  20 /** When the command did not include match criteria (!), we use the currently
  21  * focused command. Do not confuse this case with a command which included
  22  * criteria but which did not match any windows. This macro has to be called in
  23  * every command.
  24  */
  25 #define HANDLE_EMPTY_MATCH do { \
  26     if (match_is_empty(&current_match)) { \
  27         owindow *ow = smalloc(sizeof(owindow)); \
  28         ow->con = focused; \
  29         TAILQ_INIT(&owindows); \
  30         TAILQ_INSERT_TAIL(&owindows, ow, owindows); \
  31     } \
  32 } while (0)
  33
  34 typedef struct yy_buffer_state *YY_BUFFER_STATE;
  35 extern int cmdyylex(struct context *context);
  36 extern int cmdyyparse(void);
  37 extern FILE *cmdyyin;
  38 YY_BUFFER_STATE cmdyy_scan_string(const char *);
  39
  40 static struct context *context;
  41 static Match current_match;
  42
  43 /*
  44  * Helper data structure for an operation window (window on which the operation
  45  * will be performed). Used to build the TAILQ owindows.
  46  *
  47  */
  48 typedef struct owindow {
  49     Con *con;
  50     TAILQ_ENTRY(owindow) owindows;
  51 } owindow;
  52 static TAILQ_HEAD(owindows_head, owindow) owindows;
  53
  54 /* Holds the JSON which will be returned via IPC or NULL for the default return
  55  * message */
  56 static char *json_output;
  57
  58 /* We don’t need yydebug for now, as we got decent error messages using
  59  * yyerror(). Should you ever want to extend the parser, it might be handy
  60  * to just comment it in again, so it stays here. */
  61 //int cmdyydebug = 1;
  62
  63 void cmdyyerror(const char *error_message) {
  64     ELOG("\n");
  65     ELOG("CMD: %s\n", error_message);
  66     ELOG("CMD: in command:\n");
  67     ELOG("CMD:   %s\n", context->line_copy);
  68     ELOG("CMD:   ");
  69     for (int c = 1; c <= context->last_column; c++)
  70         if (c >= context->first_column)
  71                 printf("^");
  72         else printf(" ");
  73     printf("\n");
  74     ELOG("\n");
  75     context->compact_error = sstrdup(error_message);
  76 }
  77
  78 int cmdyywrap() {
  79     return 1;
  80 }
  81
  82 char *parse_cmd(const char *new) {
  83     LOG("COMMAND: *%s*\n", new);
  84     cmdyy_scan_string(new);
  85
  86     match_init(&current_match);
  87     context = scalloc(sizeof(struct context));
  88     context->filename = "cmd";
  89     FREE(json_output);
  90     if (cmdyyparse() != 0) {
  91         fprintf(stderr, "Could not parse command\n");
  92         asprintf(&json_output, "{\"success\":false, \"error\":\"%s at position %d\"}",
  93                  context->compact_error, context->first_column);
  94         FREE(context->line_copy);
  95         FREE(context->compact_error);
  96         free(context);
  97         return json_output;
  98     }
  99     printf("done, json output = %s\n", json_output);
 100
 101     FREE(context->line_copy);
 102     FREE(context->compact_error);
 103     free(context);
 104     return json_output;
 105 }
 106
 107 %}
 108
 109 %error-verbose
 110 %lex-param { struct context *context }
 111
 112 %union {
 113     char *string;
 114     char chr;
 115     int number;
 116 }
 117
 118 %token              TOK_EXEC            "exec"
 119 %token              TOK_EXIT            "exit"
 120 %token              TOK_RELOAD          "reload"
 121 %token              TOK_RESTART         "restart"
 122 %token              TOK_KILL            "kill"
 123 %token              TOK_WINDOW          "window"
 124 %token              TOK_CLIENT          "client"
 125 %token              TOK_FULLSCREEN      "fullscreen"
 126 %token              TOK_GLOBAL          "global"
 127 %token              TOK_LAYOUT          "layout"
 128 %token              TOK_DEFAULT         "default"
 129 %token              TOK_STACKED         "stacked"
 130 %token              TOK_TABBED          "tabbed"
 131 %token              TOK_BORDER          "border"
 132 %token              TOK_NORMAL          "normal"
 133 %token              TOK_NONE            "none"
 134 %token              TOK_1PIXEL          "1pixel"
 135 %token              TOK_MODE            "mode"
 136 %token              TOK_TILING          "tiling"
 137 %token              TOK_FLOATING        "floating"
 138 %token              TOK_ENABLE          "enable"
 139 %token              TOK_DISABLE         "disable"
 140 %token              TOK_WORKSPACE       "workspace"
 141 %token              TOK_TOGGLE          "toggle"
 142 %token              TOK_FOCUS           "focus"
 143 %token              TOK_MOVE            "move"
 144 %token              TOK_OPEN            "open"
 145 %token              TOK_PREV            "prev"
 146 %token              TOK_SPLIT           "split"
 147 %token              TOK_HORIZONTAL      "horizontal"
 148 %token              TOK_VERTICAL        "vertical"
 149 %token              TOK_UP              "up"
 150 %token              TOK_DOWN            "down"
 151 %token              TOK_LEFT            "left"
 152 %token              TOK_RIGHT           "right"
 153 %token              TOK_PARENT          "parent"
 154 %token              TOK_CHILD           "child"
 155 %token              TOK_APPEND_LAYOUT   "append_layout"
 156 %token              TOK_MARK            "mark"
 157 %token              TOK_RESIZE          "resize"
 158 %token              TOK_GROW            "grow"
 159 %token              TOK_SHRINK          "shrink"
 160 %token              TOK_PX              "px"
 161 %token              TOK_OR              "or"
 162 %token              TOK_PPT             "ppt"
 163 %token              TOK_NOP             "nop"
 164
 165 %token              TOK_CLASS           "class"
 166 %token              TOK_ID              "id"
 167 %token              TOK_CON_ID          "con_id"
 168 %token              TOK_TITLE           "title"
 169
 170 %token  <string>    STR                 "<string>"
 171 %token  <number>    NUMBER              "<number>"
 172
 173 %type   <number>    direction
 174 %type   <number>    split_direction
 175 %type   <number>    level
 176 %type   <number>    boolean
 177 %type   <number>    border_style
 178 %type   <number>    layout_mode
 179 %type   <number>    resize_px
 180 %type   <number>    resize_way
 181 %type   <number>    resize_tiling
 182 %type   <number>    optional_kill_mode
 183
 184 %%
 185
 186 commands:
 187     commands ';' command
 188     | command
 189     {
 190         owindow *current;
 191
 192         printf("single command completely parsed, dropping state...\n");
 193         while (!TAILQ_EMPTY(&owindows)) {
 194             current = TAILQ_FIRST(&owindows);
 195             TAILQ_REMOVE(&owindows, current, owindows);
 196             free(current);
 197         }
 198         match_init(&current_match);
 199     }
 200     ;
 201
 202 command:
 203     match operations
 204     ;
 205
 206 match:
 207     | matchstart criteria matchend
 208     {
 209         printf("match parsed\n");
 210     }
 211     ;
 212
 213 matchstart:
 214     '['
 215     {
 216         printf("start\n");
 217         match_init(&current_match);
 218         TAILQ_INIT(&owindows);
 219         /* copy all_cons */
 220         Con *con;
 221         TAILQ_FOREACH(con, &all_cons, all_cons) {
 222             owindow *ow = smalloc(sizeof(owindow));
 223             ow->con = con;
 224             TAILQ_INSERT_TAIL(&owindows, ow, owindows);
 225         }
 226     }
 227     ;
 228
 229 matchend:
 230     ']'
 231     {
 232         owindow *next, *current;
 233
 234         printf("match specification finished, matching...\n");
 235         /* copy the old list head to iterate through it and start with a fresh
 236          * list which will contain only matching windows */
 237         struct owindows_head old = owindows;
 238         TAILQ_INIT(&owindows);
 239         for (next = TAILQ_FIRST(&old); next != TAILQ_END(&old);) {
 240             /* make a copy of the next pointer and advance the pointer to the
 241              * next element as we are going to invalidate the element’s
 242              * next/prev pointers by calling TAILQ_INSERT_TAIL later */
 243             current = next;
 244             next = TAILQ_NEXT(next, owindows);
 245
 246             printf("checking if con %p / %s matches\n", current->con, current->con->name);
 247             if (current_match.con_id != NULL) {
 248                 if (current_match.con_id == current->con) {
 249                     printf("matches container!\n");
 250                     TAILQ_INSERT_TAIL(&owindows, current, owindows);
 251
 252                 }
 253             } else if (current_match.mark != NULL && current->con->mark != NULL &&
 254                     strcasecmp(current_match.mark, current->con->mark) == 0) {
 255                 printf("match by mark\n");
 256                     TAILQ_INSERT_TAIL(&owindows, current, owindows);
 257
 258             } else {
 259                 if (current->con->window == NULL)
 260                     continue;
 261                 if (match_matches_window(&current_match, current->con->window)) {
 262                     printf("matches window!\n");
 263                     TAILQ_INSERT_TAIL(&owindows, current, owindows);
 264                 } else {
 265                     printf("doesnt match\n");
 266                     free(current);
 267                 }
 268             }
 269         }
 270
 271         TAILQ_FOREACH(current, &owindows, owindows) {
 272             printf("matching: %p / %s\n", current->con, current->con->name);
 273         }
 274
 275     }
 276     ;
 277
 278 criteria:
 279     criteria criterion
 280     | criterion
 281     ;
 282
 283 criterion:
 284     TOK_CLASS '=' STR
 285     {
 286         printf("criteria: class = %s\n", $3);
 287         current_match.class = $3;
 288     }
 289     | TOK_CON_ID '=' STR
 290     {
 291         printf("criteria: id = %s\n", $3);
 292         char *end;
 293         long parsed = strtol($3, &end, 10);
 294         if (parsed == LONG_MIN ||
 295             parsed == LONG_MAX ||
 296             parsed < 0 ||
 297             (end && *end != '\0')) {
 298             ELOG("Could not parse con id \"%s\"\n", $3);
 299         } else {
 300             current_match.con_id = (Con*)parsed;
 301             printf("id as int = %p\n", current_match.con_id);
 302         }
 303     }
 304     | TOK_ID '=' STR
 305     {
 306         printf("criteria: window id = %s\n", $3);
 307         char *end;
 308         long parsed = strtol($3, &end, 10);
 309         if (parsed == LONG_MIN ||
 310             parsed == LONG_MAX ||
 311             parsed < 0 ||
 312             (end && *end != '\0')) {
 313             ELOG("Could not parse window id \"%s\"\n", $3);
 314         } else {
 315             current_match.id = parsed;
 316             printf("window id as int = %d\n", current_match.id);
 317         }
 318     }
 319     | TOK_MARK '=' STR
 320     {
 321         printf("criteria: mark = %s\n", $3);
 322         current_match.mark = $3;
 323     }
 324     | TOK_TITLE '=' STR
 325     {
 326         printf("criteria: title = %s\n", $3);
 327         current_match.title = $3;
 328     }
 329     ;
 330
 331 operations:
 332     operation
 333     | operations ',' operation
 334     ;
 335
 336 operation:
 337     exec
 338     | exit
 339     | restart
 340     | reload
 341     | border
 342     | layout
 343     | append_layout
 344     | move
 345     | workspace
 346     | focus
 347     | kill
 348     | open
 349     | fullscreen
 350     | split
 351     | floating
 352     | mark
 353     | resize
 354     | nop
 355     | mode
 356     ;
 357
 358 exec:
 359     TOK_EXEC STR
 360     {
 361         printf("should execute %s\n", $2);
 362         start_application($2);
 363         free($2);
 364     }
 365     ;
 366
 367 exit:
 368     TOK_EXIT
 369     {
 370         printf("exit, bye bye\n");
 371         exit(0);
 372     }
 373     ;
 374
 375 reload:
 376     TOK_RELOAD
 377     {
 378         printf("reloading\n");
 379         load_configuration(conn, NULL, true);
 380         x_set_i3_atoms();
 381         /* Send an IPC event just in case the ws names have changed */
 382         ipc_send_event("workspace", I3_IPC_EVENT_WORKSPACE, "{\"change\":\"reload\"}");
 383     }
 384     ;
 385
 386 restart:
 387     TOK_RESTART
 388     {
 389         printf("restarting i3\n");
 390         i3_restart(false);
 391     }
 392     ;
 393
 394 focus:
 395     TOK_FOCUS
 396     {
 397         owindow *current;
 398
 399         if (match_is_empty(&current_match)) {
 400             ELOG("You have to specify which window/container should be focused.\n");
 401             ELOG("Example: [class=\"urxvt\" title=\"irssi\"] focus\n");
 402
 403             asprintf(&json_output, "{\"success\":false, \"error\":\"You have to "
 404                      "specify which window/container should be focused\"}");
 405             break;
 406         }
 407
 408         int count = 0;
 409         TAILQ_FOREACH(current, &owindows, owindows) {
 410             LOG("focusing %p / %s\n", current->con, current->con->name);
 411             con_focus(current->con);
 412             count++;
 413         }
 414
 415         if (count > 1)
 416             LOG("WARNING: Your criteria for the focus command matches %d containers, "
 417                 "while only exactly one container can be focused at a time.\n", count);
 418
 419         tree_render();
 420     }
 421     | TOK_FOCUS direction
 422     {
 423         int direction = $2;
 424         switch (direction) {
 425             case TOK_LEFT:
 426                 LOG("Focusing left\n");
 427                 tree_next('p', HORIZ);
 428                 break;
 429             case TOK_RIGHT:
 430                 LOG("Focusing right\n");
 431                 tree_next('n', HORIZ);
 432                 break;
 433             case TOK_UP:
 434                 LOG("Focusing up\n");
 435                 tree_next('p', VERT);
 436                 break;
 437             case TOK_DOWN:
 438                 LOG("Focusing down\n");
 439                 tree_next('n', VERT);
 440                 break;
 441             default:
 442                 ELOG("Invalid focus direction (%d)\n", direction);
 443                 break;
 444         }
 445
 446         tree_render();
 447     }
 448     | TOK_FOCUS level
 449     {
 450         if ($2 == TOK_PARENT)
 451             level_up();
 452         else level_down();
 453
 454         tree_render();
 455     }
 456     ;
 457
 458 level:
 459     TOK_PARENT  { $$ = TOK_PARENT; }
 460     | TOK_CHILD { $$ = TOK_CHILD;  }
 461     ;
 462
 463 kill:
 464     TOK_KILL optional_kill_mode
 465     {
 466         owindow *current;
 467
 468         printf("killing!\n");
 469         /* check if the match is empty, not if the result is empty */
 470         if (match_is_empty(&current_match))
 471             tree_close_con($2);
 472         else {
 473             TAILQ_FOREACH(current, &owindows, owindows) {
 474                 printf("matching: %p / %s\n", current->con, current->con->name);
 475                 tree_close(current->con, $2, false);
 476             }
 477         }
 478
 479         tree_render();
 480     }
 481     ;
 482
 483 optional_kill_mode:
 484     /* empty */             { $$ = KILL_WINDOW; }
 485     | TOK_WINDOW { $$ = KILL_WINDOW; }
 486     | TOK_CLIENT { $$ = KILL_CLIENT; }
 487     ;
 488
 489 workspace:
 490     TOK_WORKSPACE STR
 491     {
 492         printf("should switch to workspace %s\n", $2);
 493         workspace_show($2);
 494         free($2);
 495
 496         tree_render();
 497     }
 498     ;
 499
 500 open:
 501     TOK_OPEN
 502     {
 503         printf("opening new container\n");
 504         Con *con = tree_open_con(NULL, NULL);
 505         con_focus(con);
 506         asprintf(&json_output, "{\"success\":true, \"id\":%ld}", (long int)con);
 507
 508         tree_render();
 509     }
 510     ;
 511
 512 fullscreen:
 513     TOK_FULLSCREEN
 514     {
 515         printf("toggling fullscreen\n");
 516         owindow *current;
 517
 518
 519         HANDLE_EMPTY_MATCH;
 520
 521         TAILQ_FOREACH(current, &owindows, owindows) {
 522             printf("matching: %p / %s\n", current->con, current->con->name);
 523             con_toggle_fullscreen(current->con);
 524         }
 525
 526         tree_render();
 527     }
 528     ;
 529
 530 split:
 531     TOK_SPLIT split_direction
 532     {
 533         /* TODO: use matches */
 534         printf("splitting in direction %c\n", $2);
 535         tree_split(focused, ($2 == 'v' ? VERT : HORIZ));
 536
 537         tree_render();
 538     }
 539     ;
 540
 541 split_direction:
 542     TOK_HORIZONTAL  { $$ = 'h'; }
 543     | 'h'           { $$ = 'h'; }
 544     | TOK_VERTICAL  { $$ = 'v'; }
 545     | 'v'           { $$ = 'v'; }
 546     ;
 547
 548 floating:
 549     TOK_FLOATING boolean
 550     {
 551         HANDLE_EMPTY_MATCH;
 552
 553         owindow *current;
 554         TAILQ_FOREACH(current, &owindows, owindows) {
 555             printf("matching: %p / %s\n", current->con, current->con->name);
 556             if ($2 == TOK_TOGGLE) {
 557                 printf("should toggle mode\n");
 558                 toggle_floating_mode(current->con, false);
 559             } else {
 560                 printf("should switch mode to %s\n", ($2 == TOK_FLOATING ? "floating" : "tiling"));
 561                 if ($2 == TOK_ENABLE) {
 562                     floating_enable(current->con, false);
 563                 } else {
 564                     floating_disable(current->con, false);
 565                 }
 566             }
 567         }
 568
 569         tree_render();
 570     }
 571     ;
 572
 573 boolean:
 574     TOK_ENABLE    { $$ = TOK_ENABLE; }
 575     | TOK_DISABLE { $$ = TOK_DISABLE; }
 576     | TOK_TOGGLE  { $$ = TOK_TOGGLE; }
 577     ;
 578
 579 border:
 580     TOK_BORDER border_style
 581     {
 582         printf("border style should be changed to %d\n", $2);
 583         owindow *current;
 584
 585         HANDLE_EMPTY_MATCH;
 586
 587         TAILQ_FOREACH(current, &owindows, owindows) {
 588             printf("matching: %p / %s\n", current->con, current->con->name);
 589             current->con->border_style = $2;
 590         }
 591
 592         tree_render();
 593     }
 594     ;
 595
 596 border_style:
 597     TOK_NORMAL      { $$ = BS_NORMAL; }
 598     | TOK_NONE      { $$ = BS_NONE; }
 599     | TOK_1PIXEL    { $$ = BS_1PIXEL; }
 600     ;
 601
 602 move:
 603     TOK_MOVE direction
 604     {
 605         printf("moving in direction %d\n", $2);
 606         tree_move($2);
 607
 608         tree_render();
 609     }
 610     | TOK_MOVE TOK_WORKSPACE STR
 611     {
 612         owindow *current;
 613
 614         printf("should move window to workspace %s\n", $3);
 615         /* get the workspace */
 616         Con *ws = workspace_get($3, NULL);
 617         free($3);
 618
 619         HANDLE_EMPTY_MATCH;
 620
 621         TAILQ_FOREACH(current, &owindows, owindows) {
 622             printf("matching: %p / %s\n", current->con, current->con->name);
 623             con_move_to_workspace(current->con, ws);
 624         }
 625
 626         tree_render();
 627     }
 628     ;
 629
 630 append_layout:
 631     TOK_APPEND_LAYOUT STR
 632     {
 633         printf("restoring \"%s\"\n", $2);
 634         tree_append_json($2);
 635         free($2);
 636         tree_render();
 637     }
 638     ;
 639
 640 layout:
 641     TOK_LAYOUT layout_mode
 642     {
 643         printf("changing layout to %d\n", $2);
 644         owindow *current;
 645
 646         /* check if the match is empty, not if the result is empty */
 647         if (match_is_empty(&current_match))
 648             con_set_layout(focused->parent, $2);
 649         else {
 650             TAILQ_FOREACH(current, &owindows, owindows) {
 651                 printf("matching: %p / %s\n", current->con, current->con->name);
 652                 con_set_layout(current->con, $2);
 653             }
 654         }
 655
 656         tree_render();
 657     }
 658     ;
 659
 660 layout_mode:
 661     TOK_DEFAULT   { $$ = L_DEFAULT; }
 662     | TOK_STACKED { $$ = L_STACKED; }
 663     | TOK_TABBED  { $$ = L_TABBED; }
 664     ;
 665
 666 mark:
 667     TOK_MARK STR
 668     {
 669         printf("marking window with str %s\n", $2);
 670         owindow *current;
 671
 672         HANDLE_EMPTY_MATCH;
 673
 674         TAILQ_FOREACH(current, &owindows, owindows) {
 675             printf("matching: %p / %s\n", current->con, current->con->name);
 676             current->con->mark = sstrdup($2);
 677         }
 678
 679         free($<string>2);
 680
 681         tree_render();
 682     }
 683     ;
 684
 685 nop:
 686     TOK_NOP STR
 687     {
 688         printf("-------------------------------------------------\n");
 689         printf("  NOP: %s\n", $2);
 690         printf("-------------------------------------------------\n");
 691         free($2);
 692     }
 693     ;
 694
 695 resize:
 696     TOK_RESIZE resize_way direction resize_px resize_tiling
 697     {
 698         /* resize <grow|shrink> <direction> [<px> px] [or <ppt> ppt] */
 699         printf("resizing in way %d, direction %d, px %d or ppt %d\n", $2, $3, $4, $5);
 700         int direction = $3;
 701         int px = $4;
 702         int ppt = $5;
 703         if ($2 == TOK_SHRINK) {
 704             px *= -1;
 705             ppt *= -1;
 706         }
 707
 708         if (con_is_floating(focused)) {
 709             printf("floating resize\n");
 710             if (direction == TOK_UP) {
 711                 focused->parent->rect.y -= px;
 712                 focused->parent->rect.height += px;
 713             } else if (direction == TOK_DOWN) {
 714                 focused->rect.height += px;
 715             } else if (direction == TOK_LEFT) {
 716                 focused->rect.x -= px;
 717                 focused->rect.width += px;
 718             } else {
 719                 focused->rect.width += px;
 720             }
 721         } else {
 722             LOG("tiling resize\n");
 723             /* get the default percentage */
 724             int children = con_num_children(focused->parent);
 725             Con *other;
 726             LOG("ins. %d children\n", children);
 727             double percentage = 1.0 / children;
 728             LOG("default percentage = %f\n", percentage);
 729
 730             if (direction == TOK_UP || direction == TOK_LEFT) {
 731                 other = TAILQ_PREV(focused, nodes_head, nodes);
 732             } else {
 733                 other = TAILQ_NEXT(focused, nodes);
 734             }
 735             if (other == TAILQ_END(workspaces)) {
 736                 LOG("No other container in this direction found, cannot resize.\n");
 737                 return 0;
 738             }
 739             LOG("other->percent = %f\n", other->percent);
 740             LOG("focused->percent before = %f\n", focused->percent);
 741             if (focused->percent == 0.0)
 742                 focused->percent = percentage;
 743             if (other->percent == 0.0)
 744                 other->percent = percentage;
 745             focused->percent += ((double)ppt / 100.0);
 746             other->percent -= ((double)ppt / 100.0);
 747             LOG("focused->percent after = %f\n", focused->percent);
 748             LOG("other->percent after = %f\n", other->percent);
 749         }
 750
 751         tree_render();
 752     }
 753     ;
 754
 755 resize_px:
 756     /* empty */
 757     {
 758         $$ = 10;
 759     }
 760     | NUMBER TOK_PX
 761     {
 762         $$ = $1;
 763     }
 764     ;
 765
 766 resize_tiling:
 767     /* empty */
 768     {
 769         $$ = 10;
 770     }
 771     | TOK_OR NUMBER TOK_PPT
 772     {
 773         $$ = $2;
 774     }
 775     ;
 776
 777 resize_way:
 778     TOK_GROW        { $$ = TOK_GROW; }
 779     | TOK_SHRINK    { $$ = TOK_SHRINK; }
 780     ;
 781
 782 direction:
 783     TOK_UP          { $$ = TOK_UP; }
 784     | TOK_DOWN      { $$ = TOK_DOWN; }
 785     | TOK_LEFT      { $$ = TOK_LEFT; }
 786     | TOK_RIGHT     { $$ = TOK_RIGHT; }
 787     ;
 788
 789 mode:
 790     TOK_MODE STR
 791     {
 792         switch_mode($2);
 793     }
 794     ;