Function forstat

lua/lparser.c:1172–1430

static void forstat (LexState *ls, int line) {
  /* forstat -> FOR (fornum | forlist) END */
  FuncState *fs = ls->fs;
  TString *varname;
  BlockCnt bl;
  enterblock(fs, &bl, 1);  /* scope for loop and control variables */
  luaX_next(ls);  /* skip `for' */
  varname = str_checkname(ls);  /* first variable name */
  switch (ls->t.token) {
    case '=': fornum(ls, varname, line); break;
    case ',': case TK_IN: forlist(ls, varname); break;
    default: luaX_syntaxerror(ls, LUA_QL("=") " or " LUA_QL("in") " expected");
  }
  check_match(ls, TK_END, TK_FOR, line);
  leaveblock(fs);  /* loop scope (`break' jumps to this point) */
}


static int test_then_block (LexState *ls) {
  /* test_then_block -> [IF | ELSEIF] cond THEN block */
  int condexit;
  luaX_next(ls);  /* skip IF or ELSEIF */
  condexit = cond(ls);
  checknext(ls, TK_THEN);
  block(ls);  /* `then' part */
  return condexit;
}


static void ifstat (LexState *ls, int line) {
  /* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */
  FuncState *fs = ls->fs;
  int flist;
  int escapelist = NO_JUMP;
  flist = test_then_block(ls);  /* IF cond THEN block */
  while (ls->t.token == TK_ELSEIF) {
    luaK_concat(fs, &escapelist, luaK_jump(fs));
    luaK_patchtohere(fs, flist);
    flist = test_then_block(ls);  /* ELSEIF cond THEN block */
  }
  if (ls->t.token == TK_ELSE) {
    luaK_concat(fs, &escapelist, luaK_jump(fs));
    luaK_patchtohere(fs, flist);
    luaX_next(ls);  /* skip ELSE (after patch, for correct line info) */
    block(ls);  /* `else' part */
  }
  else
    luaK_concat(fs, &escapelist, flist);
  luaK_patchtohere(fs, escapelist);
  check_match(ls, TK_END, TK_IF, line);
}


static void localfunc (LexState *ls) {
  expdesc v, b;
  FuncState *fs = ls->fs;
  new_localvar(ls, str_checkname(ls), 0);
  init_exp(&v, VLOCAL, fs->freereg);