Function enumstat

src/lparser.cpp:4888–4951

static void enumstat (LexState *ls) {
  /* enumstat -> ENUM [[CLASS] NAME] BEGIN NAME ['=' INT] { ',' NAME ['=' INT] } END */

  luaX_next(ls); /* skip 'enum' */

  EnumDesc *ed = nullptr;
  bool is_enum_class = false;
  if (gett(ls) != TK_BEGIN && gett(ls) != TK_DO) { /* enum has name (and possibly modifier)? */
    if (ls->t.token == TK_CLASS
      || (ls->t.token == TK_NAME && strcmp(getstr(ls->t.seminfo.ts), "class") == 0)
      ) {
      is_enum_class = true;
      luaX_next(ls);
    }
    auto vidx = new_localvar(ls, str_checkname(ls, 0), ls->getLineNumber());
    auto var = getlocalvardesc(ls->fs, vidx);
    var->vd.kind = RDKENUM;
    setivalue(&var->k, ls->enums.size());
    ed = &ls->enums.emplace_back(EnumDesc{});
    ls->fs->nactvar++;
  }

  const auto line_begin = ls->getLineNumber();
  if (!testnext(ls, TK_DO))
    checknext(ls, TK_BEGIN);

  lua_Integer i = 1;
  while (gett(ls) != TK_END) {
    TString *name = str_checkname(ls, 0);
    int vidx;
    if (!is_enum_class) {
      vidx = new_localvar(ls, name, ls->getLineNumber());
    }
    if (testnext(ls, '=')) {
      expdesc v;
      expr(ls, &v);
      if (v.k == VCONST) { /* compile-time constant? */
        TValue *k = &ls->dyd->actvar.arr[v.u.info].k;
        if (ttype(k) == LUA_TNUMBER && ttisinteger(k)) { /* integer value? */
          init_exp(&v, VKINT, 0);
          v.u.ival = ivalue(k);
        }
      }
      if (v.k != VKINT) { /* assert expdesc kind */
        throwerr(ls, "expected integer constant", "unexpected expression type");
      }
      i = v.u.ival;
    }
    if (ed) {
      ed->enumerators.emplace_back(EnumDesc::Enumerator{ name, i });
    }
    if (!is_enum_class) {
      auto var = getlocalvardesc(ls->fs, vidx);
      var->vd.kind = RDKCTC;
      setivalue(&var->k, i);
      ls->fs->nactvar++;
    }
    i++;