Function testpattern

other_src/lua/src/lpeg.cpp:1158–1169

static int testpattern (lua_State *L, int idx) {
  if (lua_touserdata(L, idx)) {  /* value is a userdata? */
    if (lua_getmetatable(L, idx)) {  /* does it have a metatable? */
      luaL_getmetatable(L, PATTERN_T);
      if (lua_rawequal(L, -1, -2)) {  /* does it have the correct mt? */
        lua_pop(L, 2);  /* remove both metatables */
        return 1;
      }
    }
  }
  return 0;
}


static Instruction *fix_l (lua_State *L, int t) {