case KW_NULL:
consumeLookAhead();
return conclude(srOf(lastLexElement(), new ExpNull()));
case DOLLAR:
consumeLookAhead();
return conclude(srOf(lastLexElement(), new ExpArrayLength()));
case GROUP_INTEGER:
consumeLookAhead();
return conclude(srOf(lastLexElement(), new ExpLiteralInteger(lastLexElement())));
case CHARACTER: