case GROUP_INTEGER:
consumeLookAhead();
return conclude(srOf(lastLexElement(), new ExpLiteralInteger(lastLexElement())));
case CHARACTER:
consumeLookAhead();
return conclude(srOf(lastLexElement(), new ExpLiteralChar(lastLexElement())));
case GROUP_FLOAT:
consumeLookAhead();
return conclude(srOf(lastLexElement(), new ExpLiteralFloat(lastLexElement())));
case GROUP_STRING:
return parseStringLiteral();