c++ - 重复的 switch 语句需要重构

Question

许多重复的 switch 语句似乎需要 DRY'd。有什么建议么？ (包括什么都不做!)

AnimMapIter _iter;
    _iter = _animations->find(name);
    if(_iter == _animations->end()) return;

    if(_curName != name) {
        _curName = name;

        switch(dir) {
        case DIR_FORWARD_LOOPING: /* Fall through to DIR_FORWARD_NONLOOPING */
        case DIR_FORWARD_NONLOOPING:
            _iter->second->First();
            break;
        case DIR_REVERSE_LOOPING: /* Fall through to DIR_REVERSE_NONLOOPING */
        case DIR_REVERSE_NONLOOPING:
            _iter->second->Last();
            break;
        }
    } else {

        switch(dir) {
        case DIR_FORWARD_LOOPING: /* Fall through to DIR_FORWARD_NONLOOPING */
        case DIR_FORWARD_NONLOOPING:
            _iter->second->Next();
            break;
        case DIR_REVERSE_LOOPING: /* Fall through to DIR_REVERSE_NONLOOPING */
        case DIR_REVERSE_NONLOOPING:
            _iter->second->Previous();
            break;
        }

        switch(dir) {
            case DIR_FORWARD_LOOPING:
                if(_iter->second->IsAtEnd())
                    _iter->second->First();
                break;
            case DIR_FORWARD_NONLOOPING:
                if(_iter->second->IsAtEnd())
                    _iter->second->Last();
                break;
            case DIR_REVERSE_LOOPING:
                if(_iter->second->IsAtFront())
                    _iter->second->Last();
                break;
            case DIR_REVERSE_NONLOOPING:
                if(_iter->second->IsAtFront())
                    _iter->second->First();
                break;
        }
    }

Answer 1

else 下的所有内容都应该合并为一个开关，以拉近相关步骤；例如

case DIR_FORWARD_LOOPING:
    _iter->second->Next();
    if (_iter->second->IsAtEnd()) {
        _iter->second->First();
    }
    break;

...都在那个案例中。重复几个函数调用并不是什么大问题，因为它可以使整个操作顺序更加清晰。