在RapidJSON中解析数组内的对象 [英] Parsing object inside array in rapidjson

问题描述

我在实现递归函数时遇到问题，该函数遍历从json输入的解析中得到的树.

I'm having problems implementing a recursive function that goes over the tree I get from the parsing of a json input.

json输入.例如:

json input. e.g.:

{
  "attr" : { "a": 1, "ovec": [ { "b": 2, "c": 3 }, { "d": 4} ] }
}

这就是我们所说的属性的复合值"，该值只是一个JSON文档.它的内容是完全任意的(只要其有效的JSON).

This is what we call a 'compound value of an attribute', and the value is simply a JSON doc. Its content is completely arbitrary (as long as its valid JSON).

问题在于，使用Vector时，我必须使用Value :: ConstValueIterator类型进行循环(与Object不同，在这里我使用Value :: ConstMemberIterator).

The problem is that with a Vector I have to loop using the type Value::ConstValueIterator (unlike for Object, where I use Value::ConstMemberIterator).

我的递归函数将Value :: ConstMemberIterator作为参数，直到在向量中遇到Vector/Object为止一切正常-对于递归调用，我需要类型为Value :: ConstMemberIterator的迭代器.

My recursive function has Value::ConstMemberIterator as parameter and all is OK until I encounter a Vector/Object inside a Vector - for the recursive call I'd need an iterator of the type Value::ConstMemberIterator.

遍历"功能的相关部分:

Relevant parts of the "traversing" function:

int parseContextAttributeCompoundValue
(
    const Value::ConstMemberIterator&  node
)
{
    std::string type = jsonParseTypeNames[node->value.GetType()];
    if (type == "Array")
    {
        for (Value::ConstValueIterator iter = node->value.Begin(); iter != node->value.End(); ++iter)
        {
            std::string nodeType = jsonParseTypeNames[iter->value.GetType()];
            if (nodeType == "String")
            {
                val = iter->GetString();
            }
            // else if ...
            if ((nodeType == "Object") || (nodeType == "Array"))
            {
                // Here's my problem - need to convert 'iter' to Value::ConstMemberIterator
                // in order to recursively call parseContextAttributeCompoundValue for this object/array
                parseContextAttributeCompoundValue(iter); // COMPILATION ERROR
            }
        }
    }
    else if (type == "Object")
    {
        for (Value::ConstMemberIterator iter = node->value.MemberBegin(); iter != node->value.MemberEnd(); ++iter)
        {
            std::string nodeType = jsonParseTypeNames[iter->value.GetType()];
            if (nodeType == "String")
            {
                val = iter->value.GetString();
            }
            else if (nodeType == "Number")
            {

            if ((nodeType == "Object") || (nodeType == "Array"))
            {
                // Here I'm just fine as iter is of the desired type already
                parseContextAttributeCompoundValue(iter);
            }
        }
    }
}

我已经尝试了一些操作，例如调用iter-> value.MemberBegin()以转换"为所需的类型，但到目前为止没有成功

I've tried a few things like calling iter->value.MemberBegin() to "convert" to the desired type, but so far without any success

非常感谢您在这里提供的帮助...

More than thankful for some help here ...

推荐答案

您可以简单地调用具有Value类型的函数，而不用传递迭代器:

You can simply call a function with a Value type, instead of passing iterator:

void parseContextAttributeCompoundValue(const Value& v) {
    if (v.IsObject()) {
        // ...
    }
    else if (v.IsArray() {
        // ...
    }
}

然后从呼叫站点:

for (Value::ConstValueIterator iter = ...) {
    parseContextAttributeCompoundValue(*iter);
}

for (Value::ConstMemberIterator iter = ...) {
    parseContextAttributeCompoundValue(iter->value);
}

这篇关于在RapidJSON中解析数组内的对象的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！