Error: Vizualising the json of C++ graph view is failing

[arjunarjun07]

I am trying to visualize a graph view of a heap using a cpp std::vector. Following is the code snippet:

std::string serialize_as_heap(const std::vector<int>& heap) {
    if (heap.empty()) {
        return json().dump();
    }

    json serialized = {
        {"kind", {{"graph", true}}},
        {"nodes", json::array()},
        {"edges", json::array()}
    };

    for (size_t i = 0; i < heap.size(); ++i) {
        serialized["nodes"].push_back({{"id", std::to_string(i)}, {"label", std::to_string(heap[i])}});
    }

    for (size_t i = 0; i < heap.size(); ++i) {
        size_t left_child_index = 2 * i + 1;
        size_t right_child_index = 2 * i + 2;

        if (left_child_index < heap.size()) {
            serialized["edges"].push_back({{"from", std::to_string(i)}, {"to", std::to_string(left_child_index)}});
        }

        if (right_child_index < heap.size()) {
            serialized["edges"].push_back({{"from", std::to_string(i)}, {"to", std::to_string(right_child_index)}});
        }
    }
    return serialized.dump();
}

int main() {

    auto res = std::string("");

    std::vector<int> heap = {10, 20, 30, 40, 50, 60, 70};
    res = serialize_as_heap(heap); //Passed "res" to the DebugVisualizer textbox

return 0;    
}

res value: //Escaped json given by cpp debugger

"{\"edges\":[{\"from\":\"0\",\"to\":\"1\"},{\"from\":\"0\",\"to\":\"2\"},{\"from\":\"1\",\"to\":\"3\"},{\"from\":\"1\",\"to\":\"4\"},{\"from\":\"2\",\"to\":\"5\"},{\"from\":\"2\",\"to\":\"6\"}],\"kind\":{\"graph\":true},\"nodes\":[{\"id\":\"0\",\"label\":\"10\"},{\"id\":\"1\",\"label\":\"20\"},{\"id\":\"2\",\"label\":\"30\"},{\"id\":\"3\",\"label\":\"40\"},{\"id\":\"4\",\"label\":\"50\"},{\"id\":\"5\",\"label\":\"60\"},{\"id\":\"6\",\"label\":\"70\"}]}"

It is showing the following error:

P.S: I tried to unescape the above json and tested the result in the playground. It is working fine
https://hediet.github.io/visualization/?darkTheme=1

Environment details:
vscode: 1.91.1
cppstd: 20
compiler details:

g++ --version
g++.exe (Rev6, Built by MSYS2 project) 13.2.0

[arjunarjun07]

@hediet Kindly share your views on json parsing by Debug adapter: cppdebug for the above.

[arjunarjun07]

UPDATE:

The vizualisation is broken when the json is big. I tried to visualize for small heap it is working fine.

std::vector<int> heap = {10, 20, 30};

"{\"edges\":[{\"from\":\"0\",\"to\":\"1\"},{\"from\":\"0\",\"to\":\"2\"}],\"kind\":{\"graph\":true},\"nodes\":[{\"id\":\"0\",\"label\":\"10\"},{\"id\":\"1\",\"label\":\"20\"},{\"id\":\"2\",\"label\":\"30\"}]}"

Looks like the plugin json parser is failing somehow for bigger json.

[arjunarjun07]

Found a solution for this. from this comment
#53 (comment)

Instead of running this commands everytime manually in the debug console, I created a .gdbinit file with the following and it should be in the following location. %USERPROFILE%\.gdbinit

set print elements 0
set print repeats 0

[hediet]

Thanks for posting the solution!

Because this extension is debugger-independent, it relies on the debugger returning the full string content when requesting an evaluation of a string variable/expression. In this case, the debugger had a limit where it would cut off the string (probably in the middle, which is difficult to spot in the initial screenshot). In other cases, the string is escaped in unexpected ways (there are already some double-escaping heuristics in place).

I'm not sure how this can be improved.

[arjunarjun07]

Thanks for making this great plugin. This really makes the debugging interactive and lively. I hope more contributors will jump in to expand the support for the C++ community. @hediet