Get specific element from System.Text.Json array without enumerating

With JsonValueKind.Object you can use:

value.GetProperty("XXX")

With JsonValueKind.Array you can use:

value.EnumerateArray().ElementAtOrDefault(2)

But is it also possible to get a specific index without enumerating the array?

The reason is that this is called in a tight loop.

I could read all values and cache them in a dictionary myself, but as I read that System.Text.Json is specifically made for performance I don't want to allocate unnecessary dictionaries.

Here's an example.

static void Main(string[] args)
{
    var json = JsonSerializer.Deserialize<JsonElement>(@"[ ""item1"", ""item2""]");

    // (seems) to enumerate the whole object - so slow in loops with large arrays
    var test1 = json.EnumerateArray().ElementAtOrDefault(1);

    // FIXME: crashes
    var test2 = json.GetProperty("1");

    // would love to have (return null when not existing - does not enumerate array - dictionary-like performance)
    // var test3 = json.GetElementAt("1"); 
}

Note that

• the actual code is called in a tight loop - it needs close to O(1) performnce
• the array can be quite large (not just two elements)