Flatten arrays

It would be cool, if the library would allow serializing arrays as scalar values like:

input:

[{
    name: "Jack",
    age: 39,
    friends: [{ name: "Oliver", age: 40 }, { name: "Harry", age: 50 }],
}, {
    name: "Thomas",
    age: 40,
    friends: [{ name: "Harry", age: 35 }]
}]

output:

name,age,friends.0.name,friends.0.age,friends.1.name,friends.1.age
Jack,39,Oliver,40,Harry,50
Thomas,40,Harry,35

[knownasilya]

I think we could do a backward compatible version, maybe even keeping flatten as-is and adding flattenArrays option. My rational is that this seems like a fringe case, since we are just now seeing a request for it and there probably won’t be additional options to flatten of the same nature, since there is no other complex data structures that you’d see in json. If we do see a reason for making it one option, we could do that in a future major version, e.g. v5.

[kuchta]

I like flatten = true|'objects'|'arrays'|false more, but I understand that I would introduce backward incompatible change, which is probably OK for major version change. Do you mean, that true would flatten both objects and arrays, right? I just can’t see use case for flatten = 'arrays'. Maybe ```flatten = true|‘evenArrays’|false would be better since it could be backward compatible when true means flatten just objects.