Make nested struct generation works

[ying-jeanne]

An example of expected input/output of cuetsy: https://gist.github.com/sdboyer/5d0b9e8e7ba0f60e427c84626a0eb11a

[sdboyer]

Indeed, we absolutely need to have codegen work for nested structs. It may be kinda tricky to implement, but there's no way around it.

[ying-jeanne]

The generation of nested struct itself is easy, but to generate the default is a bit tricky. writing down some test cases that should be covered by the code.
(pre-calculate the depth of nested struct, then go iteratively would not work? since a nested struct could contains several children, and each of them could have different depth?)