I don't know what AT is doing but I can say that while JSON Schema is okay as a validation schema it is less okay as codegen schema. I don't know if there is a fundamental divide between these two uses but in JSON Schema there is definitely an impedance mismatch.
For example, the JSON Schema structures: `anyOf`, `oneOf` and `allOf` are fairly clear when applied toward validation. But how do you map these to generating code for, say, C++ data structures?
You can of course minimize the problem by restricting to a subset of JSON Schema. But that leaves others. For example, a limited JSON Schema `object` construct can be mapped to, say, a C++ `struct` but it can also map to a homogeneous associative array, eg `std::map` or a fixed heterogeneous AA, eg `std::tuple`. It can also be mapped to an open-ended hetero AA which has no standard form in C++ (maybe `std::map<string,variant<...>>`). Figuring out the mapping intended by the author of the JSON Schema is non trivial and can be ambiguous.
At some level, I think this is an inherent divide as each language one targets for codegen supports different types of data structures differently. One can not escape that codegen is not always a fully functional transformation.
For example, the JSON Schema structures: `anyOf`, `oneOf` and `allOf` are fairly clear when applied toward validation. But how do you map these to generating code for, say, C++ data structures?
You can of course minimize the problem by restricting to a subset of JSON Schema. But that leaves others. For example, a limited JSON Schema `object` construct can be mapped to, say, a C++ `struct` but it can also map to a homogeneous associative array, eg `std::map` or a fixed heterogeneous AA, eg `std::tuple`. It can also be mapped to an open-ended hetero AA which has no standard form in C++ (maybe `std::map<string,variant<...>>`). Figuring out the mapping intended by the author of the JSON Schema is non trivial and can be ambiguous.
At some level, I think this is an inherent divide as each language one targets for codegen supports different types of data structures differently. One can not escape that codegen is not always a fully functional transformation.