We use a single enum(TypeCode) to represent ArgTypeCode and DLDataTypeCode.
However, as we start to expand more data types, it is clear that argument
type code(in the FFI convention) and data type code needs to evolve separately.
So that we can add first class for data types without having changing the FFI ABI.
This PR makes the distinction clear and refactored the code to separate the two.
- [PY] Separate ArgTypeCode from DataTypeCode
- [WEB] Separate ArgTypeCode from DataTypeCode
- [JAVA] Separate ArgTypeCode from DataTypeCode
Tianqi Chen
8a98782cdf