RocketPy

RocketPy copied to clipboard

Pull request type

• [X] Code changes (bugfix, features)

Checklist

• [X] Tests for the changes have been added (partially done)
• [ ] Docs have been reviewed and added / updated (future PR)
• [X] Lint (black rocketpy/ tests/) has passed locally
• [X] All tests (pytest tests -m slow --runslow) have passed locally
• [X] CHANGELOG.md has been updated (if relevant)

Current behavior

Currently the _encoding module is just a stub and cannot still encode full simulations into a JSON like format.

New behavior

This PR expand this module bringing the following:

• Custom Encoding for more types;
• Customized behavior for some required classes with methods to_dict;
• Support for Function encoding.

Breaking change

• [ ] Yes
• [X] No

Additional information

There is much to discuss here on the implementation and maintainability side of things. Main discussion points:

• Should we add a to_dict and (in the future) a from_dict method to some (or all) rocketpy classes?
  • My Opinion: I think adding the methods to everything might be the only way out. But there is some work and maintainability considerations.
• The current status of the encoding can be fully deserialized?
  • My Opinion: All the information is there, but the typing should be improved to know which objects to decode (deserialize) into. For that reason, I kept the _encoders private.
• Are there any other modules to make our work easier?
  • From my research, I have tested the following:
    • simplejson: brings some more types and speed into encoding, but does not help much with custom types;
    • jsonpickle: really great for the typing handler (already writes by default each object type) and is able to serialize. The problem is that is does not handle functions/lambdas and I did not find a good way to implement custom handlers for our use case;
    • pickle / dill: the most plug and play solution, however the output is not human readable and not generally compatible between different rocketpy versions.

Of course, this is what I understood upon researching and testing, feel free to make any comments or suggest other modules.