api: how should the args dictionary be stored on server?

[EdAyers]

Answer: store it as a string-keyed dictionary, each item of the dictionary is a content hash.

interface Eval  {
  ...rest
  args : {
    "foo" : contenthash
    "bar": contenthash
  }
}

I think in the future it might be useful to replace contenthash with a type something like

type Content =
  | { kind : "inline", value: bytes }
  | { kind : "blob", digest: str } 

And this is done in messagepack or our own encoding.

[EdAyers]

Starting with #78 , there is lots of extra info that we would like to store with the args:

• was it a default argument assignment? these can be shown in grey
• some type annotation info about the argument (this should be associated with the function definition not the evaluation or argument) so this should be its own issue.
• the'kind' of parameter, python has 5 different kinds
• the ordering of the arguments is also important, they should be shown in that order.

[EdAyers]

This is completed, follow up changes are in #79