Split Atom suggestion entry to Type and Constructor

[4e6]

Pull Request Description

Changelog:

• update: split Atom suggestion to Type and Constructor
• update: gui API
• update: JSONRPC doc

Important Notes

Checklist

Please include the following checklist in your PR:

• The documentation has been updated if necessary.
• All code conforms to the
  Scala,
  Java,
  and
  Rust
  style guides.
• All code has been tested:
  • Unit tests have been written where possible.
  • If GUI codebase was changed: Enso GUI was tested when built using BOTH
    ./run ide build and ./run ide watch.

[farmaazon]

What is the returnType of the Type? I assume it will be always the type? I would left this field in Constructor, here it does not make much sense.

[4e6]

Agree, it can be re-constructed from the module name and the type name. Removed

[farmaazon]

1. Docs still use atom term.
2. Isn't module entirely deducible from returnType field? Is there a possibility of "Extension constructors"?

[4e6]

Good catch, I updated all atom references in the doc.

The module can probably be deducible from returnType right now. But later when we start supporting more complex types, it might not be the case. I'd leave this field as is

[JaroslavTulach]

The parts on the engine side look fine from my perspective. I suggest to get a review from @kustosz - he can judge the best whether SuggestionBuilder records the properties of the language properly.

[hubertp]

Minor nits

[kustosz]

I have some reservations regarding Type having a returnType, and, in particular, the returnType being the type itself. This is only true for no-constructor types, such as Nothing. For types that have constructors, the type itself has a singleton type (containing the static methods). There isn't a notation for this singleton type AFAIK, but probably one should be made up. Otherwise we run the risk of IDE providing wrong suggestions. If a method expects a Maybe, the word Maybe is not an acceptable argument. So we shouldn't tell them that Maybe: Maybe

[4e6]

So we shouldn't tell them that Maybe: Maybe

The returnType is only used internally and not exposed to the IDE in the JSONRPC protocol. We need it as an index in the suggestions database. And it is much cheaper to store it in a field than to compute it.

[farmaazon]

The Rust part LGTM.