Visibility Modifiers

[b-studios]

This PR reorganizes parsing of modifiers on declaraionts, which are now grouped in Info. It also adds one new modifier private, which is parsed, but then ignored.

[b-studios]

@marvinborner I slightly refactored the parser w.r.t. to doc. My goal is to get rid of all usages of documentedKind and maybeDocumentation, since this will help me to generalize Doc to arbitrary meta data about a definition.

Could you check whether my changes so far make sense or whether you can construct an example which either:

1. does not parse
2. has different spans

[b-studios]

Sidenote: I removed a couple of nonterminal calls since the corresponding function was always called immediately under another nonterminal call.

[marvinborner]

I'll have to try more later, but it looks good so far.

[b-studios]

There are two very annoying things:

1. featureFlagFromCapture, this is necessary since parsing the info already consumed the feature flag. This will automatically be better if we drop parsing captures at the front of a definition.
2. documented takes a flag parseCaptures: Boolean. This is necessary to avoid eating the name of a constructor or operation as a capture set. Again, this will be automatically better once we drop parsing captures at the front of a definition.

[b-studios]

I am also very open to changing the design of this info object. In order to report some errors on the flags, they are positioned (using Maybe[Unit] is a hack). However, an empty Info object still contains a lot of position info and thus complicates the tests etc.

[b-studios]

We could be more precise by having a type hierarchy of Info. This way certain modifiers could be excluded by construction.

[b-studios]

I'm fine with merging this now in order to avoid conflicts with other PRs (especially #1097). Merging it now will parse private and then simply ignore it. We can later decide what to do with this info :)

[b-studios]

@timsueberkrueb what do you think?

[b-studios]

@jiribenes is it possible to run this on the community build before merging?

[timsueberkrueb]

@b-studios I'm happy with this being merged and rebasing my changes.

[b-studios]

Merging since its not (yet) Friday :)