More inspections

[dnbln]

This PR adds inspections for the first 3 ideas mentioned in #18 + 3 extra.

[AzureMarker]

This is looking pretty good!

[AzureMarker]

I think it may be possible to support nonterminals with params by generating unit structs in Rust file. What do you think?

[dnbln]

I'm not really sure what you mean. ctx.canCombineTypes() would return true only if both types are (), right? What do you have in mind?

PS: sorry for not answering sooner, I was way too busy this week.

[AzureMarker]

No worries about responding slower; it's the holiday season now 🙂.

For each type/rule parameter, the generated Rust code could have a RuleN struct which is used in place of the generic type. For example:

MyNonterminal<K, V>: HashMap<K, V> = ...; // alternative type resolves to std::collections::HashMap<K, V>

// imports

struct Rule1;
struct Rule2;

type T1 = HashMap<Rule1, Rule2>;
type T2 = std::collections::HashMap<Rule1, Rule2>;

There might be some issues if the generic type has bounds, like Hash in this case. It may be better to check if the Rust plugin supports comparing types with unbound generics (i.e. type T1<K, V> = HashMap<K, V>;).

But I think this can wait for a future PR, if you think it's worthwhile to pursue.

[AzureMarker]

I'm ready to merge this, but I'll wait in case you're planning on adding more commits.

[AzureMarker]

@dblanovschi Let me know when you're ready for this PR to be merged. I'll probably make a release right afterwards.

[dnbln]

With the last commit, there is only #22 (comment) left. I think that'd be worth looking into, but some other time. There is nothing else I'd like to add here. Edit: I just found out that precedence annotations were merged onto lalrpop, so I'd like to add an inspection to validate them (the rules described in "Prevalidation" here at least)

[AzureMarker]

Thanks again for contributing! These inspections look great!