feature(rome_js_semantic): semantic model built from semantic events

[xunilrj]

This PR creates the semantic model and allows navigation and querying the model.

The idea is to enable rules from #2743 to be implemented.

This is the code example:

function f(){let a = arguments[0]; let b = a + 1;}

The interesting part are:

scope navigation

let block_scope = arguments_reference.scope(&model);
let func_scope = block_scope.parent().unwrap();
let global_scope = func_scope.parent().unwrap();

assert!(global_scope.parent().is_none());

iterate scope bindings

let mut bindings = block_scope.bindings();

let binding0 = bindings.next().unwrap();
assert_eq!("a", binding0.syntax().text_trimmed());

let binding1 = bindings.next().unwrap();
assert_eq!("b", binding1.syntax().text_trimmed());

assert!(bindings.next().is_none());

get scope binding by name

let binding = block_scope.get_binding("arguments");
assert!(binding.is_none());

let binding = block_scope.get_binding("a").unwrap();
assert_eq!("a", binding.syntax().text_trimmed());

get declaration of a reference

let arguments_declaration = arguments_reference.declaration(&model);
assert!(arguments_declaration.is_none());

let a_declaration = a_reference.declaration(&model).unwrap();
assert_eq!("a", a_declaration.syntax().text_trimmed());

bindings

We do not allocate when saving bindings names, which is fine. But to enable this the event now needs to carry the SyntaxTokenText, which brings a green node with it.

This was not my initial idea.

I am fine with this for now, but if in the end no other solution appear, I will change SemanticEvents to return SyntaxNode, SynaxtToken instead.

SemanticModelData

The "heart" of the semantic model is inside the struct SemanticModelData. This struct lives behind an Arc that is shared with all semantic structs.

                             ┌───────────────────────┐
 ┌─────────────┐             │                       │
 │SemanticModel├──────┐      │   SemanticModelData   │
 └─────────────┘      │      │                       │
                      │      └─────────────▲─────────┘
 ┌─────┐              │                    │
 │Scope├────────┐     │      ┌──────┐      │
 └─────┘        │     │      │      │      │
                └─────┼──────► Arc  ├──────┘
 ┌───────┐            │      │      │
 │Binding├────────────┘      └──────┘
 └───────┘

rust-lapper

To allow any node/token to have a scope function, I am using interval trees (https://en.wikipedia.org/wiki/Interval_tree). In this case, using the crate https://github.com/sstadick/rust-lapper.

[github-actions]

Playground for commit 3f71771

[cloudflare-pages]

Deploying with    Cloudflare Pages

Latest commit:	31720fa
Status:	✅  Deploy successful!
Preview URL:	https://6a0fe0d0.tools-8rn.pages.dev
Branch Preview URL:	https://feature-semantic-model.tools-8rn.pages.dev

View logs

[github-actions]

Parser conformance results on ubuntu-latest

js/262

Test result	main count	This PR count	Difference
Total	45878	45878	0
Passed	44938	44938	0
Failed	940	940	0
Panics	0	0	0
Coverage	97.95%	97.95%	0.00%

jsx/babel

Test result	main count	This PR count	Difference
Total	39	39	0
Passed	36	36	0
Failed	3	3	0
Panics	0	0	0
Coverage	92.31%	92.31%	0.00%

symbols/microsoft

Test result	main count	This PR count	Difference
Total	5946	5946	0
Passed	388	388	0
Failed	5558	5558	0
Panics	0	0	0
Coverage	6.53%	6.53%	0.00%

ts/babel

Test result	main count	This PR count	Difference
Total	588	588	0
Passed	519	519	0
Failed	69	69	0
Panics	0	0	0
Coverage	88.27%	88.27%	0.00%

ts/microsoft

Test result	main count	This PR count	Difference
Total	16257	16257	0
Passed	12393	12393	0
Failed	3864	3864	0
Panics	0	0	0
Coverage	76.23%	76.23%	0.00%

[ematipico]

We should document this public object and explain the contents of data, because SemanticModelData is private at the moment.

[xunilrj]

Done.

[ematipico]

Can we add a string that explains the reason of this debug assertion?

[xunilrj]

Done.

[ematipico]

The debug assertion will disappear in production, but self.data.scopes[self.id] will stay. Is this operation safe?

[xunilrj]

Yes. I pushed an explanation of why.

[ematipico]

Suggested change

	/// Allows navigation to parent and children scope and binding information.
	/// Allows navigation to parent and children scopes and binding information.

[ematipico]

Suggested change

	/// Return this scope parent.
	/// Return the parent this scope.

[ematipico]

Suggested change

	/// Provides all information regarding to a specific binding.
	/// Provides information of a specific binding.