Scoping

Scoping decides what a reference can see. Just like in a programming language, some names are visible only locally while others are exported for wider lookup.

Once your language has names and references, scoping determines what is visible from a given reference site and what stays hidden. You customize it in one of three layers:

• Naming — how declarations are exported.
• Scope computation — which symbols exist locally or globally.
• Scope lookup — which of those symbols are visible at a reference site.

These map to three phases of the document lifecycle:

• Symbol indexing — globally exported names.
• Scope computation — local symbol availability.
• Linking — final reference resolution.

Where to start

Pick the narrowest change that solves your problem:

• Use Qualified Names when declarations should be exported as package.Type or namespace.symbol.
• Use Custom Scope Provider when lookup needs different visibility rules.

Practical advice

Debug scoping problems in this order:

1. Verify how declarations are named.
2. Verify which symbols are exported or kept local.
3. Verify lookup behavior at the reference site.

Related pages

• Semantic Model
• Document Lifecycle
• LSP Services