prometeu-studio/discussion/workflow/plans/PLN-0112-migrate-semantic-tokens-to-generic-frontend-language-service.md

id	ticket	title	status	created	ref_decisions	tags
PLN-0112	multi-frontend-remove-pbs-branches	Migrate semantic tokens to generic frontend language service	open	2026-07-15	DEC-0042	compiler compiler-general compiler-pbs studio frontend coupling multi-frontend

Briefing

DEC-0042 requires the LSP common path to project semantic token behavior from the selected frontend through generic frontend contracts. Semantic presentation already lives mostly in FrontendSpec, so this is the lowest-risk capability migration.

Objective

Make LSP semantic token handling consume generic frontend language-service APIs while preserving frontend-owned semantic presentation and PBS semantic token behavior.

Dependencies

• Depends on PLN-0111 for the generic frontend editorial surface.
• Requires accepted decision DEC-0042.

Scope

• Route semantic token requests through the provider's optional generic language service.
• Preserve FrontendSpec.getSemanticPresentation() as the source of token keys, host projections, themes, and default theme.
• Keep deterministic empty semantic tokens when a frontend has no language service or no semantic-token capability.

Non-Goals

• Changing PBS semantic classification rules.
• Implementing semantic-token improvements from PBS-specific agendas.
• Migrating completion, hover, or signature help.
• Removing every PBS import from CompilerLanguageServiceBridge.

Execution Method

1. Inspect CompilerLanguageServiceBridge.semanticTokens(...) and PBSFrontendLanguageService.semanticTokens(...).
2. Add a generic semantic-token method to the frontend language-service surface if not already introduced by PLN-0111.
3. Adapt PBSFrontendLanguageService to return generic frontend semantic token records or a compatible generic token model.
4. Update CompilerLanguageServiceBridge.semanticTokens(...) to resolve FrontendProvider by context.languageId(), read presentation from provider.specification(), and call the generic semantic-token capability when present.
5. Ensure missing capability returns an empty token list with the frontend presentation legend.
6. Keep VS Code/LSP4J mapping inside prometeu-lsp.

Acceptance Criteria

• LSP semantic token handling no longer needs PBS-specific language-service casts.
• Frontend semantic presentation remains frontend-owned.
• PBS semantic token regression tests continue to pass.
• Compile-only or no-language-service providers return deterministic empty semantic tokens.

Tests

• Existing LSP semantic token tests.
• PBS frontend semantic presentation tests.
• Missing language-service fallback tests in CompilerLanguageServiceBridgeTest.

Affected Artifacts

• prometeu-lsp/prometeu-lsp-v1/src/main/java/p/studio/lsp/services/compiler/CompilerLanguageServiceBridge.java
• prometeu-compiler/frontends/prometeu-frontend-pbs/src/main/java/p/studio/compiler/PBSFrontendLanguageService.java
• prometeu-compiler/prometeu-frontend-api/src/main/java/p/studio/compiler/services/...
• LSP semantic-token tests.

TBD.

Objective

TBD.

Dependencies

TBD.

Scope

TBD.

Non-Goals

TBD.

Execution Method

TBD.

Acceptance Criteria

TBD.

Tests

TBD.

Affected Artifacts

TBD.