Merge pull request 'dev/multi-frontend-remove-pbs-branches' (#16) from dev/multi-frontend-remove-pbs-branches into master

Reviewed-on: #16

discussion/index.ndjson

@@ -1,4 +1,4 @@
-{"type":"meta","next_id":{"DSC":66,"AGD":69,"DEC":42,"PLN":111,"LSN":58,"CLSN":1}}
+{"type":"meta","next_id":{"DSC":66,"AGD":69,"DEC":43,"PLN":117,"LSN":59,"CLSN":1}}
 {"type":"discussion","id":"DSC-0065","status":"open","ticket":"multi-frontend-avoid-premature-abstractions","title":"Evitar abstracoes prematuras na preparacao multi-frontend","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["compiler","compiler-general","studio","frontend","architecture","multi-frontend","simplicity"],"agendas":[{"id":"AGD-0068","file":"AGD-0068-multi-frontend-avoid-premature-abstractions.md","status":"open","created_at":"2026-07-15","updated_at":"2026-07-15"}],"decisions":[],"plans":[],"lessons":[]}
 {"type":"discussion","id":"DSC-0064","status":"open","ticket":"multi-frontend-architectural-tests","title":"Testes arquiteturais para fronteiras multi-frontend","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["compiler","compiler-general","studio","frontend","architecture","tests","multi-frontend"],"agendas":[{"id":"AGD-0067","file":"AGD-0067-multi-frontend-architectural-tests.md","status":"open","created_at":"2026-07-15","updated_at":"2026-07-15"}],"decisions":[],"plans":[],"lessons":[]}
 {"type":"discussion","id":"DSC-0063","status":"open","ticket":"multi-frontend-synthetic-test-frontend","title":"Frontend sintetico de teste para provar neutralidade do pipeline","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["compiler","compiler-general","frontend","tests","backend","multi-frontend"],"agendas":[{"id":"AGD-0066","file":"AGD-0066-multi-frontend-synthetic-test-frontend.md","status":"open","created_at":"2026-07-15","updated_at":"2026-07-15"}],"decisions":[],"plans":[],"lessons":[]}
@@ -8,7 +8,7 @@
 {"type":"discussion","id":"DSC-0059","status":"open","ticket":"multi-frontend-common-lifecycle","title":"Extrair lifecycle comum das responsabilidades do frontend PBS","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["compiler","compiler-general","compiler-pbs","lifecycle","backend","multi-frontend"],"agendas":[{"id":"AGD-0062","file":"AGD-0062-multi-frontend-common-lifecycle.md","status":"open","created_at":"2026-07-15","updated_at":"2026-07-15"}],"decisions":[],"plans":[],"lessons":[]}
 {"type":"discussion","id":"DSC-0058","status":"open","ticket":"multi-frontend-serializable-ir","title":"Manter a IR comum serializavel por design","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["compiler","compiler-general","ir","backend","serialization","multi-frontend"],"agendas":[{"id":"AGD-0061","file":"AGD-0061-multi-frontend-serializable-ir.md","status":"open","created_at":"2026-07-15","updated_at":"2026-07-15"}],"decisions":[],"plans":[],"lessons":[]}
 {"type":"discussion","id":"DSC-0057","status":"open","ticket":"multi-frontend-frontend-backend-contract","title":"Estabilizar contrato entre frontend e backend comum","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["compiler","compiler-general","compiler-pbs","ir","backend","multi-frontend"],"agendas":[{"id":"AGD-0060","file":"AGD-0060-multi-frontend-frontend-backend-contract.md","status":"open","created_at":"2026-07-15","updated_at":"2026-07-15"}],"decisions":[],"plans":[],"lessons":[]}
-{"type":"discussion","id":"DSC-0056","status":"open","ticket":"multi-frontend-remove-pbs-branches","title":"Remover verificacoes explicitas de PBS do codigo comum","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["compiler","compiler-general","compiler-pbs","studio","frontend","coupling","multi-frontend"],"agendas":[{"id":"AGD-0059","file":"AGD-0059-multi-frontend-remove-pbs-branches.md","status":"open","created_at":"2026-07-15","updated_at":"2026-07-15"}],"decisions":[],"plans":[],"lessons":[]}
+{"type":"discussion","id":"DSC-0056","status":"done","ticket":"multi-frontend-remove-pbs-branches","title":"Generalizar o contrato LSP/editorial para frontends","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["compiler","compiler-general","compiler-pbs","studio","frontend","coupling","multi-frontend"],"agendas":[],"decisions":[],"plans":[],"lessons":[{"id":"LSN-0058","file":"discussion/lessons/DSC-0056-multi-frontend-remove-pbs-branches/LSN-0058-generic-frontend-editorial-contract-for-lsp.md","status":"done","created_at":"2026-07-15","updated_at":"2026-07-15"}]}
 {"type":"discussion","id":"DSC-0055","status":"done","ticket":"multi-frontend-compiler-vs-language-services","title":"Separar compilacao de servicos editoriais de frontend","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["compiler","compiler-general","studio","lsp","editor","frontend","multi-frontend"],"agendas":[],"decisions":[],"plans":[],"lessons":[{"id":"LSN-0056","file":"discussion/lessons/DSC-0055-multi-frontend-compiler-vs-language-services/LSN-0056-compile-first-frontends-with-optional-editorial-capabilities.md","status":"done","created_at":"2026-07-15","updated_at":"2026-07-15"}]}
 {"type":"discussion","id":"DSC-0054","status":"done","ticket":"multi-frontend-provider-contract","title":"Introduzir provider completo de frontend","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["compiler","compiler-general","studio","frontend","registry","multi-frontend"],"agendas":[],"decisions":[],"plans":[],"lessons":[{"id":"LSN-0055","file":"discussion/lessons/DSC-0054-multi-frontend-provider-contract/LSN-0055-static-frontend-providers-before-plugin-architecture.md","status":"done","created_at":"2026-07-15","updated_at":"2026-07-15"}]}
 {"type":"discussion","id":"DSC-0053","status":"open","ticket":"pbs-lsp-call-and-type-hierarchy","title":"PBS LSP Call and Type Hierarchy","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["studio","lsp","vscode","compiler-pbs","editor","call-hierarchy","type-hierarchy"],"agendas":[{"id":"AGD-0056","file":"AGD-0056-pbs-lsp-call-and-type-hierarchy.md","status":"open","created_at":"2026-07-15","updated_at":"2026-07-15"}],"decisions":[],"plans":[],"lessons":[]}

discussion/lessons/DSC-0056-multi-frontend-remove-pbs-branches/LSN-0058-generic-frontend-editorial-contract-for-lsp.md

@@ -0,0 +1,92 @@
+---
+id: LSN-0058
+ticket: multi-frontend-remove-pbs-branches
+title: Generic Frontend Editorial Contract for LSP
+created: 2026-07-15
+tags: [compiler, compiler-general, compiler-pbs, studio, frontend, lsp, coupling, multi-frontend]
+---
+
+## Original Problem
+
+Prometeu was preparing for multiple compiler frontends while the LSP bridge still knew too much about PBS internals. The first framing was broad: remove explicit PBS checks from common code. After inspection, that was too blunt.
+
+PBS was already mostly centered in `prometeu-frontend-pbs`. Defaults, templates, `.pbs` fixtures, VS Code language registration, semantic keys, and composition-root bootstrap were legitimate PBS references. The real architectural problem was narrower: common LSP code imported and called PBS-specific editorial types and services for semantic tokens, completion, hover, signature help, and semantic read preparation.
+
+## Consolidated Decision
+
+The common LSP/editorial path must consume frontend-provided editorial capabilities through generic contracts exposed by `prometeu-frontend-api`.
+
+The provider contract remains stable:
+
+1. `FrontendProvider.compiler()` is mandatory.
+2. `FrontendProvider.languageService()` is optional.
+3. Compile-only frontends are valid.
+4. Unknown `languageId` values fail explicitly.
+5. PBS may be the product default only when the user has not chosen a language.
+
+PBS is not the shared editor model. PBS implements the generic contract from inside its frontend boundary.
+
+## Final Implementation Shape
+
+The implementation introduced generic frontend editorial DTOs and default methods in `FrontendLanguageService`:
+
+1. `FrontendDocumentRequest`
+2. `FrontendEditorialContext`
+3. `FrontendCompletionCandidate`
+4. `FrontendHover`
+5. `FrontendSignatureHelp`
+6. `FrontendSignature`
+7. `FrontendSymbolKind`
+8. `FrontendDocumentation`
+
+`CompilerLanguageServiceBridge` now resolves the selected provider and calls generic `FrontendLanguageService` methods for semantic tokens, completion, hover, and signature help.
+
+PBS-specific analysis setup moved behind `PBSFrontendLanguageService.prepareEditorialContext(...)`. The bridge no longer imports `p.studio.compiler.pbs.*`, no longer knows `PbsAst.File`, and no longer calls `PBSFrontendPhaseService.semanticReadSurface(...)` directly.
+
+An architectural test now protects the common LSP code from reintroducing PBS implementation imports.
+
+## Examples
+
+A frontend with no language service remains valid:
+
+```java
+public final class CompileOnlyFrontendProvider implements FrontendProvider {
+    @Override
+    public FrontendSpec specification() {
+        return SPEC;
+    }
+
+    @Override
+    public FrontendPhaseService compiler() {
+        return compiler;
+    }
+}
+```
+
+An LSP consumer should resolve the selected provider, ask for `languageService()`, and fall back deterministically when editorial capability is absent.
+
+PBS can still keep rich internal models such as `PbsEditorialResolvedSymbol`, but those models must be mapped to generic `FrontendHover`, `FrontendCompletionCandidate`, or `FrontendSignatureHelp` before common LSP consumes them.
+
+## Pitfalls
+
+Do not remove legitimate PBS defaults just because they mention PBS. PBS remains the product default when the user has not chosen another language.
+
+Do not use PBS as a fallback for unknown `languageId`. Unknown language identity is a configuration error and must fail explicitly.
+
+Do not make editor assistance mandatory. Compilation and editor support are separate frontend capabilities.
+
+Do not move frontend semantic ownership into LSP or Studio. The LSP bridge transports frontend-owned editorial results; it does not author language semantics.
+
+Do not reintroduce PBS imports in common LSP code for convenience. If a capability needs PBS-specific state, create or extend a frontend-owned generic boundary and keep the PBS mapping inside `prometeu-frontend-pbs`.
+
+## References
+
+- `DEC-0042` locked the generic frontend editorial language-service contract.
+- `PLN-0111` introduced generic frontend editorial DTOs and defaults.
+- `PLN-0112` migrated semantic tokens.
+- `PLN-0113` migrated completion.
+- `PLN-0114` migrated hover and documentation.
+- `PLN-0115` migrated signature help.
+- `PLN-0116` removed PBS imports from common LSP and added boundary coverage.
+- Related lesson: `LSN-0055` Static frontend providers before plugin architecture.
+- Related lesson: `LSN-0056` Compile-first frontends with optional editorial capabilities.

discussion/workflow/agendas/AGD-0059-multi-frontend-remove-pbs-branches.md

@@ -1,78 +0,0 @@
----
-id: AGD-0059
-ticket: multi-frontend-remove-pbs-branches
-title: Remover verificacoes explicitas de PBS do codigo comum
-status: open
-created: 2026-07-15
-resolved:
-decision:
-tags: [compiler, compiler-general, compiler-pbs, studio, frontend, coupling, multi-frontend]
----
-
-# Agenda - Remover verificacoes explicitas de PBS do codigo comum
-
-## Objetivo
-
-Domain owner: `compiler/general`, com impacto em `studio` e `compiler/pbs`.
-
-Definir uma auditoria e remocao incremental de branches, instanciacoes e chamadas estaticas PBS em codigo comum.
-
-## Contexto atual
-
-O documento de alinhamento aponta ocorrencias como `"pbs"`, `PBSDefinitions`, `PBSFrontendPhaseService`, `PBSFrontend`, `PbsParser`, `PbsSemantic` e `languageId`. A primeira busca no repo confirma ocorrencias espalhadas em docs, testes, frontend PBS, build pipeline e Studio.
-
-## Escopo
-
-- Classificar ocorrencias como internas ao PBS, composition root, testes PBS ou referencias indevidas.
-- Substituir referencias indevidas por provider, spec, capability ou servico registrado.
-- Manter excecoes explicitas documentadas.
-
-## Fora de escopo
-
-- Remover constantes PBS internas do proprio frontend.
-- Alterar templates explicitamente PBS.
-- Renomear packages.
-
-## Arquivos e componentes a inspecionar
-
-- `prometeu-app/src/main/java/p/studio/AppContainer.java`
-- `prometeu-studio/src/main/java/p/studio/window/NewProjectWizard.java`
-- `prometeu-studio/src/main/java/p/studio/projects/...`
-- `prometeu-compiler/prometeu-build-pipeline/...`
-- `prometeu-compiler/frontends/prometeu-frontend-pbs/...`
-- testes que importam `p.studio.compiler.pbs...`
-
-## Alteracoes propostas
-
-Opcao A: auditoria textual primeiro, seguida de PRs pequenos por area.
-
-Opcao B: criar teste arquitetural antes e usar falhas para guiar remocao.
-
-Recomendacao inicial: fazer auditoria textual e classificar em tabela curta antes de alterar; em seguida adicionar teste arquitetural para impedir regressao.
-
-## Estrategia de implementacao
-
-Usar `rg` para localizar termos, confirmar nomes reais, registrar classificacao no plano derivado e migrar apenas uma fronteira por vez.
-
-## Testes necessarios
-
-- Teste de dependencia impedindo imports PBS em packages comuns.
-- Testes de build existentes do PBS.
-- Testes de Studio/project wizard para garantir templates PBS ainda funcionam.
-
-## Criterios de aceitacao
-
-- Codigo comum nao decide comportamento por `"pbs"`.
-- Excecoes ficam restritas a composition root, testes PBS, templates PBS e frontend PBS.
-
-## Riscos
-
-- Remover uma referencia valida do PBS por classificacao apressada.
-- Quebrar setup de projeto existente ao mover extensoes e templates para provider.
-
-## Decisoes que devem ser registradas
-
-- Lista de excecoes permitidas.
-- Criterio de ownership para cada pacote comum.
-- Ordem de migracao por area.
-

prometeu-compiler/frontends/prometeu-frontend-pbs/src/main/java/p/studio/compiler/PBSFrontendLanguageService.java

@@ -1,13 +1,27 @@
 package p.studio.compiler;
 
 import p.studio.compiler.messages.FESurfaceContext;
+import p.studio.compiler.messages.BuildingIssueSink;
+import p.studio.compiler.messages.FrontendPhaseContext;
 import p.studio.compiler.models.FrontendSemanticToken;
 import p.studio.compiler.pbs.ast.PbsAst;
 import p.studio.compiler.pbs.semantics.PbsEditorialCompletionCandidate;
 import p.studio.compiler.pbs.semantics.PbsEditorialResolvedSymbol;
 import p.studio.compiler.pbs.semantics.PbsEditorialSignatureHelp;
+import p.studio.compiler.pbs.semantics.PbsEditorialSymbolKind;
 import p.studio.compiler.pbs.semantics.PbsEditorialSupportService;
+import p.studio.compiler.services.FrontendCompletionCandidate;
+import p.studio.compiler.services.FrontendDocumentRequest;
+import p.studio.compiler.services.FrontendDocumentation;
+import p.studio.compiler.services.FrontendEditorialContext;
+import p.studio.compiler.services.FrontendHover;
 import p.studio.compiler.services.FrontendLanguageService;
+import p.studio.compiler.services.FrontendSignature;
+import p.studio.compiler.services.FrontendSignatureHelp;
+import p.studio.compiler.services.FrontendSymbolKind;
+import p.studio.compiler.services.PBSFrontendPhaseService;
+import p.studio.compiler.source.diagnostics.DiagnosticSink;
+import p.studio.compiler.source.identifiers.FileId;
 import p.studio.utilities.structures.ReadOnlyList;
 
 import java.util.List;
@@ -29,6 +43,27 @@ public final class PBSFrontendLanguageService implements FrontendLanguageService
         this.semanticTokenProvider = Objects.requireNonNull(semanticTokenProvider, "semanticTokenProvider");
     }
 
+    @Override
+    public Optional<FrontendEditorialContext> prepareEditorialContext(
+            final FrontendPhaseContext phaseContext,
+            final FileId fileId) {
+        if (phaseContext == null || fileId == null) {
+            return Optional.empty();
+        }
+        final var semanticReadSurface = PBSFrontendPhaseService.semanticReadSurface(
+                phaseContext,
+                DiagnosticSink.empty(),
+                BuildingIssueSink.empty());
+        final var ast = semanticReadSurface.astByFile().get(fileId);
+        if (ast == null) {
+            return Optional.empty();
+        }
+        return Optional.of(new FrontendEditorialContext(
+                ast,
+                semanticReadSurface.supplementalTopDeclsByFile().getOrDefault(fileId, ReadOnlyList.empty()),
+                phaseContext.feSurfaceContext()));
+    }
+
     public List<PbsEditorialCompletionCandidate> completion(
             final String sourceText,
             final PbsAst.File ast,
@@ -38,6 +73,32 @@ public final class PBSFrontendLanguageService implements FrontendLanguageService
         return editorialSupportService.completion(sourceText, ast, supplementalTopDecls, feSurfaceContext, offset);
     }
 
+    @Override
+    public List<FrontendCompletionCandidate> completion(
+            final FrontendDocumentRequest request,
+            final FrontendEditorialContext editorialContext,
+            final int offset) {
+        if (request == null
+                || editorialContext == null
+                || !(editorialContext.syntaxTree() instanceof PbsAst.File ast)
+                || !(editorialContext.supplementalDeclarations() instanceof ReadOnlyList<?> supplementalTopDecls)
+                || !(editorialContext.semanticContext() instanceof FESurfaceContext feSurfaceContext)) {
+            return List.of();
+        }
+
+        @SuppressWarnings("unchecked")
+        final ReadOnlyList<PbsAst.TopDecl> typedSupplementalTopDecls =
+                (ReadOnlyList<PbsAst.TopDecl>) supplementalTopDecls;
+        return completion(
+                request.documentText(),
+                ast,
+                typedSupplementalTopDecls,
+                feSurfaceContext,
+                offset).stream()
+                .map(this::toFrontendCompletionCandidate)
+                .toList();
+    }
+
     public Optional<PbsEditorialResolvedSymbol> hover(
             final String sourceText,
             final PbsAst.File ast,
@@ -47,6 +108,30 @@ public final class PBSFrontendLanguageService implements FrontendLanguageService
         return editorialSupportService.hover(sourceText, ast, supplementalTopDecls, feSurfaceContext, offset);
     }
 
+    @Override
+    public Optional<FrontendHover> hover(
+            final FrontendDocumentRequest request,
+            final FrontendEditorialContext editorialContext,
+            final int offset) {
+        if (request == null
+                || editorialContext == null
+                || !(editorialContext.syntaxTree() instanceof PbsAst.File ast)
+                || !(editorialContext.supplementalDeclarations() instanceof ReadOnlyList<?> supplementalTopDecls)
+                || !(editorialContext.semanticContext() instanceof FESurfaceContext feSurfaceContext)) {
+            return Optional.empty();
+        }
+
+        @SuppressWarnings("unchecked")
+        final ReadOnlyList<PbsAst.TopDecl> typedSupplementalTopDecls =
+                (ReadOnlyList<PbsAst.TopDecl>) supplementalTopDecls;
+        return hover(
+                request.documentText(),
+                ast,
+                typedSupplementalTopDecls,
+                feSurfaceContext,
+                offset).map(this::toFrontendHover);
+    }
+
     public Optional<PbsEditorialSignatureHelp> signatureHelp(
             final String sourceText,
             final PbsAst.File ast,
@@ -56,7 +141,76 @@ public final class PBSFrontendLanguageService implements FrontendLanguageService
         return editorialSupportService.signatureHelp(sourceText, ast, supplementalTopDecls, feSurfaceContext, offset);
     }
 
+    @Override
+    public FrontendSignatureHelp signatureHelp(
+            final FrontendDocumentRequest request,
+            final FrontendEditorialContext editorialContext,
+            final int offset) {
+        if (request == null
+                || editorialContext == null
+                || !(editorialContext.syntaxTree() instanceof PbsAst.File ast)
+                || !(editorialContext.supplementalDeclarations() instanceof ReadOnlyList<?> supplementalTopDecls)
+                || !(editorialContext.semanticContext() instanceof FESurfaceContext feSurfaceContext)) {
+            return FrontendSignatureHelp.empty();
+        }
+
+        @SuppressWarnings("unchecked")
+        final ReadOnlyList<PbsAst.TopDecl> typedSupplementalTopDecls =
+                (ReadOnlyList<PbsAst.TopDecl>) supplementalTopDecls;
+        return signatureHelp(
+                request.documentText(),
+                ast,
+                typedSupplementalTopDecls,
+                feSurfaceContext,
+                offset)
+                .map(this::toFrontendSignatureHelp)
+                .orElseGet(FrontendSignatureHelp::empty);
+    }
+
+    @Override
+    public List<FrontendSemanticToken> semanticTokens(final FrontendDocumentRequest request) {
+        return semanticTokens(request == null ? "" : request.documentText());
+    }
+
     public List<FrontendSemanticToken> semanticTokens(final String documentText) {
         return semanticTokenProvider.tokenize(documentText == null ? "" : documentText);
     }
+
+    private FrontendCompletionCandidate toFrontendCompletionCandidate(final PbsEditorialCompletionCandidate candidate) {
+        return new FrontendCompletionCandidate(
+                candidate.label(),
+                toFrontendSymbolKind(candidate.kind()),
+                candidate.detail(),
+                candidate.documentation(),
+                candidate.origin());
+    }
+
+    private FrontendHover toFrontendHover(final PbsEditorialResolvedSymbol symbol) {
+        return new FrontendHover(
+                symbol.displayName(),
+                toFrontendSymbolKind(symbol.kind()),
+                symbol.detail(),
+                symbol.origin(),
+                symbol.signatures().stream()
+                        .map(this::toFrontendSignature)
+                        .toList(),
+                FrontendDocumentation.markdown(symbol.documentation()));
+    }
+
+    private FrontendSignatureHelp toFrontendSignatureHelp(final PbsEditorialSignatureHelp signatureHelp) {
+        return new FrontendSignatureHelp(
+                signatureHelp.signatures().stream()
+                        .map(this::toFrontendSignature)
+                        .toList(),
+                signatureHelp.activeSignature(),
+                signatureHelp.activeParameter());
+    }
+
+    private FrontendSignature toFrontendSignature(final p.studio.compiler.pbs.semantics.PbsEditorialSignature signature) {
+        return new FrontendSignature(signature.label(), signature.parameterLabels(), "");
+    }
+
+    private FrontendSymbolKind toFrontendSymbolKind(final PbsEditorialSymbolKind kind) {
+        return FrontendSymbolKind.valueOf(kind.name());
+    }
 }

prometeu-compiler/prometeu-build-pipeline/src/test/java/p/studio/compiler/specs/FrontendProviderBoundaryTest.java

@@ -75,6 +75,29 @@ class FrontendProviderBoundaryTest {
         }
     }
 
+    @Test
+    void commonLspMustNotImportPbsImplementationPackages() throws IOException {
+        final var repoRoot = findRepoRoot(Path.of("").toAbsolutePath().normalize());
+        final var sourceRoot = repoRoot.resolve("prometeu-lsp/prometeu-lsp-v1/src/main/java");
+        final var prohibitedNeedles = List.of(
+                "p.studio.compiler.PBSFrontendLanguageService",
+                "p.studio.compiler.services.PBSFrontendPhaseService",
+                "p.studio.compiler.pbs",
+                "PbsAst",
+                "PbsEditorial");
+
+        try (final var files = Files.walk(sourceRoot)) {
+            final var violations = files
+                    .filter(path -> path.toString().endsWith(".java"))
+                    .filter(path -> prohibitedNeedles.stream().anyMatch(needle -> contains(path, needle)))
+                    .toList();
+            if (!violations.isEmpty()) {
+                fail("common LSP code must consume generic frontend language-service contracts instead of PBS implementation packages: "
+                        + violations);
+            }
+        }
+    }
+
     @Test
     void compileOnlyFrontendProviderMayOmitLanguageService() {
         final FrontendProvider provider = new CompileOnlyFrontendProvider();

prometeu-compiler/prometeu-frontend-api/src/main/java/p/studio/compiler/services/FrontendCompletionCandidate.java

@@ -0,0 +1,33 @@
+package p.studio.compiler.services;
+
+import java.util.Objects;
+
+public record FrontendCompletionCandidate(
+        String label,
+        FrontendSymbolKind kind,
+        String detail,
+        String documentation,
+        String origin) {
+
+    public FrontendCompletionCandidate {
+        label = requireText(label, "label");
+        kind = Objects.requireNonNull(kind, "kind");
+        detail = normalize(detail);
+        documentation = normalize(documentation);
+        origin = normalize(origin);
+    }
+
+    private static String normalize(final String value) {
+        return value == null ? "" : value.trim();
+    }
+
+    private static String requireText(
+            final String value,
+            final String field) {
+        final String candidate = Objects.requireNonNull(value, field).trim();
+        if (candidate.isEmpty()) {
+            throw new IllegalArgumentException(field + " must not be blank");
+        }
+        return candidate;
+    }
+}

prometeu-compiler/prometeu-frontend-api/src/main/java/p/studio/compiler/services/FrontendDocumentRequest.java

@@ -0,0 +1,22 @@
+package p.studio.compiler.services;
+
+import java.nio.file.Path;
+import java.util.Objects;
+
+public record FrontendDocumentRequest(
+        Path projectRoot,
+        Path documentPath,
+        String documentText) {
+
+    public FrontendDocumentRequest {
+        projectRoot = normalizePath(projectRoot, "projectRoot");
+        documentPath = normalizePath(documentPath, "documentPath");
+        documentText = documentText == null ? "" : documentText;
+    }
+
+    private static Path normalizePath(
+            final Path path,
+            final String field) {
+        return Objects.requireNonNull(path, field).toAbsolutePath().normalize();
+    }
+}

prometeu-compiler/prometeu-frontend-api/src/main/java/p/studio/compiler/services/FrontendDocumentation.java

@@ -0,0 +1,21 @@
+package p.studio.compiler.services;
+
+import java.util.Objects;
+
+public record FrontendDocumentation(
+        FrontendDocumentationFormat format,
+        String text) {
+
+    public FrontendDocumentation {
+        format = Objects.requireNonNull(format, "format");
+        text = text == null ? "" : text;
+    }
+
+    public boolean isBlank() {
+        return text.isBlank();
+    }
+
+    public static FrontendDocumentation markdown(final String text) {
+        return new FrontendDocumentation(FrontendDocumentationFormat.MARKDOWN, text);
+    }
+}

prometeu-compiler/prometeu-frontend-api/src/main/java/p/studio/compiler/services/FrontendDocumentationFormat.java

@@ -0,0 +1,6 @@
+package p.studio.compiler.services;
+
+public enum FrontendDocumentationFormat {
+    MARKDOWN,
+    PLAINTEXT
+}

prometeu-compiler/prometeu-frontend-api/src/main/java/p/studio/compiler/services/FrontendEditorialContext.java

@@ -0,0 +1,7 @@
+package p.studio.compiler.services;
+
+public record FrontendEditorialContext(
+        Object syntaxTree,
+        Object supplementalDeclarations,
+        Object semanticContext) {
+}

prometeu-compiler/prometeu-frontend-api/src/main/java/p/studio/compiler/services/FrontendHover.java

@@ -0,0 +1,38 @@
+package p.studio.compiler.services;
+
+import java.util.List;
+import java.util.Objects;
+
+public record FrontendHover(
+        String displayName,
+        FrontendSymbolKind kind,
+        String detail,
+        String origin,
+        List<FrontendSignature> signatures,
+        FrontendDocumentation documentation) {
+
+    public FrontendHover {
+        displayName = requireText(displayName, "displayName");
+        kind = Objects.requireNonNull(kind, "kind");
+        detail = normalize(detail);
+        origin = normalize(origin);
+        signatures = signatures == null ? List.of() : List.copyOf(signatures);
+        documentation = documentation == null
+                ? FrontendDocumentation.markdown("")
+                : documentation;
+    }
+
+    private static String normalize(final String value) {
+        return value == null ? "" : value.trim();
+    }
+
+    private static String requireText(
+            final String value,
+            final String field) {
+        final String candidate = Objects.requireNonNull(value, field).trim();
+        if (candidate.isEmpty()) {
+            throw new IllegalArgumentException(field + " must not be blank");
+        }
+        return candidate;
+    }
+}

prometeu-compiler/prometeu-frontend-api/src/main/java/p/studio/compiler/services/FrontendLanguageService.java

@@ -1,7 +1,62 @@
 package p.studio.compiler.services;
 
+import p.studio.compiler.models.FrontendSemanticToken;
+import p.studio.compiler.messages.FrontendPhaseContext;
+import p.studio.compiler.source.identifiers.FileId;
+
+import java.util.List;
+import java.util.Optional;
+
 /**
- * Marker contract for optional frontend-owned editor services.
+ * Optional frontend-owned editor services.
  */
 public interface FrontendLanguageService {
+    default Optional<FrontendEditorialContext> prepareEditorialContext(
+            final FrontendPhaseContext phaseContext,
+            final FileId fileId) {
+        return Optional.empty();
+    }
+
+    default List<FrontendSemanticToken> semanticTokens(final FrontendDocumentRequest request) {
+        return List.of();
+    }
+
+    default List<FrontendCompletionCandidate> completion(
+            final FrontendDocumentRequest request,
+            final int offset) {
+        return List.of();
+    }
+
+    default List<FrontendCompletionCandidate> completion(
+            final FrontendDocumentRequest request,
+            final FrontendEditorialContext editorialContext,
+            final int offset) {
+        return completion(request, offset);
+    }
+
+    default Optional<FrontendHover> hover(
+            final FrontendDocumentRequest request,
+            final int offset) {
+        return Optional.empty();
+    }
+
+    default Optional<FrontendHover> hover(
+            final FrontendDocumentRequest request,
+            final FrontendEditorialContext editorialContext,
+            final int offset) {
+        return hover(request, offset);
+    }
+
+    default FrontendSignatureHelp signatureHelp(
+            final FrontendDocumentRequest request,
+            final int offset) {
+        return FrontendSignatureHelp.empty();
+    }
+
+    default FrontendSignatureHelp signatureHelp(
+            final FrontendDocumentRequest request,
+            final FrontendEditorialContext editorialContext,
+            final int offset) {
+        return signatureHelp(request, offset);
+    }
 }

prometeu-compiler/prometeu-frontend-api/src/main/java/p/studio/compiler/services/FrontendSignature.java

@@ -0,0 +1,28 @@
+package p.studio.compiler.services;
+
+import java.util.List;
+import java.util.Objects;
+
+public record FrontendSignature(
+        String label,
+        List<String> parameterLabels,
+        String documentation) {
+
+    public FrontendSignature {
+        label = requireText(label, "label");
+        parameterLabels = parameterLabels == null ? List.of() : parameterLabels.stream()
+                .map(parameterLabel -> requireText(parameterLabel, "parameterLabel"))
+                .toList();
+        documentation = documentation == null ? "" : documentation.trim();
+    }
+
+    private static String requireText(
+            final String value,
+            final String field) {
+        final String candidate = Objects.requireNonNull(value, field).trim();
+        if (candidate.isEmpty()) {
+            throw new IllegalArgumentException(field + " must not be blank");
+        }
+        return candidate;
+    }
+}

prometeu-compiler/prometeu-frontend-api/src/main/java/p/studio/compiler/services/FrontendSignatureHelp.java

@@ -0,0 +1,23 @@
+package p.studio.compiler.services;
+
+import java.util.List;
+
+public record FrontendSignatureHelp(
+        List<FrontendSignature> signatures,
+        int activeSignature,
+        int activeParameter) {
+
+    public FrontendSignatureHelp {
+        signatures = signatures == null ? List.of() : List.copyOf(signatures);
+        if (activeSignature < 0) {
+            throw new IllegalArgumentException("activeSignature must be >= 0");
+        }
+        if (activeParameter < 0) {
+            throw new IllegalArgumentException("activeParameter must be >= 0");
+        }
+    }
+
+    public static FrontendSignatureHelp empty() {
+        return new FrontendSignatureHelp(List.of(), 0, 0);
+    }
+}

prometeu-compiler/prometeu-frontend-api/src/main/java/p/studio/compiler/services/FrontendSymbolKind.java

@@ -0,0 +1,21 @@
+package p.studio.compiler.services;
+
+public enum FrontendSymbolKind {
+    KEYWORD,
+    LOCAL,
+    PARAMETER,
+    FIELD,
+    FUNCTION,
+    METHOD,
+    CONSTRUCTOR,
+    STRUCT,
+    BUILTIN_TYPE,
+    SERVICE,
+    HOST,
+    CONTRACT,
+    CALLBACK,
+    ENUM,
+    ERROR,
+    GLOBAL,
+    CONST
+}

prometeu-compiler/prometeu-frontend-api/src/test/java/p/studio/compiler/services/FrontendLanguageServiceTest.java

@@ -0,0 +1,63 @@
+package p.studio.compiler.services;
+
+import org.junit.jupiter.api.Test;
+
+import java.nio.file.Path;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class FrontendLanguageServiceTest {
+
+    @Test
+    void defaultLanguageServiceCapabilitiesAreEmpty() {
+        final FrontendLanguageService service = new FrontendLanguageService() {
+        };
+        final FrontendDocumentRequest request = new FrontendDocumentRequest(
+                Path.of("."),
+                Path.of("src/main.pbs"),
+                "fun main() {}");
+
+        assertTrue(service.semanticTokens(request).isEmpty());
+        assertTrue(service.completion(request, 0).isEmpty());
+        assertTrue(service.hover(request, 0).isEmpty());
+        assertEquals(FrontendSignatureHelp.empty(), service.signatureHelp(request, 0));
+    }
+
+    @Test
+    void completionCandidateNormalizesOptionalText() {
+        final var candidate = new FrontendCompletionCandidate(
+                " draw ",
+                FrontendSymbolKind.FUNCTION,
+                " callable ",
+                " docs ",
+                " stdlib ");
+
+        assertEquals("draw", candidate.label());
+        assertEquals("callable", candidate.detail());
+        assertEquals("docs", candidate.documentation());
+        assertEquals("stdlib", candidate.origin());
+    }
+
+    @Test
+    void hoverDefaultsToEmptyMarkdownDocumentation() {
+        final var hover = new FrontendHover(
+                "draw",
+                FrontendSymbolKind.FUNCTION,
+                null,
+                null,
+                List.of(new FrontendSignature("draw(x)", List.of("x"), null)),
+                null);
+
+        assertEquals("draw", hover.displayName());
+        assertTrue(hover.documentation().isBlank());
+        assertEquals(FrontendDocumentationFormat.MARKDOWN, hover.documentation().format());
+        assertEquals(1, hover.signatures().size());
+    }
+
+    @Test
+    void signatureHelpRejectsNegativeActiveIndexes() {
+        assertThrows(IllegalArgumentException.class, () -> new FrontendSignatureHelp(List.of(), -1, 0));
+        assertThrows(IllegalArgumentException.class, () -> new FrontendSignatureHelp(List.of(), 0, -1));
+    }
+}

prometeu-lsp/prometeu-lsp-v1/src/main/java/p/studio/lsp/services/compiler/CompilerLanguageServiceBridge.java

@@ -2,12 +2,16 @@ package p.studio.lsp.services.compiler;
 
 import org.apache.commons.lang3.StringUtils;
 import p.studio.compiler.FrontendRegistryService;
-import p.studio.compiler.PBSFrontendLanguageService;
 import p.studio.compiler.messages.*;
 import p.studio.compiler.models.*;
-import p.studio.compiler.pbs.semantics.*;
+import p.studio.compiler.services.FrontendCompletionCandidate;
+import p.studio.compiler.services.FrontendDocumentRequest;
+import p.studio.compiler.services.FrontendEditorialContext;
+import p.studio.compiler.services.FrontendHover;
 import p.studio.compiler.services.FrontendProvider;
-import p.studio.compiler.services.PBSFrontendPhaseService;
+import p.studio.compiler.services.FrontendSignature;
+import p.studio.compiler.services.FrontendSignatureHelp;
+import p.studio.compiler.services.FrontendSymbolKind;
 import p.studio.compiler.source.identifiers.FileId;
 import p.studio.compiler.utilities.SourceProviderFactory;
 import p.studio.compiler.workspaces.AssetSurfaceContextLoader;
@@ -15,7 +19,6 @@ import p.studio.compiler.workspaces.BuilderPipelineService;
 import p.studio.lsp.messages.*;
 import p.studio.lsp.services.LanguageServiceBridge;
 import p.studio.utilities.logs.LogAggregator;
-import p.studio.utilities.structures.ReadOnlyList;
 
 import java.net.URI;
 import java.nio.file.Path;
@@ -72,18 +75,25 @@ public final class CompilerLanguageServiceBridge implements LanguageServiceBridg
             final int line,
             final int character) {
         Objects.requireNonNull(context, "context");
-        final Optional<PBSFrontendLanguageService> languageService = pbsLanguageService(context);
+        final var provider = frontendProvider(context);
+        final var languageService = provider.languageService();
         if (languageService.isEmpty()) {
             return new BaselineCompletion(false, List.of());
         }
         return editorialDocument(context, documentUri, text)
                 .map(document -> {
                     final int offset = new DocumentPositionMapper(document.text()).byteOffsetOf(line, character);
-                    final List<PbsEditorialCompletionCandidate> candidates = languageService.orElseThrow().completion(
-                            document.text(),
-                            document.ast(),
-                            document.supplementalTopDecls(),
-                            document.feSurfaceContext(),
+                    final FrontendDocumentRequest request = new FrontendDocumentRequest(
+                            context.projectRoot(),
+                            normalizeDocumentPath(documentUri),
+                            document.text());
+                    final FrontendEditorialContext editorialContext = new FrontendEditorialContext(
+                            document.editorialContext().syntaxTree(),
+                            document.editorialContext().supplementalDeclarations(),
+                            document.editorialContext().semanticContext());
+                    final List<FrontendCompletionCandidate> candidates = languageService.orElseThrow().completion(
+                            request,
+                            editorialContext,
                             offset);
                     return new BaselineCompletion(
                             false,
@@ -100,18 +110,25 @@ public final class CompilerLanguageServiceBridge implements LanguageServiceBridg
             final int line,
             final int character) {
         Objects.requireNonNull(context, "context");
-        final Optional<PBSFrontendLanguageService> languageService = pbsLanguageService(context);
+        final var provider = frontendProvider(context);
+        final var languageService = provider.languageService();
         if (languageService.isEmpty()) {
             return new BaselineHover("No symbol information.");
         }
         return editorialDocument(context, documentUri, text)
                 .flatMap(document -> {
                     final int offset = new DocumentPositionMapper(document.text()).byteOffsetOf(line, character);
+                    final FrontendDocumentRequest request = new FrontendDocumentRequest(
+                            context.projectRoot(),
+                            normalizeDocumentPath(documentUri),
+                            document.text());
+                    final FrontendEditorialContext editorialContext = new FrontendEditorialContext(
+                            document.editorialContext().syntaxTree(),
+                            document.editorialContext().supplementalDeclarations(),
+                            document.editorialContext().semanticContext());
                     return languageService.orElseThrow().hover(
-                            document.text(),
-                            document.ast(),
-                            document.supplementalTopDecls(),
-                            document.feSurfaceContext(),
+                            request,
+                            editorialContext,
                             offset);
                 })
                 .map(symbol -> new BaselineHover(formatHoverMarkdown(symbol)))
@@ -126,26 +143,28 @@ public final class CompilerLanguageServiceBridge implements LanguageServiceBridg
             final int line,
             final int character) {
         Objects.requireNonNull(context, "context");
-        final Optional<PBSFrontendLanguageService> languageService = pbsLanguageService(context);
+        final var provider = frontendProvider(context);
+        final var languageService = provider.languageService();
         if (languageService.isEmpty()) {
             return new BaselineSignatureHelp(List.of(), 0, 0);
         }
         return editorialDocument(context, documentUri, text)
-                .flatMap(document -> {
+                .map(document -> {
                     final int offset = new DocumentPositionMapper(document.text()).byteOffsetOf(line, character);
+                    final FrontendDocumentRequest request = new FrontendDocumentRequest(
+                            context.projectRoot(),
+                            normalizeDocumentPath(documentUri),
+                            document.text());
+                    final FrontendEditorialContext editorialContext = new FrontendEditorialContext(
+                            document.editorialContext().syntaxTree(),
+                            document.editorialContext().supplementalDeclarations(),
+                            document.editorialContext().semanticContext());
                     return languageService.orElseThrow().signatureHelp(
-                            document.text(),
-                            document.ast(),
-                            document.supplementalTopDecls(),
-                            document.feSurfaceContext(),
+                            request,
+                            editorialContext,
                             offset);
                 })
-                .map(signatureHelp -> new BaselineSignatureHelp(
-                        signatureHelp.signatures().stream()
-                                .map(signature -> new BaselineSignature(signature.label(), signature.parameterLabels(), ""))
-                                .toList(),
-                        signatureHelp.activeSignature(),
-                        signatureHelp.activeParameter()))
+                .map(this::mapSignatureHelp)
                 .orElseGet(() -> new BaselineSignatureHelp(List.of(), 0, 0));
     }
 
@@ -156,10 +175,16 @@ public final class CompilerLanguageServiceBridge implements LanguageServiceBridg
             final String text) {
         Objects.requireNonNull(context, "context");
         final String effectiveText = text == null ? "" : text;
-        final var frontend = frontendProvider(context).specification();
+        final Path documentPath = normalizeDocumentPath(documentUri);
+        final var provider = frontendProvider(context);
+        final var frontend = provider.specification();
         final FrontendSemanticPresentationSpec presentation = frontend.getSemanticPresentation();
-        final List<FrontendSemanticToken> tokens = pbsLanguageService(context)
-                .map(languageService -> languageService.semanticTokens(effectiveText))
+        final FrontendDocumentRequest request = new FrontendDocumentRequest(
+                context.projectRoot(),
+                documentPath,
+                effectiveText);
+        final List<FrontendSemanticToken> tokens = provider.languageService()
+                .map(languageService -> languageService.semanticTokens(request))
                 .orElseGet(List::of);
         final var positionMapper = new DocumentPositionMapper(effectiveText);
         final var semanticTokens = new ArrayList<BaselineSemanticToken>();
@@ -202,6 +227,10 @@ public final class CompilerLanguageServiceBridge implements LanguageServiceBridg
             final LspProjectContext context,
             final String documentUri,
             final String text) {
+        final var languageService = frontendProvider(context).languageService();
+        if (languageService.isEmpty()) {
+            return Optional.empty();
+        }
         final Path documentPath = normalizeDocumentPath(documentUri);
         final BuilderPipelineContext pipelineContext = BuilderPipelineContext.fromConfig(
                 new BuilderPipelineConfig(
@@ -222,19 +251,11 @@ public final class CompilerLanguageServiceBridge implements LanguageServiceBridg
                 pipelineContext.resolvedWorkspace.target(),
                 HostAdmissionContext.permissiveDefault(),
                 assetSurfaceContextLoader.load(pipelineContext.resolvedWorkspace.mainProject().getRootPath()));
-        final var semanticReadSurface = PBSFrontendPhaseService.semanticReadSurface(
-                frontendPhaseContext,
-                p.studio.compiler.source.diagnostics.DiagnosticSink.empty(),
-                BuildingIssueSink.empty());
-        final var ast = semanticReadSurface.astByFile().get(fileId);
-        if (ast == null) {
-            return Optional.empty();
-        }
-        return Optional.of(new EditorialDocument(
-                text == null ? readCurrentText(pipelineContext, fileId) : text,
-                ast,
-                semanticReadSurface.supplementalTopDeclsByFile().getOrDefault(fileId, ReadOnlyList.empty()),
-                frontendPhaseContext.feSurfaceContext()));
+        return languageService.orElseThrow()
+                .prepareEditorialContext(frontendPhaseContext, fileId)
+                .map(editorialContext -> new EditorialDocument(
+                        text == null ? readCurrentText(pipelineContext, fileId) : text,
+                        editorialContext));
     }
 
     private FileId findFileId(
@@ -305,7 +326,7 @@ public final class CompilerLanguageServiceBridge implements LanguageServiceBridg
         return Path.of(URI.create(Objects.requireNonNull(documentUri, "documentUri"))).toAbsolutePath().normalize();
     }
 
-    private BaselineCompletionItem mapCompletionItem(final PbsEditorialCompletionCandidate candidate) {
+    private BaselineCompletionItem mapCompletionItem(final FrontendCompletionCandidate candidate) {
         return new BaselineCompletionItem(
                 candidate.label(),
                 mapCompletionKind(candidate.kind()),
@@ -356,6 +377,18 @@ public final class CompilerLanguageServiceBridge implements LanguageServiceBridg
                 tokenStyle.underline());
     }
 
+    private BaselineSignatureHelp mapSignatureHelp(final FrontendSignatureHelp signatureHelp) {
+        return new BaselineSignatureHelp(
+                signatureHelp.signatures().stream()
+                        .map(signature -> new BaselineSignature(
+                                signature.label(),
+                                signature.parameterLabels(),
+                                signature.documentation()))
+                        .toList(),
+                signatureHelp.activeSignature(),
+                signatureHelp.activeParameter());
+    }
+
     private p.studio.compiler.models.FrontendSpec frontendSpec(final LspProjectContext context) {
         return frontendProvider(context).specification();
     }
@@ -364,13 +397,7 @@ public final class CompilerLanguageServiceBridge implements LanguageServiceBridg
         return frontendProviderResolver.apply(context.languageId());
     }
 
-    private Optional<PBSFrontendLanguageService> pbsLanguageService(final LspProjectContext context) {
-        return frontendProvider(context).languageService()
-                .filter(PBSFrontendLanguageService.class::isInstance)
-                .map(PBSFrontendLanguageService.class::cast);
-    }
-
-    private BaselineCompletionItemKind mapCompletionKind(final PbsEditorialSymbolKind kind) {
+    private BaselineCompletionItemKind mapCompletionKind(final FrontendSymbolKind kind) {
         return switch (kind) {
             case KEYWORD -> BaselineCompletionItemKind.KEYWORD;
             case LOCAL, PARAMETER -> BaselineCompletionItemKind.VARIABLE;
@@ -391,9 +418,9 @@ public final class CompilerLanguageServiceBridge implements LanguageServiceBridg
         };
     }
 
-    private String formatHoverMarkdown(final PbsEditorialResolvedSymbol symbol) {
+    private String formatHoverMarkdown(final FrontendHover symbol) {
         final StringBuilder markdown = new StringBuilder();
-        final List<PbsEditorialSignature> signatures = symbol.signatures();
+        final List<FrontendSignature> signatures = symbol.signatures();
         if (!signatures.isEmpty()) {
             markdown.append("```pbs\n");
             for (int index = 0; index < signatures.size(); index += 1) {
@@ -419,15 +446,13 @@ public final class CompilerLanguageServiceBridge implements LanguageServiceBridg
             markdown.append(" from `").append(symbol.origin()).append('`');
         }
         if (!symbol.documentation().isBlank()) {
-            markdown.append("\n\n").append(symbol.documentation());
+            markdown.append("\n\n").append(symbol.documentation().text());
         }
         return markdown.toString();
     }
 
     private record EditorialDocument(
             String text,
-            p.studio.compiler.pbs.ast.PbsAst.File ast,
-            ReadOnlyList<p.studio.compiler.pbs.ast.PbsAst.TopDecl> supplementalTopDecls,
-            p.studio.compiler.messages.FESurfaceContext feSurfaceContext) {
+            FrontendEditorialContext editorialContext) {
     }
 }