Features

Overview

Feature	Status	Phase	Description
Skill documentation	✅ Complete	LLM Skill	SKILL.md entry point with syntax reference, examples, and routing
Feature proposal template	✅ Complete	LLM Skill	PROPOSE.md template for new language features
Langium grammar definition	✅ Complete	Grammar & Parser	191-line grammar covering contexts, commands, events, deciders, and expressions
Parser test suite	✅ Complete	Grammar & Parser	37 tests across 9 files with 194 assertions
LSP integration	✅ Complete	Grammar & Parser	Langium-provided language server with autocomplete, hover, and go-to-definition
Expression grammar	✅ Complete	Core Validation	Replace opaque ExpressionFragment with operator-precedence expression grammar. Unblocks guard consistency, postcondition verification, and multi-field evolve.
Exhaustiveness check	✅ Complete	Core Validation	Verify all Command × State pairs are covered in decide clauses. 54 tests (unit, property-based, edge cases), 100% mutation score.
Evolve totality check	✅ Complete	Core Validation	Verify all Event × State pairs are handled in evolve clauses. 22 tests (unit, property-based, edge cases).
Guard consistency	✅ Complete	Core Validation	Detect contradictory guards leading to unreachable code
Error messages with positions	✅ Complete	Core Validation	Actionable diagnostics with file:line:column and fix suggestions
Dead code detection	✅ Complete	Core Validation	Detect commands and events declared but not referenced by any decider. 6 property-based tests, 100% mutation score.
Terminal state validation	✅ Complete	Core Validation	Verify no decide clause targets a terminal state, and at least one non-terminal state exists per decider. Initial state is grammar-enforced (ADR-020).
Postcondition verification	✅ Complete	Core Validation	Static verification that ensure postconditions are derivable from evolve definitions
Emmett code generation	✅ Complete	Emmett Generator	Generate TypeScript decider classes with typed decide/evolve methods
Smart Constructors	✅ Complete	Emmett Generator	Generate private constructors with Result-returning create() from validate constraints
Generator snapshot tests	✅ Complete	Emmett Generator	Snapshot tests comparing .ddd input to expected .ts output
validate command	✅ Complete	CLI	weltenwanderer validate <pattern…> — parse and validate .ddd files matching glob patterns
generate command	✅ Complete	CLI	weltenwanderer generate <file.ddd> —target emmett — produce TypeScript output
Semantic token provider	📋 Planned	Language Server	Rich syntax highlighting via LSP semantic tokens
Code actions	📋 Planned	Language Server	Quick fixes and refactoring actions for .ddd files
Code lens	📋 Planned	Language Server	Inline annotations showing decider metrics and navigation
Document symbols	📋 Planned	Language Server	Outline view and breadcrumb navigation for .ddd files
Folding ranges	📋 Planned	Language Server	Code folding for contexts, deciders, and decision blocks
Document formatting	📋 Planned	Language Server	Auto-formatting for .ddd files
Rename symbol	📋 Planned	Language Server	Safe rename across file references
Signature help	📋 Planned	Language Server	Parameter hints for command and event constructors
Workspace symbols	📋 Planned	Language Server	Cross-file symbol search
VS Code extension	📋 Planned	Language Server	VS Code extension packaging the Langium LSP client with semantic features, code generation, and validation
State machine diagrams	✅ Complete	Mermaid Diagram Generation	Generate stateDiagram-v2 output per decider with initial state, evolve transitions, and terminal markers
VS Code extension	⏳ Deferred	Deferred	VS Code extension packaging the Langium LSP client
Living documentation	⏳ Deferred	Deferred	Generate domain documentation from .ddd source files
Schema evolution	⏳ Deferred	Deferred	Event versioning with @v annotations and upcast chain verification
Flow analysis	⏳ Deferred	Deferred	Event flow graph analysis with cycle detection and termination proofs
Event Model construct	⏳ Deferred	Deferred	Event Modeling as a first-class language construct with slices and actors
DSL mutation testing	⏳ Deferred	Deferred	Mutate AST and verify specs catch mutants using equivalence class boundaries
Data classification and GDPR compliance	⏳ Deferred	Deferred	Field-level @personal/@sensitive annotations with erasure verification and compliance artifacts
Modular compiler architecture	⏳ Deferred	Deferred	Plugin-based compiler modules consuming field annotations for cross-cutting concerns
Source map support	⏳ Deferred	Deferred	V3 source maps from Langium TraceRegion for generated TypeScript debugging
Extended compile targets	⏳ Deferred	Deferred	Axon 5, PostgreSQL, SQLite, DuckDB, and WASM compile targets beyond Emmett
Lazy / JIT artifact generation	⏳ Deferred	Deferred	Runtime-metrics-driven compilation for snapshots, views, indexes, and read models
MCP server	⏳ Deferred	Deferred	Model Context Protocol server with validate, generate, analyze, suggest, and template tools
Try-it-online playground	⏳ Deferred	Deferred	Browser-based Langium Web Worker + Monaco editor for zero-install domain modeling
Domain-level debugger	⏳ Deferred	Deferred	DAP server with event-by-event navigation, typed state diffs, and time travel
Runtime architecture strategy	⏳ Deferred	Deferred	Architectural decision between polyglot generators, canonical runtime, or WASM+host adapter
Value type factory functions	⏳ Deferred	Deferred	Generate factory functions for branded types to enable value type constructors in initial state bindings
Additional CLI delivery formats	⏳ Deferred	Deferred	Debian packages, Docker images, Homebrew tap, RPM, Flatpak, and Snap distribution formats