- Add string concatenation support to + operator in typechecker
- Register ADT constructors in both type environment and interpreter
- Bind handlers as values so they can be referenced in run...with
- Fix effect checking to use subset instead of exact match
- Add built-in effects (Console, Fail, State) to run block contexts
- Suppress dead code warnings in diagnostics, modules, parser
Update all example programs with:
- Expected output documented in comments
- Proper run...with statements to execute code
Add new example programs:
- behavioral.lux: pure, idempotent, deterministic, commutative functions
- pipelines.lux: pipe operator demonstrations
- statemachine.lux: ADT-based state machines
- tailcall.lux: tail call optimization examples
- traits.lux: type classes and pattern matching
Add documentation:
- docs/IMPLEMENTATION_PLAN.md: feature roadmap and status
- docs/PERFORMANCE_AND_TRADEOFFS.md: performance analysis
Add benchmarks for performance testing.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add a Language Server Protocol (LSP) server to enable IDE integration.
The server provides:
- Real-time diagnostics (parse errors and type errors)
- Basic hover information
- Keyword completions (fn, let, if, match, type, effect, etc.)
- Go-to-definition stub (ready for implementation)
Usage: lux --lsp
The LSP server can be integrated with any editor that supports LSP,
including VS Code, Neovim, Emacs, and others.
Dependencies added:
- lsp-server 0.7
- lsp-types 0.94
- serde with derive feature
- serde_json
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add support for doc comments (/// syntax) that can be attached to
declarations for documentation purposes. The implementation:
- Adds DocComment token kind to lexer
- Recognizes /// as doc comment syntax (distinct from // regular comments)
- Parses consecutive doc comments and combines them into a single string
- Adds doc field to FunctionDecl, TypeDecl, LetDecl, EffectDecl, TraitDecl
- Passes doc comments through parser to declarations
- Multiple consecutive doc comment lines are joined with newlines
This enables documentation extraction and could be used for generating
API docs, IDE hover information, and REPL help.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add automatic effect inference for functions and lambdas that don't
explicitly declare their effects. The implementation:
- Tracks inferred effects during type checking via `inferred_effects`
- Uses `inferring_effects` flag to switch between validation and inference
- Functions without explicit `with {Effects}` have their effects inferred
- Lambda expressions also support effect inference
- When effects are explicitly declared, validates that inferred effects
are a subset of declared effects
- Pure functions are checked against both declared and inferred effects
This makes the effect system more ergonomic by not requiring explicit
effect annotations for every function while still maintaining safety.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add support for type classes (traits) with full parsing, type checking, and
validation. The implementation includes:
- Trait declarations: trait Show { fn show(x: T): String }
- Trait implementations: impl Show for Int { fn show(x: Int) = ... }
- Super traits: trait Ord: Eq { ... }
- Trait constraints in where clauses: where T: Show + Eq
- Type parameters on traits: trait Functor<F> { ... }
- Default method implementations
- Validation of required method implementations
This provides a foundation for ad-hoc polymorphism and enables
more expressive type-safe abstractions.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add trampoline-based tail call optimization to prevent stack overflow
on deeply recursive tail-recursive functions. The implementation:
- Extends EvalResult with TailCall variant for deferred evaluation
- Adds trampoline loop in eval_expr() to handle tail calls iteratively
- Propagates tail position through If, Let, Match, and Block expressions
- Updates all builtin callbacks to handle tail calls via eval_call_to_value
- Includes tests for deep recursion (10000+ calls) and accumulator patterns
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
REPL improvements:
- Tab completion for keywords, commands, and user definitions
- Persistent history saved to ~/.lux_history
- Better line editing with Emacs keybindings
- Ctrl-C to cancel input, Ctrl-D to exit
- History search with Ctrl-R
New commands:
- :info <name> - Show type information for a binding
- :env - List user-defined bindings with types
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Implements the exhaustiveness algorithm to detect non-exhaustive pattern matches:
- Detects missing Bool patterns (true/false)
- Detects missing Option patterns (Some/None)
- Detects missing Result patterns (Ok/Err)
- Recognizes wildcards and variable patterns as catch-alls
- Warns about redundant patterns after catch-all patterns
- Integrates with the type checker to report errors
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Implement beautiful, informative error messages inspired by Elm:
- Rich diagnostic rendering with source code snippets
- Colored output with proper underlines showing error locations
- Categorized error titles (Type Mismatch, Unknown Name, etc.)
- Contextual hints and suggestions for common errors
- Support for type errors, runtime errors, and parse errors
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Implement behavioral properties for functions including:
- Property annotations: is pure, is total, is idempotent, is deterministic, is commutative
- Where clause constraints: where F is pure
- Result refinements: where result >= 0 (parsing only, not enforced)
Key changes:
- AST: BehavioralProperty enum, WhereClause enum, updated FunctionDecl
- Lexer: Added keywords (is, pure, total, idempotent, deterministic, commutative, where, assume)
- Parser: parse_behavioral_properties(), parse_where_clauses(), parse_single_property()
- Types: PropertySet for tracking function properties, updated Function type
- Typechecker: Verify pure functions don't have effects, validate where clause type params
Properties are informational/guarantees rather than type constraints - a pure
function can be used anywhere a function is expected. Property requirements
are meant to be enforced via where clauses (future work: call-site checking).
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
