Adds spread operator for records, allowing concise record updates:
let p2 = { ...p, x: 5.0 }
Changes across the full pipeline:
- Lexer: new DotDotDot (...) token
- AST: optional spread field on Record variant
- Parser: detect ... at start of record expression
- Typechecker: merge spread record fields with explicit overrides
- Interpreter: evaluate spread, overlay explicit fields
- JS backend: emit native JS spread syntax
- C backend: copy spread into temp, assign overrides
- Formatter, linter, LSP, symbol table: propagate spread
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
BUG-004: Add ++ operator for string and list concatenation across all
backends (interpreter, C, JS) with type checking and formatting support.
BUG-001: Auto-invoke top-level `let main = fn () => ...` when main is
a zero-parameter function, instead of just printing the function value.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Tuple index: `pair.0`, `pair.1` syntax across parser, typechecker,
interpreter, C/JS backends, formatter, linter, and symbol table
- Multi-line function args: allow newlines inside argument lists
- Fix effect unification for callback parameters (empty expected
effects means "no constraint", not "must be pure")
Co-Authored-By: Claude Opus 4.6 <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 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>
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>
