rs-0.2.0#
Rust bootstrap compiler release, 2026-09-16. Backend: JavaScript running on Node.
Breaking syntax change#
Function and method declarations now use comma-separated parameters with no trailing semicolon:
func add(int a, int b) => a + b;
Migrate func add(int a; int b;) to the form above. Old semicolon signatures
are rejected with a migration diagnostic. Commas inside bracketed parameter
types remain part of the type. Trailing commas are not accepted. Zero-parameter
forms and statement-ending semicolons are unchanged.
Included#
- Updated parser, reference grammar, bundled examples, and syntax fixtures.
- Node execution tests plus malformed-parameter and nested-type parser checks.
- Language contract derived from the original prompts and later design decisions.
- Feature inventory, project review, and staged self-hosting roadmap.
Validation and limitations#
cargo test: 15 passing tests, with 8 known regression cases explicitly ignored.
Node must be on PATH, or selected through MARSLANG_NODE.
The broader language additions are documented targets, not implemented features:
decorators (std.Decorator), maps/deque, additional loops, library packages,
wildcard/relative module handling, and copy/immutability semantics remain pending.
Existing core gaps remain, including the bundled example's collection runtime
failure, hot substitution, compound me expressions, and line-oriented parsing.
The language contract and feature inventory are local discussion documents;
they are not distributed in the current checkout. These release notes describe
the rs-0.2.0 snapshot, not subsequent bug fixes.