Ocaml runtime translated from C to Rust, now available

A community‑driven effort has produced a line‑by‑line Rust translation of the OCaml runtime, making the source code directly comparable to the original C implementation. The repository is linked in the OCaml Discuss thread and includes every file from the runtime, rewritten in Rust without altering functionality [OCaml Discuss].

── What shipped ──

The translation is a complete copy of the runtime’s C codebase, now compiled as Rust. It preserves the same module layout, data structures, and API surface, but replaces manual memory management with Rust’s ownership model. The commit history shows a one‑to‑one mapping of C statements to Rust equivalents, allowing engineers to trace how Rust’s safety guarantees replace explicit pointer arithmetic and error‑code checks.

── Why it matters ──

The project offers three concrete takeaways. First, it demonstrates that a large, performance‑critical codebase can be expressed in safe Rust without sacrificing the original semantics. Second, side‑by‑side comparison reveals where Rust’s type system eliminates whole classes of bugs common in C, such as use‑after‑free and null‑pointer dereferences. Third, the effort provides a template for other language runtimes or low‑level libraries that wish to migrate to Rust, showing that a systematic line‑by‑line rewrite is feasible and can be audited incrementally.

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