How to not rewrite it in Rust
This article is wonderful and I hope as a setup for second article, "How to Rewrite it in Rust"!<p>> However at best, the temptation to RiiR is unproductive<p>> A much better alternative is to reuse the original library and just publish a safe interface to it.<p>Just as models are a lower dimensional representation of a more complex problem, [1] I have to re-iterate that there are no truth(ism)s in software and as in all engineering, there are trade offs. RiiR can and often is a valid choice. The author talks about "introducing bugs", under an engineering approach to a rewrite, more like a language-port, rewrites can _find_ a lot of bugs. One such way is as follows.<p>1. keep the same interface in the new system, client code should work against either system.<p>2. have a body of integration tests, capture these from the field OR write a small collection of orthogonal tests, somewhere between unit and integration.<p>3. use the tooling, bindgen, etc and generate as much of the interface programmatically as possible.<p>4. iterate on the port, doing differential testing against both systems.<p>Doing a language port is comparable in work to long term maintenance and refactoring of an existing codebase. As the tooling gets better, RiiR will be more of a smooth oxidization.<p>If you own the C/C++ that could possibly get rewritten, I'd think one needs to rationalize NOT RiiR. Better tooling (IDE, build), perf tooling is improving, low bug count, increased team velocity, build is improved, etc.<p>But the biggest reason to RiiR is safety. Integrating a body of C/C++ code into your rust codebase introduces a huge amount of unsafe code, much worse than surrounding your entire rust program with unsafe { }.<p>At least do what is outlined in the article but ALSO compile the native code into Wasm and run it from within a sandbox.<p><i></i>edit, something like a library for reading (parsing) a file format, should absolutely be RiiR or run from a sandbox. Data parsing and memory corruption vulnerabilities are excellent dance partners.<p>[1] see PCA <a href="https://en.wikipedia.org/wiki/Principal_component_analysis" rel="nofollow">https://en.wikipedia.org/wiki/Principal_component_analysis</a>