So my understanding is the hg developers are planning to rewrite a large part of hg in Rust. If so, this is an unfortunate blow to Python, because often I hear (and I do as well) Python developers cite hg as one of the largest Python-based application (regardless of the C-extension). I certainly feel sad if that is the case.
I studied hg quite in depth in undergraduate for a semester, when I was implementing "bitbucket" myself. To be really honest, the codebase was easy to navigate, and function names were pretty consistent with the actual hg commands/internal spec. While the code itself is probably hard to write any true unit tests (you'd have to monkeypatch like crazy) using mock -- which means the function has a lot of code, overall the codebase quality was pretty good for a complex software. I just had to know the variable name abbreviations, get used to them and referred back to the Hg paper.
In anyhow, whatever the decision is, I'd learn a bit Rust to help out :-)
P.S. I am still trying to find an answer to this: if FB uses Hg, then what about their git code?
I studied hg quite in depth in undergraduate for a semester, when I was implementing "bitbucket" myself. To be really honest, the codebase was easy to navigate, and function names were pretty consistent with the actual hg commands/internal spec. While the code itself is probably hard to write any true unit tests (you'd have to monkeypatch like crazy) using mock -- which means the function has a lot of code, overall the codebase quality was pretty good for a complex software. I just had to know the variable name abbreviations, get used to them and referred back to the Hg paper.
In anyhow, whatever the decision is, I'd learn a bit Rust to help out :-)
P.S. I am still trying to find an answer to this: if FB uses Hg, then what about their git code?