Fish 4.0: The Fish Of Theseus ( https://fishshell.com/blog/rustport/ ) is the full story of their rewrite from C++ to Rust. Discussed on HN here - https://news.ycombinator.com/item?id=42535217 (906 points, 198 comments). Highlights of the rewrite - 1155 files changed, 110247 insertions(+), 88941 deletions(-) (excluding translations) - 2604 commits by over 200 authors - 498 issues - Almost 2 years of work - 57K Lines…
I'm surprised Rust took more lines. Perhaps formatter makes shorter lines due to method chaining? Or improved test suite?
Also, here's a code size tracker that counts tokens not lines, which is a better measure: https://github.com/rrethy/tcount