I love Rust, but you couldn't pick a language with slower compile times... XD
Linking is also slow, and the extreme amounts of metadata produced for LLVM almost serves as a benchmark for LLVM's throughput, but that's all in an effort to produce faster, better binaries in the end.
On godbolt.org, Hello World compiles and runs in about 250ms. Zig's Hello World compiles and runs in 600ms. Of course Zig is still an unfinished language so optimisations like these are probably hardly a priority, but when it comes to lines of code per second, the difference isn't as big as people make it out to be.
What will make the most difference is how many crates the rewrite will pull in. The PORTING.md file specifies "No `tokio`, `rayon`, `hyper`, `async-trait`, `futures`" for the second phase, which should definitely get rid of the excessive compile time many people associate with Rust projects.
I guess it's all relative.
I find Rust's compile times abhorrent and it's objectively slower than many many other languages that also pull in dependencies left, right, and center. I guess that just means Rust scales very badly with amount of code.
I'd put it at a bit better than Haskell, but honestly not by much.
I really wish Rust would focus much more on compile times, or on making smaller parallel compilation units. It's quite a chore to have to keep splitting your program into smaller and smaller crates just to not sit and wait for an eternity.
As a comparison my CI job for Rust takes 14m running on a 16vCPU machine while my much larger TypeScript project compiles in 1m on a 2vCPU machine. I know people that have to spend quite a lot of work on keeping compile times manageable for Rust (nix, smaller crates, aggressive caching, etc etc).
Rust still brings me enough value that I'll stick with it, but one can still dream of a better future :)
So the practical delta is around half an hour to three quarters of an hour per day, or multiple hours per week. That directly affects flow state and experimentation speed. over the span of a month that's 2 full days worth of work waiting for the compiler. Or if you take my company's evaluation of the average engineer's hour cost it's roughly 2550 per month or almost 30k per year, obviously it's a bit exaggerated, you don't spend a full year refactoring and working like that, but even a tenth of that is still a big lump of money if you scale it to a few teams.
Now it needs to be taken with a huge pinch of salts because Rust provides other benefits that offsets the fact that it's painfully slow to compile, but still worth noting
So it's definitely a faster feedback loop and honestly completely bearable, but it's not 200ms.
