[miki123211]

I wonder if you could actually write a compiler that does this for compilation speed. Have one mode where the compiler is super fast, has no error checking and can compile some malformed programs, and another mode where the compiler does all the checks.

This would be useful for dependencies for example, in most circumstances you can safely assume that dependency code doesn't contain compilation errors, so any passes that check for them are just pure and unnecessary overhead.

I don't know how practical this is, I don't have much experience in compiler design (beyond very small and toy compilers).

[eropple]

> This would be useful for dependencies for example, in most circumstances you can safely assume that dependency code doesn't contain compilation errors, so any passes that check for them are just pure and unnecessary overhead.

It's not an identical case, but TypeScript offers this with `skipLibCheck`. Most people use it. It's generally good--until it's really not good and you eat half a day unwinding a deceptively broken dependency.

[gloryjulio]

Sounds like if the code is in JavaScript, it would be already broken anyway

[markusde]

Yes... Rust!

I don't know if you can toggle it from the front-end, but the Polonius borrow checker includes a "location insensitive" mode which is faster but accepts fewer programs.

[estebank]

I think the GP had something else in mind. You're mentioning a mode where the rules are more stringent, allowing for a faster check and consequently faster compile times. The GP is pictuting a mode where the checks are skipped altogether, only the necessary transformations occur with an assumption that everything is already correct. I'm weary of having something like that outside of nightly, unless cargo publish had more checks than it does today.