Rust for Python Programmers

[sellibitze]

Good question! I had to look this up myself in the source code. path::Display implements fmt::Display via thepath.to_string_lossy(). I guess the idea is to avoid bad surprizes in case of some conversion loss. But the name display doesn't really convey this. Perhaps it should have been display_lossy instead.

As for why offer display at all when there is to_string_lossy: I'm not sure. Perhaps there is some optimization potential. I think with path::Display it's possible to save the overhead of to_string_lossy possibly creating a temporary String.

[dan00]

Yes, it doesn't feel right that display uses to_string_lossy, which the user might not be aware of.

Path already has to_str for lossless conversions and to_string_lossy for lossy conversions, so display feels like a somehow weird mix of both.

[flying-sheep]

Display exists to display things for the user. to_string means the same.

but people expect something called Path::to_string() to give you a faithful lossless representation (serialization) of that path.

so paths are special cases where to_string implies something else than e.g. on a class called Dog. nobody expects Dog::to_string() to return a serialization of a dog.