Do you use mod.rs, the module name, or does it vary? How do you decide?
I started off avoiding mod.rs because it's the old way and I prefer having the module name as the filename. However, if the module needs a folder for submodules anyway, then there's a reason to tuck it away as mod.rs, especially if not doing so leaves lots of duplicate names (a.rs, b.rs, c.rs, ..., a/, b/, c/).
But then I don't really like to have much else in mod.rs other than mod declarations and pub use. Maybe a utility fn or a not-unwieldly implementation of struct "Foo", the module's namesake.
I use mod.rs because I like having a module entirely contained in its own directory, rather than having part of it in the parent one.
Obvious exception is when the module does not have submodules.
It also follows the same structure of crates, where mod.rs maps to lib.rs.
It has the (minor) advantage that I can trivially extract a module into its own crate by copying the module's directory and renaming mod.rs to lib.rs, but more than anything I like the homogeneity.
But then I don’t really like to have much else in mod.rs other than mod declarations and pub use. Maybe a utility fn or a not-unwieldly implementation of struct “Foo”, the module’s namesake.
Same.
My mod.rs only contains a sequence of pub use self::...;.