Allow creation (or more feedback) when attempting to create a nested module

[schneems]

Currently you can use quickfix to create a module file:

But not if there are nested modules:

It would be great to be able to either create the whole chain or if it's too ambiguous maybe give some feedback (somehow?) like "The lol module does not exist. Cannot create lol::haha. Please create lol before creating lol::haha"

This came up in a conversation on my blog post that uses rust-analyzer to teach how the module system interacts with files https://lobste.rs/s/e3lj0p/it_s_dangerous_go_alone_pub_mod_use_this_rs#c_7kz26f.

[matklad]

Not sure if we should do this. mod foo::bar isn’t a valid syntax, so the problem here is much shallower than “can’t create nested modules”, it’s that mod foo::bar isn’t a thing in Rust.

pracitclaly, yeah, type mod foo;, press cmd+., create module (this’ll focus the editor in the new file), type mod bar;, press cmd+. again.

[schneems]

isn’t a valid syntax

picard_facepalm.jpeg

Thanks. I think we can close this. Though I do wonder if a warning or error could be possible from analyzer “mod foo::bar; is not valid syntax” ideally if we could go so far as to recommend/guess what the person wants it could be even better, though that might be better in a compiler error.