Rust modules
From wikinotes
Modules are rust libraries.
The std::prelude
module is included in the scope of every program.
Documentation
cargo book: package layout https://doc.rust-lang.org/cargo/guide/project-layout.html
Tutorials
rust module system https://www.sheshbabu.com/posts/rust-module-system/
Scrap
The core idea is that
main.rs/lib.rs
must import all paths.
mod
allows access to namespace,
using namespace,
for modules in same-directory
(ex../my_module.rs
,./my_module/mod.rs
)use
sample-1: (kwd mod) use module from namespace
src/ main.rs house.rs
src/main.rs
// main.rs mod house; fn main() { println!("{}", house::house_name()); }
house.rs
/house/mod.rs
// house.rs / house/mod.rs pub fn house_name() -> String { String:from("hi") }sample-2 (kwd mod) use file from submodule
src/ main.rs street/ mod.rs lamps.rs
main.rs
// main.rs mod street; fn main() { printlnt("{}", street::lamps::brightness()); }
street/mod.rs
// street/mod.rs pub mod lamps;
street/lamps.rs
// street/lamps.rs pub fn brightness() -> isize { 100 }
Entrypoint
For modules to be compiled, they must be used (however indirectly)
from either your crate'smain.rs
orlib.rs
.
Naming/Paths
Module names govern where they can be found within the filesystem.
Module locations are based on where they are defined# from the rust book: backyard ├── Cargo.lock ├── Cargo.toml └── src ├── garden │ └── vegetables.rs ├── garden.rs └── main.rsThe module
foo
's code could be
src/foo.rs
src/foo/mod.rs
Imports
use
merge namespace into current (ex.use foo; myfn();
)mod
enables you to access from namespace (ex.mod foo; foo::myfn();
)
use
(merge with current namespace)use std::io; // merges objects from namespace into your own use std::io::*; // use std::fs::File; // import 'File' only into current namespace use std::fs::{File, DirBuilder}; // import multiple types/functions into current namespace std::io::stdin() // you also can access objects directly from their namespace without `use`
mod
(access namespace)
Access Control
By default, a module's code is public to itself and it's children,
but private to it's parents and/or callers.pub mod house { pub mod livingroom { // ... } mod bedroom { // ... } }