Crates

Compilation unit in Rust.

When a file is called like rustc some_file.rs first all its mod get expanded and inserted in place. Then compilation occurs. some_file.rs is called a crate. Not the modules.

A crate can be compiled into a binary or into a library.

Creating a Library

$ rustc --create-type=lib sample.rs
$ ls lib* # by default libraries and prefixed with "lib", can be overridden with --crate-name
libsample.rlib

Using a Library

# Where libsample.rlib is the path to the compiled library, assumed that it's
# in the same directory here:
$ rustc executable.rs --extern rary=libsample.rlib && ./executable
called rary's `public_function()`
called rary's `indirect_access()`, that
> called rary's `private_function()`

// extern crate rary; // May be required for Rust 2015 edition or earlier
 
fn main() {
    sample::public_function();
 
    // Error! `private_function` is private
    //sample::private_function();
 
    sample::indirect_access();
}