文件层级

模块可以映射到文件/目录层级结构。 让我们分解可见性示例到文件中

$ tree .
.
├── my
│   ├── inaccessible.rs
│   └── nested.rs
├── my.rs
└── split.rs

在 split.rs 中

// This declaration will look for a file named `my.rs` and will
// insert its contents inside a module named `my` under this scope
mod my;

fn function() {
    println!("called `function()`");
}

fn main() {
    my::function();

    function();

    my::indirect_access();

    my::nested::function();
}

在 my.rs 中

// Similarly `mod inaccessible` and `mod nested` will locate the `nested.rs`
// and `inaccessible.rs` files and insert them here under their respective
// modules
mod inaccessible;
pub mod nested;

pub fn function() {
    println!("called `my::function()`");
}

fn private_function() {
    println!("called `my::private_function()`");
}

pub fn indirect_access() {
    print!("called `my::indirect_access()`, that\n> ");

    private_function();
}

在 my/nested.rs 中

pub fn function() {
    println!("called `my::nested::function()`");
}

#[allow(dead_code)]
fn private_function() {
    println!("called `my::nested::private_function()`");
}

在 my/inaccessible.rs 中

#[allow(dead_code)]
pub fn public_function() {
    println!("called `my::inaccessible::public_function()`");
}

让我们检查一下，事情是否仍然像以前一样工作

$ rustc split.rs && ./split
called `my::function()`
called `function()`
called `my::indirect_access()`, that
> called `my::private_function()`
called `my::nested::function()`