如何在多个文件中使用一个文件中的函数? [英] How to use functions from one file among multiple files?

问题描述

我正在尝试将一个文件中的函数与多个其他文件一起使用.

I'm trying to use the functions from one file with multiple other files.

当我尝试向文件添加mod somefile"时，Rust 编译器希望它们嵌套在一个子文件夹中，这不是我想要构建项目的方式，因为这意味着每次都复制文件.

When I try adding 'mod somefile' to the files, the Rust compiler wants them to be nested in a subfolder, which isn't how I want to structure the project, as it would mean duplicating the file each time.

// src/main.rs
mod aaa;
mod bbb;

fn main() {
    aaa::do_something();
    bbb::do_something_else();
}

// src/aaa.rs
mod zzz; // rust compiler wants the file to be nested in a subfolder as aaa/zzz.rs

pub fn do_something() {
    zzz::do_stuff();
}

// src/bbb.rs
mod zzz; // again, compiler wants the file nested in a subfolder as bbb/zzz.rs

pub fn do_something_else() {
    zzz::do_stuff();
}

// src/zzz.rs

pub fn do_stuff() {
    // does stuff here
}

我希望能够将 src/zzz.rs 留在根 src 文件夹中，并在项目中的任何其他文件中使用其功能，而不是必须在每个文件的子文件夹中复制它(例如:src/aaa/zzz.rs、src/bbb/zzz.rs).

I would like to be able to leave src/zzz.rs in the root src folder and use its functions among any of the other files in the project, instead of having to duplicate it in subfolders for each file (ex: src/aaa/zzz.rs, src/bbb/zzz.rs).

推荐答案

您只需要 mod zzz; 在 main.rs 中一次.

You need mod zzz; only once in the main.rs.

在aaa.rs 和bbb.rs 中，你需要一个use crate::zzz;，而不是mod zzz;.

In aaa.rs and bbb.rs you need a use crate::zzz;, not a mod zzz;.

示例:

文件src/aaa.rs:

use crate::zzz; // `crate::` is required since 2018 edition

pub fn do_something() {
    zzz::do_stuff();
}

文件src/bbb.rs:

use crate::zzz;

pub fn do_something_else() {
    zzz::do_stuff();
}

文件src/main.rs:

// src/main.rs
mod aaa;
mod bbb;
mod zzz;

fn main() {
    aaa::do_something();
    bbb::do_something_else();
}

文件src/zzz.rs:

pub fn do_stuff() {
    println!("does stuff zzz");
}

<小时>

只有当您有一个名为 aaa 的目录并且其中有一个文件时，您才需要 mod zzz; 在 aaa 模块中<代码>mod.rs 和 zzz.rs.然后，您必须将 mod zzz; 放在 mod.rs 中，以使子模块 aaa::zzz 对程序的其余部分可见.

---

You would need a mod zzz; inside of aaa module only if you had a directory called aaa and inside of it a files mod.rs and zzz.rs. Then you would have to put mod zzz; in mod.rs to make the submodule aaa::zzz visible to the rest of your program.

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