看不懂 Rust 模块系统
Can't understand Rust module system
我出于教育目的创建了一个简单的项目,因此我有一个主要功能和 3 个特征 Battery
、Display
和 GSM
以及它们的实现。我希望主要功能位于文件 main.rs 中,而 3 个特征位于另一个名为 phone.rs:
的文件中
phone.rs
mod phone{
pub struct Battery{
model : String,
hours_idle : i16,
hours_talk : i16
}
pub struct Display{
size : i16,
number_of_colors : i32
}
pub struct GSM{
model : String,
manufactor : String,
price : f32,
owner : String,
battery: Battery,
display : Display
}
impl Battery {
pub fn new(model : String, hours_idle : i16, hours_talk : i16) -> Battery{
Battery {model : model, hours_idle : hours_idle ,hours_talk : hours_talk}
}
pub fn print(&self){
println!("Battery model: {}", self.model);
println!("Hours idle: {}", self.hours_idle);
println!("hours talk: {}", self.hours_talk);
}
}
impl Display {
pub fn new(size: i16, number_of_colors : i32) -> Display{
Display{size : size, number_of_colors : number_of_colors}
}
pub fn print(&self){
println!("size: {}", self.size);
println!("number_of_colors: {}", self.number_of_colors);
}
}
impl GSM {
pub fn new(model : String, manufactor : String, price : f32, owner : String, battery : Battery, display : Display) -> GSM{
GSM{model : model, manufactor : manufactor, price : price, owner : owner, battery : battery, display : display }
}
pub fn print(&self){
println!("Model: {}, Manufactor: {}", self.model, self.manufactor);
println!("price: {}", self.price);
println!("owner: {}", self.owner);
self.battery.print();
self.display.print();
}
}
}
main.rs
pub mod phone;
fn main(){
let battey = phone::Battery::new("modelBattery".to_string(), 1,2);
let display = phone::Display::new(10,20);
//model : String, manufactor : String, price : f32, owner : String, baterry : Battery, display : Display
let gsm = phone::GSM::new("modelPhone".to_string(), "manufactor".to_string(), 100.0, "owner".to_string(), battey, display);
gsm.print();
}
起初,所有内容都在一个文件中 (main.rs),并且一切正常(有一些不同,例如我在 Display
、[=15] 前面添加了 phone::
=] 和 main.rs 中的 Battery
),当我移动特征并在 phone.rs 中添加 mod phone{}
并在 main.rs 中添加 pub mod phone
时,我得到了编译器出现以下错误:
src\main.rs:3:18: 3:37 error: failed to resolve. Could not find `Battery` in `phone` [E0433]
src\main.rs:3 let battey = phone::Battery::new("modelBattery".to_string(), 1,2);
^~~~~~~~~~~~~~~~~~~
src\main.rs:3:18: 3:37 help: run `rustc --explain E0433` to see a detailed explanation
src\main.rs:3:18: 3:37 error: unresolved name `phone::Battery::new` [E0425]
src\main.rs:3 let battey = phone::Battery::new("modelBattery".to_string(), 1,2);
^~~~~~~~~~~~~~~~~~~
src\main.rs:3:18: 3:37 help: run `rustc --explain E0425` to see a detailed explanation
src\main.rs:4:20: 4:39 error: failed to resolve. Could not find `Display` in `phone` [E0433]
src\main.rs:4 let display = phone::Display::new(10,20);
^~~~~~~~~~~~~~~~~~~
src\main.rs:4:20: 4:39 help: run `rustc --explain E0433` to see a detailed explanation
src\main.rs:4:20: 4:39 error: unresolved name `phone::Display::new` [E0425]
src\main.rs:4 let display = phone::Display::new(10,20);
^~~~~~~~~~~~~~~~~~~
src\main.rs:4:20: 4:39 help: run `rustc --explain E0425` to see a detailed explanation
src\main.rs:6:16: 6:31 error: failed to resolve. Could not find `GSM` in `phone` [E0433]
src\main.rs:6 let gsm = phone::GSM::new("modelPhone".to_string(), "manufactor".to_string(), 100.0, "owner".to_string(), battey, display);
^~~~~~~~~~~~~~~
src\main.rs:6:16: 6:31 help: run `rustc --explain E0433` to see a detailed explanation
src\main.rs:6:16: 6:31 error: unresolved name `phone::GSM::new` [E0425]
src\main.rs:6 let gsm = phone::GSM::new("modelPhone".to_string(), "manufactor".to_string(), 100.0, "owner".to_string(), battey, display);
^~~~~~~~~~~~~~~
src\main.rs:6:16: 6:31 help: run `rustc --explain E0425` to see a detailed explanation
src\main.rs:7:5: 7:16 error: the type of this value must be known in this context
src\main.rs:7 gsm.print();
我不明白它们,我在此处和 Google 中进行了搜索,但未能找到解决方案。此外,我收到很多警告,指出从未使用 phone.rs 中的方法 #[warn(dead_code)]
,感谢任何帮助。
简短回答:您不需要 phone.rs
中的 mod phone
。只需删除它,您的代码就会工作(假设其余代码正确)。
更长的答案:main.rs
中的以下代码:
pub mod phone;
相当于:
pub mod phone {
// literally insert the contents of phone.rs here
}
所以你不需要在 mod phone {}
.
中包装 phone.rs
中的所有内容
您当前的代码转换为:
pub mod phone {
pub mod phone {
pub struct Battery { ... }
...
}
}
这意味着您需要在 main.rs
.[=23= 中访问 Battery
作为 phone::phone::Battery
(以及 Display
作为 phone::phone::Display
,等等) ]
我出于教育目的创建了一个简单的项目,因此我有一个主要功能和 3 个特征 Battery
、Display
和 GSM
以及它们的实现。我希望主要功能位于文件 main.rs 中,而 3 个特征位于另一个名为 phone.rs:
phone.rs
mod phone{
pub struct Battery{
model : String,
hours_idle : i16,
hours_talk : i16
}
pub struct Display{
size : i16,
number_of_colors : i32
}
pub struct GSM{
model : String,
manufactor : String,
price : f32,
owner : String,
battery: Battery,
display : Display
}
impl Battery {
pub fn new(model : String, hours_idle : i16, hours_talk : i16) -> Battery{
Battery {model : model, hours_idle : hours_idle ,hours_talk : hours_talk}
}
pub fn print(&self){
println!("Battery model: {}", self.model);
println!("Hours idle: {}", self.hours_idle);
println!("hours talk: {}", self.hours_talk);
}
}
impl Display {
pub fn new(size: i16, number_of_colors : i32) -> Display{
Display{size : size, number_of_colors : number_of_colors}
}
pub fn print(&self){
println!("size: {}", self.size);
println!("number_of_colors: {}", self.number_of_colors);
}
}
impl GSM {
pub fn new(model : String, manufactor : String, price : f32, owner : String, battery : Battery, display : Display) -> GSM{
GSM{model : model, manufactor : manufactor, price : price, owner : owner, battery : battery, display : display }
}
pub fn print(&self){
println!("Model: {}, Manufactor: {}", self.model, self.manufactor);
println!("price: {}", self.price);
println!("owner: {}", self.owner);
self.battery.print();
self.display.print();
}
}
}
main.rs
pub mod phone;
fn main(){
let battey = phone::Battery::new("modelBattery".to_string(), 1,2);
let display = phone::Display::new(10,20);
//model : String, manufactor : String, price : f32, owner : String, baterry : Battery, display : Display
let gsm = phone::GSM::new("modelPhone".to_string(), "manufactor".to_string(), 100.0, "owner".to_string(), battey, display);
gsm.print();
}
起初,所有内容都在一个文件中 (main.rs),并且一切正常(有一些不同,例如我在 Display
、[=15] 前面添加了 phone::
=] 和 main.rs 中的 Battery
),当我移动特征并在 phone.rs 中添加 mod phone{}
并在 main.rs 中添加 pub mod phone
时,我得到了编译器出现以下错误:
src\main.rs:3:18: 3:37 error: failed to resolve. Could not find `Battery` in `phone` [E0433]
src\main.rs:3 let battey = phone::Battery::new("modelBattery".to_string(), 1,2);
^~~~~~~~~~~~~~~~~~~
src\main.rs:3:18: 3:37 help: run `rustc --explain E0433` to see a detailed explanation
src\main.rs:3:18: 3:37 error: unresolved name `phone::Battery::new` [E0425]
src\main.rs:3 let battey = phone::Battery::new("modelBattery".to_string(), 1,2);
^~~~~~~~~~~~~~~~~~~
src\main.rs:3:18: 3:37 help: run `rustc --explain E0425` to see a detailed explanation
src\main.rs:4:20: 4:39 error: failed to resolve. Could not find `Display` in `phone` [E0433]
src\main.rs:4 let display = phone::Display::new(10,20);
^~~~~~~~~~~~~~~~~~~
src\main.rs:4:20: 4:39 help: run `rustc --explain E0433` to see a detailed explanation
src\main.rs:4:20: 4:39 error: unresolved name `phone::Display::new` [E0425]
src\main.rs:4 let display = phone::Display::new(10,20);
^~~~~~~~~~~~~~~~~~~
src\main.rs:4:20: 4:39 help: run `rustc --explain E0425` to see a detailed explanation
src\main.rs:6:16: 6:31 error: failed to resolve. Could not find `GSM` in `phone` [E0433]
src\main.rs:6 let gsm = phone::GSM::new("modelPhone".to_string(), "manufactor".to_string(), 100.0, "owner".to_string(), battey, display);
^~~~~~~~~~~~~~~
src\main.rs:6:16: 6:31 help: run `rustc --explain E0433` to see a detailed explanation
src\main.rs:6:16: 6:31 error: unresolved name `phone::GSM::new` [E0425]
src\main.rs:6 let gsm = phone::GSM::new("modelPhone".to_string(), "manufactor".to_string(), 100.0, "owner".to_string(), battey, display);
^~~~~~~~~~~~~~~
src\main.rs:6:16: 6:31 help: run `rustc --explain E0425` to see a detailed explanation
src\main.rs:7:5: 7:16 error: the type of this value must be known in this context
src\main.rs:7 gsm.print();
我不明白它们,我在此处和 Google 中进行了搜索,但未能找到解决方案。此外,我收到很多警告,指出从未使用 phone.rs 中的方法 #[warn(dead_code)]
,感谢任何帮助。
简短回答:您不需要 phone.rs
中的 mod phone
。只需删除它,您的代码就会工作(假设其余代码正确)。
更长的答案:main.rs
中的以下代码:
pub mod phone;
相当于:
pub mod phone {
// literally insert the contents of phone.rs here
}
所以你不需要在 mod phone {}
.
phone.rs
中的所有内容
您当前的代码转换为:
pub mod phone {
pub mod phone {
pub struct Battery { ... }
...
}
}
这意味着您需要在 main.rs
.[=23= 中访问 Battery
作为 phone::phone::Battery
(以及 Display
作为 phone::phone::Display
,等等) ]