러스트로 작성된 복합체

복합체 패턴은 객체들을 트리 구조들로 구성한 후, 이러한 구조들을 개별 객체들처럼 다룰 수 있도록 하는 구조 패턴입니다.

복합체는 트리 구조를 생성해야 하는 대부분 문제에 대해 인기 있는 해결책입니다. 전체 트리 구조에 대해 재귀적으로 메서드들을 실행하고 결과를 요약하는 기능은 복합체의 훌륭한 기능 중 하나입니다.

복합체에 대하여 더 자세히 알아보세요

내비게이션

소개

Files and Folders

mod

file

folder

main

Files and Folders

Let’s try to understand the Composite pattern with an example of an operating system’s file system. In the file system, there are two types of objects: files and folders. There are cases when files and folders should be treated to be the same way. This is where the Composite pattern comes in handy.

File and Directory are both of the trait Component with a single search method. For a file, it will just look into the contents of the file; for a folder, it will go through all files of that folder to find that keyword.

fs/mod.rs

mod file;
mod folder;

pub use file::File;
pub use folder::Folder;

pub trait Component {
    fn search(&self, keyword: &str);
}

fs/file.rs

use super::Component;

pub struct File {
    name: &'static str,
}

impl File {
    pub fn new(name: &'static str) -> Self {
        Self { name }
    }
}

impl Component for File {
    fn search(&self, keyword: &str) {
        println!("Searching for keyword {} in file {}", keyword, self.name);
    }
}

fs/folder.rs

use super::Component;

pub struct Folder {
    name: &'static str,
    components: Vec<Box<dyn Component>>,
}

impl Folder {
    pub fn new(name: &'static str) -> Self {
        Self {
            name,
            components: vec![],
        }
    }

    pub fn add(&mut self, component: impl Component + 'static) {
        self.components.push(Box::new(component));
    }
}

impl Component for Folder {
    fn search(&self, keyword: &str) {
        println!(
            "Searching recursively for keyword {} in folder {}",
            keyword, self.name
        );

        for component in self.components.iter() {
            component.search(keyword);
        }
    }
}

main.rs

mod fs;

use fs::{Component, File, Folder};

fn main() {
    let file1 = File::new("File 1");
    let file2 = File::new("File 2");
    let file3 = File::new("File 3");

    let mut folder1 = Folder::new("Folder 1");
    folder1.add(file1);

    let mut folder2 = Folder::new("Folder 2");
    folder2.add(file2);
    folder2.add(file3);
    folder2.add(folder1);

    folder2.search("rose");
}

Output

Searching recursively for keyword rose in folder Folder 2
Searching for keyword rose in file File 2
Searching for keyword rose in file File 3
Searching recursively for keyword rose in folder Folder 1
Searching for keyword rose in file File 1
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