Initial commit.

aggregator/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "aggregator"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

aggregator/src/bin/test_case.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println! ("媒体聚合器");
+}

aggregator/src/lib.rs

@@ -0,0 +1,56 @@
+pub trait Summary {
+    fn summarize_author(&self) -> String;
+
+    fn summarize(&self) -> String {
+        format! ("（了解更多来自 {} ......）", self.summarize_author())
+    }
+}
+
+pub struct NewsArticle {
+    pub headline: String,
+    pub location: String,
+    pub author: String,
+    pub content: String,
+}
+
+impl Summary for NewsArticle {
+    fn summarize_author(&self) -> String {
+        format! ("{}", self.author)
+    }
+}
+
+pub struct Tweet {
+    pub username: String,
+    pub content: String,
+    pub reply: bool,
+    pub retweet: bool,
+}
+
+impl Summary for Tweet {
+    fn summarize_author(&self) -> String {
+        format! ("@{}", self.username)
+    }
+}
+
+use std::fmt::Display;
+
+pub struct Pair<T> {
+    pub x: T,
+    pub y: T,
+}
+
+impl<T> Pair<T> {
+    pub fn new(x: T, y: T) -> Self {
+        Self { x, y }
+    }
+}
+
+impl<T: Display + PartialOrd> Pair<T> {
+    pub fn cmp_display(&self) {
+        if self.x >= self.y {
+            println! ("极大数为 x = {}", self.x);
+        } else {
+            println! ("极大数为 y = {}", self.y);
+        }
+    }
+}

aggregator/src/main.rs

@@ -0,0 +1,54 @@
+use aggregator::{Summary, Tweet, NewsArticle, Pair};
+
+pub fn notify<T: Summary>(item: &T) {
+    println! ("突发新闻！{}", item.summarize());
+}
+
+fn return_summarizable() -> impl Summary {
+    Tweet {
+        username: String::from("horse_ebooks"),
+        content: String::from(
+            "当然，如同你或许已经知道的一样，朋友们"
+        ),
+        reply: false,
+        retweet: false,
+    }
+}
+
+fn main() {
+    let tweet = Tweet {
+        username: String::from("horse_ebooks"),
+        content: String::from(
+            "当然，跟大家已经清楚的一样了，朋友们",
+        ),
+        reply: false,
+        retweet: false,
+    };
+
+    println!("1 条新推文: {}", tweet.summarize());
+    notify(&tweet);
+
+
+    let article = NewsArticle {
+        headline: String::from("企鹅队赢得斯坦利杯锦标赛！"),
+        location: String::from("美国，宾夕法尼亚州，匹兹堡"),
+        author: String::from("Iceburgh"),
+        content: String::from(
+            "匹兹堡企鹅队再度成为美国曲棍球联盟 \
+            NHL 中的最佳球队。"
+        ),
+    };
+
+    println! ("有新文章可读！{}", article.summarize());
+    notify(&article);
+
+    println! ("1 条旧推文: {}", return_summarizable().summarize());
+
+    let pair = Pair::new(5, 10);
+    pair.cmp_display();
+
+    let pair = Pair::new("这是一个测试", "This is a test.");
+    pair.cmp_display();
+
+    println! ("{}", 3.to_string());
+}