shortener.rs

use std::collections::HashMap;

type Token = String;
type Url = String;

struct World { id: int, urls: HashMap<Token, Url> }

fn main() {
    let mut world = World { urls: HashMap::new(), id: 0i };

    let url = "justincampbell.me".to_string();
    print!("{} -> ", url);
    let token = world.shorten(url);
    print!("{} -> ", token);

    match world.expand(token) {
        Some(expanded_url) => println!("{}", expanded_url),
        None => println!("Could not find url for token")
        // Need to figure out how to keep an immutable copy of token after we
        // give it to expand()
        // None => println!("Could not find url for token {}", token)
    }
}

impl World {
    fn shorten(&mut self, url: Url) -> Token {
        self.id += 1;
        let token = World::tokenize(self.id);

        self.urls.insert(token.to_string(), url);

        token
    }

    fn expand(&self, token: Token) -> Option<&Url> {
        self.urls.get(&token)
    }

    fn tokenize(id: int) -> String {
        id.to_string()
    }
}