foo.rs

extern crate hyper;

extern crate rustc_serialize;
extern crate url;
use rustc_serialize::json::Json;
use url::Url;

use std::io::Read;

use hyper::Client;
use hyper::header::Connection;

pub struct SearchResult {
    pub url: String,
    pub title: String,
    pub desc: String
}

fn parse_results(resp: String) -> Vec<SearchResult> {
    Json::from_str(&resp).unwrap().find_path(&["responseData", "results"])
        .and_then(Json::as_array).unwrap()
        .into_iter()
        .map(|val| {
            let val = val.as_object().unwrap();
            SearchResult {
                url: val.get("url").and_then(Json::as_string).map(str::to_string).unwrap(),
                title: val.get("titleNoFormatting").and_then(Json::as_string).map(str::to_string).unwrap(),
                desc: val.get("content").and_then(Json::as_string).map(str::to_string).unwrap(),
            }
        })
        .collect()
}

fn retrieve(url: Url) -> Vec<SearchResult> {
    let client = Client::new();
    let mut res = client.get(url)
                    .header(Connection::close())
                    .send().unwrap();
    let mut body = String::new();
    res.read_to_string(&mut body).unwrap();
    parse_results(body)
}

pub fn search(query: &str, max_results: i32) -> Vec<SearchResult> {
    let mut url = Url::parse("http://ajax.googleapis.com/ajax/services/search/web").unwrap();
    let max_results = &max_results.to_string();

    url.set_query_from_pairs(&[
        ("v"  , "1.0"),
        ("rsz", max_results),
        ("q"  , query)
    ]);

    retrieve(url)
}

fn main() {}