How to make rust work?

test.rs

// Run it with:
// echo -e "John Smith\nData1\nData2" > /tmp/in.txt; rustc test.rs && ./test
// Then change the output command in the loop in main() and try again
use std::io::prelude::*;
use std::fs::File;
use std::io::{BufReader,Stdout,self};

#[derive(Debug)]
pub struct Data<'a>{
    name: &'a str,
    value: String
}

pub struct Client<IN: BufRead, OUT: Write>{
    reader: IN,   // file or some tcp connect
    writer: OUT,  // stdout, file or another tcp connect
    name: Option<String>
}

impl<IN: BufRead, OUT: Write> Client<IN, OUT> {
    pub fn read_string(&mut self) -> Option<String> {
        let mut s = String::new();
        if self.reader.read_line(&mut s).unwrap() > 0 {
            Some(s.trim().to_string())
        } else {
            None
        }
    }
    pub fn read_name(&mut self) {
        match self.name{
            Some(_) => (),
            None => { self.name = self.read_string() }
        };
    }
    pub fn read_data<'a>(&'a mut self) -> Option<Data<'a>>{
        self.read_name();
        match self.read_string() {
            Some(v) => Some(Data{name: self.name.as_ref().unwrap(), value: v}),
            None => None
        }
    }
    pub fn write_data(&mut self, data: Data) {
        self.writer.write_fmt(format_args!("data from {:?}: {:?}", data.name, data.value));
    }
}

pub fn main() {
    let mut cl = Client{
        reader: BufReader::new(File::open("/tmp/in.txt").unwrap()),
        writer: io::stdout(),
        name: None
    };
    loop {
        match cl.read_data() {
            Some(data) => {
                // this line works
                println!("data from {:?}: {:?}", data.name, data.value);
                // this line doesn't work
                //cl.write_data(data);
                ()
            }
            None => break
        }
    }
}