rust - Trouble reading from TcpStream -

i'm attempting implement haskell irc bot tutorial in rust , having difficulty reading server sends me after connecting. seems happen connect, read ~5 kb server, , 240 seconds later dumped @ once instead of being read line-by-line when ping timeout closes connection (which should happen eventually, since don't yet have ping-pong function reply with). here's have far:

use std::net::tcpstream; use std::io::read; use std::io::write;  fn main() {     let mut stream = tcpstream::connect("irc.freenode.org:6667").unwrap();      let _ = stream.write(b"nick g-serufu\r\n");     let _ = stream.write(b"user g-serufu 0 * :brobot\r\n");     let _ = stream.write(b"join #tutbot-testing\r\n");      let mut line = string::with_capacity(512);     loop {         let result = stream.read_to_string(&mut line);         match result {             ok(n) => println!("received {} bytes",n),             _ => {},         }         line.clear();     } } 

but when modifiy loop bit using array instead of string, output expect:

let mut line; loop {     line = [0; 512];     let result = stream.read(&mut line);     match result {         ok(n) => println!("received {} bytes",n),         _ => {},     } } 

so conclusion stream.read_to_string(&mut line) somehow culprit. know why might case, or there obvious i'm overlooking?

note: i'm using 1.0 stable release

edit: more specific, in first case output appears after ping timeout, upon following printed:

//around 4 minutes elapse before printed console received 5323 bytes received 0 bytes received 0 bytes received 0 bytes //continues print "received 0 bytes" since connection has closed haven't broken out of infinite loop 

in second case using array, receive correct output immediately:

received 64 bytes received 51 bytes received 512 bytes received 512 bytes received 350 bytes received 512 bytes received 512 bytes ... 

check out docs read_to_string:

read bytes until eof in source, placing them buf.

(emphasis mine)

notably, aren't reading 512 bytes in first example, pre-allocating 512 bytes of space , reading every byte until socket closes - 4 minutes later.

it sounds want use bufread::read_line:

read bytes until newline byte (the 0xa byte) reached, , append them provided buffer.

this function continue read (and buffer) bytes underlying stream until newline delimiter (the 0xa byte) or eof found. once found, bytes to, , including, delimiter (if found) appended buf.