Random string generation in Rust (for Weasel)

randomstring.rs

use std::rand;
use std::rand::Rng;
use std::str;

static TARGET: &'static str = "methinks it is like a weasel";

static ALPHABET: [char, ..26] = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i',
                                 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r',
                                 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'];

fn random_char() -> char {
  rand::rng().choose(ALPHABET)
}

fn builder(push: &fn(v: char)) {
  for _ in range(0,TARGET.len()) {
    push(random_char());
  }
}

fn random_string () -> ~str {
  let result = std::vec::build(Some(TARGET.len()), builder);
  str::from_chars(result)
}

fn main() {
  println(random_string());
}