main.rs

use std::io;
use std::collections::HashMap;
use std::collections::hash_map::Entry::{Occupied,Vacant};
use std::ascii::AsciiExt;

fn main() {
    let mut words: HashMap<String, uint> = HashMap::new();
    for line in io::stdin().lock().lines() {
        for word in line.unwrap().words() {
            let lc = word.to_string().to_ascii_lower();
            match words.entry(lc) {
                Occupied(mut entry) => *entry.get_mut() += 1,
                Vacant(entry) => { entry.set(1); },
            }
        }
    }
    for (word, count) in words.iter() {
        println!("{}: {}", *word, *count);
    }
}