word-freq.rs

use std::collections::HashMap;
use std::fs::File;
use std::io::Read;

fn main() {

    let mut counter = HashMap::new();

    let mut f = File::open("sherlock.txt")
        .expect("cannot open file");
    let mut text = String::new();
    f.read_to_string(&mut text).expect("non UTF8 content");

    for s in text.split(|c: char| ! c.is_alphabetic()).filter(|&c| c != "") {
        let word = s.to_lowercase();
        let count = counter.entry(word).or_insert(0);
        *count += 1;
    }

    let mut entries: Vec<_> = counter.into_iter().collect();
    entries.sort_by(|a, b| b.1.cmp(&a.1));

    for e in entries.iter().take(20) {
        println!("{} {}", e.0, e.1);
    }
}