index.rs

use std::io;
use std::fs;
use std::env;
use std::fmt;
use std::process;
use std::collections::{HashMap, HashSet};
use std::io::BufRead;

pub fn or_exit<T, E: fmt::Display>(r: Result<T, E>) -> T {
    r.unwrap_or_else(|e: E| -> T {
        println!("Error: {}", e);
        process::exit(1)
    })
}

fn main() {
    let mut idx = HashMap::new();

    for fname in env::args().skip(1) {
        let reader = or_exit(fs::File::open(&fname).map(io::BufReader::new));

        for line in reader.lines() {
            let line = or_exit(line);

            for token in line.split_whitespace() {
                idx.entry(token.to_owned())
                    .or_insert(HashSet::new())
                    .insert(fname.to_owned());
            }
        }
    }

    println!("Please enter a search term and press enter:");
    print!("> ");

    let stdin = io::stdin();
    for query in stdin.lock().lines() {
        match idx.get(&query.unwrap()) {
            Some(files) => println!("appears in {:?}", files),
            None => println!("does not appear in any files"),
        };
        print!("> ");
    }
}