Rust string references allowed

rustrefsgood.rs

use std::error::Error;
use std::io::{BufRead, BufReader};

#[derive(Debug)]
struct Record<'a> {
    line: &'a str,
    words: Vec<&'a str>,
}

impl<'a> Record<'a> {
    fn new() -> Record<'a> {
        Record {
            line: "",
            words: Vec::new(),
        }
    }

    fn parse(s: &'a str) -> Record<'a> {
        let mut r = Record::new();
        r.line = s;
        r.words = r.line.split_whitespace().collect();
        r
    }
}

fn main() -> Result<(), Box<dyn Error>> {
    let s = r#"
    ’Twas brillig, and the slithy toves
        Did gyre and gimble in the wabe:
    All mimsy were the borogoves,
        And the mome raths outgrabe.
    "#;

    let mut records: Vec<Record> = Vec::new();
    let rdr = BufReader::new(s.as_bytes());
    let all_lines: Vec<String> = rdr.lines().filter_map(Result::ok).collect();

    for line in &all_lines {
        records.push(Record::parse(line));
    }
    println!("Number of records: {}", records.len());
    let numwords: usize = records.iter().map(|r| r.words.len()).sum();
    println!("Number of words: {}", numwords);

    Ok(())
}