warning: `filter_map()` will run forever if the iterator repeatedly produces an `Err`
  --> src/words.rs:34:10
   |
34 |         .filter_map(|l| l.ok())
   |          ^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `map_while(Result::ok)`
   |
note: this expression returning a `std::io::Lines` may produce an infinite number of `Err` in case of a read error
  --> src/words.rs:32:8
   |
32 |       Ok(BufReader::new(file)
   |  ________^
33 | |         .lines()
   | |________________^
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#lines_filter_map_ok
   = note: `#[warn(clippy::lines_filter_map_ok)]` on by default