CMUSphinx pronunciation dictionary

This is a fork of the original rust library for getting pronunciations from the CMUSphinx pronunciation dictionary.

The major changes are:

• switched from the depreciated failure crate to thiserror based errors
• switched to rust 2018 in the cargo config
• removed the utility function to download
• removed a lot of dependencies that were either no longer needed or depreciated
• fixed hung lookup bug (due to the new internals (I still don't know what caused it))
• changed the internals so file i/o wasn't needed for every lookup (and as a result simplified them)

The last of those changes is where the name comes from - as a result of the entire dictionary being loaded into volitile memory, each individual lookup is much faster than the original crate (O(k) where k is the maximum length of all words in the dictionary). Of course, there's the downside that it takes longer to create the object and uses more memory, but for the application I initially created this for the lookup time was essential. To adress the obvious, yes, this is slower than a hashmap since it uses a Radix tree internally (like the original crate). Still, it's much faster than the range-based file lookup or whatever you'd call it old crate used, while also being less complicated.

Installation

To use in your rust project, add the following to your Cargo.toml:

[dependencies]
cmudict-fast = "0.5"

Usage

To use the dictionary, you have to get an instance of the Cmudict struct:

use cmudict_fast::Cmudict;

fn main() {
  let dict = Cmudict::new("./path/to/a/cmudict/file").expect("Couldn't make Cmudict");
}

You can retrieve the pronunciation for a word like this:

use cmudict_fast::Cmudict;

fn main() {
  let dict = Cmudict::new("path/to/cmudict").expect("Couldn't get/make Cmudict");
  let word = dict.get("apple").unwrap().pronunciation();
  println!("{:?}", word); // &[Symbol::AE(Stress::Primary), Symbol::P, Symbol::AH(Stress::None), Symbol::L]
}