Labello: a fast label encoder in Rust

This crate provides a simple API for encoding labels represented by vectors. It uses a hashmap as internal data structure for classes and their mapping.

Example

```rust

// load data in a vector let data: Vec = vec!["hello".tostring(), "world".tostring(), "world".tostring(), "world".tostring(), "world".tostring(), "again".tostring(), "hello".tostring(), "again".tostring(), "goodbye".to_string()];

// define type of encoder and configuration for fitting let enctype = EncoderType::Ordinal; let config = Config{ maxnclasses: Some(3), mappingfunction: None }; // create encoder of let mut enc: Encoder = Encoder::new(Some(enctype));

// fit encoder with this configuration enc.fit(&data, &config);

// transform original data to internal encoded representation let trans_data = enc.transform(&data);

// inverse transform internal encoded representation to original data let recondata = enc.inversetransform(&trans_data);

// get unique original elements let uniques = enc.uniques(); ```