Module rust_bert::reformer

Expand description

Reformer: The Efficient Transformer (Kitaev et al.)

Implementation of the Reformer language model (Reformer: The Efficient Transformer Kitaev, kaiser, Levskaya, 2020). The base model is implemented in the reformer_model::ReformerModel struct. The model also includes a language model head: reformer_model::ReformerModelWithLMHead implementing the common generation_utils::LMHeadModel trait shared between the models used for generation (see pipelines for more information).

Model set-up and pre-trained weights loading

A full working example is provided in examples/generation_reformer, run with cargo run --example generation_reformer. All models expect the following resources:

Configuration file expected to have a structure following the Transformers library
Model weights are expected to have a structure and parameter names following the Transformers library. A conversion using the Python utility scripts is required to convert the .bin weights to the .ot format.
ReformerTokenizer using a spiece.model BPE model Pretrained models on “Crime and Punishment” (Dostoevsky) are available and can be downloaded using RemoteResources.

use tch::{nn, Device};
use rust_bert::reformer::{ReformerConfig, ReformerModel};
use rust_bert::resources::{LocalResource, ResourceProvider};
use rust_bert::Config;
use rust_tokenizers::tokenizer::ReformerTokenizer;

let config_resource = LocalResource {
    local_path: PathBuf::from("path/to/config.json"),
};
let weights_resource = LocalResource {
    local_path: PathBuf::from("path/to/weights.ot"),
};
let vocab_resource = LocalResource {
    local_path: PathBuf::from("path/to/spiece.model"),
};
let config_path = config_resource.get_local_path()?;
let weights_path = weights_resource.get_local_path()?;
let vocab_path = vocab_resource.get_local_path()?;

let device = Device::cuda_if_available();
let mut vs = nn::VarStore::new(device);
let tokenizer: ReformerTokenizer =
    ReformerTokenizer::from_file(vocab_path.to_str().unwrap(), true)?;
let config = ReformerConfig::from_file(config_path);
let bart_model = ReformerModel::new(&vs.root(), &config);
vs.load(weights_path)?;