How to Use HuggingFace Fast Tokenizers Efficiently
A practical guide to HuggingFace fast tokenizers for ML engineers: how Rust-backed fast tokenizers differ from slow Python tokenizers, using offset mappings for NER and QA span alignment, high-throughput batched tokenisation with datasets.map and multiprocessing, sliding window tokenisation for long documents with stride and overflow, training a custom BPE vocabulary with the tokenizers library, and debugging gotchas around special tokens and sequence pair handling.