The **regexp‑stream‑tokenizer** package provides a tiny Node.js Transform stream that splits incoming data into tokens based on a user‑supplied regular expression. It works only in object‑mode streams, lets you optionally keep separators, customize token handling, and even simulate look‑behind, making it useful for developers who need a simple, configurable way to tokenize streaming text (e.g., log parsers, language preprocessors, or data pipelines).