What is winnow?

Winnow is a toolkit that makes it easier to write code that reads and interprets structured text or data. Instead of writing parsing logic from scratch, you get pre-built pieces that you can snap together like LEGO blocks to handle your specific format. Think of parsing like translating a document. When you receive a CSV file, JSON blob, or custom config format, your program needs to understand what's in it, where the boundaries are, what each piece means, how to extract the data you care about. Winnow provides small, focused building blocks (called "combinators") that handle common parsing tasks: matching a specific word, extracting numbers, skipping whitespace, repeating a pattern multiple times, and so on. You combine these pieces to build a parser tailored to your format. Who would use this? Anyone writing software that needs to read a file or string with a specific structure. A backend engineer parsing API responses, someone building a config file parser for their application, a tool developer who needs to extract data from log files, or a hobbyist building a small programming language. Instead of manually writing conditional logic to check characters and track position in the string, you describe what you're looking for and let Winnow handle the grunt work. The project is written in Rust, a programming language popular for systems work, and comes with a tutorial and detailed documentation to help you get started. The README notes that this is a continuation of earlier work, it evolved from a well-known Rust parsing library, building on years of community feedback about what makes parsing easier in practice.