Module chapter_0

Available on crate feature unstable-doc only.

Chapter 0: Introduction

This tutorial assumes that you are:

• Already familiar with Rust
• Using winnow for the first time

The focus will be on parsing in-memory strings (&str). Once done, you might want to check the Special Topics for more specialized topics or examples.

About

winnow is a parser-combinator library. In other words, it gives you tools to define:

• “parsers”, or functions that take an input and give back an output
• “combinators”, or functions that take parsers and combine them together!

While “combinator” might be an unfamiliar word, you are likely using them in your rust code today, like with the Iterator trait:

let data = vec![1, 2, 3, 4, 5];
let even_count = data.iter()
    .copied()  // combinator
    .filter(|d| d % 2 == 0)  // combinator
    .count();  // combinator

Parser combinators are great because:

• Individual parser functions are small, focused on one thing, ignoring the rest
• You can write tests focused on individual parsers (unit tests and property-based tests) in addition to testing the top-level parser as a whole.
• Top-level parsing code looks close to the grammar you would have written

Re-exports

• pub use super::chapter_1 as next;
• pub use crate::_tutorial as table_of_contents;