//! # For `nom` users //! //! ## Migrating from `nom` //! //! For comparisons with `nom`, see //! - [Why `winnow`][super::why] //! - [parse-rosetta-rs](https://github.com/rosetta-rs/parse-rosetta-rs/) //! //! What approach you take depends on the size and complexity of your parser. //! For small, simple parsers, its likely easiest to directly port from `nom`. //! When trying to look for the equivalent of a `nom` combinator, search in the docs for the name //! of the `nom` combinator. It is expected that, where names diverge, a doc alias exists. //! See also the [List of combinators][crate::combinator]. //! //! ### Complex migrations //! //! For larger parsers, it is likely best to take smaller steps //! - Easier to debug when something goes wrong //! - Deprecation messages will help assist through the process //! //! The workflow goes something like: //! 1. Run `cargo rm nom && cargo add winnow@0.3` //! 1. Ensure everything compiles and tests pass, ignoring deprecation messages (see [migration //! notes](https://github.com/winnow-rs/winnow/blob/main/CHANGELOG.md#nom-migration-guide)) //! 1. Commit //! 1. Switch any `impl FnMut(I) -> IResult` to `impl Parser` //! 1. Resolve deprecation messages //! 1. Commit //! 1. Run `cargo add winnow@0.4` //! 1. Ensure everything compiles and tests pass, ignoring deprecation messages (see [changelog](https://github.com/winnow-rs/winnow/blob/main/CHANGELOG.md#040---2023-03-18) for more details) //! 1. Commit //! 1. Resolve deprecation messages //! 1. Commit //! 1. Run `cargo add winnow@0.5` //! 1. Ensure everything compiles and tests pass, ignoring deprecation messages (see [migration //! notes](https://github.com/winnow-rs/winnow/blob/main/CHANGELOG.md#050---2023-07-13)) //! 1. Commit //! 1. Resolve deprecation messages //! 1. Commit //! //! ### Examples //! //! For example migrations, see //! - [git-config-env](https://github.com/gitext-rs/git-config-env/pull/11) (nom to winnow 0.3) //! - [git-conventional](https://github.com/crate-ci/git-conventional/pull/37) (nom to winnow 0.3, //! adds explicit tracing for easier debugging) //! - [typos](https://github.com/crate-ci/typos/pull/664) (nom to winnow 0.3) //! - [cargo-smart-release](https://github.com/Byron/gitoxide/pull/948) (gradual migration from nom //! to winnow 0.5) //! - [gix-config](https://github.com/Byron/gitoxide/pull/951) (gradual migration from nom //! to winnow 0.5) //! - [gix-protocol](https://github.com/Byron/gitoxide/pull/1009) (gradual migration from nom //! to winnow 0.5) //! - [gitoxide](https://github.com/Byron/gitoxide/pull/956) (gradual migration from nom //! to winnow 0.5) //! //! ## API differences //! //! ### Renamed APIs //! //! Names have changed for consistency or clarity. //! //! To find a parser you are looking for, //! - Search the docs for the `nom` parser //! - See the [List of combinators][crate::combinator] //! //! ### `&mut I` //! //! For an explanation of this change, see [Why `winnow`][super::why] //! //! To save and restore from intermediate states, [`Stream::checkpoint`] and [`Stream::reset`] can help: //! ```rust //! use winnow::stream::Stream as _; //! # let mut i = ""; //! # let i = &mut i; //! //! let start = i.checkpoint(); //! // ... //! i.reset(&start); //! ``` //! //! When the Output of a parser is a slice, you have to add a lifetime: //! ```rust //! # use winnow::prelude::*; //! fn foo<'i>(i: &mut &'i str) -> PResult<&'i str> { //! // ... //! # winnow::token::rest.parse_next(i) //! } //! ``` //! //! When writing a closure, you need to annotate the type: //! ```rust //! # use winnow::prelude::*; //! # use winnow::combinator::trace; //! fn foo(i: &mut &str) -> PResult { //! trace("foo", |i: &mut _| { //! // ... //! # Ok(0) //! }).parse_next(i) //! } //! ``` #![allow(unused_imports)] use crate::stream::Stream;