<!DOCTYPE html><htmllang="en"><head><metacharset="utf-8"><metaname="viewport"content="width=device-width, initial-scale=1.0"><metaname="generator"content="rustdoc"><metaname="description"content="Used by `Parser::context` to add custom data to error while backtracking"><title>AddContext in winnow::error - Rust</title><script>if(window.location.protocol!=="file:")document.write(`<link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/SourceSerif4-Regular-46f98efaafac5295.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/FiraSans-Regular-018c141bf0843ffd.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/FiraSans-Medium-8f9a781e4970d388.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2">`)</script><linkrel="stylesheet"href="../../static.files/normalize-76eba96aa4d2e634.css"><linkrel="stylesheet"href="../../static.files/rustdoc-e935ef01ae1c1829.css"><metaname="rustdoc-vars"data-root-path="../../"data-static-root-path="../../static.files/"data-current-crate="winnow"data-themes=""data-resource-suffix=""data-rustdoc-version="1.78.0 (9b00956e5 2024-04-29)"data-channel="1.78.0"data-search-js="search-42d8da7a6b9792c2.js"data-settings-js="settings-4313503d2e1961c2.js"><scriptsrc="../../static.files/storage-4c98445ec4002617.js"></script><scriptdefersrc="sidebar-items.js"></script><scriptdefersrc="../../static.files/main-12cf3b4f4f9dc36d.js"></script><noscript><linkrel="stylesheet"href="../../static.files/noscript-04d5337699b92874.css"></noscript><linkrel="alternate icon"type="image/png"href="../../static.files/favicon-16x16-8b506e7a72182f1c.png"><linkrel="alternate icon"type="image/png"href="../../static.files/favicon-32x32-422f7d1d52889060.png"><linkrel="icon"type="image/svg+xml"href="../../static.files/favicon-2c020d218678b618.svg"></head><bodyclass="rustdoc trait"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><navclass="mobile-topbar"><buttonclass="sidebar-menu-toggle"title="show sidebar"></button></nav><navclass="sidebar"><divclass="sidebar-crate"><h2><ahref="../../winnow/index.html">winnow</a><spanclass="version">0.6.7</span></h2></div><h2class="location"><ahref="#">AddContext</a></h2><divclass="sidebar-elems"><section><h3><ahref="#provided-methods">Provided Methods</a></h3><ulclass="block"><li><ahref="#method.add_context">add_context</a></li></ul><h3><ahref="#foreign-impls">Implementations on Foreign Types</a></h3><ulclass="block"><li><ahref="#impl-AddContext%3CI,+C%3E-for-()">()</a></li></ul><h3><ahref="#object-safety">Object Safety</a></h3><h3><ahref="#implementors">Implementors</a></h3></section><h2><ahref="index.html">In winnow::error</a></h2></div></nav><divclass="sidebar-resizer"></div>
<main><divclass="width-limiter"><navclass="sub"><formclass="search-form"><span></span><divid="sidebar-button"tabindex="-1"><ahref="../../winnow/all.html"title="show sidebar"></a></div><inputclass="search-input"name="search"aria-label="Run search in the documentation"autocomplete="off"spellcheck="false"placeholder="Click or press ‘S’ to search, ‘?’ for more options…"type="search"><divid="help-button"tabindex="-1"><ahref="../../help.html"title="help">?</a></div><divid="settings-menu"tabindex="-1"><ahref="../../settings.html"title="settings"><imgwidth="22"height="22"alt="Change settings"src="../../static.files/wheel-7b819b6101059cd0.svg"></a></div></form></nav><sectionid="main-content"class="content"><divclass="main-heading"><h1>Trait <ahref="../index.html">winnow</a>::<wbr><ahref="index.html">error</a>::<wbr><aclass="trait"href="#">AddContext</a><buttonid="copy-path"title="Copy item path to clipboard"><imgsrc="../../static.files/clipboard-7571035ce49a181d.svg"width="19"height="18"alt="Copy item path"></button></h1><spanclass="out-of-band"><aclass="src"href="../../src/winnow/error.rs.html#305-319">source</a> · <buttonid="toggle-all-docs"title="collapse all docs">[<span>−</span>]</button></span></div><preclass="rust item-decl"><code>pub trait AddContext<I: <aclass="trait"href="../stream/trait.Stream.html"title="trait winnow::stream::Stream">Stream</a>, C = &'static <aclass="primitive"href="https://doc.rust-lang.org/1.78.0/std/primitive.str.html">str</a>>: <aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/marker/trait.Sized.html"title="trait core::marker::Sized">Sized</a> {
_token_start: &<I as <aclass="trait"href="../stream/trait.Stream.html"title="trait winnow::stream::Stream">Stream</a>>::<aclass="associatedtype"href="../stream/trait.Stream.html#associatedtype.Checkpoint"title="type winnow::stream::Stream::Checkpoint">Checkpoint</a>,
_context: C
) -> Self { ... }
}</code></pre><detailsclass="toggle top-doc"open><summaryclass="hideme"><span>Expand description</span></summary><divclass="docblock"><p>Used by <ahref="../trait.Parser.html#method.context"title="method winnow::Parser::context"><code>Parser::context</code></a> to add custom data to error while backtracking</p>
<p>May be implemented multiple times for different kinds of context.</p>
_token_start: &<I as <aclass="trait"href="../stream/trait.Stream.html"title="trait winnow::stream::Stream">Stream</a>>::<aclass="associatedtype"href="../stream/trait.Stream.html#associatedtype.Checkpoint"title="type winnow::stream::Stream::Checkpoint">Checkpoint</a>,
_context: C
) -> Self</h4></section></summary><divclass="docblock"><p>Append to an existing error custom data</p>
<p>This is used mainly by <ahref="../trait.Parser.html#method.context"title="method winnow::Parser::context"><code>Parser::context</code></a>, to add user friendly information
to errors when backtracking through a parse tree</p>
