<!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="Error management"><title>winnow::error - Rust</title><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/SourceSerif4-Regular-46f98efaafac5295.ttf.woff2"><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/FiraSans-Regular-018c141bf0843ffd.woff2"><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/FiraSans-Medium-8f9a781e4970d388.woff2"><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2"><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2"><linkrel="stylesheet"href="../../static.files/normalize-76eba96aa4d2e634.css"><linkrel="stylesheet"href="../../static.files/rustdoc-5bc39a1768837dd0.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="1.77.2 (25ef9e3d8 2024-04-09)"data-channel="1.77.2"data-search-js="search-dd67cee4cfa65049.js"data-settings-js="settings-4313503d2e1961c2.js"><scriptsrc="../../static.files/storage-4c98445ec4002617.js"></script><scriptdefersrc="../sidebar-items.js"></script><scriptdefersrc="../../static.files/main-48f368f3872407c8.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 mod"><!--[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">0.6.6</span></h2></div><h2class="location"><ahref="#">Module error</a></h2><divclass="sidebar-elems"><section><ulclass="block"><li><ahref="#structs">Structs</a></li><li><ahref="#enums">Enums</a></li><li><ahref="#traits">Traits</a></li><li><ahref="#types">Type Aliases</a></li></ul></section><h2><ahref="../index.html">In crate winnow</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>Module <ahref="../index.html">winnow</a>::<wbr><aclass="mod"href="#">error</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#1-1406">source</a> · <buttonid="toggle-all-docs"title="collapse all docs">[<span>−</span>]</button></span></div><detailsclass="toggle top-doc"open><summaryclass="hideme"><span>Expand description</span></summary><divclass="docblock"><h2id="error-management"><aclass="doc-anchor"href="#error-management">§</a>Error management</h2>
<p>Errors are designed with multiple needs in mind:</p>
<ul>
<li>Accumulate more <ahref="../trait.Parser.html#method.context"title="method winnow::Parser::context">context</a> as the error goes up the parser chain</li>
<li>Distinguish between <ahref="enum.ErrMode.html"title="enum winnow::error::ErrMode">recoverable errors,
unrecoverable errors, and more data is needed</a></li>
<li>Have a very low overhead, as errors are often discarded by the calling parser (examples: <code>repeat</code>, <code>alt</code>)</li>
<li>Can be modified according to the user’s needs, because some languages need a lot more information</li>
<li>Help thread-through the <ahref="../stream/index.html"title="mod winnow::stream">stream</a></li>
</ul>
<p>To abstract these needs away from the user, generally <code>winnow</code> parsers use the <ahref="type.PResult.html"title="type winnow::error::PResult"><code>PResult</code></a>
alias, rather than <ahref="https://doc.rust-lang.org/1.77.2/core/result/enum.Result.html"title="enum core::result::Result"><code>Result</code></a>. <ahref="../trait.Parser.html#method.parse"title="method winnow::Parser::parse"><code>Parser::parse</code></a> is a top-level operation
</div></details><h2id="structs"class="section-header">Structs<ahref="#structs"class="anchor">§</a></h2><ulclass="item-table"><li><divclass="item-name"><aclass="struct"href="struct.ContextError.html"title="struct winnow::error::ContextError">ContextError</a></div><divclass="desc docblock-short">Accumulate context while backtracking errors</div></li><li><divclass="item-name"><aclass="struct"href="struct.InputError.html"title="struct winnow::error::InputError">InputError</a></div><divclass="desc docblock-short">Capture input on error</div></li><li><divclass="item-name"><aclass="struct"href="struct.ParseError.html"title="struct winnow::error::ParseError">ParseError</a></div><divclass="desc docblock-short">See <ahref="../trait.Parser.html#method.parse"title="method winnow::Parser::parse"><code>Parser::parse</code></a></div></li><li><divclass="item-name"><aclass="struct"href="struct.TreeErrorBase.html"title="struct winnow::error::TreeErrorBase">TreeErrorBase</a></div><divclass="desc docblock-short">See <ahref="enum.TreeErrorFrame.html#variant.Kind"title="variant winnow::error::TreeErrorFrame::Kind"><code>TreeErrorFrame::Kind</code></a>, <ahref="trait.ParserError.html#tymethod.append"title="method winnow::error::ParserError::append"><code>ParserError::append</code></a></div></li><li><divclass="item-name"><aclass="struct"href="struct.TreeErrorContext.html"title="struct winnow::error::TreeErrorContext">TreeErrorContext</a></div><divclass="desc docblock-short">See <ahref="enum.TreeErrorFrame.html#variant.Context"title="variant winnow::error::TreeErrorFrame::Context"><code>TreeErrorFrame::Context</code></a>, <ahref="trait.AddContext.html#method.add_context"title="method winnow::error::AddContext::add_context"><code>AddContext::add_context</code></a></div></li></ul><h2id="enums"class="section-header">Enums<ahref="#enums"class="anchor">§</a></h2><ulclass="item-table"><li><divclass="item-name"><aclass="enum"href="enum.ErrMode.html"title="enum winnow::error::ErrMode">ErrMode</a></div><divclass="desc docblock-short">Add parse error state to <ahref="trait.ParserError.html"title="trait winnow::error::ParserError"><code>ParserError</code></a>s</div></li><li><divclass="item-name"><aclass="enum"href="enum.ErrorKind.html"title="enum winnow::error::ErrorKind">ErrorKind</a></div><divclass="desc docblock-short">Provide some minor debug context for errors</div></li><li><divclass="item-name"><aclass="enum"href="enum.Needed.html"title="enum winnow::error::Needed">Needed</a></div><divclass="desc docblock-short">Contains information on needed data if a parser returned <code>Incomplete</code></div></li><li><divclass="item-name"><aclass="enum"href="enum.StrContext.html"title="enum winnow::error::StrContext">StrContext</a></div><divclass="desc docblock-short">Additional parse context for <ahref="struct.ContextError.html"title="struct winnow::error::ContextError"><code>ContextError</code></a> added via <ahref="../trait.Parser.html#method.context"title="method winnow::Parser::context"><code>Parser::context</code></a></div></li><li><divclass="item-name"><aclass="enum"href="enum.StrContextValue.html"title="enum winnow::error::StrContextValue">StrContextValue</a></div><divclass="desc docblock-short">See <ahref="enum.StrContext.html"title="enum winnow::error::StrContext"><code>StrContext</code></a></div></li><li><divclass="item-name"><aclass="enum"href="enum.TreeError.html"title="enum winnow::error::TreeError">TreeError</a></div><divclass="desc docblock-short">Trace all error paths, particularly for tests</div></li><li><divclass="item-name"><aclass="enum"href="enum.TreeErrorFrame.html"title="enum winnow::error::TreeErrorFrame">TreeErrorFrame</a></div><divclass="desc docblock-short">See <ahref="enum.TreeError.html#variant.Stack"title="variant winnow::error::TreeError::Stack"><code>TreeError::Stack</code></a></div></li></ul><h2id="traits"class="section-header">Traits<ahref="#traits"class="anchor">§</a></h2><ulclass="item-table"><li><divclass="item-name"><aclass=
parser.</div></li><li><divclass="item-name"><aclass="type"href="type.PResult.html"title="type winnow::error::PResult">PResult</a></div><divclass="desc docblock-short">For use with <ahref="../trait.Parser.html#tymethod.parse_next"title="method winnow::Parser::parse_next"><code>Parser::parse_next</code></a></div></li></ul></section></div></main></body></html>
