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<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="`Accumulate` the output of a parser into a container, like `Vec`"><title>repeat in winnow::combinator - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-46f98efaafac5295.ttf.woff2,FiraSans-Regular-018c141bf0843ffd.woff2,FiraSans-Medium-8f9a781e4970d388.woff2,SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2,SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../../static.files/normalize-76eba96aa4d2e634.css"><link rel="stylesheet" href="../../static.files/rustdoc-dd39b87e5fcfba68.css"><meta name="rustdoc-vars" data-root-path="../../" data-static-root-path="../../static.files/" data-current-crate="winnow" data-themes="" data-resource-suffix="" data-rustdoc-version="1.80.0 (051478957 2024-07-21)" data-channel="1.80.0" data-search-js="search-d52510db62a78183.js" data-settings-js="settings-4313503d2e1961c2.js" ><script src="../../static.files/storage-118b08c4c78b968e.js"></script><script defer src="sidebar-items.js"></script><script defer src="../../static.files/main-20a3ad099b048cf2.js"></script><noscript><link rel="stylesheet" href="../../static.files/noscript-df360f571f6edeae.css"></noscript><link rel="alternate icon" type="image/png" href="../../static.files/favicon-32x32-422f7d1d52889060.png"><link rel="icon" type="image/svg+xml" href="../../static.files/favicon-2c020d218678b618.svg"></head><body class="rustdoc fn"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle" title="show sidebar"></button></nav><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../../winnow/index.html">winnow</a><span class="version">0.6.16</span></h2></div><div class="sidebar-elems"><h2><a href="index.html">In winnow::combinator</a></h2></div></nav><div class="sidebar-resizer"></div><main><div class="width-limiter"><rustdoc-search></rustdoc-search><section id="main-content" class="content"><div class="main-heading"><h1>Function <a href="../index.html">winnow</a>::<wbr><a href="index.html">combinator</a>::<wbr><a class="fn" href="#">repeat</a><button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><span class="out-of-band"><a class="src" href="../../src/winnow/combinator/multi.rs.html#111-129">source</a> · <button id="toggle-all-docs" title="collapse all docs">[<span>&#x2212;</span>]</button></span></div><pre class="rust item-decl"><code>pub fn repeat&lt;Input, Output, Accumulator, Error, ParseNext&gt;(
occurrences: impl <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/convert/trait.Into.html" title="trait core::convert::Into">Into</a>&lt;<a class="struct" href="../stream/struct.Range.html" title="struct winnow::stream::Range">Range</a>&gt;,
parser: ParseNext,
) -&gt; <a class="struct" href="struct.Repeat.html" title="struct winnow::combinator::Repeat">Repeat</a>&lt;ParseNext, Input, Output, Accumulator, Error&gt;<div class="where">where
Input: <a class="trait" href="../stream/trait.Stream.html" title="trait winnow::stream::Stream">Stream</a>,
Accumulator: <a class="trait" href="../stream/trait.Accumulate.html" title="trait winnow::stream::Accumulate">Accumulate</a>&lt;Output&gt;,
ParseNext: <a class="trait" href="../trait.Parser.html" title="trait winnow::Parser">Parser</a>&lt;Input, Output, Error&gt;,
Error: <a class="trait" href="../error/trait.ParserError.html" title="trait winnow::error::ParserError">ParserError</a>&lt;Input&gt;,</div></code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p><a href="../stream/trait.Accumulate.html" title="trait winnow::stream::Accumulate"><code>Accumulate</code></a> the output of a parser into a container, like <code>Vec</code></p>
<p>This stops before <code>n</code> when the parser returns <a href="../error/enum.ErrMode.html#variant.Backtrack" title="variant winnow::error::ErrMode::Backtrack"><code>ErrMode::Backtrack</code></a>. To instead chain an error up, see
<a href="fn.cut_err.html" title="fn winnow::combinator::cut_err"><code>cut_err</code></a>.</p>
<p>To take a series of tokens, <a href="../stream/trait.Accumulate.html" title="trait winnow::stream::Accumulate"><code>Accumulate</code></a> into a <code>()</code>
(e.g. with <a href="../trait.Parser.html#method.map" title="method winnow::Parser::map"><code>.map(|()| ())</code></a>)
and then <a href="../trait.Parser.html#method.take" title="method winnow::Parser::take"><code>Parser::take</code></a>.</p>
<p><strong>Warning:</strong> If the parser passed to <code>repeat</code> accepts empty inputs
(like <code>alpha0</code> or <code>digit0</code>), <code>repeat</code> will return an error,
to prevent going into an infinite loop.</p>
<h2 id="example"><a class="doc-anchor" href="#example">§</a>Example</h2>
<p>Zero or more repetitions:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>winnow::combinator::repeat;
<span class="kw">fn </span>parser(s: <span class="kw-2">&amp;</span>str) -&gt; IResult&lt;<span class="kw-2">&amp;</span>str, Vec&lt;<span class="kw-2">&amp;</span>str&gt;&gt; {
repeat(<span class="number">0</span>.., <span class="string">"abc"</span>).parse_peek(s)
}
<span class="macro">assert_eq!</span>(parser(<span class="string">"abcabc"</span>), <span class="prelude-val">Ok</span>((<span class="string">""</span>, <span class="macro">vec!</span>[<span class="string">"abc"</span>, <span class="string">"abc"</span>])));
<span class="macro">assert_eq!</span>(parser(<span class="string">"abc123"</span>), <span class="prelude-val">Ok</span>((<span class="string">"123"</span>, <span class="macro">vec!</span>[<span class="string">"abc"</span>])));
<span class="macro">assert_eq!</span>(parser(<span class="string">"123123"</span>), <span class="prelude-val">Ok</span>((<span class="string">"123123"</span>, <span class="macro">vec!</span>[])));
<span class="macro">assert_eq!</span>(parser(<span class="string">""</span>), <span class="prelude-val">Ok</span>((<span class="string">""</span>, <span class="macro">vec!</span>[])));</code></pre></div>
<p>One or more repetitions:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>winnow::combinator::repeat;
<span class="kw">fn </span>parser(s: <span class="kw-2">&amp;</span>str) -&gt; IResult&lt;<span class="kw-2">&amp;</span>str, Vec&lt;<span class="kw-2">&amp;</span>str&gt;&gt; {
repeat(<span class="number">1</span>.., <span class="string">"abc"</span>).parse_peek(s)
}
<span class="macro">assert_eq!</span>(parser(<span class="string">"abcabc"</span>), <span class="prelude-val">Ok</span>((<span class="string">""</span>, <span class="macro">vec!</span>[<span class="string">"abc"</span>, <span class="string">"abc"</span>])));
<span class="macro">assert_eq!</span>(parser(<span class="string">"abc123"</span>), <span class="prelude-val">Ok</span>((<span class="string">"123"</span>, <span class="macro">vec!</span>[<span class="string">"abc"</span>])));
<span class="macro">assert_eq!</span>(parser(<span class="string">"123123"</span>), <span class="prelude-val">Err</span>(ErrMode::Backtrack(InputError::new(<span class="string">"123123"</span>, ErrorKind::Tag))));
<span class="macro">assert_eq!</span>(parser(<span class="string">""</span>), <span class="prelude-val">Err</span>(ErrMode::Backtrack(InputError::new(<span class="string">""</span>, ErrorKind::Tag))));</code></pre></div>
<p>Fixed number of repetitions:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>winnow::combinator::repeat;
<span class="kw">fn </span>parser(s: <span class="kw-2">&amp;</span>str) -&gt; IResult&lt;<span class="kw-2">&amp;</span>str, Vec&lt;<span class="kw-2">&amp;</span>str&gt;&gt; {
repeat(<span class="number">2</span>, <span class="string">"abc"</span>).parse_peek(s)
}
<span class="macro">assert_eq!</span>(parser(<span class="string">"abcabc"</span>), <span class="prelude-val">Ok</span>((<span class="string">""</span>, <span class="macro">vec!</span>[<span class="string">"abc"</span>, <span class="string">"abc"</span>])));
<span class="macro">assert_eq!</span>(parser(<span class="string">"abc123"</span>), <span class="prelude-val">Err</span>(ErrMode::Backtrack(InputError::new(<span class="string">"123"</span>, ErrorKind::Tag))));
<span class="macro">assert_eq!</span>(parser(<span class="string">"123123"</span>), <span class="prelude-val">Err</span>(ErrMode::Backtrack(InputError::new(<span class="string">"123123"</span>, ErrorKind::Tag))));
<span class="macro">assert_eq!</span>(parser(<span class="string">""</span>), <span class="prelude-val">Err</span>(ErrMode::Backtrack(InputError::new(<span class="string">""</span>, ErrorKind::Tag))));
<span class="macro">assert_eq!</span>(parser(<span class="string">"abcabcabc"</span>), <span class="prelude-val">Ok</span>((<span class="string">"abc"</span>, <span class="macro">vec!</span>[<span class="string">"abc"</span>, <span class="string">"abc"</span>])));</code></pre></div>
<p>Arbitrary repetitions:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>winnow::combinator::repeat;
<span class="kw">fn </span>parser(s: <span class="kw-2">&amp;</span>str) -&gt; IResult&lt;<span class="kw-2">&amp;</span>str, Vec&lt;<span class="kw-2">&amp;</span>str&gt;&gt; {
repeat(<span class="number">0</span>..=<span class="number">2</span>, <span class="string">"abc"</span>).parse_peek(s)
}
<span class="macro">assert_eq!</span>(parser(<span class="string">"abcabc"</span>), <span class="prelude-val">Ok</span>((<span class="string">""</span>, <span class="macro">vec!</span>[<span class="string">"abc"</span>, <span class="string">"abc"</span>])));
<span class="macro">assert_eq!</span>(parser(<span class="string">"abc123"</span>), <span class="prelude-val">Ok</span>((<span class="string">"123"</span>, <span class="macro">vec!</span>[<span class="string">"abc"</span>])));
<span class="macro">assert_eq!</span>(parser(<span class="string">"123123"</span>), <span class="prelude-val">Ok</span>((<span class="string">"123123"</span>, <span class="macro">vec!</span>[])));
<span class="macro">assert_eq!</span>(parser(<span class="string">""</span>), <span class="prelude-val">Ok</span>((<span class="string">""</span>, <span class="macro">vec!</span>[])));
<span class="macro">assert_eq!</span>(parser(<span class="string">"abcabcabc"</span>), <span class="prelude-val">Ok</span>((<span class="string">"abc"</span>, <span class="macro">vec!</span>[<span class="string">"abc"</span>, <span class="string">"abc"</span>])));</code></pre></div>
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