| <!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="Constructs a parser out of an environment and a function which needs the given environment to do the parsing. This is commonly useful to allow multiple parsers to share some environment while still allowing the parsers to be written in separate functions."><meta name="keywords" content="rust, rustlang, rust-lang, env_parser"><title>env_parser in combine::parser::function - Rust</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../../normalize.css"><link rel="stylesheet" href="../../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../../ayu.css" disabled><link rel="stylesheet" href="../../../dark.css" disabled><link rel="stylesheet" href="../../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../../storage.js"></script><script defer src="sidebar-items.js"></script><script defer src="../../../main.js"></script><noscript><link rel="stylesheet" href="../../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../../favicon.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">☰</button><a class="sidebar-logo" href="../../../combine/index.html"><div class="logo-container"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></div></a><h2></h2></nav><nav class="sidebar"><a class="sidebar-logo" href="../../../combine/index.html"><div class="logo-container"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></div></a><div class="sidebar-elems"><h2><a href="index.html">In combine::parser::function</a></h2></div></nav><main><div class="width-limiter"><nav class="sub"><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="main-heading"><h1 class="fqn">Function <a href="../../index.html">combine</a>::<wbr><a href="../index.html">parser</a>::<wbr><a href="index.html">function</a>::<wbr><a class="fn" href="#">env_parser</a><button id="copy-path" onclick="copy_path(this)" title="Copy item path to clipboard"><img src="../../../clipboard.svg" width="19" height="18" alt="Copy item path"></button></h1><span class="out-of-band"><a class="srclink" href="../../../src/combine/parser/function.rs.html#170-179">source</a> · <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">−</span>]</a></span></div><div class="item-decl"><pre class="rust fn"><code>pub fn env_parser<E, Input, O>(<br> env: E,<br> parser: fn(_: E, _: &mut Input) -> <a class="type" href="../../type.StdParseResult.html" title="type combine::StdParseResult">StdParseResult</a><O, Input><br>) -> <a class="struct" href="struct.EnvParser.html" title="struct combine::parser::function::EnvParser">EnvParser</a><E, Input, O><span class="where fmt-newline">where<br> E: Clone,<br> Input: <a class="trait" href="../../trait.Stream.html" title="trait combine::Stream">Stream</a>,</span></code></pre></div><details class="rustdoc-toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Constructs a parser out of an environment and a function which needs the given environment to |
| do the parsing. This is commonly useful to allow multiple parsers to share some environment |
| while still allowing the parsers to be written in separate functions.</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">struct </span>Interner(HashMap<String, u32>); |
| <span class="kw">impl </span>Interner { |
| <span class="kw">fn </span>string<Input>(<span class="kw-2">&</span><span class="self">self</span>, input: <span class="kw-2">&mut </span>Input) -> StdParseResult<u32, Input> |
| <span class="kw">where </span>Input: Stream<Token = char>, |
| Input::Error: ParseError<Input::Token, Input::Range, Input::Position>, |
| { |
| many(letter()) |
| .map(|s: String| <span class="self">self</span>.<span class="number">0</span>.get(<span class="kw-2">&</span>s).cloned().unwrap_or(<span class="number">0</span>)) |
| .parse_stream(input) |
| .into_result() |
| } |
| } |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>map = HashMap::new(); |
| map.insert(<span class="string">"hello"</span>.into(), <span class="number">1</span>); |
| map.insert(<span class="string">"test"</span>.into(), <span class="number">2</span>); |
| |
| <span class="kw">let </span>env = Interner(map); |
| <span class="kw">let </span><span class="kw-2">mut </span>parser = env_parser(<span class="kw-2">&</span>env, Interner::string); |
| |
| <span class="kw">let </span>result = parser.parse(<span class="string">"hello"</span>); |
| <span class="macro">assert_eq!</span>(result, <span class="prelude-val">Ok</span>((<span class="number">1</span>, <span class="string">""</span>))); |
| |
| <span class="kw">let </span>result = parser.parse(<span class="string">"world"</span>); |
| <span class="macro">assert_eq!</span>(result, <span class="prelude-val">Ok</span>((<span class="number">0</span>, <span class="string">""</span>)));</code></pre></div> |
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