| <!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="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/combine-4.6.6/src/parser/function.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>function.rs - source</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="../../../source-script.js"></script><script defer src="../../../source-files.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 source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><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></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../../combine/index.html"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></a><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="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
| <span id="2">2</span> |
| <span id="3">3</span> |
| <span id="4">4</span> |
| <span id="5">5</span> |
| <span id="6">6</span> |
| <span id="7">7</span> |
| <span id="8">8</span> |
| <span id="9">9</span> |
| <span id="10">10</span> |
| <span id="11">11</span> |
| <span id="12">12</span> |
| <span id="13">13</span> |
| <span id="14">14</span> |
| <span id="15">15</span> |
| <span id="16">16</span> |
| <span id="17">17</span> |
| <span id="18">18</span> |
| <span id="19">19</span> |
| <span id="20">20</span> |
| <span id="21">21</span> |
| <span id="22">22</span> |
| <span id="23">23</span> |
| <span id="24">24</span> |
| <span id="25">25</span> |
| <span id="26">26</span> |
| <span id="27">27</span> |
| <span id="28">28</span> |
| <span id="29">29</span> |
| <span id="30">30</span> |
| <span id="31">31</span> |
| <span id="32">32</span> |
| <span id="33">33</span> |
| <span id="34">34</span> |
| <span id="35">35</span> |
| <span id="36">36</span> |
| <span id="37">37</span> |
| <span id="38">38</span> |
| <span id="39">39</span> |
| <span id="40">40</span> |
| <span id="41">41</span> |
| <span id="42">42</span> |
| <span id="43">43</span> |
| <span id="44">44</span> |
| <span id="45">45</span> |
| <span id="46">46</span> |
| <span id="47">47</span> |
| <span id="48">48</span> |
| <span id="49">49</span> |
| <span id="50">50</span> |
| <span id="51">51</span> |
| <span id="52">52</span> |
| <span id="53">53</span> |
| <span id="54">54</span> |
| <span id="55">55</span> |
| <span id="56">56</span> |
| <span id="57">57</span> |
| <span id="58">58</span> |
| <span id="59">59</span> |
| <span id="60">60</span> |
| <span id="61">61</span> |
| <span id="62">62</span> |
| <span id="63">63</span> |
| <span id="64">64</span> |
| <span id="65">65</span> |
| <span id="66">66</span> |
| <span id="67">67</span> |
| <span id="68">68</span> |
| <span id="69">69</span> |
| <span id="70">70</span> |
| <span id="71">71</span> |
| <span id="72">72</span> |
| <span id="73">73</span> |
| <span id="74">74</span> |
| <span id="75">75</span> |
| <span id="76">76</span> |
| <span id="77">77</span> |
| <span id="78">78</span> |
| <span id="79">79</span> |
| <span id="80">80</span> |
| <span id="81">81</span> |
| <span id="82">82</span> |
| <span id="83">83</span> |
| <span id="84">84</span> |
| <span id="85">85</span> |
| <span id="86">86</span> |
| <span id="87">87</span> |
| <span id="88">88</span> |
| <span id="89">89</span> |
| <span id="90">90</span> |
| <span id="91">91</span> |
| <span id="92">92</span> |
| <span id="93">93</span> |
| <span id="94">94</span> |
| <span id="95">95</span> |
| <span id="96">96</span> |
| <span id="97">97</span> |
| <span id="98">98</span> |
| <span id="99">99</span> |
| <span id="100">100</span> |
| <span id="101">101</span> |
| <span id="102">102</span> |
| <span id="103">103</span> |
| <span id="104">104</span> |
| <span id="105">105</span> |
| <span id="106">106</span> |
| <span id="107">107</span> |
| <span id="108">108</span> |
| <span id="109">109</span> |
| <span id="110">110</span> |
| <span id="111">111</span> |
| <span id="112">112</span> |
| <span id="113">113</span> |
| <span id="114">114</span> |
| <span id="115">115</span> |
| <span id="116">116</span> |
| <span id="117">117</span> |
| <span id="118">118</span> |
| <span id="119">119</span> |
| <span id="120">120</span> |
| <span id="121">121</span> |
| <span id="122">122</span> |
| <span id="123">123</span> |
| <span id="124">124</span> |
| <span id="125">125</span> |
| <span id="126">126</span> |
| <span id="127">127</span> |
| <span id="128">128</span> |
| <span id="129">129</span> |
| <span id="130">130</span> |
| <span id="131">131</span> |
| <span id="132">132</span> |
| <span id="133">133</span> |
| <span id="134">134</span> |
| <span id="135">135</span> |
| <span id="136">136</span> |
| <span id="137">137</span> |
| <span id="138">138</span> |
| <span id="139">139</span> |
| <span id="140">140</span> |
| <span id="141">141</span> |
| <span id="142">142</span> |
| <span id="143">143</span> |
| <span id="144">144</span> |
| <span id="145">145</span> |
| <span id="146">146</span> |
| <span id="147">147</span> |
| <span id="148">148</span> |
| <span id="149">149</span> |
| <span id="150">150</span> |
| <span id="151">151</span> |
| <span id="152">152</span> |
| <span id="153">153</span> |
| <span id="154">154</span> |
| <span id="155">155</span> |
| <span id="156">156</span> |
| <span id="157">157</span> |
| <span id="158">158</span> |
| <span id="159">159</span> |
| <span id="160">160</span> |
| <span id="161">161</span> |
| <span id="162">162</span> |
| <span id="163">163</span> |
| <span id="164">164</span> |
| <span id="165">165</span> |
| <span id="166">166</span> |
| <span id="167">167</span> |
| <span id="168">168</span> |
| <span id="169">169</span> |
| <span id="170">170</span> |
| <span id="171">171</span> |
| <span id="172">172</span> |
| <span id="173">173</span> |
| <span id="174">174</span> |
| <span id="175">175</span> |
| <span id="176">176</span> |
| <span id="177">177</span> |
| <span id="178">178</span> |
| <span id="179">179</span> |
| </pre><pre class="rust"><code><span class="doccomment">//! Parsers constructor from regular functions |
| |
| </span><span class="kw">use crate</span>::{ |
| error::{ParseResult, StdParseResult}, |
| lib::marker::PhantomData, |
| stream::Stream, |
| Parser, |
| }; |
| |
| <span class="kw">impl</span><<span class="lifetime">'a</span>, Input: Stream, O> Parser<Input> |
| <span class="kw">for dyn </span>FnMut(<span class="kw-2">&mut </span>Input) -> StdParseResult<O, Input> + <span class="lifetime">'a |
| </span>{ |
| <span class="kw">type </span>Output = O; |
| <span class="kw">type </span>PartialState = (); |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>parse_lazy(<span class="kw-2">&mut </span><span class="self">self</span>, input: <span class="kw-2">&mut </span>Input) -> ParseResult<O, Input::Error> { |
| <span class="self">self</span>(input).into() |
| } |
| } |
| |
| <span class="attribute">#[derive(Copy, Clone)] |
| </span><span class="kw">pub struct </span>FnParser<Input, F>(F, PhantomData<<span class="kw">fn</span>(Input) -> Input>); |
| |
| <span class="doccomment">/// Wraps a function, turning it into a parser. |
| /// |
| /// Mainly needed to turn closures into parsers as function types can be casted to function pointers |
| /// to make them usable as a parser. |
| /// |
| /// ``` |
| /// extern crate combine; |
| /// # use combine::*; |
| /// # use combine::parser::char::digit; |
| /// # use combine::error::{Commit, StreamError}; |
| /// # use combine::stream::easy; |
| /// # fn main() { |
| /// let mut even_digit = parser(|input| { |
| /// // Help type inference out |
| /// let _: &mut easy::Stream<&str> = input; |
| /// let position = input.position(); |
| /// let (char_digit, committed) = digit().parse_stream(input).into_result()?; |
| /// let d = (char_digit as i32) - ('0' as i32); |
| /// if d % 2 == 0 { |
| /// Ok((d, committed)) |
| /// } |
| /// else { |
| /// //Return an empty error since we only tested the first token of the stream |
| /// let errors = easy::Errors::new( |
| /// position, |
| /// StreamError::expected("even number") |
| /// ); |
| /// Err(Commit::Peek(errors.into())) |
| /// } |
| /// }); |
| /// let result = even_digit |
| /// .easy_parse("8") |
| /// .map(|x| x.0); |
| /// assert_eq!(result, Ok(8)); |
| /// # } |
| /// ``` |
| </span><span class="kw">pub fn </span>parser<Input, O, F>(f: F) -> FnParser<Input, F> |
| <span class="kw">where |
| </span>Input: Stream, |
| F: FnMut(<span class="kw-2">&mut </span>Input) -> StdParseResult<O, Input>, |
| { |
| FnParser(f, PhantomData) |
| } |
| |
| <span class="kw">impl</span><Input, O, F> Parser<Input> <span class="kw">for </span>FnParser<Input, F> |
| <span class="kw">where |
| </span>Input: Stream, |
| F: FnMut(<span class="kw-2">&mut </span>Input) -> StdParseResult<O, Input>, |
| { |
| <span class="kw">type </span>Output = O; |
| <span class="kw">type </span>PartialState = (); |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>parse_lazy(<span class="kw-2">&mut </span><span class="self">self</span>, input: <span class="kw-2">&mut </span>Input) -> ParseResult<O, Input::Error> { |
| (<span class="self">self</span>.<span class="number">0</span>)(input).into() |
| } |
| } |
| |
| <span class="kw">impl</span><Input, O> Parser<Input> <span class="kw">for fn</span>(<span class="kw-2">&mut </span>Input) -> StdParseResult<O, Input> |
| <span class="kw">where |
| </span>Input: Stream, |
| { |
| <span class="kw">type </span>Output = O; |
| <span class="kw">type </span>PartialState = (); |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>parse_lazy(<span class="kw-2">&mut </span><span class="self">self</span>, input: <span class="kw-2">&mut </span>Input) -> ParseResult<O, Input::Error> { |
| <span class="self">self</span>(input).into() |
| } |
| } |
| |
| <span class="attribute">#[derive(Copy)] |
| </span><span class="kw">pub struct </span>EnvParser<E, Input, T> |
| <span class="kw">where |
| </span>Input: Stream, |
| { |
| env: E, |
| parser: <span class="kw">fn</span>(E, <span class="kw-2">&mut </span>Input) -> StdParseResult<T, Input>, |
| } |
| |
| <span class="kw">impl</span><E, Input, T> Clone <span class="kw">for </span>EnvParser<E, Input, T> |
| <span class="kw">where |
| </span>Input: Stream, |
| E: Clone, |
| { |
| <span class="kw">fn </span>clone(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="self">Self </span>{ |
| EnvParser { |
| env: <span class="self">self</span>.env.clone(), |
| parser: <span class="self">self</span>.parser, |
| } |
| } |
| } |
| |
| <span class="kw">impl</span><Input, E, O> Parser<Input> <span class="kw">for </span>EnvParser<E, Input, O> |
| <span class="kw">where |
| </span>E: Clone, |
| Input: Stream, |
| { |
| <span class="kw">type </span>Output = O; |
| <span class="kw">type </span>PartialState = (); |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>parse_lazy(<span class="kw-2">&mut </span><span class="self">self</span>, input: <span class="kw-2">&mut </span>Input) -> ParseResult<O, Input::Error> { |
| (<span class="self">self</span>.parser)(<span class="self">self</span>.env.clone(), input).into() |
| } |
| } |
| |
| <span class="doccomment">/// 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. |
| /// |
| /// ``` |
| /// # extern crate combine; |
| /// # use std::collections::HashMap; |
| /// # use combine::*; |
| /// # use combine::parser::function::env_parser; |
| /// # use combine::parser::char::letter; |
| /// # fn main() { |
| /// struct Interner(HashMap<String, u32>); |
| /// impl Interner { |
| /// fn string<Input>(&self, input: &mut Input) -> StdParseResult<u32, Input> |
| /// where Input: Stream<Token = char>, |
| /// Input::Error: ParseError<Input::Token, Input::Range, Input::Position>, |
| /// { |
| /// many(letter()) |
| /// .map(|s: String| self.0.get(&s).cloned().unwrap_or(0)) |
| /// .parse_stream(input) |
| /// .into_result() |
| /// } |
| /// } |
| /// |
| /// let mut map = HashMap::new(); |
| /// map.insert("hello".into(), 1); |
| /// map.insert("test".into(), 2); |
| /// |
| /// let env = Interner(map); |
| /// let mut parser = env_parser(&env, Interner::string); |
| /// |
| /// let result = parser.parse("hello"); |
| /// assert_eq!(result, Ok((1, ""))); |
| /// |
| /// let result = parser.parse("world"); |
| /// assert_eq!(result, Ok((0, ""))); |
| /// # } |
| /// ``` |
| </span><span class="kw">pub fn </span>env_parser<E, Input, O>( |
| env: E, |
| parser: <span class="kw">fn</span>(E, <span class="kw-2">&mut </span>Input) -> StdParseResult<O, Input>, |
| ) -> EnvParser<E, Input, O> |
| <span class="kw">where |
| </span>E: Clone, |
| Input: Stream, |
| { |
| EnvParser { env, parser } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="combine" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |