| <!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/itertools-0.10.5/src/intersperse.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>intersperse.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="../../itertools/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="../../itertools/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> |
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| </pre><pre class="rust"><code><span class="kw">use </span>std::iter::{Fuse, FusedIterator}; |
| <span class="kw">use </span><span class="kw">super</span>::size_hint; |
| |
| <span class="kw">pub trait </span>IntersperseElement<Item> { |
| <span class="kw">fn </span>generate(<span class="kw-2">&mut </span><span class="self">self</span>) -> Item; |
| } |
| |
| <span class="attribute">#[derive(Debug, Clone)] |
| </span><span class="kw">pub struct </span>IntersperseElementSimple<Item>(Item); |
| |
| <span class="kw">impl</span><Item: Clone> IntersperseElement<Item> <span class="kw">for </span>IntersperseElementSimple<Item> { |
| <span class="kw">fn </span>generate(<span class="kw-2">&mut </span><span class="self">self</span>) -> Item { |
| <span class="self">self</span>.<span class="number">0</span>.clone() |
| } |
| } |
| |
| <span class="doccomment">/// An iterator adaptor to insert a particular value |
| /// between each element of the adapted iterator. |
| /// |
| /// Iterator element type is `I::Item` |
| /// |
| /// This iterator is *fused*. |
| /// |
| /// See [`.intersperse()`](crate::Itertools::intersperse) for more information. |
| </span><span class="kw">pub type </span>Intersperse<I> = IntersperseWith<I, IntersperseElementSimple<<I <span class="kw">as </span>Iterator>::Item>>; |
| |
| <span class="doccomment">/// Create a new Intersperse iterator |
| </span><span class="kw">pub fn </span>intersperse<I>(iter: I, elt: I::Item) -> Intersperse<I> |
| <span class="kw">where </span>I: Iterator, |
| { |
| intersperse_with(iter, IntersperseElementSimple(elt)) |
| } |
| |
| <span class="kw">impl</span><Item, F: FnMut()->Item> IntersperseElement<Item> <span class="kw">for </span>F { |
| <span class="kw">fn </span>generate(<span class="kw-2">&mut </span><span class="self">self</span>) -> Item { |
| <span class="self">self</span>() |
| } |
| } |
| |
| <span class="doccomment">/// An iterator adaptor to insert a particular value created by a function |
| /// between each element of the adapted iterator. |
| /// |
| /// Iterator element type is `I::Item` |
| /// |
| /// This iterator is *fused*. |
| /// |
| /// See [`.intersperse_with()`](crate::Itertools::intersperse_with) for more information. |
| </span><span class="attribute">#[must_use = <span class="string">"iterator adaptors are lazy and do nothing unless consumed"</span>] |
| #[derive(Clone, Debug)] |
| </span><span class="kw">pub struct </span>IntersperseWith<I, ElemF> |
| <span class="kw">where </span>I: Iterator, |
| { |
| element: ElemF, |
| iter: Fuse<I>, |
| peek: <span class="prelude-ty">Option</span><I::Item>, |
| } |
| |
| <span class="doccomment">/// Create a new `IntersperseWith` iterator |
| </span><span class="kw">pub fn </span>intersperse_with<I, ElemF>(iter: I, elt: ElemF) -> IntersperseWith<I, ElemF> |
| <span class="kw">where </span>I: Iterator, |
| { |
| <span class="kw">let </span><span class="kw-2">mut </span>iter = iter.fuse(); |
| IntersperseWith { |
| peek: iter.next(), |
| iter, |
| element: elt, |
| } |
| } |
| |
| <span class="kw">impl</span><I, ElemF> Iterator <span class="kw">for </span>IntersperseWith<I, ElemF> |
| <span class="kw">where </span>I: Iterator, |
| ElemF: IntersperseElement<I::Item> |
| { |
| <span class="kw">type </span>Item = I::Item; |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>next(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>::Item> { |
| <span class="kw">if </span><span class="self">self</span>.peek.is_some() { |
| <span class="self">self</span>.peek.take() |
| } <span class="kw">else </span>{ |
| <span class="self">self</span>.peek = <span class="self">self</span>.iter.next(); |
| <span class="kw">if </span><span class="self">self</span>.peek.is_some() { |
| <span class="prelude-val">Some</span>(<span class="self">self</span>.element.generate()) |
| } <span class="kw">else </span>{ |
| <span class="prelude-val">None |
| </span>} |
| } |
| } |
| |
| <span class="kw">fn </span>size_hint(<span class="kw-2">&</span><span class="self">self</span>) -> (usize, <span class="prelude-ty">Option</span><usize>) { |
| <span class="comment">// 2 * SH + { 1 or 0 } |
| </span><span class="kw">let </span>has_peek = <span class="self">self</span>.peek.is_some() <span class="kw">as </span>usize; |
| <span class="kw">let </span>sh = <span class="self">self</span>.iter.size_hint(); |
| size_hint::add_scalar(size_hint::add(sh, sh), has_peek) |
| } |
| |
| <span class="kw">fn </span>fold<B, F>(<span class="kw-2">mut </span><span class="self">self</span>, init: B, <span class="kw-2">mut </span>f: F) -> B <span class="kw">where |
| </span><span class="self">Self</span>: Sized, F: FnMut(B, <span class="self">Self</span>::Item) -> B, |
| { |
| <span class="kw">let </span><span class="kw-2">mut </span>accum = init; |
| |
| <span class="kw">if let </span><span class="prelude-val">Some</span>(x) = <span class="self">self</span>.peek.take() { |
| accum = f(accum, x); |
| } |
| |
| <span class="kw">let </span>element = <span class="kw-2">&mut </span><span class="self">self</span>.element; |
| |
| <span class="self">self</span>.iter.fold(accum, |
| |accum, x| { |
| <span class="kw">let </span>accum = f(accum, element.generate()); |
| f(accum, x) |
| }) |
| } |
| } |
| |
| <span class="kw">impl</span><I, ElemF> FusedIterator <span class="kw">for </span>IntersperseWith<I, ElemF> |
| <span class="kw">where </span>I: Iterator, |
| ElemF: IntersperseElement<I::Item> |
| {} |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="itertools" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
