mentat/petgraph/algo/fn.astar.html
2018-08-22 17:04:13 +00:00

164 lines
No EOL
12 KiB
HTML
Raw Permalink Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!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="API documentation for the Rust `astar` fn in crate `petgraph`.">
<meta name="keywords" content="rust, rustlang, rust-lang, astar">
<title>petgraph::algo::astar - Rust</title>
<link rel="stylesheet" type="text/css" href="../../normalize.css">
<link rel="stylesheet" type="text/css" href="../../rustdoc.css" id="mainThemeStyle">
<link rel="stylesheet" type="text/css" href="../../dark.css">
<link rel="stylesheet" type="text/css" href="../../main.css" id="themeStyle">
<script src="../../storage.js"></script>
</head>
<body class="rustdoc fn">
<!--[if lte IE 8]>
<div class="warning">
This old browser is unsupported and will most likely display funky
things.
</div>
<![endif]-->
<nav class="sidebar">
<div class="sidebar-menu">&#9776;</div>
<p class='location'><a href='../index.html'>petgraph</a>::<wbr><a href='index.html'>algo</a></p><script>window.sidebarCurrent = {name: 'astar', ty: 'fn', relpath: ''};</script><script defer src="sidebar-items.js"></script>
</nav>
<div class="theme-picker">
<button id="theme-picker" aria-label="Pick another theme!">
<img src="../../brush.svg" width="18" alt="Pick another theme!">
</button>
<div id="theme-choices"></div>
</div>
<script src="../../theme.js"></script>
<nav class="sub">
<form class="search-form js-only">
<div class="search-container">
<input class="search-input" name="search"
autocomplete="off"
placeholder="Click or press S to search, ? for more options…"
type="search">
</div>
</form>
</nav>
<section id='main' class="content">
<h1 class='fqn'><span class='in-band'>Function <a href='../index.html'>petgraph</a>::<wbr><a href='index.html'>algo</a>::<wbr><a class="fn" href=''>astar</a></span><span class='out-of-band'><span id='render-detail'>
<a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">
[<span class='inner'>&#x2212;</span>]
</a>
</span><a class='srclink' href='../../src/petgraph/astar.rs.html#67-133' title='goto source code'>[src]</a></span></h1>
<pre class='rust fn'>pub fn astar&lt;G, F, H, K, IsGoal&gt;(<br>&nbsp;&nbsp;&nbsp;&nbsp;graph: G, <br>&nbsp;&nbsp;&nbsp;&nbsp;start: G::<a class="type" href="../../petgraph/visit/trait.GraphBase.html#associatedtype.NodeId" title="type petgraph::visit::GraphBase::NodeId">NodeId</a>, <br>&nbsp;&nbsp;&nbsp;&nbsp;is_goal: IsGoal, <br>&nbsp;&nbsp;&nbsp;&nbsp;edge_cost: F, <br>&nbsp;&nbsp;&nbsp;&nbsp;estimate_cost: H<br>) -&gt; <a class="enum" href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.tuple.html">(</a>K, <a class="struct" href="https://doc.rust-lang.org/nightly/alloc/vec/struct.Vec.html" title="struct alloc::vec::Vec">Vec</a>&lt;G::<a class="type" href="../../petgraph/visit/trait.GraphBase.html#associatedtype.NodeId" title="type petgraph::visit::GraphBase::NodeId">NodeId</a>&gt;<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.tuple.html">)</a>&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;G: <a class="trait" href="../../petgraph/visit/trait.IntoEdges.html" title="trait petgraph::visit::IntoEdges">IntoEdges</a> + <a class="trait" href="../../petgraph/visit/trait.Visitable.html" title="trait petgraph::visit::Visitable">Visitable</a>,<br>&nbsp;&nbsp;&nbsp;&nbsp;IsGoal: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnMut.html" title="trait core::ops::function::FnMut">FnMut</a>(G::<a class="type" href="../../petgraph/visit/trait.GraphBase.html#associatedtype.NodeId" title="type petgraph::visit::GraphBase::NodeId">NodeId</a>) -&gt; <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a>,<br>&nbsp;&nbsp;&nbsp;&nbsp;G::<a class="type" href="../../petgraph/visit/trait.GraphBase.html#associatedtype.NodeId" title="type petgraph::visit::GraphBase::NodeId">NodeId</a>: <a class="trait" href="https://doc.rust-lang.org/nightly/core/cmp/trait.Eq.html" title="trait core::cmp::Eq">Eq</a> + <a class="trait" href="https://doc.rust-lang.org/nightly/core/hash/trait.Hash.html" title="trait core::hash::Hash">Hash</a>,<br>&nbsp;&nbsp;&nbsp;&nbsp;F: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnMut.html" title="trait core::ops::function::FnMut">FnMut</a>(G::<a class="type" href="../../petgraph/visit/trait.IntoEdgeReferences.html#associatedtype.EdgeRef" title="type petgraph::visit::IntoEdgeReferences::EdgeRef">EdgeRef</a>) -&gt; K,<br>&nbsp;&nbsp;&nbsp;&nbsp;H: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnMut.html" title="trait core::ops::function::FnMut">FnMut</a>(G::<a class="type" href="../../petgraph/visit/trait.GraphBase.html#associatedtype.NodeId" title="type petgraph::visit::GraphBase::NodeId">NodeId</a>) -&gt; K,<br>&nbsp;&nbsp;&nbsp;&nbsp;K: <a class="trait" href="../../petgraph/algo/trait.Measure.html" title="trait petgraph::algo::Measure">Measure</a> + <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Copy.html" title="trait core::marker::Copy">Copy</a>,&nbsp;</span></pre><div class='docblock'><p>[Generic] A* shortest path algorithm.</p>
<p>Computes the shortest path from <code>start</code> to <code>finish</code>, including the total path cost.</p>
<p><code>finish</code> is implicitly given via the <code>is_goal</code> callback, which should return <code>true</code> if the
given node is the finish node.</p>
<p>The function <code>edge_cost</code> should return the cost for a particular edge. Edge costs must be
non-negative.</p>
<p>The function <code>estimate_cost</code> should return the estimated cost to the finish for a particular
node. For the algorithm to find the actual shortest path, it should be admissible, meaning that
it should never overestimate the actual cost to get to the nearest goal node. Estimate costs
must also be non-negative.</p>
<p>The graph should be <code>Visitable</code> and implement <code>IntoEdges</code>.</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">petgraph</span>::<span class="ident">Graph</span>;
<span class="kw">use</span> <span class="ident">petgraph</span>::<span class="ident">algo</span>::<span class="ident">astar</span>;
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">g</span> <span class="op">=</span> <span class="ident">Graph</span>::<span class="ident">new</span>();
<span class="kw">let</span> <span class="ident">a</span> <span class="op">=</span> <span class="ident">g</span>.<span class="ident">add_node</span>((<span class="number">0.</span>, <span class="number">0.</span>));
<span class="kw">let</span> <span class="ident">b</span> <span class="op">=</span> <span class="ident">g</span>.<span class="ident">add_node</span>((<span class="number">2.</span>, <span class="number">0.</span>));
<span class="kw">let</span> <span class="ident">c</span> <span class="op">=</span> <span class="ident">g</span>.<span class="ident">add_node</span>((<span class="number">1.</span>, <span class="number">1.</span>));
<span class="kw">let</span> <span class="ident">d</span> <span class="op">=</span> <span class="ident">g</span>.<span class="ident">add_node</span>((<span class="number">0.</span>, <span class="number">2.</span>));
<span class="kw">let</span> <span class="ident">e</span> <span class="op">=</span> <span class="ident">g</span>.<span class="ident">add_node</span>((<span class="number">3.</span>, <span class="number">3.</span>));
<span class="kw">let</span> <span class="ident">f</span> <span class="op">=</span> <span class="ident">g</span>.<span class="ident">add_node</span>((<span class="number">4.</span>, <span class="number">2.</span>));
<span class="ident">g</span>.<span class="ident">extend_with_edges</span>(<span class="kw-2">&amp;</span>[
(<span class="ident">a</span>, <span class="ident">b</span>, <span class="number">2</span>),
(<span class="ident">a</span>, <span class="ident">d</span>, <span class="number">4</span>),
(<span class="ident">b</span>, <span class="ident">c</span>, <span class="number">1</span>),
(<span class="ident">b</span>, <span class="ident">f</span>, <span class="number">7</span>),
(<span class="ident">c</span>, <span class="ident">e</span>, <span class="number">5</span>),
(<span class="ident">e</span>, <span class="ident">f</span>, <span class="number">1</span>),
(<span class="ident">d</span>, <span class="ident">e</span>, <span class="number">1</span>),
]);
<span class="kw">let</span> <span class="ident">path</span> <span class="op">=</span> <span class="ident">astar</span>(<span class="kw-2">&amp;</span><span class="ident">g</span>, <span class="ident">a</span>, <span class="op">|</span><span class="ident">finish</span><span class="op">|</span> <span class="ident">finish</span> <span class="op">==</span> <span class="ident">f</span>, <span class="op">|</span><span class="ident">e</span><span class="op">|</span> <span class="kw-2">*</span><span class="ident">e</span>.<span class="ident">weight</span>(), <span class="op">|</span>_<span class="op">|</span> <span class="number">0</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">path</span>, <span class="prelude-val">Some</span>((<span class="number">6</span>, <span class="macro">vec</span><span class="macro">!</span>[<span class="ident">a</span>, <span class="ident">d</span>, <span class="ident">e</span>, <span class="ident">f</span>])));</pre>
<p>Returns the total cost + the path of subsequent <code>NodeId</code> from start to finish, if one was
found.</p>
</div></section>
<section id='search' class="content hidden"></section>
<section class="footer"></section>
<aside id="help" class="hidden">
<div>
<h1 class="hidden">Help</h1>
<div class="shortcuts">
<h2>Keyboard Shortcuts</h2>
<dl>
<dt><kbd>?</kbd></dt>
<dd>Show this help dialog</dd>
<dt><kbd>S</kbd></dt>
<dd>Focus the search field</dd>
<dt><kbd></kbd></dt>
<dd>Move up in search results</dd>
<dt><kbd></kbd></dt>
<dd>Move down in search results</dd>
<dt><kbd></kbd></dt>
<dd>Switch tab</dd>
<dt><kbd>&#9166;</kbd></dt>
<dd>Go to active search result</dd>
<dt><kbd>+</kbd></dt>
<dd>Expand all sections</dd>
<dt><kbd>-</kbd></dt>
<dd>Collapse all sections</dd>
</dl>
</div>
<div class="infos">
<h2>Search Tricks</h2>
<p>
Prefix searches with a type followed by a colon (e.g.
<code>fn:</code>) to restrict the search to a given type.
</p>
<p>
Accepted types are: <code>fn</code>, <code>mod</code>,
<code>struct</code>, <code>enum</code>,
<code>trait</code>, <code>type</code>, <code>macro</code>,
and <code>const</code>.
</p>
<p>
Search functions by type signature (e.g.
<code>vec -> usize</code> or <code>* -> vec</code>)
</p>
</div>
</div>
</aside>
<script>
window.rootPath = "../../";
window.currentCrate = "petgraph";
</script>
<script src="../../main.js"></script>
<script defer src="../../search-index.js"></script>
</body>
</html>