| <!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="Map is a lexicographically ordered map from byte strings to integers."><meta name="keywords" content="rust, rustlang, rust-lang, Map"><title>Map in tantivy_fst - 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" 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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="../tantivy_fst/index.html"><div class="logo-container"><img class="rust-logo" src="../rust-logo.svg" alt="logo"></div></a><h2 class="location"><a href="#">Map</a></h2><div class="sidebar-elems"><section><h3><a href="#implementations">Methods</a></h3><ul class="block"><li><a href="#method.as_fst">as_fst</a></li><li><a href="#method.contains_key">contains_key</a></li><li><a href="#method.from_bytes">from_bytes</a></li><li><a href="#method.from_iter">from_iter</a></li><li><a href="#method.get">get</a></li><li><a href="#method.is_empty">is_empty</a></li><li><a href="#method.keys">keys</a></li><li><a href="#method.len">len</a></li><li><a href="#method.op">op</a></li><li><a href="#method.range">range</a></li><li><a href="#method.search">search</a></li><li><a href="#method.stream">stream</a></li><li><a href="#method.values">values</a></li></ul><h3><a href="#trait-implementations">Trait Implementations</a></h3><ul class="block"><li><a href="#impl-AsRef%3CFst%3CData%3E%3E-for-Map%3CData%3E">AsRef<Fst<Data>></a></li><li><a href="#impl-Debug-for-Map%3CData%3E">Debug</a></li><li><a href="#impl-From%3CFst%3CData%3E%3E-for-Map%3CData%3E">From<Fst<Data>></a></li><li><a href="#impl-IntoStreamer%3C%27a%3E-for-%26%27m%20Map%3CData%3E">IntoStreamer<'a></a></li></ul><h3><a href="#synthetic-implementations">Auto Trait Implementations</a></h3><ul class="block"><li><a href="#impl-RefUnwindSafe-for-Map%3CData%3E">RefUnwindSafe</a></li><li><a href="#impl-Send-for-Map%3CData%3E">Send</a></li><li><a href="#impl-Sync-for-Map%3CData%3E">Sync</a></li><li><a href="#impl-Unpin-for-Map%3CData%3E">Unpin</a></li><li><a href="#impl-UnwindSafe-for-Map%3CData%3E">UnwindSafe</a></li></ul><h3><a href="#blanket-implementations">Blanket Implementations</a></h3><ul class="block"><li><a href="#impl-Any-for-Map%3CData%3E">Any</a></li><li><a href="#impl-Borrow%3CT%3E-for-Map%3CData%3E">Borrow<T></a></li><li><a href="#impl-BorrowMut%3CT%3E-for-Map%3CData%3E">BorrowMut<T></a></li><li><a href="#impl-From%3CT%3E-for-Map%3CData%3E">From<T></a></li><li><a href="#impl-Into%3CU%3E-for-Map%3CData%3E">Into<U></a></li><li><a href="#impl-TryFrom%3CU%3E-for-Map%3CData%3E">TryFrom<U></a></li><li><a href="#impl-TryInto%3CU%3E-for-Map%3CData%3E">TryInto<U></a></li></ul></section><h2><a href="index.html">In tantivy_fst</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">Struct <a href="index.html">tantivy_fst</a>::<wbr><a class="struct" href="#">Map</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/tantivy_fst/map.rs.html#57">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 struct"><code>pub struct Map<Data>(_);</code></pre></div><details class="rustdoc-toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Map is a lexicographically ordered map from byte strings to integers.</p> |
| <p>A <code>Map</code> is constructed with the <code>MapBuilder</code> type. Alternatively, a <code>Map</code> |
| can be constructed in memory from a lexicographically ordered iterator |
| of key-value pairs (<code>Map::from_iter</code>).</p> |
| <p>A key feature of <code>Map</code> is that it can be serialized to disk compactly. Its |
| underlying representation is built such that the <code>Map</code> can be memory mapped |
| (<code>Map::from_path</code>) and searched without necessarily loading the entire |
| map into memory.</p> |
| <p>It supports most common operations associated with maps, such as key |
| lookup and search. It also supports set operations on its keys along with |
| the ability to specify how conflicting values are merged together. Maps |
| also support range queries and automata based searches (e.g. a regular |
| expression).</p> |
| <p>Maps are represented by a finite state transducer where inputs are the keys |
| and outputs are the values. As such, maps have the following invariants:</p> |
| <ol> |
| <li>Once constructed, a <code>Map</code> can never be modified.</li> |
| <li>Maps must be constructed with lexicographically ordered byte sequences. |
| There is no restricting on the ordering of values.</li> |
| </ol> |
| <h2 id="differences-with-sets"><a href="#differences-with-sets">Differences with sets</a></h2> |
| <p>Maps and sets are represented by the same underlying data structure: the |
| finite state transducer. The principal difference between them is that |
| sets always have their output values set to <code>0</code>. This has an impact on the |
| representation size and is reflected in the type system for convenience. |
| A secondary but subtle difference is that duplicate values can be added |
| to a set, but it is an error to do so with maps. That is, a set can have |
| the same key added sequentially, but a map can’t.</p> |
| <h2 id="the-future"><a href="#the-future">The future</a></h2> |
| <p>It is regrettable that the output value is fixed to <code>u64</code>. Indeed, it is |
| not necessary, but it was a major simplification in the implementation. |
| In the future, the value type may become generic to an extent (outputs must |
| satisfy a basic algebra).</p> |
| <p>Keys will always be byte strings; however, we may grow more conveniences |
| around dealing with them (such as a serialization/deserialization step, |
| although it isn’t clear where exactly this should live).</p> |
| </div></details><h2 id="implementations" class="small-section-header">Implementations<a href="#implementations" class="anchor"></a></h2><div id="implementations-list"><details class="rustdoc-toggle implementors-toggle" open><summary><section id="impl-Map%3CVec%3Cu8%3E%3E" class="impl has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#59-90">source</a><a href="#impl-Map%3CVec%3Cu8%3E%3E" class="anchor"></a><h3 class="code-header">impl <a class="struct" href="map/struct.Map.html" title="struct tantivy_fst::map::Map">Map</a><Vec<u8>></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.from_bytes" class="method has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#68-70">source</a><h4 class="code-header">pub fn <a href="#method.from_bytes" class="fnname">from_bytes</a>(bytes: Vec<u8>) -> <a class="type" href="type.Result.html" title="type tantivy_fst::Result">Result</a><<a class="struct" href="map/struct.Map.html" title="struct tantivy_fst::map::Map">Map</a><Vec<u8>>></h4></section></summary><div class="docblock"><p>Creates a map from its representation as a raw byte sequence.</p> |
| <p>Note that this operation is very cheap (no allocations and no copies).</p> |
| <p>The map must have been written with a compatible finite state |
| transducer builder (<code>MapBuilder</code> qualifies). If the format is invalid |
| or if there is a mismatch between the API version of this library |
| and the map, then an error is returned.</p> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.from_iter" class="method has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#81-89">source</a><h4 class="code-header">pub fn <a href="#method.from_iter" class="fnname">from_iter</a><K, I>(iter: I) -> <a class="type" href="type.Result.html" title="type tantivy_fst::Result">Result</a><Self><span class="where fmt-newline">where<br> K: AsRef<[u8]>,<br> I: IntoIterator<Item = (K, u64)>,</span></h4></section></summary><div class="docblock"><p>Create a <code>Map</code> from an iterator of lexicographically ordered byte |
| strings and associated values.</p> |
| <p>If the iterator does not yield unique keys in lexicographic order, then |
| an error is returned.</p> |
| <p>Note that this is a convenience function to build a map in memory. |
| To build a map that streams to an arbitrary <code>io::Write</code>, use |
| <code>MapBuilder</code>.</p> |
| </div></details></div></details><details class="rustdoc-toggle implementors-toggle" open><summary><section id="impl-Map%3CData%3E" class="impl has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#92-358">source</a><a href="#impl-Map%3CData%3E" class="anchor"></a><h3 class="code-header">impl<Data: Deref<Target = [u8]>> <a class="struct" href="map/struct.Map.html" title="struct tantivy_fst::map::Map">Map</a><Data></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.contains_key" class="method has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#105-107">source</a><h4 class="code-header">pub fn <a href="#method.contains_key" class="fnname">contains_key</a><K: AsRef<[u8]>>(&self, key: K) -> bool</h4></section></summary><div class="docblock"><p>Tests the membership of a single key.</p> |
| <h5 id="example"><a href="#example">Example</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tantivy_fst::Map; |
| |
| <span class="kw">let </span>map = Map::from_iter(<span class="macro">vec!</span>[(<span class="string">"a"</span>, <span class="number">1</span>), (<span class="string">"b"</span>, <span class="number">2</span>), (<span class="string">"c"</span>, <span class="number">3</span>)]).unwrap(); |
| |
| <span class="macro">assert_eq!</span>(map.contains_key(<span class="string">"b"</span>), <span class="bool-val">true</span>); |
| <span class="macro">assert_eq!</span>(map.contains_key(<span class="string">"z"</span>), <span class="bool-val">false</span>);</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.get" class="method has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#123-125">source</a><h4 class="code-header">pub fn <a href="#method.get" class="fnname">get</a><K: AsRef<[u8]>>(&self, key: K) -> Option<u64></h4></section></summary><div class="docblock"><p>Retrieves the value associated with a key.</p> |
| <p>If the key does not exist, then <code>None</code> is returned.</p> |
| <h5 id="example-1"><a href="#example-1">Example</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tantivy_fst::Map; |
| |
| <span class="kw">let </span>map = Map::from_iter(<span class="macro">vec!</span>[(<span class="string">"a"</span>, <span class="number">1</span>), (<span class="string">"b"</span>, <span class="number">2</span>), (<span class="string">"c"</span>, <span class="number">3</span>)]).unwrap(); |
| |
| <span class="macro">assert_eq!</span>(map.get(<span class="string">"b"</span>), <span class="prelude-val">Some</span>(<span class="number">2</span>)); |
| <span class="macro">assert_eq!</span>(map.get(<span class="string">"z"</span>), <span class="prelude-val">None</span>);</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.stream" class="method has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#160-162">source</a><h4 class="code-header">pub fn <a href="#method.stream" class="fnname">stream</a>(&self) -> <a class="struct" href="map/struct.Stream.html" title="struct tantivy_fst::map::Stream">Stream</a><'_></h4></section></summary><div class="docblock"><p>Return a lexicographically ordered stream of all key-value pairs in |
| this map.</p> |
| <p>While this is a stream, it does require heap space proportional to the |
| longest key in the map.</p> |
| <p>If the map is memory mapped, then no further heap space is needed. |
| Note though that your operating system may fill your page cache |
| (which will cause the resident memory usage of the process to go up |
| correspondingly).</p> |
| <h5 id="example-2"><a href="#example-2">Example</a></h5> |
| <p>Since streams are not iterators, the traditional <code>for</code> loop cannot be |
| used. <code>while let</code> is useful instead:</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tantivy_fst::{IntoStreamer, Streamer, Map}; |
| |
| <span class="kw">let </span>map = Map::from_iter(<span class="macro">vec!</span>[(<span class="string">"a"</span>, <span class="number">1</span>), (<span class="string">"b"</span>, <span class="number">2</span>), (<span class="string">"c"</span>, <span class="number">3</span>)]).unwrap(); |
| <span class="kw">let </span><span class="kw-2">mut </span>stream = map.stream(); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>kvs = <span class="macro">vec!</span>[]; |
| <span class="kw">while let </span><span class="prelude-val">Some</span>((k, v)) = stream.next() { |
| kvs.push((k.to_vec(), v)); |
| } |
| <span class="macro">assert_eq!</span>(kvs, <span class="macro">vec!</span>[ |
| (<span class="string">b"a"</span>.to_vec(), <span class="number">1</span>), |
| (<span class="string">b"b"</span>.to_vec(), <span class="number">2</span>), |
| (<span class="string">b"c"</span>.to_vec(), <span class="number">3</span>), |
| ]);</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.keys" class="method has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#183-185">source</a><h4 class="code-header">pub fn <a href="#method.keys" class="fnname">keys</a>(&self) -> <a class="struct" href="map/struct.Keys.html" title="struct tantivy_fst::map::Keys">Keys</a><'_></h4></section></summary><div class="docblock"><p>Return a lexicographically ordered stream of all keys in this map.</p> |
| <p>Memory requirements are the same as described on <code>Map::stream</code>.</p> |
| <h5 id="example-3"><a href="#example-3">Example</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tantivy_fst::{IntoStreamer, Streamer, Map}; |
| |
| <span class="kw">let </span>map = Map::from_iter(<span class="macro">vec!</span>[(<span class="string">"a"</span>, <span class="number">1</span>), (<span class="string">"b"</span>, <span class="number">2</span>), (<span class="string">"c"</span>, <span class="number">3</span>)]).unwrap(); |
| <span class="kw">let </span><span class="kw-2">mut </span>stream = map.keys(); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>keys = <span class="macro">vec!</span>[]; |
| <span class="kw">while let </span><span class="prelude-val">Some</span>(k) = stream.next() { |
| keys.push(k.to_vec()); |
| } |
| <span class="macro">assert_eq!</span>(keys, <span class="macro">vec!</span>[<span class="string">b"a"</span>, <span class="string">b"b"</span>, <span class="string">b"c"</span>]);</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.values" class="method has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#207-209">source</a><h4 class="code-header">pub fn <a href="#method.values" class="fnname">values</a>(&self) -> <a class="struct" href="map/struct.Values.html" title="struct tantivy_fst::map::Values">Values</a><'_></h4></section></summary><div class="docblock"><p>Return a stream of all values in this map ordered lexicographically |
| by each value’s corresponding key.</p> |
| <p>Memory requirements are the same as described on <code>Map::stream</code>.</p> |
| <h5 id="example-4"><a href="#example-4">Example</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tantivy_fst::{IntoStreamer, Streamer, Map}; |
| |
| <span class="kw">let </span>map = Map::from_iter(<span class="macro">vec!</span>[(<span class="string">"a"</span>, <span class="number">1</span>), (<span class="string">"b"</span>, <span class="number">2</span>), (<span class="string">"c"</span>, <span class="number">3</span>)]).unwrap(); |
| <span class="kw">let </span><span class="kw-2">mut </span>stream = map.values(); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>values = <span class="macro">vec!</span>[]; |
| <span class="kw">while let </span><span class="prelude-val">Some</span>(v) = stream.next() { |
| values.push(v); |
| } |
| <span class="macro">assert_eq!</span>(values, <span class="macro">vec!</span>[<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>]);</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.range" class="method has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#243-245">source</a><h4 class="code-header">pub fn <a href="#method.range" class="fnname">range</a>(&self) -> <a class="struct" href="map/struct.StreamBuilder.html" title="struct tantivy_fst::map::StreamBuilder">StreamBuilder</a><'_></h4></section></summary><div class="docblock"><p>Return a builder for range queries.</p> |
| <p>A range query returns a subset of key-value pairs in this map in a |
| range given in lexicographic order.</p> |
| <p>Memory requirements are the same as described on <code>Map::stream</code>. |
| Notably, only the keys in the range are read; keys outside the range |
| are not.</p> |
| <h5 id="example-5"><a href="#example-5">Example</a></h5> |
| <p>Returns only the key-value pairs in the range given.</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tantivy_fst::{IntoStreamer, Streamer, Map}; |
| |
| <span class="kw">let </span>map = Map::from_iter(<span class="macro">vec!</span>[ |
| (<span class="string">"a"</span>, <span class="number">1</span>), (<span class="string">"b"</span>, <span class="number">2</span>), (<span class="string">"c"</span>, <span class="number">3</span>), (<span class="string">"d"</span>, <span class="number">4</span>), (<span class="string">"e"</span>, <span class="number">5</span>), |
| ]).unwrap(); |
| <span class="kw">let </span><span class="kw-2">mut </span>stream = map.range().ge(<span class="string">"b"</span>).lt(<span class="string">"e"</span>).into_stream(); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>kvs = <span class="macro">vec!</span>[]; |
| <span class="kw">while let </span><span class="prelude-val">Some</span>((k, v)) = stream.next() { |
| kvs.push((k.to_vec(), v)); |
| } |
| <span class="macro">assert_eq!</span>(kvs, <span class="macro">vec!</span>[ |
| (<span class="string">b"b"</span>.to_vec(), <span class="number">2</span>), |
| (<span class="string">b"c"</span>.to_vec(), <span class="number">3</span>), |
| (<span class="string">b"d"</span>.to_vec(), <span class="number">4</span>), |
| ]);</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.search" class="method has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#289-291">source</a><h4 class="code-header">pub fn <a href="#method.search" class="fnname">search</a><A: <a class="trait" href="automaton/trait.Automaton.html" title="trait tantivy_fst::automaton::Automaton">Automaton</a>>(&self, aut: A) -> <a class="struct" href="map/struct.StreamBuilder.html" title="struct tantivy_fst::map::StreamBuilder">StreamBuilder</a><'_, A></h4></section></summary><div class="docblock"><p>Executes an automaton on the keys of this map.</p> |
| <p>Note that this returns a <code>StreamBuilder</code>, which can be used to |
| add a range query to the search (see the <code>range</code> method).</p> |
| <p>Memory requirements are the same as described on <code>Map::stream</code>.</p> |
| <h5 id="example-6"><a href="#example-6">Example</a></h5> |
| <p>An implementation of regular expressions for <code>Automaton</code> is available |
| in the <code>fst-regex</code> crate, which can be used to search maps.</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code> |
| <span class="kw">use </span>std::error::Error; |
| |
| <span class="kw">use </span>tantivy_fst::{IntoStreamer, Streamer, Map}; |
| <span class="kw">use </span>tantivy_fst::Regex; |
| |
| <span class="kw">fn </span>example() -> <span class="prelude-ty">Result</span><(), Box<Error>> { |
| <span class="kw">let </span>map = Map::from_iter(<span class="macro">vec!</span>[ |
| (<span class="string">"foo"</span>, <span class="number">1</span>), (<span class="string">"foo1"</span>, <span class="number">2</span>), (<span class="string">"foo2"</span>, <span class="number">3</span>), (<span class="string">"foo3"</span>, <span class="number">4</span>), (<span class="string">"foobar"</span>, <span class="number">5</span>), |
| ]).unwrap(); |
| |
| <span class="kw">let </span>re = Regex::new(<span class="string">"f[a-z]+3?"</span>).unwrap(); |
| <span class="kw">let </span><span class="kw-2">mut </span>stream = map.search(<span class="kw-2">&</span>re).into_stream(); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>kvs = <span class="macro">vec!</span>[]; |
| <span class="kw">while let </span><span class="prelude-val">Some</span>((k, v)) = stream.next() { |
| kvs.push((k.to_vec(), v)); |
| } |
| <span class="macro">assert_eq!</span>(kvs, <span class="macro">vec!</span>[ |
| (<span class="string">b"foo"</span>.to_vec(), <span class="number">1</span>), |
| (<span class="string">b"foo3"</span>.to_vec(), <span class="number">4</span>), |
| (<span class="string">b"foobar"</span>.to_vec(), <span class="number">5</span>), |
| ]); |
| |
| <span class="prelude-val">Ok</span>(()) |
| } |
| </code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.len" class="method has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#295-297">source</a><h4 class="code-header">pub fn <a href="#method.len" class="fnname">len</a>(&self) -> usize</h4></section></summary><div class="docblock"><p>Returns the number of elements in this map.</p> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.is_empty" class="method has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#301-303">source</a><h4 class="code-header">pub fn <a href="#method.is_empty" class="fnname">is_empty</a>(&self) -> bool</h4></section></summary><div class="docblock"><p>Returns true if and only if this map is empty.</p> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.op" class="method has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#349-351">source</a><h4 class="code-header">pub fn <a href="#method.op" class="fnname">op</a>(&self) -> <a class="struct" href="map/struct.OpBuilder.html" title="struct tantivy_fst::map::OpBuilder">OpBuilder</a><'_></h4></section></summary><div class="docblock"><p>Creates a new map operation with this map added to it.</p> |
| <p>The <code>OpBuilder</code> type can be used to add additional map streams |
| and perform set operations like union, intersection, difference and |
| symmetric difference on the keys of the map. These set operations also |
| allow one to specify how conflicting values are merged in the stream.</p> |
| <h5 id="example-7"><a href="#example-7">Example</a></h5> |
| <p>This example demonstrates a union on multiple map streams. Notice that |
| the stream returned from the union is not a sequence of key-value |
| pairs, but rather a sequence of keys associated with one or more |
| values. Namely, a key is associated with each value associated with |
| that same key in the all of the streams.</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tantivy_fst::{Streamer, Map}; |
| <span class="kw">use </span>tantivy_fst::{map::IndexedValue}; |
| |
| <span class="kw">let </span>map1 = Map::from_iter(<span class="macro">vec!</span>[ |
| (<span class="string">"a"</span>, <span class="number">1</span>), (<span class="string">"b"</span>, <span class="number">2</span>), (<span class="string">"c"</span>, <span class="number">3</span>), |
| ]).unwrap(); |
| <span class="kw">let </span>map2 = Map::from_iter(<span class="macro">vec!</span>[ |
| (<span class="string">"a"</span>, <span class="number">10</span>), (<span class="string">"y"</span>, <span class="number">11</span>), (<span class="string">"z"</span>, <span class="number">12</span>), |
| ]).unwrap(); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>union = map1.op().add(<span class="kw-2">&</span>map2).union(); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>kvs = <span class="macro">vec!</span>[]; |
| <span class="kw">while let </span><span class="prelude-val">Some</span>((k, vs)) = union.next() { |
| kvs.push((k.to_vec(), vs.to_vec())); |
| } |
| <span class="macro">assert_eq!</span>(kvs, <span class="macro">vec!</span>[ |
| (<span class="string">b"a"</span>.to_vec(), <span class="macro">vec!</span>[ |
| IndexedValue { index: <span class="number">0</span>, value: <span class="number">1 </span>}, |
| IndexedValue { index: <span class="number">1</span>, value: <span class="number">10 </span>}, |
| ]), |
| (<span class="string">b"b"</span>.to_vec(), <span class="macro">vec!</span>[IndexedValue { index: <span class="number">0</span>, value: <span class="number">2 </span>}]), |
| (<span class="string">b"c"</span>.to_vec(), <span class="macro">vec!</span>[IndexedValue { index: <span class="number">0</span>, value: <span class="number">3 </span>}]), |
| (<span class="string">b"y"</span>.to_vec(), <span class="macro">vec!</span>[IndexedValue { index: <span class="number">1</span>, value: <span class="number">11 </span>}]), |
| (<span class="string">b"z"</span>.to_vec(), <span class="macro">vec!</span>[IndexedValue { index: <span class="number">1</span>, value: <span class="number">12 </span>}]), |
| ]);</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.as_fst" class="method has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#355-357">source</a><h4 class="code-header">pub fn <a href="#method.as_fst" class="fnname">as_fst</a>(&self) -> &<a class="struct" href="raw/struct.Fst.html" title="struct tantivy_fst::raw::Fst">Fst</a><Data></h4></section></summary><div class="docblock"><p>Returns a reference to the underlying raw finite state transducer.</p> |
| </div></details></div></details></div><h2 id="trait-implementations" class="small-section-header">Trait Implementations<a href="#trait-implementations" class="anchor"></a></h2><div id="trait-implementations-list"><details class="rustdoc-toggle implementors-toggle" open><summary><section id="impl-AsRef%3CFst%3CData%3E%3E-for-Map%3CData%3E" class="impl has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#385-390">source</a><a href="#impl-AsRef%3CFst%3CData%3E%3E-for-Map%3CData%3E" class="anchor"></a><h3 class="code-header">impl<Data> AsRef<<a class="struct" href="raw/struct.Fst.html" title="struct tantivy_fst::raw::Fst">Fst</a><Data>> for <a class="struct" href="map/struct.Map.html" title="struct tantivy_fst::map::Map">Map</a><Data></h3></section></summary><div class="docblock"><p>Returns the underlying finite state transducer.</p> |
| </div><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.as_ref" class="method trait-impl has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#387-389">source</a><a href="#method.as_ref" class="anchor"></a><h4 class="code-header">fn <a class="fnname">as_ref</a>(&self) -> &<a class="struct" href="raw/struct.Fst.html" title="struct tantivy_fst::raw::Fst">Fst</a><Data></h4></section></summary><div class='docblock'>Converts this type into a shared reference of the (usually inferred) input type.</div></details></div></details><details class="rustdoc-toggle implementors-toggle" open><summary><section id="impl-Debug-for-Map%3CData%3E" class="impl has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#360-374">source</a><a href="#impl-Debug-for-Map%3CData%3E" class="anchor"></a><h3 class="code-header">impl<Data: Deref<Target = [u8]>> Debug for <a class="struct" href="map/struct.Map.html" title="struct tantivy_fst::map::Map">Map</a><Data></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.fmt" class="method trait-impl has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#361-373">source</a><a href="#method.fmt" class="anchor"></a><h4 class="code-header">fn <a class="fnname">fmt</a>(&self, f: &mut Formatter<'_>) -> Result</h4></section></summary><div class='docblock'>Formats the value using the given formatter. <a>Read more</a></div></details></div></details><details class="rustdoc-toggle implementors-toggle" open><summary><section id="impl-From%3CFst%3CData%3E%3E-for-Map%3CData%3E" class="impl has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#377-382">source</a><a href="#impl-From%3CFst%3CData%3E%3E-for-Map%3CData%3E" class="anchor"></a><h3 class="code-header">impl<Data> From<<a class="struct" href="raw/struct.Fst.html" title="struct tantivy_fst::raw::Fst">Fst</a><Data>> for <a class="struct" href="map/struct.Map.html" title="struct tantivy_fst::map::Map">Map</a><Data></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.from" class="method trait-impl has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#379-381">source</a><a href="#method.from" class="anchor"></a><h4 class="code-header">fn <a class="fnname">from</a>(fst: <a class="struct" href="raw/struct.Fst.html" title="struct tantivy_fst::raw::Fst">Fst</a><Data>) -> Self</h4></section></summary><div class='docblock'>Converts to this type from the input type.</div></details></div></details><details class="rustdoc-toggle implementors-toggle" open><summary><section id="impl-IntoStreamer%3C%27a%3E-for-%26%27m%20Map%3CData%3E" class="impl has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#392-400">source</a><a href="#impl-IntoStreamer%3C%27a%3E-for-%26%27m%20Map%3CData%3E" class="anchor"></a><h3 class="code-header">impl<'m, 'a, Data: Deref<Target = [u8]>> <a class="trait" href="trait.IntoStreamer.html" title="trait tantivy_fst::IntoStreamer">IntoStreamer</a><'a> for &'m <a class="struct" href="map/struct.Map.html" title="struct tantivy_fst::map::Map">Map</a><Data></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle" open><summary><section id="associatedtype.Item" class="associatedtype trait-impl has-srclink"><a href="#associatedtype.Item" class="anchor"></a><h4 class="code-header">type <a href="trait.IntoStreamer.html#associatedtype.Item" class="associatedtype">Item</a> = (&'a [u8], u64)</h4></section></summary><div class='docblock'>The type of the item emitted by the stream.</div></details><details class="rustdoc-toggle" open><summary><section id="associatedtype.Into" class="associatedtype trait-impl has-srclink"><a href="#associatedtype.Into" class="anchor"></a><h4 class="code-header">type <a href="trait.IntoStreamer.html#associatedtype.Into" class="associatedtype">Into</a> = <a class="struct" href="map/struct.Stream.html" title="struct tantivy_fst::map::Stream">Stream</a><'m, <a class="struct" href="automaton/struct.AlwaysMatch.html" title="struct tantivy_fst::automaton::AlwaysMatch">AlwaysMatch</a>></h4></section></summary><div class='docblock'>The type of the stream to be constructed.</div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.into_stream" class="method trait-impl has-srclink"><a class="srclink rightside" href="../src/tantivy_fst/map.rs.html#397-399">source</a><a href="#method.into_stream" class="anchor"></a><h4 class="code-header">fn <a href="trait.IntoStreamer.html#tymethod.into_stream" class="fnname">into_stream</a>(self) -> Self::<a class="associatedtype" href="trait.IntoStreamer.html#associatedtype.Into" title="type tantivy_fst::IntoStreamer::Into">Into</a></h4></section></summary><div class='docblock'>Construct a stream from <code>Self</code>.</div></details></div></details></div><h2 id="synthetic-implementations" class="small-section-header">Auto Trait Implementations<a href="#synthetic-implementations" class="anchor"></a></h2><div id="synthetic-implementations-list"><section id="impl-RefUnwindSafe-for-Map%3CData%3E" class="impl has-srclink"><a href="#impl-RefUnwindSafe-for-Map%3CData%3E" class="anchor"></a><h3 class="code-header">impl<Data> RefUnwindSafe for <a class="struct" href="map/struct.Map.html" title="struct tantivy_fst::map::Map">Map</a><Data><span class="where fmt-newline">where<br> Data: RefUnwindSafe,</span></h3></section><section id="impl-Send-for-Map%3CData%3E" class="impl has-srclink"><a href="#impl-Send-for-Map%3CData%3E" class="anchor"></a><h3 class="code-header">impl<Data> Send for <a class="struct" href="map/struct.Map.html" title="struct tantivy_fst::map::Map">Map</a><Data><span class="where fmt-newline">where<br> Data: Send,</span></h3></section><section id="impl-Sync-for-Map%3CData%3E" class="impl has-srclink"><a href="#impl-Sync-for-Map%3CData%3E" class="anchor"></a><h3 class="code-header">impl<Data> Sync for <a class="struct" href="map/struct.Map.html" title="struct tantivy_fst::map::Map">Map</a><Data><span class="where fmt-newline">where<br> Data: Sync,</span></h3></section><section id="impl-Unpin-for-Map%3CData%3E" class="impl has-srclink"><a href="#impl-Unpin-for-Map%3CData%3E" class="anchor"></a><h3 class="code-header">impl<Data> Unpin for <a class="struct" href="map/struct.Map.html" title="struct tantivy_fst::map::Map">Map</a><Data><span class="where fmt-newline">where<br> Data: Unpin,</span></h3></section><section id="impl-UnwindSafe-for-Map%3CData%3E" class="impl has-srclink"><a href="#impl-UnwindSafe-for-Map%3CData%3E" class="anchor"></a><h3 class="code-header">impl<Data> UnwindSafe for <a class="struct" href="map/struct.Map.html" title="struct tantivy_fst::map::Map">Map</a><Data><span class="where fmt-newline">where<br> Data: UnwindSafe,</span></h3></section></div><h2 id="blanket-implementations" class="small-section-header">Blanket Implementations<a href="#blanket-implementations" class="anchor"></a></h2><div id="blanket-implementations-list"><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-Any-for-Map%3CData%3E" class="impl has-srclink"><a href="#impl-Any-for-Map%3CData%3E" class="anchor"></a><h3 class="code-header">impl<T> Any for T<span class="where fmt-newline">where<br> T: 'static + ?Sized,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.type_id" class="method trait-impl has-srclink"><a href="#method.type_id" class="anchor"></a><h4 class="code-header">fn <a class="fnname">type_id</a>(&self) -> TypeId</h4></section></summary><div class='docblock'>Gets the <code>TypeId</code> of <code>self</code>. <a>Read more</a></div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-Borrow%3CT%3E-for-Map%3CData%3E" class="impl has-srclink"><a href="#impl-Borrow%3CT%3E-for-Map%3CData%3E" class="anchor"></a><h3 class="code-header">impl<T> Borrow<T> for T<span class="where fmt-newline">where<br> T: ?Sized,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.borrow" class="method trait-impl has-srclink"><span class="since rightside" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/91522" title="Tracking issue for const_borrow">unstable</a></span><a href="#method.borrow" class="anchor"></a><h4 class="code-header">fn <a class="fnname">borrow</a>(&self) -> &T</h4></section></summary><div class='docblock'>Immutably borrows from an owned value. <a>Read more</a></div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-BorrowMut%3CT%3E-for-Map%3CData%3E" class="impl has-srclink"><a href="#impl-BorrowMut%3CT%3E-for-Map%3CData%3E" class="anchor"></a><h3 class="code-header">impl<T> BorrowMut<T> for T<span class="where fmt-newline">where<br> T: ?Sized,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.borrow_mut" class="method trait-impl has-srclink"><span class="since rightside" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/91522" title="Tracking issue for const_borrow">unstable</a></span><a href="#method.borrow_mut" class="anchor"></a><h4 class="code-header">fn <a class="fnname">borrow_mut</a>(&mut self) -> &mut T</h4></section></summary><div class='docblock'>Mutably borrows from an owned value. <a>Read more</a></div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-From%3CT%3E-for-Map%3CData%3E" class="impl has-srclink"><a href="#impl-From%3CT%3E-for-Map%3CData%3E" class="anchor"></a><h3 class="code-header">impl<T> From<T> for T</h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.from-1" class="method trait-impl has-srclink"><span class="since rightside" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/88674" title="Tracking issue for const_convert">unstable</a></span><a href="#method.from-1" class="anchor"></a><h4 class="code-header">fn <a class="fnname">from</a>(t: T) -> T</h4></section></summary><div class="docblock"><p>Returns the argument unchanged.</p> |
| </div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-Into%3CU%3E-for-Map%3CData%3E" class="impl has-srclink"><a href="#impl-Into%3CU%3E-for-Map%3CData%3E" class="anchor"></a><h3 class="code-header">impl<T, U> Into<U> for T<span class="where fmt-newline">where<br> U: From<T>,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.into" class="method trait-impl has-srclink"><span class="since rightside" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/88674" title="Tracking issue for const_convert">unstable</a></span><a href="#method.into" class="anchor"></a><h4 class="code-header">fn <a class="fnname">into</a>(self) -> U</h4></section></summary><div class="docblock"><p>Calls <code>U::from(self)</code>.</p> |
| <p>That is, this conversion is whatever the implementation of |
| <code>[From]<T> for U</code> chooses to do.</p> |
| </div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-TryFrom%3CU%3E-for-Map%3CData%3E" class="impl has-srclink"><a href="#impl-TryFrom%3CU%3E-for-Map%3CData%3E" class="anchor"></a><h3 class="code-header">impl<T, U> TryFrom<U> for T<span class="where fmt-newline">where<br> U: Into<T>,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle" open><summary><section id="associatedtype.Error-1" class="associatedtype trait-impl has-srclink"><a href="#associatedtype.Error-1" class="anchor"></a><h4 class="code-header">type <a class="associatedtype">Error</a> = Infallible</h4></section></summary><div class='docblock'>The type returned in the event of a conversion error.</div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.try_from" class="method trait-impl has-srclink"><span class="since rightside" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/88674" title="Tracking issue for const_convert">unstable</a></span><a href="#method.try_from" class="anchor"></a><h4 class="code-header">fn <a class="fnname">try_from</a>(value: U) -> Result<T, <T as TryFrom<U>>::Error></h4></section></summary><div class='docblock'>Performs the conversion.</div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-TryInto%3CU%3E-for-Map%3CData%3E" class="impl has-srclink"><a href="#impl-TryInto%3CU%3E-for-Map%3CData%3E" class="anchor"></a><h3 class="code-header">impl<T, U> TryInto<U> for T<span class="where fmt-newline">where<br> U: TryFrom<T>,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle" open><summary><section id="associatedtype.Error" class="associatedtype trait-impl has-srclink"><a href="#associatedtype.Error" class="anchor"></a><h4 class="code-header">type <a class="associatedtype">Error</a> = <U as TryFrom<T>>::Error</h4></section></summary><div class='docblock'>The type returned in the event of a conversion error.</div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.try_into" class="method trait-impl has-srclink"><span class="since rightside" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/88674" title="Tracking issue for const_convert">unstable</a></span><a href="#method.try_into" class="anchor"></a><h4 class="code-header">fn <a class="fnname">try_into</a>(self) -> Result<U, <U as TryFrom<T>>::Error></h4></section></summary><div class='docblock'>Performs the conversion.</div></details></div></details></div></section></div></main><div id="rustdoc-vars" data-root-path="../" data-current-crate="tantivy_fst" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
