| <!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="A possibly `Scalar` `Array`"><title>Datum in arrow_array - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Italic-81dc35de.woff2,FiraSans-Regular-0fe48ade.woff2,FiraSans-MediumItalic-ccf7e434.woff2,FiraSans-Medium-e1aa3f0a.woff2,SourceCodePro-Regular-8badfe75.ttf.woff2,SourceCodePro-Semibold-aa29a496.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2"href="../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../static.files/rustdoc-ca0dd0c4.css"><meta name="rustdoc-vars" data-root-path="../" data-static-root-path="../static.files/" data-current-crate="arrow_array" data-themes="" data-resource-suffix="" data-rustdoc-version="1.93.0-nightly (d5419f1e9 2025-10-30)" data-channel="nightly" data-search-js="search-6acd48a0.js" data-stringdex-js="stringdex-c3e638e9.js" data-settings-js="settings-c38705f0.js" ><script src="../static.files/storage-e2aeef58.js"></script><script defer src="sidebar-items.js"></script><script defer src="../static.files/main-ce535bd0.js"></script><noscript><link rel="stylesheet" href="../static.files/noscript-263c88ec.css"></noscript><link rel="icon" href="https://arrow.apache.org/img/arrow-logo_chevrons_black-txt_transparent-bg.svg"></head><body class="rustdoc trait"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><rustdoc-topbar><h2><a href="#">Datum</a></h2></rustdoc-topbar><nav class="sidebar"><div class="sidebar-crate"><a class="logo-container" href="../arrow_array/index.html"><img src="https://arrow.apache.org/img/arrow-logo_chevrons_black-txt_white-bg.svg" alt="logo"></a><h2><a href="../arrow_array/index.html">arrow_<wbr>array</a><span class="version">57.0.0</span></h2></div><div class="sidebar-elems"><section id="rustdoc-toc"><h2 class="location"><a href="#">Datum</a></h2><h3><a href="#required-methods">Required Methods</a></h3><ul class="block"><li><a href="#tymethod.get" title="get">get</a></li></ul><h3><a href="#implementors">Implementors</a></h3></section><div id="rustdoc-modnav"><h2 class="in-crate"><a href="index.html">In crate arrow_<wbr>array</a></h2></div></div></nav><div class="sidebar-resizer" title="Drag to resize sidebar"></div><main><div class="width-limiter"><section id="main-content" class="content"><div class="main-heading"><div class="rustdoc-breadcrumbs"><a href="index.html">arrow_array</a></div><h1>Trait <span class="trait">Datum</span> <button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><rustdoc-toolbar></rustdoc-toolbar><span class="sub-heading"><a class="src" href="../src/arrow_array/scalar.rs.html#78-81">Source</a> </span></div><pre class="rust item-decl"><code>pub trait Datum { |
| // Required method |
| fn <a href="#tymethod.get" class="fn">get</a>(&self) -> (&dyn <a class="trait" href="array/trait.Array.html" title="trait arrow_array::array::Array">Array</a>, <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a>); |
| }</code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>A possibly <a href="struct.Scalar.html" title="struct arrow_array::Scalar"><code>Scalar</code></a> <a href="array/trait.Array.html" title="trait arrow_array::array::Array"><code>Array</code></a></p> |
| <p>This allows optimised binary kernels where one or more arguments are constant</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">fn </span>eq_impl<T: ArrowPrimitiveType>( |
| a: <span class="kw-2">&</span>PrimitiveArray<T>, |
| a_scalar: bool, |
| b: <span class="kw-2">&</span>PrimitiveArray<T>, |
| b_scalar: bool, |
| ) -> BooleanArray { |
| <span class="kw">let </span>(array, scalar) = <span class="kw">match </span>(a_scalar, b_scalar) { |
| (<span class="bool-val">true</span>, <span class="bool-val">true</span>) | (<span class="bool-val">false</span>, <span class="bool-val">false</span>) => { |
| <span class="kw">let </span>len = a.len().min(b.len()); |
| <span class="kw">let </span>nulls = NullBuffer::union(a.nulls(), b.nulls()); |
| <span class="kw">let </span>buffer = BooleanBuffer::collect_bool(len, |idx| a.value(idx) == b.value(idx)); |
| <span class="kw">return </span>BooleanArray::new(buffer, nulls); |
| } |
| (<span class="bool-val">true</span>, <span class="bool-val">false</span>) => (b, (a.null_count() == <span class="number">0</span>).then(|| a.value(<span class="number">0</span>))), |
| (<span class="bool-val">false</span>, <span class="bool-val">true</span>) => (a, (b.null_count() == <span class="number">0</span>).then(|| b.value(<span class="number">0</span>))), |
| }; |
| <span class="kw">match </span>scalar { |
| <span class="prelude-val">Some</span>(v) => { |
| <span class="kw">let </span>len = array.len(); |
| <span class="kw">let </span>nulls = array.nulls().cloned(); |
| <span class="kw">let </span>buffer = BooleanBuffer::collect_bool(len, |idx| array.value(idx) == v); |
| BooleanArray::new(buffer, nulls) |
| } |
| <span class="prelude-val">None </span>=> BooleanArray::new_null(array.len()), |
| } |
| } |
| |
| <span class="kw">pub fn </span>eq(l: <span class="kw-2">&</span><span class="kw">dyn </span>Datum, r: <span class="kw-2">&</span><span class="kw">dyn </span>Datum) -> <span class="prelude-ty">Result</span><BooleanArray, ArrowError> { |
| <span class="kw">let </span>(l_array, l_scalar) = l.get(); |
| <span class="kw">let </span>(r_array, r_scalar) = r.get(); |
| <span class="macro">downcast_primitive_array!</span>( |
| (l_array, r_array) => <span class="prelude-val">Ok</span>(eq_impl(l_array, l_scalar, r_array, r_scalar)), |
| (a, b) => <span class="prelude-val">Err</span>(ArrowError::NotYetImplemented(<span class="macro">format!</span>(<span class="string">"{a} == {b}"</span>))), |
| ) |
| } |
| |
| <span class="comment">// Comparison of two arrays |
| </span><span class="kw">let </span>a = Int32Array::from(<span class="macro">vec!</span>[<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>]); |
| <span class="kw">let </span>b = Int32Array::from(<span class="macro">vec!</span>[<span class="number">1</span>, <span class="number">2</span>, <span class="number">4</span>, <span class="number">7</span>, <span class="number">3</span>]); |
| <span class="kw">let </span>r = eq(<span class="kw-2">&</span>a, <span class="kw-2">&</span>b).unwrap(); |
| <span class="kw">let </span>values: Vec<<span class="kw">_</span>> = r.values().iter().collect(); |
| <span class="macro">assert_eq!</span>(values, <span class="kw-2">&</span>[<span class="bool-val">true</span>, <span class="bool-val">true</span>, <span class="bool-val">false</span>, <span class="bool-val">false</span>, <span class="bool-val">false</span>]); |
| |
| <span class="comment">// Comparison of an array and a scalar |
| </span><span class="kw">let </span>a = Int32Array::from(<span class="macro">vec!</span>[<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>]); |
| <span class="kw">let </span>b = Int32Array::new_scalar(<span class="number">1</span>); |
| <span class="kw">let </span>r = eq(<span class="kw-2">&</span>a, <span class="kw-2">&</span>b).unwrap(); |
| <span class="kw">let </span>values: Vec<<span class="kw">_</span>> = r.values().iter().collect(); |
| <span class="macro">assert_eq!</span>(values, <span class="kw-2">&</span>[<span class="bool-val">true</span>, <span class="bool-val">false</span>, <span class="bool-val">false</span>, <span class="bool-val">false</span>, <span class="bool-val">false</span>]);</code></pre></div></div></details><h2 id="required-methods" class="section-header">Required Methods<a href="#required-methods" class="anchor">§</a></h2><div class="methods"><details class="toggle method-toggle" open><summary><section id="tymethod.get" class="method"><a class="src rightside" href="../src/arrow_array/scalar.rs.html#80">Source</a><h4 class="code-header">fn <a href="#tymethod.get" class="fn">get</a>(&self) -> (&dyn <a class="trait" href="array/trait.Array.html" title="trait arrow_array::array::Array">Array</a>, <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a>)</h4></section></summary><div class="docblock"><p>Returns the value for this <a href="trait.Datum.html" title="trait arrow_array::Datum"><code>Datum</code></a> and a boolean indicating if the value is scalar</p> |
| </div></details></div><h2 id="implementors" class="section-header">Implementors<a href="#implementors" class="anchor">§</a></h2><div id="implementors-list"><section id="impl-Datum-for-%26dyn+Array" class="impl"><a class="src rightside" href="../src/arrow_array/scalar.rs.html#95-99">Source</a><a href="#impl-Datum-for-%26dyn+Array" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="trait.Datum.html" title="trait arrow_array::Datum">Datum</a> for &dyn <a class="trait" href="array/trait.Array.html" title="trait arrow_array::array::Array">Array</a></h3></section><section id="impl-Datum-for-dyn+Array" class="impl"><a class="src rightside" href="../src/arrow_array/scalar.rs.html#89-93">Source</a><a href="#impl-Datum-for-dyn+Array" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="trait.Datum.html" title="trait arrow_array::Datum">Datum</a> for dyn <a class="trait" href="array/trait.Array.html" title="trait arrow_array::array::Array">Array</a></h3></section><section id="impl-Datum-for-Scalar%3CT%3E" class="impl"><a class="src rightside" href="../src/arrow_array/scalar.rs.html#148-152">Source</a><a href="#impl-Datum-for-Scalar%3CT%3E" class="anchor">§</a><h3 class="code-header">impl<T: <a class="trait" href="array/trait.Array.html" title="trait arrow_array::array::Array">Array</a>> <a class="trait" href="trait.Datum.html" title="trait arrow_array::Datum">Datum</a> for <a class="struct" href="struct.Scalar.html" title="struct arrow_array::Scalar">Scalar</a><T></h3></section><section id="impl-Datum-for-T" class="impl"><a class="src rightside" href="../src/arrow_array/scalar.rs.html#83-87">Source</a><a href="#impl-Datum-for-T" class="anchor">§</a><h3 class="code-header">impl<T: <a class="trait" href="array/trait.Array.html" title="trait arrow_array::array::Array">Array</a>> <a class="trait" href="trait.Datum.html" title="trait arrow_array::Datum">Datum</a> for T</h3></section></div><script src="../trait.impl/arrow_array/scalar/trait.Datum.js" async></script></section></div></main></body></html> |
