edlang/yansi/fn.whenever.html

<!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="Dynamically enables and disables styling globally based on `condition`."><title>whenever in yansi - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-46f98efaafac5295.ttf.woff2,FiraSans-Regular-018c141bf0843ffd.woff2,FiraSans-Medium-8f9a781e4970d388.woff2,SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2,SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../static.files/normalize-76eba96aa4d2e634.css"><link rel="stylesheet" href="../static.files/rustdoc-dd39b87e5fcfba68.css"><meta name="rustdoc-vars" data-root-path="../" data-static-root-path="../static.files/" data-current-crate="yansi" data-themes="" data-resource-suffix="" data-rustdoc-version="1.80.0 (051478957 2024-07-21)" data-channel="1.80.0" data-search-js="search-d52510db62a78183.js" data-settings-js="settings-4313503d2e1961c2.js" ><script src="../static.files/storage-118b08c4c78b968e.js"></script><script defer src="sidebar-items.js"></script><script defer src="../static.files/main-20a3ad099b048cf2.js"></script><noscript><link rel="stylesheet" href="../static.files/noscript-df360f571f6edeae.css"></noscript><link rel="alternate icon" type="image/png" href="../static.files/favicon-32x32-422f7d1d52889060.png"><link rel="icon" type="image/svg+xml" href="../static.files/favicon-2c020d218678b618.svg"></head><body class="rustdoc fn"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle" title="show sidebar"></button><a class="logo-container" href="../yansi/index.html"><img src="https://raw.githubusercontent.com/SergioBenitez/yansi/master/.github/yansi-logo.png" alt=""></a></nav><nav class="sidebar"><div class="sidebar-crate"><a class="logo-container" href="../yansi/index.html"><img src="https://raw.githubusercontent.com/SergioBenitez/yansi/master/.github/yansi-logo.png" alt="logo"></a><h2><a href="../yansi/index.html">yansi</a><span class="version">1.0.1</span></h2></div><div class="sidebar-elems"></div></nav><div class="sidebar-resizer"></div><main><div class="width-limiter"><rustdoc-search></rustdoc-search><section id="main-content" class="content"><div class="main-heading"><h1>Function <a href="index.html">yansi</a>::<wbr><a class="fn" href="#">whenever</a><button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><span class="out-of-band"><a class="src" href="../src/yansi/global.rs.html#82-84">source</a> · <button id="toggle-all-docs" title="collapse all docs">[<span>&#x2212;</span>]</button></span></div><pre class="rust item-decl"><code>pub fn whenever(condition: <a class="struct" href="struct.Condition.html" title="struct yansi::Condition">Condition</a>)</code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Dynamically enables and disables styling globally based on <code>condition</code>.</p>
<p><code>condition</code> is expected to be fast: it is checked dynamically, each time a
<a href="struct.Painted.html" title="struct yansi::Painted"><code>Painted</code></a> value is displayed.</p>
<h2 id="example"><a class="doc-anchor" href="#example">§</a>Example</h2>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>yansi::Condition;

yansi::whenever(Condition::STDOUT_IS_TTY);

<span class="comment">// On each styling, check if we have TTYs.
</span>yansi::whenever(Condition::STDOUTERR_ARE_TTY_LIVE);

<span class="comment">// Check `NO_COLOR`, `CLICOLOR`, and if we have TTYs.
</span><span class="kw">const </span>HAVE_COLOR: Condition = Condition(|| {
    std::env::var_os(<span class="string">"NO_COLOR"</span>).is_none()
        &amp;&amp; (Condition::CLICOLOR_LIVE)()
        &amp;&amp; Condition::stdouterr_are_tty_live()
});

<span class="comment">// This will call `HAVE_COLOR` every time styling is needed. In this
// example, this means that env vars will be checked on each styling.
</span>yansi::whenever(HAVE_COLOR);

<span class="comment">// This instead caches the value (checking `env()` exactly once, now).
</span>yansi::whenever(Condition::cached((HAVE_COLOR)()));

<span class="comment">// Is identical to this:
</span><span class="kw">match </span>(HAVE_COLOR)() {
    <span class="bool-val">true </span>=&gt; yansi::enable(),
    <span class="bool-val">false </span>=&gt; yansi::disable(),
}</code></pre></div>
</div></details></section></div></main></body></html>
deploy: b3bd34a9bbae9c73eb2d66a212d6921bd7499b69 2024-07-26 09:42:18 +00:00			<!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="Dynamically enables and disables styling globally based on `condition`."><title>whenever in yansi - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-46f98efaafac5295.ttf.woff2,FiraSans-Regular-018c141bf0843ffd.woff2,FiraSans-Medium-8f9a781e4970d388.woff2,SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2,SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../static.files/normalize-76eba96aa4d2e634.css"><link rel="stylesheet" href="../static.files/rustdoc-dd39b87e5fcfba68.css"><meta name="rustdoc-vars" data-root-path="../" data-static-root-path="../static.files/" data-current-crate="yansi" data-themes="" data-resource-suffix="" data-rustdoc-version="1.80.0 (051478957 2024-07-21)" data-channel="1.80.0" data-search-js="search-d52510db62a78183.js" data-settings-js="settings-4313503d2e1961c2.js" ><script src="../static.files/storage-118b08c4c78b968e.js"></script><script defer src="sidebar-items.js"></script><script defer src="../static.files/main-20a3ad099b048cf2.js"></script><noscript><link rel="stylesheet" href="../static.files/noscript-df360f571f6edeae.css"></noscript><link rel="alternate icon" type="image/png" href="../static.files/favicon-32x32-422f7d1d52889060.png"><link rel="icon" type="image/svg+xml" href="../static.files/favicon-2c020d218678b618.svg"></head><body class="rustdoc fn"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle" title="show sidebar"></button><a class="logo-container" href="../yansi/index.html"><img src="https://raw.githubusercontent.com/SergioBenitez/yansi/master/.github/yansi-logo.png" alt=""></a></nav><nav class="sidebar"><div class="sidebar-crate"><a class="logo-container" href="../yansi/index.html"><img src="https://raw.githubusercontent.com/SergioBenitez/yansi/master/.github/yansi-logo.png" alt="logo"></a><h2><a href="../yansi/index.html">yansi</a><span class="version">1.0.1</span></h2></div><div class="sidebar-elems"></div></nav><div class="sidebar-resizer"></div><main><div class="width-limiter"><rustdoc-search></rustdoc-search><section id="main-content" class="content"><div class="main-heading"><h1>Function <a href="index.html">yansi</a>::<wbr><a class="fn" href="#">whenever</a><button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><span class="out-of-band"><a class="src" href="../src/yansi/global.rs.html#82-84">source</a> · <button id="toggle-all-docs" title="collapse all docs">[<span>−</span>]</button></span></div><pre class="rust item-decl"><code>pub fn whenever(condition: <a class="struct" href="struct.Condition.html" title="struct yansi::Condition">Condition</a>)</code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Dynamically enables and disables styling globally based on <code>condition</code>.</p>
deploy: 03a244db41b752280f505ceeaea877cc9b95537b 2024-05-05 09:43:20 +00:00			`<p><code>condition</code> is expected to be fast: it is checked dynamically, each time a`
			`<a href="struct.Painted.html" title="struct yansi::Painted"><code>Painted</code></a> value is displayed.</p>`
			`<h2 id="example"><a class="doc-anchor" href="#example">§</a>Example</h2>`
			`<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>yansi::Condition;`

			`yansi::whenever(Condition::STDOUT_IS_TTY);`

			`<span class="comment">// On each styling, check if we have TTYs.`
			`</span>yansi::whenever(Condition::STDOUTERR_ARE_TTY_LIVE);`

			<span class="comment">// Check `NO_COLOR`, `CLICOLOR`, and if we have TTYs.
			`</span><span class="kw">const </span>HAVE_COLOR: Condition = Condition(\|\| {`
			`std::env::var_os(<span class="string">"NO_COLOR"</span>).is_none()`
			`&& (Condition::CLICOLOR_LIVE)()`
			`&& Condition::stdouterr_are_tty_live()`
			`});`

			<span class="comment">// This will call `HAVE_COLOR` every time styling is needed. In this
			`// example, this means that env vars will be checked on each styling.`
			`</span>yansi::whenever(HAVE_COLOR);`

			<span class="comment">// This instead caches the value (checking `env()` exactly once, now).
			`</span>yansi::whenever(Condition::cached((HAVE_COLOR)()));`

			`<span class="comment">// Is identical to this:`
			`</span><span class="kw">match </span>(HAVE_COLOR)() {`
			`<span class="bool-val">true </span>=> yansi::enable(),`
			`<span class="bool-val">false </span>=> yansi::disable(),`
			`}</code></pre></div>`
			`</div></details></section></div></main></body></html>`