mentat/docs/apis/rust/tabwriter/index.html

208 lines
9.8 KiB
HTML
Raw Normal View History

2018-06-21 14:44:35 +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="API documentation for the Rust `tabwriter` crate.">
<meta name="keywords" content="rust, rustlang, rust-lang, tabwriter">
<title>tabwriter - 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="../light.css" id="themeStyle">
<script src="../storage.js"></script>
</head>
<body class="rustdoc mod">
<!--[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'>Crate tabwriter</p><div class="sidebar-elems"><div class="block items"><ul><li><a href="#structs">Structs</a></li></ul></div><p class='location'></p><script>window.sidebarCurrent = {name: 'tabwriter', ty: 'mod', relpath: '../'};</script></div>
</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'>Crate <a class="mod" href=''>tabwriter</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/tabwriter/lib.rs.html#1-389' title='goto source code'>[src]</a></span></h1><div class='docblock'><p>This crate provides an implementation of
<a href="http://nickgravgaard.com/elastictabstops/index.html">elastic tabstops</a>.
It is a minimal port of Go's
<a href="http://golang.org/pkg/text/tabwriter/">tabwriter</a> package.
Namely, its main mode of operation is to wrap a <code>Writer</code> and implement
elastic tabstops for the text written to the wrapped <code>Writer</code>.</p>
<p>This package is also bundled with a program, <code>tabwriter</code>,
that exposes this functionality at the command line.</p>
<p>Here's an example that shows basic alignment:</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">io</span>::<span class="ident">Write</span>;
<span class="kw">use</span> <span class="ident">tabwriter</span>::<span class="ident">TabWriter</span>;
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">tw</span> <span class="op">=</span> <span class="ident">TabWriter</span>::<span class="ident">new</span>(<span class="macro">vec</span><span class="macro">!</span>[]);
<span class="macro">write</span><span class="macro">!</span>(<span class="kw-2">&amp;</span><span class="kw-2">mut</span> <span class="ident">tw</span>, <span class="string">&quot;
Bruce Springsteen\tBorn to Run
Bob Seger\tNight Moves
Metallica\tBlack
The Boss\tDarkness on the Edge of Town
&quot;</span>).<span class="ident">unwrap</span>();
<span class="ident">tw</span>.<span class="ident">flush</span>().<span class="ident">unwrap</span>();
<span class="kw">let</span> <span class="ident">written</span> <span class="op">=</span> <span class="ident">String</span>::<span class="ident">from_utf8</span>(<span class="ident">tw</span>.<span class="ident">into_inner</span>().<span class="ident">unwrap</span>()).<span class="ident">unwrap</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="kw-2">&amp;</span><span class="kw-2">*</span><span class="ident">written</span>, <span class="string">&quot;
Bruce Springsteen Born to Run
Bob Seger Night Moves
Metallica Black
The Boss Darkness on the Edge of Town
&quot;</span>);</pre>
<p>Note that <code>flush</code> <strong>must</strong> be called or else <code>TabWriter</code> may never write
anything. This is because elastic tabstops requires knowing about future
lines in order to align output. More precisely, all text considered in a
single alignment must fit into memory.</p>
<p>Here's another example that demonstrates how <em>only</em> contiguous columns
are aligned:</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">io</span>::<span class="ident">Write</span>;
<span class="kw">use</span> <span class="ident">tabwriter</span>::<span class="ident">TabWriter</span>;
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">tw</span> <span class="op">=</span> <span class="ident">TabWriter</span>::<span class="ident">new</span>(<span class="macro">vec</span><span class="macro">!</span>[]).<span class="ident">padding</span>(<span class="number">1</span>);
<span class="macro">write</span><span class="macro">!</span>(<span class="kw-2">&amp;</span><span class="kw-2">mut</span> <span class="ident">tw</span>, <span class="string">&quot;
fn foobar() {{
let mut x = 1+1;\t// addition
x += 1;\t// increment in place
let y = x * x * x * x;\t// multiply!
y += 1;\t// this is another group
y += 2 * 2;\t// that is separately aligned
}}
&quot;</span>).<span class="ident">unwrap</span>();
<span class="ident">tw</span>.<span class="ident">flush</span>().<span class="ident">unwrap</span>();
<span class="kw">let</span> <span class="ident">written</span> <span class="op">=</span> <span class="ident">String</span>::<span class="ident">from_utf8</span>(<span class="ident">tw</span>.<span class="ident">into_inner</span>().<span class="ident">unwrap</span>()).<span class="ident">unwrap</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="kw-2">&amp;</span><span class="kw-2">*</span><span class="ident">written</span>, <span class="string">&quot;
fn foobar() {
let mut x = 1+1; // addition
x += 1; // increment in place
let y = x * x * x * x; // multiply!
y += 1; // this is another group
y += 2 * 2; // that is separately aligned
}
&quot;</span>);</pre>
</div><h2 id='structs' class='section-header'><a href="#structs">Structs</a></h2>
<table>
<tr class=' module-item'>
<td><a class="struct" href="struct.IntoInnerError.html"
title='struct tabwriter::IntoInnerError'>IntoInnerError</a></td>
<td class='docblock-short'>
<p>An error returned by <code>into_inner</code>.</p>
</td>
</tr>
<tr class=' module-item'>
<td><a class="struct" href="struct.TabWriter.html"
title='struct tabwriter::TabWriter'>TabWriter</a></td>
<td class='docblock-short'>
<p>TabWriter wraps an arbitrary writer and aligns tabbed output.</p>
</td>
</tr></table></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 = "tabwriter";
</script>
<script src="../main.js"></script>
<script defer src="../search-index.js"></script>
</body>
</html>