mentat/tabwriter/index.html

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<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>
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<h1 class='fqn'><span class='in-band'>Crate <a class="mod" href=''>tabwriter</a></span><span class='out-of-band'><span id='render-detail'>
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<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>
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