mirror of
https://github.com/bspeice/bspeice.github.io
synced 2025-11-04 02:10:26 -05:00
Fix notebooks not showing up
This commit is contained in:
Bradlee Speice
@ -4,20 +4,22 @@
|
||||
<meta charset="utf-8">
|
||||
<meta http-equiv="X-UA-Compatible" content="IE=edge">
|
||||
<meta name="viewport" content="width=device-width, initial-scale=1">
|
||||
<meta name="description" content="I listen to a lot of Drum and Bass music, because it's beautiful music. And there's a particular site, Bassdrive.com that hosts a lot of great content. Specifically, the archives section of the...">
|
||||
<meta name="description" content="I listen to a lot of Drum and Bass music, because it's beautiful music. And there's a particular site, Bassdrive.com that hosts a lot of great content. Specifically, the archives section of the ...">
|
||||
<meta name="keywords" content="nutone, Rust">
|
||||
<link rel="icon" href="/favicon.ico">
|
||||
<link rel="icon" href="https://bspeice.github.io/favicon.ico">
|
||||
|
||||
<title>A Rustic Re-Podcasting Server (Part 1) - Bradlee Speice</title>
|
||||
|
||||
<!-- Stylesheets -->
|
||||
<link href="/theme/css/bootstrap.min.css" rel="stylesheet">
|
||||
<link href="/theme/css/fonts.css" rel="stylesheet">
|
||||
<link href="/theme/css/nest.css" rel="stylesheet">
|
||||
<link href="/theme/css/pygment.css" rel="stylesheet">
|
||||
<link href="https://bspeice.github.io/theme/css/bootstrap.min.css" rel="stylesheet">
|
||||
<link href="https://bspeice.github.io/theme/css/fonts.css" rel="stylesheet">
|
||||
<link href="https://bspeice.github.io/theme/css/nest.css" rel="stylesheet">
|
||||
<link href="https://bspeice.github.io/theme/css/pygment.css" rel="stylesheet">
|
||||
<!-- /Stylesheets -->
|
||||
|
||||
<!-- RSS Feeds -->
|
||||
<link href="https://bspeice.github.io/feeds/all.atom.xml" type="application/atom+xml" rel="alternate" title="Bradlee Speice Full Atom Feed" />
|
||||
<link href="https://bspeice.github.io/feeds/blog.atom.xml" type="application/atom+xml" rel="alternate" title="Bradlee Speice Categories Atom Feed" />
|
||||
<!-- /RSS Feeds -->
|
||||
|
||||
<!-- HTML5 shim and Respond.js for IE8 support of HTML5 elements and media queries -->
|
||||
@ -26,6 +28,17 @@
|
||||
<script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script>
|
||||
<![endif]-->
|
||||
|
||||
<!-- Google Analytics -->
|
||||
<script>
|
||||
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
|
||||
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
|
||||
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
|
||||
})(window,document,'script','//www.google-analytics.com/analytics.js','ga');
|
||||
|
||||
ga('create', 'UA-74711362-1', 'auto');
|
||||
ga('send', 'pageview');
|
||||
</script>
|
||||
<!-- /Google Analytics -->
|
||||
|
||||
|
||||
</head>
|
||||
@ -39,7 +52,7 @@
|
||||
<div class="container">
|
||||
<div class="header-nav">
|
||||
<div class="header-logo">
|
||||
<a class="pull-left" href="/"><img class="mr20" src="/images/logo.svg" alt="logo">Bradlee Speice</a>
|
||||
<a class="pull-left" href="https://bspeice.github.io/"><img class="mr20" src="https://bspeice.github.io/images/logo.svg" alt="logo">Bradlee Speice</a>
|
||||
</div>
|
||||
<div class="nav pull-right">
|
||||
</div>
|
||||
@ -54,12 +67,12 @@
|
||||
<div class="col-lg-12">
|
||||
<div class="header-content">
|
||||
<h1 class="header-title">A Rustic Re-Podcasting Server (Part 1)</h1>
|
||||
<p class="header-date"> <a href="/author/bradlee-speice.html">Bradlee Speice</a>, Sat 22 October 2016, <a href="/category/blog.html">Blog</a></p>
|
||||
<p class="header-date"> <a href="https://bspeice.github.io/author/bradlee-speice.html">Bradlee Speice</a>, Sat 22 October 2016, <a href="https://bspeice.github.io/category/blog.html">Blog</a></p>
|
||||
<div class="header-underline"></div>
|
||||
<div class="clearfix"></div>
|
||||
<p class="pull-right header-tags">
|
||||
<span class="glyphicon glyphicon-tags mr5" aria-hidden="true"></span>
|
||||
<a href="/tag/nutone.html">nutone</a>, <a href="/tag/rust.html">Rust</a> </p>
|
||||
<a href="https://bspeice.github.io/tag/nutone.html">nutone</a>, <a href="https://bspeice.github.io/tag/rust.html">Rust</a> </p>
|
||||
</div>
|
||||
</div>
|
||||
</div>
|
||||
@ -115,15 +128,15 @@ on some bad cases, <code>str <-> bytes</code> specifically), but Rust is h
|
||||
should be incredibly simple: All I want is to echo back
|
||||
<code>Didn't find URL: <url></code>. Shouldn't be that hard right? In Python I'd just do
|
||||
something like:</p>
|
||||
<div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">echo_handler</span><span class="p">(</span><span class="n">request</span><span class="p">):</span>
|
||||
<div class="highlight"><pre><span class="k">def</span> <span class="nf">echo_handler</span><span class="p">(</span><span class="n">request</span><span class="p">):</span>
|
||||
<span class="k">return</span> <span class="s2">"You're visiting: {}"</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="n">request</span><span class="o">.</span><span class="n">uri</span><span class="p">)</span>
|
||||
</pre></div>
|
||||
|
||||
|
||||
<p>And we'd call it a day. Rust isn't so simple. Let's start with the trivial
|
||||
examples people post online:</p>
|
||||
<div class="highlight"><pre><span></span><span class="k">fn</span> <span class="nf">hello_world</span><span class="p">(</span><span class="n">req</span>: <span class="kp">&</span><span class="nc">mut</span><span class="w"> </span><span class="n">Request</span><span class="p">)</span><span class="w"> </span>-> <span class="nc">IronResult</span><span class="o"><</span><span class="n">Response</span><span class="o">></span><span class="w"> </span><span class="p">{</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="nb">Ok</span><span class="p">(</span><span class="n">Response</span>::<span class="n">with</span><span class="p">((</span><span class="n">status</span>::<span class="nb">Ok</span><span class="p">,</span><span class="w"> </span><span class="s">"You found the server!"</span><span class="p">)))</span><span class="w"></span>
|
||||
<div class="highlight"><pre><span class="k">fn</span><span class="w"> </span><span class="n">hello_world</span><span class="p">(</span><span class="n">req</span><span class="o">:</span><span class="w"> </span><span class="o">&</span><span class="k">mut</span><span class="w"> </span><span class="n">Request</span><span class="p">)</span><span class="w"> </span><span class="o">-></span><span class="w"> </span><span class="n">IronResult</span><span class="o"><</span><span class="n">Response</span><span class="o">></span><span class="w"> </span><span class="p">{</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="nb">Ok</span><span class="p">(</span><span class="n">Response</span><span class="o">::</span><span class="n">with</span><span class="p">((</span><span class="n">status</span><span class="o">::</span><span class="nb">Ok</span><span class="p">,</span><span class="w"> </span><span class="s">"You found the server!"</span><span class="p">)))</span><span class="w"></span>
|
||||
<span class="p">}</span><span class="w"></span>
|
||||
</pre></div>
|
||||
|
||||
@ -132,22 +145,22 @@ examples people post online:</p>
|
||||
version! All we need to do is just send back a string of some form. So, we
|
||||
look up the documentation for <a href="http://ironframework.io/doc/iron/request/struct.Request.html"><code>Request</code></a> and see a <code>url</code> field that will contain
|
||||
what we want. Let's try the first iteration:</p>
|
||||
<div class="highlight"><pre><span></span><span class="k">fn</span> <span class="nf">hello_world</span><span class="p">(</span><span class="n">req</span>: <span class="kp">&</span><span class="nc">mut</span><span class="w"> </span><span class="n">Request</span><span class="p">)</span><span class="w"> </span>-> <span class="nc">IronResult</span><span class="o"><</span><span class="n">Response</span><span class="o">></span><span class="w"> </span><span class="p">{</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="nb">Ok</span><span class="p">(</span><span class="n">Response</span>::<span class="n">with</span><span class="p">((</span><span class="n">status</span>::<span class="nb">Ok</span><span class="p">,</span><span class="w"> </span><span class="s">"You found the URL: "</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">req</span><span class="p">.</span><span class="n">url</span><span class="p">)))</span><span class="w"></span>
|
||||
<div class="highlight"><pre><span class="k">fn</span><span class="w"> </span><span class="n">hello_world</span><span class="p">(</span><span class="n">req</span><span class="o">:</span><span class="w"> </span><span class="o">&</span><span class="k">mut</span><span class="w"> </span><span class="n">Request</span><span class="p">)</span><span class="w"> </span><span class="o">-></span><span class="w"> </span><span class="n">IronResult</span><span class="o"><</span><span class="n">Response</span><span class="o">></span><span class="w"> </span><span class="p">{</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="nb">Ok</span><span class="p">(</span><span class="n">Response</span><span class="o">::</span><span class="n">with</span><span class="p">((</span><span class="n">status</span><span class="o">::</span><span class="nb">Ok</span><span class="p">,</span><span class="w"> </span><span class="s">"You found the URL: "</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">req</span><span class="p">.</span><span class="n">url</span><span class="p">)))</span><span class="w"></span>
|
||||
<span class="p">}</span><span class="w"></span>
|
||||
</pre></div>
|
||||
|
||||
|
||||
<p>Which yields the error:</p>
|
||||
<div class="highlight"><pre><span></span>error[E0369]: binary operation `+` cannot be applied to type `&'static str`
|
||||
<div class="highlight"><pre>error[E0369]: binary operation `+` cannot be applied to type `&'static str`
|
||||
</pre></div>
|
||||
|
||||
|
||||
<p>OK, what's going on here? Time to start Googling for <a href="https://www.google.com/#q=concatenate+strings+in+rust">"concatenate strings in Rust"</a>. That's what we
|
||||
want to do right? Concatenate a static string and the URL.</p>
|
||||
<p>After Googling, we come across a helpful <a href="https://doc.rust-lang.org/std/macro.concat!.html"><code>concat!</code></a> macro that looks really nice! Let's try that one:</p>
|
||||
<div class="highlight"><pre><span></span><span class="k">fn</span> <span class="nf">hello_world</span><span class="p">(</span><span class="n">req</span>: <span class="kp">&</span><span class="nc">mut</span><span class="w"> </span><span class="n">Request</span><span class="p">)</span><span class="w"> </span>-> <span class="nc">IronResult</span><span class="o"><</span><span class="n">Response</span><span class="o">></span><span class="w"> </span><span class="p">{</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="nb">Ok</span><span class="p">(</span><span class="n">Response</span>::<span class="n">with</span><span class="p">((</span><span class="n">status</span>::<span class="nb">Ok</span><span class="p">,</span><span class="w"> </span><span class="n">concat</span><span class="o">!</span><span class="p">(</span><span class="s">"You found the URL: "</span><span class="p">,</span><span class="w"> </span><span class="n">req</span><span class="p">.</span><span class="n">url</span><span class="p">))))</span><span class="w"></span>
|
||||
<div class="highlight"><pre><span class="k">fn</span><span class="w"> </span><span class="n">hello_world</span><span class="p">(</span><span class="n">req</span><span class="o">:</span><span class="w"> </span><span class="o">&</span><span class="k">mut</span><span class="w"> </span><span class="n">Request</span><span class="p">)</span><span class="w"> </span><span class="o">-></span><span class="w"> </span><span class="n">IronResult</span><span class="o"><</span><span class="n">Response</span><span class="o">></span><span class="w"> </span><span class="p">{</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="nb">Ok</span><span class="p">(</span><span class="n">Response</span><span class="o">::</span><span class="n">with</span><span class="p">((</span><span class="n">status</span><span class="o">::</span><span class="nb">Ok</span><span class="p">,</span><span class="w"> </span><span class="n">concat</span><span class="o">!</span><span class="p">(</span><span class="s">"You found the URL: "</span><span class="p">,</span><span class="w"> </span><span class="n">req</span><span class="p">.</span><span class="n">url</span><span class="p">))))</span><span class="w"></span>
|
||||
<span class="p">}</span><span class="w"></span>
|
||||
</pre></div>
|
||||
|
||||
@ -159,8 +172,8 @@ at compile time what <code>req.url</code> is. Which, in my outsider opinion, is
|
||||
strange. <code>println!</code> and <code>format!</code>, etc., all handle values they don't know at
|
||||
compile time. Why can't <code>concat!</code>? By any means, we need a new plan of attack.
|
||||
How about we try formatting strings?</p>
|
||||
<div class="highlight"><pre><span></span><span class="k">fn</span> <span class="nf">hello_world</span><span class="p">(</span><span class="n">req</span>: <span class="kp">&</span><span class="nc">mut</span><span class="w"> </span><span class="n">Request</span><span class="p">)</span><span class="w"> </span>-> <span class="nc">IronResult</span><span class="o"><</span><span class="n">Response</span><span class="o">></span><span class="w"> </span><span class="p">{</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="nb">Ok</span><span class="p">(</span><span class="n">Response</span>::<span class="n">with</span><span class="p">((</span><span class="n">status</span>::<span class="nb">Ok</span><span class="p">,</span><span class="w"> </span><span class="n">format</span><span class="o">!</span><span class="p">(</span><span class="s">"You found the URL: {}"</span><span class="p">,</span><span class="w"> </span><span class="n">req</span><span class="p">.</span><span class="n">url</span><span class="p">))))</span><span class="w"></span>
|
||||
<div class="highlight"><pre><span class="k">fn</span><span class="w"> </span><span class="n">hello_world</span><span class="p">(</span><span class="n">req</span><span class="o">:</span><span class="w"> </span><span class="o">&</span><span class="k">mut</span><span class="w"> </span><span class="n">Request</span><span class="p">)</span><span class="w"> </span><span class="o">-></span><span class="w"> </span><span class="n">IronResult</span><span class="o"><</span><span class="n">Response</span><span class="o">></span><span class="w"> </span><span class="p">{</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="nb">Ok</span><span class="p">(</span><span class="n">Response</span><span class="o">::</span><span class="n">with</span><span class="p">((</span><span class="n">status</span><span class="o">::</span><span class="nb">Ok</span><span class="p">,</span><span class="w"> </span><span class="n">format</span><span class="o">!</span><span class="p">(</span><span class="s">"You found the URL: {}"</span><span class="p">,</span><span class="w"> </span><span class="n">req</span><span class="p">.</span><span class="n">url</span><span class="p">))))</span><span class="w"></span>
|
||||
<span class="p">}</span><span class="w"></span>
|
||||
</pre></div>
|
||||
|
||||
@ -191,9 +204,9 @@ working on things that are a bit more complex?</p>
|
||||
<p>We're going to cover that here. Our first try: creating a function which returns
|
||||
other functions. This is a principle called <a href="http://stackoverflow.com/a/36321/1454178">currying</a>. We set up a function that allows us to keep some data in scope
|
||||
for another function to come later.</p>
|
||||
<div class="highlight"><pre><span></span><span class="k">fn</span> <span class="nf">build_handler</span><span class="p">(</span><span class="n">message</span>: <span class="nb">String</span><span class="p">)</span><span class="w"> </span>-> <span class="nb">Fn</span><span class="p">(</span><span class="o">&</span><span class="k">mut</span><span class="w"> </span><span class="n">Request</span><span class="p">)</span><span class="w"> </span>-> <span class="nc">IronResult</span><span class="o"><</span><span class="n">Response</span><span class="o">></span><span class="w"> </span><span class="p">{</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="k">move</span><span class="w"> </span><span class="o">|</span><span class="n">_</span>: <span class="kp">&</span><span class="nc">mut</span><span class="w"> </span><span class="n">Request</span><span class="o">|</span><span class="w"> </span><span class="p">{</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="nb">Ok</span><span class="p">(</span><span class="n">Response</span>::<span class="n">with</span><span class="p">((</span><span class="n">status</span>::<span class="nb">Ok</span><span class="p">,</span><span class="w"> </span><span class="n">message</span><span class="p">)))</span><span class="w"></span>
|
||||
<div class="highlight"><pre><span class="k">fn</span><span class="w"> </span><span class="n">build_handler</span><span class="p">(</span><span class="n">message</span><span class="o">:</span><span class="w"> </span><span class="nb">String</span><span class="p">)</span><span class="w"> </span><span class="o">-></span><span class="w"> </span><span class="nb">Fn</span><span class="p">(</span><span class="o">&</span><span class="k">mut</span><span class="w"> </span><span class="n">Request</span><span class="p">)</span><span class="w"> </span><span class="o">-></span><span class="w"> </span><span class="n">IronResult</span><span class="o"><</span><span class="n">Response</span><span class="o">></span><span class="w"> </span><span class="p">{</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="n">move</span><span class="w"> </span><span class="o">|</span><span class="n">_</span><span class="o">:</span><span class="w"> </span><span class="o">&</span><span class="k">mut</span><span class="w"> </span><span class="n">Request</span><span class="o">|</span><span class="w"> </span><span class="p">{</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="nb">Ok</span><span class="p">(</span><span class="n">Response</span><span class="o">::</span><span class="n">with</span><span class="p">((</span><span class="n">status</span><span class="o">::</span><span class="nb">Ok</span><span class="p">,</span><span class="w"> </span><span class="n">message</span><span class="p">)))</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="p">}</span><span class="w"></span>
|
||||
<span class="p">}</span><span class="w"></span>
|
||||
</pre></div>
|
||||
@ -202,7 +215,7 @@ for another function to come later.</p>
|
||||
<p>We've simply set up a function that returns another anonymous function with the
|
||||
<code>message</code> parameter scoped in. If you compile this, you get not 1, not 2, but 5
|
||||
new errors. 4 of them are the same though:</p>
|
||||
<div class="highlight"><pre><span></span>error[E0277]: the trait bound `for<'r, 'r, 'r> std::ops::Fn(&'r mut iron::Request<'r, 'r>) -> std::result::Result<iron::Response, iron::IronError> + 'static: std::marker::Sized` is not satisfied
|
||||
<div class="highlight"><pre>error[E0277]: the trait bound `for<'r, 'r, 'r> std::ops::Fn(&'r mut iron::Request<'r, 'r>) -> std::result::Result<iron::Response, iron::IronError> + 'static: std::marker::Sized` is not satisfied
|
||||
</pre></div>
|
||||
|
||||
|
||||
@ -230,19 +243,19 @@ we've been working with so far.</p>
|
||||
<p>The principle is that we need to define a new <code>struct</code> to hold our data, then
|
||||
implement that <code>handle()</code> method to return the result. Something that looks
|
||||
like this might do:</p>
|
||||
<div class="highlight"><pre><span></span><span class="k">struct</span> <span class="nc">EchoHandler</span><span class="w"> </span><span class="p">{</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="n">message</span>: <span class="nb">String</span>
|
||||
<div class="highlight"><pre><span class="k">struct</span><span class="w"> </span><span class="n">EchoHandler</span><span class="w"> </span><span class="p">{</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="n">message</span><span class="o">:</span><span class="w"> </span><span class="nb">String</span><span class="w"></span>
|
||||
<span class="p">}</span><span class="w"></span>
|
||||
|
||||
<span class="k">impl</span><span class="w"> </span><span class="n">Handler</span><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="n">EchoHandler</span><span class="w"> </span><span class="p">{</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="k">fn</span> <span class="nf">handle</span><span class="p">(</span><span class="o">&</span><span class="bp">self</span><span class="p">,</span><span class="w"> </span><span class="n">_</span>: <span class="kp">&</span><span class="nc">mut</span><span class="w"> </span><span class="n">Request</span><span class="p">)</span><span class="w"> </span>-> <span class="nc">IronResult</span><span class="o"><</span><span class="n">Response</span><span class="o">></span><span class="w"> </span><span class="p">{</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="nb">Ok</span><span class="p">(</span><span class="n">Response</span>::<span class="n">with</span><span class="p">((</span><span class="n">status</span>::<span class="nb">Ok</span><span class="p">,</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">message</span><span class="p">)))</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">handle</span><span class="p">(</span><span class="o">&</span><span class="bp">self</span><span class="p">,</span><span class="w"> </span><span class="n">_</span><span class="o">:</span><span class="w"> </span><span class="o">&</span><span class="k">mut</span><span class="w"> </span><span class="n">Request</span><span class="p">)</span><span class="w"> </span><span class="o">-></span><span class="w"> </span><span class="n">IronResult</span><span class="o"><</span><span class="n">Response</span><span class="o">></span><span class="w"> </span><span class="p">{</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="nb">Ok</span><span class="p">(</span><span class="n">Response</span><span class="o">::</span><span class="n">with</span><span class="p">((</span><span class="n">status</span><span class="o">::</span><span class="nb">Ok</span><span class="p">,</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">message</span><span class="p">)))</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="p">}</span><span class="w"></span>
|
||||
<span class="p">}</span><span class="w"></span>
|
||||
|
||||
<span class="c1">// Later in the code when we set up the router...</span>
|
||||
<span class="kd">let</span><span class="w"> </span><span class="n">echo</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">EchoHandler</span><span class="w"> </span><span class="p">{</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="n">message</span>: <span class="s">"Is it working yet?"</span><span class="w"></span>
|
||||
<span class="w"> </span><span class="n">message</span><span class="o">:</span><span class="w"> </span><span class="s">"Is it working yet?"</span><span class="w"></span>
|
||||
<span class="p">}</span><span class="w"></span>
|
||||
<span class="n">router</span><span class="p">.</span><span class="n">get</span><span class="p">(</span><span class="s">"/"</span><span class="p">,</span><span class="w"> </span><span class="n">echo</span><span class="p">.</span><span class="n">handle</span><span class="p">,</span><span class="w"> </span><span class="s">"index"</span><span class="p">);</span><span class="w"></span>
|
||||
</pre></div>
|
||||
@ -251,38 +264,38 @@ like this might do:</p>
|
||||
<p>We attempt to build a struct, and give its <code>handle</code> method off to the router
|
||||
so the router knows what to do.</p>
|
||||
<p>You guessed it, more errors:</p>
|
||||
<div class="highlight"><pre><span></span><span class="n">error</span><span class="o">:</span> <span class="n">attempted</span> <span class="n">to</span> <span class="n">take</span> <span class="n">value</span> <span class="n">of</span> <span class="n">method</span> <span class="err">`</span><span class="n">handle</span><span class="err">`</span> <span class="n">on</span> <span class="n">type</span> <span class="err">`</span><span class="n">EchoHandler</span><span class="err">`</span>
|
||||
<div class="highlight"><pre><span class="n">error</span><span class="o">:</span> <span class="n">attempted</span> <span class="n">to</span> <span class="n">take</span> <span class="n">value</span> <span class="n">of</span> <span class="n">method</span> <span class="err">`</span><span class="n">handle</span><span class="err">`</span> <span class="n">on</span> <span class="n">type</span> <span class="err">`</span><span class="n">EchoHandler</span><span class="err">`</span>
|
||||
</pre></div>
|
||||
|
||||
|
||||
<p>Now, the Rust compiler is actually a really nice fellow, and offers us help:</p>
|
||||
<div class="highlight"><pre><span></span><span class="n">help</span><span class="o">:</span> <span class="n">maybe</span> <span class="n">a</span> <span class="err">`</span><span class="o">()</span><span class="err">`</span> <span class="n">to</span> <span class="n">call</span> <span class="n">it</span> <span class="k">is</span> <span class="n">missing</span><span class="o">?</span> <span class="n">If</span> <span class="n">not</span><span class="o">,</span> <span class="k">try</span> <span class="n">an</span> <span class="n">anonymous</span> <span class="kd">function</span>
|
||||
<div class="highlight"><pre><span class="n">help</span><span class="o">:</span> <span class="n">maybe</span> <span class="n">a</span> <span class="err">`</span><span class="o">()</span><span class="err">`</span> <span class="n">to</span> <span class="n">call</span> <span class="n">it</span> <span class="k">is</span> <span class="n">missing</span><span class="o">?</span> <span class="n">If</span> <span class="n">not</span><span class="o">,</span> <span class="k">try</span> <span class="n">an</span> <span class="n">anonymous</span> <span class="kd">function</span>
|
||||
</pre></div>
|
||||
|
||||
|
||||
<p>We definitely don't want to call that function, so maybe try an anonymous
|
||||
function as it recommends?</p>
|
||||
<div class="highlight"><pre><span></span><span class="n">router</span><span class="p">.</span><span class="n">get</span><span class="p">(</span><span class="s">"/"</span><span class="p">,</span><span class="w"> </span><span class="o">|</span><span class="n">req</span>: <span class="kp">&</span><span class="nc">mut</span><span class="w"> </span><span class="n">Request</span><span class="o">|</span><span class="w"> </span><span class="n">echo</span><span class="p">.</span><span class="n">handle</span><span class="p">(</span><span class="n">req</span><span class="p">),</span><span class="w"> </span><span class="s">"index"</span><span class="p">);</span><span class="w"></span>
|
||||
<div class="highlight"><pre><span class="n">router</span><span class="p">.</span><span class="n">get</span><span class="p">(</span><span class="s">"/"</span><span class="p">,</span><span class="w"> </span><span class="o">|</span><span class="n">req</span><span class="o">:</span><span class="w"> </span><span class="o">&</span><span class="k">mut</span><span class="w"> </span><span class="n">Request</span><span class="o">|</span><span class="w"> </span><span class="n">echo</span><span class="p">.</span><span class="n">handle</span><span class="p">(</span><span class="n">req</span><span class="p">),</span><span class="w"> </span><span class="s">"index"</span><span class="p">);</span><span class="w"></span>
|
||||
</pre></div>
|
||||
|
||||
|
||||
<p>Another error:</p>
|
||||
<div class="highlight"><pre><span></span>error[E0373]: closure may outlive the current function, but it borrows `echo`, which is owned by the current function
|
||||
<div class="highlight"><pre>error[E0373]: closure may outlive the current function, but it borrows `echo`, which is owned by the current function
|
||||
</pre></div>
|
||||
|
||||
|
||||
<p>Another helpful message:</p>
|
||||
<div class="highlight"><pre><span></span><span class="n">help</span><span class="o">:</span> <span class="n">to</span> <span class="n">force</span> <span class="n">the</span> <span class="n">closure</span> <span class="n">to</span> <span class="n">take</span> <span class="n">ownership</span> <span class="n">of</span> <span class="err">`</span><span class="n">echo</span><span class="err">`</span> <span class="o">(</span><span class="n">and</span> <span class="n">any</span> <span class="n">other</span> <span class="n">referenced</span> <span class="n">variables</span><span class="o">),</span> <span class="n">use</span> <span class="n">the</span> <span class="err">`</span><span class="n">move</span><span class="err">`</span> <span class="n">keyword</span>
|
||||
<div class="highlight"><pre><span class="n">help</span><span class="o">:</span> <span class="n">to</span> <span class="n">force</span> <span class="n">the</span> <span class="n">closure</span> <span class="n">to</span> <span class="n">take</span> <span class="n">ownership</span> <span class="n">of</span> <span class="err">`</span><span class="n">echo</span><span class="err">`</span> <span class="o">(</span><span class="n">and</span> <span class="n">any</span> <span class="n">other</span> <span class="n">referenced</span> <span class="n">variables</span><span class="o">),</span> <span class="n">use</span> <span class="n">the</span> <span class="err">`</span><span class="n">move</span><span class="err">`</span> <span class="n">keyword</span>
|
||||
</pre></div>
|
||||
|
||||
|
||||
<p>We're getting closer though! Let's implement this change:</p>
|
||||
<div class="highlight"><pre><span></span><span class="n">router</span><span class="p">.</span><span class="n">get</span><span class="p">(</span><span class="s">"/"</span><span class="p">,</span><span class="w"> </span><span class="k">move</span><span class="w"> </span><span class="o">|</span><span class="n">req</span>: <span class="kp">&</span><span class="nc">mut</span><span class="w"> </span><span class="n">Request</span><span class="o">|</span><span class="w"> </span><span class="n">echo</span><span class="p">.</span><span class="n">handle</span><span class="p">(</span><span class="n">req</span><span class="p">),</span><span class="w"> </span><span class="s">"index"</span><span class="p">);</span><span class="w"></span>
|
||||
<div class="highlight"><pre><span class="n">router</span><span class="p">.</span><span class="n">get</span><span class="p">(</span><span class="s">"/"</span><span class="p">,</span><span class="w"> </span><span class="n">move</span><span class="w"> </span><span class="o">|</span><span class="n">req</span><span class="o">:</span><span class="w"> </span><span class="o">&</span><span class="k">mut</span><span class="w"> </span><span class="n">Request</span><span class="o">|</span><span class="w"> </span><span class="n">echo</span><span class="p">.</span><span class="n">handle</span><span class="p">(</span><span class="n">req</span><span class="p">),</span><span class="w"> </span><span class="s">"index"</span><span class="p">);</span><span class="w"></span>
|
||||
</pre></div>
|
||||
|
||||
|
||||
<p>And here's where things get strange:</p>
|
||||
<div class="highlight"><pre><span></span>error[E0507]: cannot move out of borrowed content
|
||||
<div class="highlight"><pre>error[E0507]: cannot move out of borrowed content
|
||||
--> src/main.rs:18:40
|
||||
|
|
||||
18 | Ok(Response::with((status::Ok, self.message)))
|
||||
@ -307,7 +320,7 @@ instead of transferring ownership</li>
|
||||
audience out. Because <code>iron</code> won't accept a reference, we are forced into the
|
||||
second option: making a copy. To do so, we just need to change the function
|
||||
to look like this:</p>
|
||||
<div class="highlight"><pre><span></span><span class="nb">Ok</span><span class="p">(</span><span class="n">Response</span>::<span class="n">with</span><span class="p">((</span><span class="n">status</span>::<span class="nb">Ok</span><span class="p">,</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">message</span><span class="p">.</span><span class="n">clone</span><span class="p">())))</span><span class="w"></span>
|
||||
<div class="highlight"><pre><span class="nb">Ok</span><span class="p">(</span><span class="n">Response</span><span class="o">::</span><span class="n">with</span><span class="p">((</span><span class="n">status</span><span class="o">::</span><span class="nb">Ok</span><span class="p">,</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">message</span><span class="p">.</span><span class="n">clone</span><span class="p">())))</span><span class="w"></span>
|
||||
</pre></div>
|
||||
|
||||
|
||||
@ -343,6 +356,20 @@ incredibly precise about how I use it.</p>
|
||||
going to take me a lot longer to do this than I originally thought.</p>
|
||||
|
||||
|
||||
<div class="comments">
|
||||
<div id="disqus_thread"></div>
|
||||
<script type="text/javascript">
|
||||
var disqus_shortname = 'bradleespeice';
|
||||
var disqus_identifier = 'a-rustic-re-podcasting-server-part-1.html';
|
||||
var disqus_url = 'https://bspeice.github.io/a-rustic-re-podcasting-server-part-1.html';
|
||||
(function() {
|
||||
var dsq = document.createElement('script'); dsq.type = 'text/javascript'; dsq.async = true;
|
||||
dsq.src = '//' + disqus_shortname + '.disqus.com/embed.js';
|
||||
(document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(dsq);
|
||||
})();
|
||||
</script>
|
||||
<noscript>Please enable JavaScript to view the comments.</noscript>
|
||||
</div>
|
||||
|
||||
</div>
|
||||
<!-- /Content -->
|
||||
@ -354,6 +381,7 @@ going to take me a lot longer to do this than I originally thought.</p>
|
||||
<div class="col-xs-4 col-sm-3 col-md-3 col-lg-3">
|
||||
<div class="footer-title"></div>
|
||||
<ul class="list-unstyled">
|
||||
<li><a href="https://bspeice.github.io/feeds/all.atom.xml" type="application/atom+xml" rel="alternate"></a></li>
|
||||
</ul>
|
||||
</div>
|
||||
<div class="col-xs-4 col-sm-3 col-md-3 col-lg-3">
|
||||
|
||||
Reference in New Issue
Block a user