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After go1.16, go will use module mode by default, even when the repository is checked out under GOPATH or in a one-off directory. Add go.mod, go.sum to keep this repo buildable without opting out of the module mode. > go mod init github.com/mmcgrana/gobyexample > go mod tidy > go mod vendor In module mode, the 'vendor' directory is special and its contents will be actively maintained by the go command. pygments aren't the dependency the go will know about, so it will delete the contents from vendor directory. Move it to `third_party` directory now. And, vendor the blackfriday package. Note: the tutorial contents are not affected by the change in go1.16 because all the examples in this tutorial ask users to run the go command with the explicit list of files to be compiled (e.g. `go run hello-world.go` or `go build command-line-arguments.go`). When the source list is provided, the go command does not have to compute the build list and whether it's running in GOPATH mode or module mode becomes irrelevant.
161 lines
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161 lines
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<!DOCTYPE html>
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<html>
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<head>
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<meta charset="utf-8">
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<title>Go by Example: Channel Buffering</title>
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<link rel=stylesheet href="site.css">
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</head>
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<script>
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onkeydown = (e) => {
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if (e.key == "ArrowLeft") {
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window.location.href = 'channels';
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}
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if (e.key == "ArrowRight") {
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window.location.href = 'channel-synchronization';
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}
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}
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</script>
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<body>
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<div class="example" id="channel-buffering">
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<h2><a href="./">Go by Example</a>: Channel Buffering</h2>
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<table>
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<tr>
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<td class="docs">
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<p>By default channels are <em>unbuffered</em>, meaning that they
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will only accept sends (<code>chan <-</code>) if there is a
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corresponding receive (<code><- chan</code>) ready to receive the
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sent value. <em>Buffered channels</em> accept a limited
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number of values without a corresponding receiver for
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those values.</p>
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</td>
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<td class="code empty leading">
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</td>
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</tr>
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<tr>
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<td class="docs">
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</td>
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<td class="code leading">
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<a href="http://play.golang.org/p/3BRCdRnRszb"><img title="Run code" src="play.png" class="run" /></a><img title="Copy code" src="clipboard.png" class="copy" />
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<div class="highlight"><pre><span class="kn">package</span> <span class="nx">main</span>
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</pre></div>
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</td>
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</tr>
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<tr>
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<td class="docs">
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</td>
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<td class="code leading">
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<div class="highlight"><pre><span class="kn">import</span> <span class="s">"fmt"</span>
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</pre></div>
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</td>
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</tr>
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<tr>
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<td class="docs">
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</td>
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<td class="code leading">
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<div class="highlight"><pre><span class="kd">func</span> <span class="nx">main</span><span class="p">()</span> <span class="p">{</span>
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</pre></div>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p>Here we <code>make</code> a channel of strings buffering up to
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2 values.</p>
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</td>
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<td class="code leading">
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<div class="highlight"><pre> <span class="nx">messages</span> <span class="o">:=</span> <span class="nb">make</span><span class="p">(</span><span class="kd">chan</span> <span class="kt">string</span><span class="p">,</span> <span class="mi">2</span><span class="p">)</span>
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</pre></div>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p>Because this channel is buffered, we can send these
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values into the channel without a corresponding
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concurrent receive.</p>
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</td>
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<td class="code leading">
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<div class="highlight"><pre> <span class="nx">messages</span> <span class="o"><-</span> <span class="s">"buffered"</span>
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<span class="nx">messages</span> <span class="o"><-</span> <span class="s">"channel"</span>
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</pre></div>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p>Later we can receive these two values as usual.</p>
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</td>
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<td class="code">
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<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="o"><-</span><span class="nx">messages</span><span class="p">)</span>
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<span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="o"><-</span><span class="nx">messages</span><span class="p">)</span>
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<span class="p">}</span>
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</pre></div>
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</td>
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</tr>
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</table>
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<table>
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<tr>
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<td class="docs">
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</td>
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<td class="code">
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<div class="highlight"><pre><span class="gp">$</span> go run channel-buffering.go
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<span class="go">buffered</span>
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<span class="go">channel</span>
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</pre></div>
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</td>
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</tr>
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</table>
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<p class="next">
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Next example: <a href="channel-synchronization">Channel Synchronization</a>.
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</p>
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<p class="footer">
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by <a href="https://markmcgranaghan.com">Mark McGranaghan</a> | <a href="https://github.com/mmcgrana/gobyexample/blob/master/examples/channel-buffering">source</a> | <a href="https://github.com/mmcgrana/gobyexample#license">license</a>
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</p>
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</div>
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<script>
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var codeLines = [];
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codeLines.push('');codeLines.push('package main\u000A');codeLines.push('import \"fmt\"\u000A');codeLines.push('func main() {\u000A');codeLines.push(' messages :\u003D make(chan string, 2)\u000A');codeLines.push(' messages \u003C- \"buffered\"\u000A messages \u003C- \"channel\"\u000A');codeLines.push(' fmt.Println(\u003C-messages)\u000A fmt.Println(\u003C-messages)\u000A}\u000A');codeLines.push('');
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</script>
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<script src="site.js" async></script>
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</body>
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</html>
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