161 lines
5.7 KiB
Plaintext
Generated
161 lines
5.7 KiB
Plaintext
Generated
<!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 в примерах: Перебор значений из каналов (Range over Channels)</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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<body>
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<div class="example" id="range-over-channels">
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<h2><a href="./">Go в примерах</a>: Перебор значений из каналов (Range over Channels)</h2>
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<table>
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<tr>
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<td class="docs">
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<p>В <a href="range">предыдущем</a> примере мы виделе как <code>for</code> и
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<code>range</code> позволяют перебирать базовые структуры. Мы
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так же можем использовать этот синтаксис для чтения
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значений из канала.</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/zbl7ytLnFCK" target="_blank"><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>Мы будем итерировать 2 значения в канале <code>queue</code>.</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">queue</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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<span class="nx">queue</span> <span class="o"><-</span> <span class="s">"one"</span>
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<span class="nx">queue</span> <span class="o"><-</span> <span class="s">"two"</span>
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<span class="nb">close</span><span class="p">(</span><span class="nx">queue</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>Этот <code>range</code> будет перебирать каждый элемент
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полученный из канала <code>queue</code>. Но т.к. мы <code>закрыли</code>
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канал ранее, перебор элементов завершится после
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получения двух элементов.</p>
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</td>
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<td class="code">
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<div class="highlight"><pre> <span class="k">for</span> <span class="nx">elem</span> <span class="o">:=</span> <span class="k">range</span> <span class="nx">queue</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="nx">elem</span><span class="p">)</span>
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<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 leading">
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<div class="highlight"><pre><span class="gp">$</span> go run range-over-channels.go
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<span class="go">one</span>
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<span class="go">two</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>Этот пример так же демонстрирует, что возможно
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прочитать данные из канала уже после его закрытия.</p>
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</td>
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<td class="code empty">
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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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Следующий пример: <a href="timers">Таймеры (Timers)</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/range-over-channels">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(' queue := make(chan string, 2)\u000A queue \x3C- \"one\"\u000A queue \x3C- \"two\"\u000A close(queue)\u000A');codeLines.push(' for elem := range queue {\u000A fmt.Println(elem)\u000A }\u000A}\u000A');codeLines.push('');codeLines.push('');
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</script>
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<script src="site.js" async></script>
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</html>
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