yeray/gobyexample
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
gobyexample/public/collection-functions
badkaktus 94b86c03fd link to my project
2019-10-15 15:02:01 +03:00

381 lines
21 KiB
Plaintext
Generated
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Go в примерах: Функции коллекции (Collection Functions)</title>
<link rel=stylesheet href="site.css">
</head>
<script>
onkeydown = (e) => {
if (e.key == "ArrowLeft") {
window.location.href = 'defer';
}
if (e.key == "ArrowRight") {
window.location.href = 'string-functions';
}
}
</script>
<body>
<div class="example" id="collection-functions">
<h2><a href="./">Go в примерах</a>: Функции коллекции (Collection Functions)</h2>
<table>
<tr>
<td class="docs">
<p>Нам часто нужны наши программы для выполнения операций
с коллекциями данных, таких как выбор всех элементов,
которые удовлетворяют данному предикату, или отображение
всех элементов в новую коллекцию с помощью
пользовательской функции.</p>
</td>
<td class="code empty leading">
</td>
</tr>
<tr>
<td class="docs">
<p>В некоторых языках идиоматично использовать <a href="http://en.wikipedia.org/wiki/Generic_programming">дженерики</a>
и алгоритмы. Go не поддерживает дженерики; в Go, как
правило, предоставляют функции коллекции если они
необходимы конкретно для вашей программы и ваших
типов данных.</p>
</td>
<td class="code empty leading">
</td>
</tr>
<tr>
<td class="docs">
<p>Вот несколько примеров функций коллекции для срезов
со <code>строковыми значениями</code>. Вы можете использовать эти
примеры, чтобы сделать собственные функции. Обратите
внимание, что в некоторых случаях, возможно, было бы
более явным встроить код, манипулирующий коллекциями,
вместо создания создания вспомогательных функций.</p>
</td>
<td class="code empty leading">
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<a href="http://play.golang.org/p/urAoHQtRHro" target="_blank"><img title="Run code" src="play.png" class="run" /></a><img title="Copy code" src="clipboard.png" class="copy" />
<div class="highlight"><pre><span class="kn">package</span> <span class="nx">main</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<div class="highlight"><pre><span class="kn">import</span> <span class="p">(</span>
<span class="s">&quot;fmt&quot;</span>
<span class="s">&quot;strings&quot;</span>
<span class="p">)</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
<p>Возвращает первый индекс совпадения со строкой <code>t</code> или -1
если совпадение не найдено.</p>
</td>
<td class="code leading">
<div class="highlight"><pre><span class="kd">func</span> <span class="nx">Index</span><span class="p">(</span><span class="nx">vs</span> <span class="p">[]</span><span class="kt">string</span><span class="p">,</span> <span class="nx">t</span> <span class="kt">string</span><span class="p">)</span> <span class="kt">int</span> <span class="p">{</span>
<span class="k">for</span> <span class="nx">i</span><span class="p">,</span> <span class="nx">v</span> <span class="o">:=</span> <span class="k">range</span> <span class="nx">vs</span> <span class="p">{</span>
<span class="k">if</span> <span class="nx">v</span> <span class="o">==</span> <span class="nx">t</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">i</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="k">return</span> <span class="o">-</span><span class="mi">1</span>
<span class="p">}</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
<p>Возвращает <code>true</code> если строка <code>t</code> находится в срезе.</p>
</td>
<td class="code leading">
<div class="highlight"><pre><span class="kd">func</span> <span class="nx">Include</span><span class="p">(</span><span class="nx">vs</span> <span class="p">[]</span><span class="kt">string</span><span class="p">,</span> <span class="nx">t</span> <span class="kt">string</span><span class="p">)</span> <span class="kt">bool</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">Index</span><span class="p">(</span><span class="nx">vs</span><span class="p">,</span> <span class="nx">t</span><span class="p">)</span> <span class="o">&gt;=</span> <span class="mi">0</span>
<span class="p">}</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
<p>Возвращает <code>true</code> если одна из строк в срезе
удовлетворяет условию <code>f</code>.</p>
</td>
<td class="code leading">
<div class="highlight"><pre><span class="kd">func</span> <span class="nx">Any</span><span class="p">(</span><span class="nx">vs</span> <span class="p">[]</span><span class="kt">string</span><span class="p">,</span> <span class="nx">f</span> <span class="kd">func</span><span class="p">(</span><span class="kt">string</span><span class="p">)</span> <span class="kt">bool</span><span class="p">)</span> <span class="kt">bool</span> <span class="p">{</span>
<span class="k">for</span> <span class="nx">_</span><span class="p">,</span> <span class="nx">v</span> <span class="o">:=</span> <span class="k">range</span> <span class="nx">vs</span> <span class="p">{</span>
<span class="k">if</span> <span class="nx">f</span><span class="p">(</span><span class="nx">v</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="kc">true</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="k">return</span> <span class="kc">false</span>
<span class="p">}</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
<p>Возвращает <code>true</code> если все из строк в срезе
удовлетворяют условие <code>f</code>.</p>
</td>
<td class="code leading">
<div class="highlight"><pre><span class="kd">func</span> <span class="nx">All</span><span class="p">(</span><span class="nx">vs</span> <span class="p">[]</span><span class="kt">string</span><span class="p">,</span> <span class="nx">f</span> <span class="kd">func</span><span class="p">(</span><span class="kt">string</span><span class="p">)</span> <span class="kt">bool</span><span class="p">)</span> <span class="kt">bool</span> <span class="p">{</span>
<span class="k">for</span> <span class="nx">_</span><span class="p">,</span> <span class="nx">v</span> <span class="o">:=</span> <span class="k">range</span> <span class="nx">vs</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">!</span><span class="nx">f</span><span class="p">(</span><span class="nx">v</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="kc">false</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="k">return</span> <span class="kc">true</span>
<span class="p">}</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
<p>Возвращает новый срез, содержащий все строки в срезе,
которые удовлетворяют условие <code>f</code>.</p>
</td>
<td class="code leading">
<div class="highlight"><pre><span class="kd">func</span> <span class="nx">Filter</span><span class="p">(</span><span class="nx">vs</span> <span class="p">[]</span><span class="kt">string</span><span class="p">,</span> <span class="nx">f</span> <span class="kd">func</span><span class="p">(</span><span class="kt">string</span><span class="p">)</span> <span class="kt">bool</span><span class="p">)</span> <span class="p">[]</span><span class="kt">string</span> <span class="p">{</span>
<span class="nx">vsf</span> <span class="o">:=</span> <span class="nb">make</span><span class="p">([]</span><span class="kt">string</span><span class="p">,</span> <span class="mi">0</span><span class="p">)</span>
<span class="k">for</span> <span class="nx">_</span><span class="p">,</span> <span class="nx">v</span> <span class="o">:=</span> <span class="k">range</span> <span class="nx">vs</span> <span class="p">{</span>
<span class="k">if</span> <span class="nx">f</span><span class="p">(</span><span class="nx">v</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">vsf</span> <span class="p">=</span> <span class="nb">append</span><span class="p">(</span><span class="nx">vsf</span><span class="p">,</span> <span class="nx">v</span><span class="p">)</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="k">return</span> <span class="nx">vsf</span>
<span class="p">}</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
<p>Возвращает новый срез, содержащий результаты выполнения
функции <code>f</code> с каждой строкой исходного слайса.</p>
</td>
<td class="code leading">
<div class="highlight"><pre><span class="kd">func</span> <span class="nx">Map</span><span class="p">(</span><span class="nx">vs</span> <span class="p">[]</span><span class="kt">string</span><span class="p">,</span> <span class="nx">f</span> <span class="kd">func</span><span class="p">(</span><span class="kt">string</span><span class="p">)</span> <span class="kt">string</span><span class="p">)</span> <span class="p">[]</span><span class="kt">string</span> <span class="p">{</span>
<span class="nx">vsm</span> <span class="o">:=</span> <span class="nb">make</span><span class="p">([]</span><span class="kt">string</span><span class="p">,</span> <span class="nb">len</span><span class="p">(</span><span class="nx">vs</span><span class="p">))</span>
<span class="k">for</span> <span class="nx">i</span><span class="p">,</span> <span class="nx">v</span> <span class="o">:=</span> <span class="k">range</span> <span class="nx">vs</span> <span class="p">{</span>
<span class="nx">vsm</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span> <span class="p">=</span> <span class="nx">f</span><span class="p">(</span><span class="nx">v</span><span class="p">)</span>
<span class="p">}</span>
<span class="k">return</span> <span class="nx">vsm</span>
<span class="p">}</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<div class="highlight"><pre><span class="kd">func</span> <span class="nx">main</span><span class="p">()</span> <span class="p">{</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
<p>Здесь мы пробуем различные функции коллекций.</p>
</td>
<td class="code leading">
<div class="highlight"><pre> <span class="kd">var</span> <span class="nx">strs</span> <span class="p">=</span> <span class="p">[]</span><span class="kt">string</span><span class="p">{</span><span class="s">&quot;peach&quot;</span><span class="p">,</span> <span class="s">&quot;apple&quot;</span><span class="p">,</span> <span class="s">&quot;pear&quot;</span><span class="p">,</span> <span class="s">&quot;plum&quot;</span><span class="p">}</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="nx">Index</span><span class="p">(</span><span class="nx">strs</span><span class="p">,</span> <span class="s">&quot;pear&quot;</span><span class="p">))</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="nx">Include</span><span class="p">(</span><span class="nx">strs</span><span class="p">,</span> <span class="s">&quot;grape&quot;</span><span class="p">))</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="nx">Any</span><span class="p">(</span><span class="nx">strs</span><span class="p">,</span> <span class="kd">func</span><span class="p">(</span><span class="nx">v</span> <span class="kt">string</span><span class="p">)</span> <span class="kt">bool</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">strings</span><span class="p">.</span><span class="nx">HasPrefix</span><span class="p">(</span><span class="nx">v</span><span class="p">,</span> <span class="s">&quot;p&quot;</span><span class="p">)</span>
<span class="p">}))</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="nx">All</span><span class="p">(</span><span class="nx">strs</span><span class="p">,</span> <span class="kd">func</span><span class="p">(</span><span class="nx">v</span> <span class="kt">string</span><span class="p">)</span> <span class="kt">bool</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">strings</span><span class="p">.</span><span class="nx">HasPrefix</span><span class="p">(</span><span class="nx">v</span><span class="p">,</span> <span class="s">&quot;p&quot;</span><span class="p">)</span>
<span class="p">}))</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="nx">Filter</span><span class="p">(</span><span class="nx">strs</span><span class="p">,</span> <span class="kd">func</span><span class="p">(</span><span class="nx">v</span> <span class="kt">string</span><span class="p">)</span> <span class="kt">bool</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">strings</span><span class="p">.</span><span class="nx">Contains</span><span class="p">(</span><span class="nx">v</span><span class="p">,</span> <span class="s">&quot;e&quot;</span><span class="p">)</span>
<span class="p">}))</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
<p>Все примеры, приведенные выше, использовали
анонимные функции, но вы можете использовать именные
функции корректного типа.</p>
</td>
<td class="code leading">
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="nx">Map</span><span class="p">(</span><span class="nx">strs</span><span class="p">,</span> <span class="nx">strings</span><span class="p">.</span><span class="nx">ToUpper</span><span class="p">))</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code">
<div class="highlight"><pre><span class="p">}</span>
</pre></div>
</td>
</tr>
</table>
<table>
<tr>
<td class="docs">
</td>
<td class="code">
<div class="highlight"><pre><span class="gp">$</span> go run collection-functions.go
<span class="go">2</span>
<span class="go">false</span>
<span class="go">true</span>
<span class="go">false</span>
<span class="go">[peach apple pear]</span>
<span class="go">[PEACH APPLE PEAR PLUM]</span>
</pre></div>
</td>
</tr>
</table>
<p class="next">
Следующий пример: <a href="string-functions">Строковые функции (String Functions)</a>.
</p>
<p class="footer">
by <a href="https://markmcgranaghan.com">Mark McGranaghan</a> | <a href="https://github.com/mmcgrana/gobyexample/blob/master/examples/collection-functions">source</a> | <a href="https://github.com/mmcgrana/gobyexample#license">license</a>
<br/>
переведено Nick S. | <a href="https://github.com/badkaktus/gobyexample">исходники</a>
</p>
</div>
<script>
var codeLines = [];
codeLines.push('');codeLines.push('');codeLines.push('');codeLines.push('package main\u000A');codeLines.push('import (\u000A \"fmt\"\u000A \"strings\"\u000A)\u000A');codeLines.push('func Index(vs []string, t string) int {\u000A for i, v := range vs {\u000A if v == t {\u000A return i\u000A }\u000A }\u000A return -1\u000A}\u000A');codeLines.push('func Include(vs []string, t string) bool {\u000A return Index(vs, t) \x3E= 0\u000A}\u000A');codeLines.push('func Any(vs []string, f func(string) bool) bool {\u000A for _, v := range vs {\u000A if f(v) {\u000A return true\u000A }\u000A }\u000A return false\u000A}\u000A');codeLines.push('func All(vs []string, f func(string) bool) bool {\u000A for _, v := range vs {\u000A if !f(v) {\u000A return false\u000A }\u000A }\u000A return true\u000A}\u000A');codeLines.push('func Filter(vs []string, f func(string) bool) []string {\u000A vsf := make([]string, 0)\u000A for _, v := range vs {\u000A if f(v) {\u000A vsf = append(vsf, v)\u000A }\u000A }\u000A return vsf\u000A}\u000A');codeLines.push('func Map(vs []string, f func(string) string) []string {\u000A vsm := make([]string, len(vs))\u000A for i, v := range vs {\u000A vsm[i] = f(v)\u000A }\u000A return vsm\u000A}\u000A');codeLines.push('func main() {\u000A');codeLines.push(' var strs = []string{\"peach\", \"apple\", \"pear\", \"plum\"}\u000A');codeLines.push(' fmt.Println(Index(strs, \"pear\"))\u000A');codeLines.push(' fmt.Println(Include(strs, \"grape\"))\u000A');codeLines.push(' fmt.Println(Any(strs, func(v string) bool {\u000A return strings.HasPrefix(v, \"p\")\u000A }))\u000A');codeLines.push(' fmt.Println(All(strs, func(v string) bool {\u000A return strings.HasPrefix(v, \"p\")\u000A }))\u000A');codeLines.push(' fmt.Println(Filter(strs, func(v string) bool {\u000A return strings.Contains(v, \"e\")\u000A }))\u000A');codeLines.push(' fmt.Println(Map(strs, strings.ToUpper))\u000A');codeLines.push('}\u000A');codeLines.push('');
</script>
<script src="site.js" async></script>
</body>
</html>
Reference in New Issue View Git Blame Copy Permalink