Add repeat() (#193)

Author: phanan

composer.json

@@ -92,6 +92,7 @@
             "src/Functional/ReduceRight.php",
             "src/Functional/Reindex.php",
             "src/Functional/Reject.php",
+            "src/Functional/Repeat.php",
             "src/Functional/Retry.php",
             "src/Functional/Select.php",
             "src/Functional/SelectKeys.php",

docs/functional-php.md

@@ -65,6 +65,7 @@
   - [const_function()](#const_function)
   - [id()](#id)
   - [tap()](#tap)
+  - [repeat()](#repeat)
 
 <!-- END doctoc generated TOC please keep comment here to allow auto update -->
 
@@ -1024,7 +1025,7 @@ just a shortcut to `compare_on` as it composes the given key function with `spl_
 # Miscellaneous
 
 ## concat()
-Concatenates zero or more strings
+Concatenates zero or more strings.
 
 ```php
 <?php
@@ -1034,7 +1035,7 @@ $fooBar = concat('foo', 'bar');
 ```
 
 ## const_function()
-Returns new function, that will constantly return its first argument (constant function)
+Returns a new function that will constantly return its first argument.
 
 ```php
 <?php
@@ -1046,7 +1047,7 @@ $one(); // -> 1
 
 
 ## id()
-Proxy function, that do nothing, except returning its first argument
+Proxy function that does nothing except returning its first argument.
 
 ```php
 <?php
@@ -1058,7 +1059,7 @@ use function Functional\id;
 ## tap()
 ``mixed tap(mixed $value, callable $callback)``
 
-Call the given Closure with the given value, then return the value.
+Calls the given Closure with the given value, then returns the value.
 
 ```php
 <?php 
@@ -1068,3 +1069,14 @@ tap(User::create('John Doe'), function (User $user) {
 })->login();
 ```
 
+## repeat()
+
+Creates and returns a function that can be used to execute the given closure multiple times.
+
+```php
+<?php
+use function Functional\repeat;
+repeat(function () {
+    echo 'foo';
+})(3); // 'foofoofoo'
+``` 

src/Functional/Functional.php

@@ -349,6 +349,11 @@ final class Functional
      */
     const reject = '\Functional\reject';
 
+    /**
+     * @see \Functional\repeat
+     */
+    const repeat = '\Functional\repeat';
+
     /**
      * @see \Functional\retry
      */

src/Functional/Repeat.php

@@ -0,0 +1,44 @@
+<?php
+/**
+ * Copyright (C) 2011-2017 by Lars Strojny <lstrojny@php.net>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+namespace Functional;
+
+use Closure;
+use Functional\Exceptions\InvalidArgumentException;
+
+/**
+ * Creates a function that can be used to repeat the execution of $callback.
+ *
+ * @param callable $callback
+ *
+ * @return Closure
+ */
+function repeat(callable $callback)
+{
+    return function ($times) use ($callback) {
+        InvalidArgumentException::assertPositiveInteger($times, __FUNCTION__, 1);
+
+        for ($i = 0; $i < $times; $i++) {
+            $callback();
+        }
+    };
+}

tests/Functional/RepeatTest.php

@@ -0,0 +1,65 @@
+<?php
+/**
+ * Copyright (C) 2011-2017 by Lars Strojny <lstrojny@php.net>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the 'Software'), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+namespace Functional\Tests;
+
+use Functional\Exceptions\InvalidArgumentException;
+use function Functional\repeat;
+use PHPUnit\Framework\MockObject\MockObject;
+
+class Repeated
+{
+    public function foo()
+    {
+    }
+}
+
+class RepeatTest extends AbstractTestCase
+{
+    /** @var Repeated|MockObject */
+    private $repeated;
+
+    public function setUp()
+    {
+        parent::setUp();
+        $this->repeated = $this->createMock(Repeated::class);
+    }
+
+    public function test()
+    {
+        $this->repeated
+            ->expects($this->exactly(10))
+            ->method('foo');
+
+        repeat([$this->repeated, 'foo'])(10);
+    }
+
+    public function testNegativeRepeatedTimes()
+    {
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionMessage(
+            'Functional\{closure}() expects parameter 1 to be positive integer, negative integer given'
+        );
+
+        repeat([$this->repeated, 'foo'])(-1);
+    }
+}