+ php 8.0 support

+ ArrayList extended with `collect` and `collectToString` methods

composer.json

@@ -25,16 +25,18 @@
         }
     ],
     "autoload": {
-        "psr-4": {"Seboettg\\Collection\\": "src/"}
+        "psr-4": {"Seboettg\\Collection\\": "src/"},
+        "files": [
+            "src/ArrayList/Functions.php"
+        ]
     },
     "autoload-dev": {
         "psr-4": {"Seboettg\\Collection\\Test\\": "tests/"}
     },
     "require": {
-        "php": ">=7.1"
+        "php": ">=7.3"
     },
     "require-dev": {
-        "phpunit/phpunit": "6.5.*",
-        "satooshi/php-coveralls": "2.*"
+        "phpunit/phpunit": "8.5.*"
     }
 }

src/ArrayList/ArrayListInterface.php

@@ -184,4 +184,24 @@ public function map(callable $mapFunction): ArrayListInterface;
      * @return ArrayListInterface
      */
     public function flatten(): ArrayListInterface;
+
+    /**
+     * Expects a callable function which collects the elements of this list and returns any object. The callable
+     * function gets passed the entire array of the list
+     *
+     * @param callable $collectionFunction
+     * @return mixed
+     */
+    public function collect(callable $collectionFunction);
+
+    /**
+     * Tries to convert each element of the list to a string and concatenates them with given delimiter.
+     * Throws a <code>NotConvertibleToStringException</code> if any of the objects in the list is not a string or is not
+     * convertible to string.
+     *
+     * @param string $delimiter
+     * @throws NotConvertibleToStringException
+     * @return string
+     */
+    public function collectToString(string $delimiter): string;
 }

src/ArrayList/ArrayListTrait.php

@@ -11,6 +11,8 @@
 
 namespace Seboettg\Collection\ArrayList;
 
+use function Seboettg\Collection\ArrayList\strval;
+
 /**
  * Trait ArrayListTrait
  * @package Seboettg\Collection
@@ -251,4 +253,36 @@ public function merge(ArrayListInterface $list): void
     {
         $this->array = array_merge($this->array, $list->toArray());
     }
+
+    /**
+     * @inheritDoc
+     * @param callable $collectFunction
+     * @return mixed
+     */
+    public function collect(callable $collectFunction)
+    {
+        return $collectFunction($this->array);
+    }
+
+    /**
+     * @inheritDoc
+     * @param string $delimiter
+     * @return string
+     */
+    public function collectToString(string $delimiter): string
+    {
+        return implode($delimiter, $this->map(function ($item) {
+            if (is_scalar($item)) {
+                return strval($item);
+            } else if (is_object($item)) {
+                if (method_exists($item, "toString")) {
+                    return $item->toString();
+                }
+            }
+            throw new NotConvertibleToStringException(
+                "Couldn't collectToString since any object in list contains objects which are not " .
+                "convertible to string.");
+        })->toArray());
+    }
 }
+

src/ArrayList/Functions.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace Seboettg\Collection\ArrayList;
+
+final class Functions
+{
+
+    public static function strval($value): string {
+        if (is_double($value)) {
+            $str = \strval($value);
+            if (strlen($str) == 1) {
+                return sprintf("%1\$.1f",$value);
+            }
+            return \strval($value);
+        }
+        if (is_bool($value)) {
+            return $value ? "true" : "false";
+        }
+        return "$value";
+    }
+}
+
+function strval($value): string {
+    return Functions::strval($value);
+}

src/ArrayList/NotConvertibleToStringException.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace Seboettg\Collection\ArrayList;
+
+use Exception;
+
+class NotConvertibleToStringException extends Exception
+{
+
+}

tests/ArrayListTest.php

@@ -16,6 +16,9 @@
 use Seboettg\Collection\Collections;
 use Seboettg\Collection\Comparable\Comparable;
 use Seboettg\Collection\Comparable\Comparator;
+use Seboettg\Collection\Stack;
+
+use function Seboettg\Collection\ArrayList\strval;
 
 class ArrayListTest extends TestCase
 {
@@ -31,7 +34,7 @@ class ArrayListTest extends TestCase
     private $hashMap;
 
 
-    public function setUp()
+    public function setUp(): void
     {
         $this->numeratedArrayList = new ArrayList(
             new Element("a", "aa"),
@@ -323,6 +326,43 @@ public function testMerge()
         $this->assertEquals(count($array), $first->count());
         $this->assertEquals($first->toArray(), $array);
     }
+
+    public function testCollect()
+    {
+        $arrayList = new ArrayList('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h');
+        /** @var Stack $stack */
+        $stack = $arrayList
+            ->collect(function(array $list) {
+                $result = new Stack();
+                foreach ($list as $item) {
+                    $result->push($item);
+                }
+                return $result;
+            });
+        $this->assertEquals(8, $stack->count());
+        $this->assertTrue('h' == $stack->pop());
+    }
+
+    public function testCollectToString()
+    {
+        $arrayList = new ArrayList('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h');
+        $result = $arrayList->collectToString(", ");
+        $this->assertEquals("a, b, c, d, e, f, g, h", $result);
+    }
+
+    public function testCollectToStringWithDoubleValues()
+    {
+        $arrayList = new ArrayList(1.0, 1.1, 1.2, 1.3);
+        $result = $arrayList->collectToString("; ");
+        $this->assertEquals("1.0; 1.1; 1.2; 1.3", $result);
+    }
+
+    public function testCollectToStringWithToStringObjects()
+    {
+        $arrayList = new ArrayList(new StringableObject(2), new StringableObject(3.1), new StringableObject(true));
+        $result = $arrayList->collectToString("; ");
+        $this->assertEquals("2; 3.1; true", $result);
+    }
 }
 
 class Element implements Comparable
@@ -391,3 +431,23 @@ public function compareTo(Comparable $b): int
         return strcmp($this->attr1, $b->getAttr1());
     }
 }
+
+class StringableObject {
+    private $value;
+    public function __construct($value)
+    {
+        $this->value = $value;
+    }
+    public function setValue($value) {
+        $this->value = $value;
+    }
+    public function getValue($value) {
+        return $value;
+    }
+    public function toString(): string {
+        return strval($this->value);
+    }
+    public function __toString(): string {
+        return $this->toString();
+    }
+}