Allow closure as parameter for duplicates()

Author: aimeos

README.md

@@ -1902,7 +1902,7 @@ Returns the duplicate values from the map.
 public function duplicates( string $col = null ) : self
 ```
 
-* @param **string|null** `$col` Key of the nested array or object to check for
+* @param **\Closure|string|null** `$col` Key, path of the nested array or anonymous function with ($item, $key) parameters returning the value for comparison
 * @return **self<int|string,mixed>** New map
 
 For nested arrays, you have to pass the name of the column of the nested array which
@@ -1925,7 +1925,10 @@ Map::from( [['p' => '1'], ['p' => 1], ['p' => 2]] )->duplicates( 'p' )
 // [1 => ['p' => 1]]
 
 Map::from( [['i' => ['p' => '1']], ['i' => ['p' => 1]]] )->duplicates( 'i/p' )
-// [1 => ['i' => ['p' => '1']]]
+// [1 => ['i' => ['p' => 1]]]
+
+Map::from( [['i' => ['p' => '1']], ['i' => ['p' => 1]]] )->unique( fn( $item, $key ) => $item['i']['p'] );
+// [1 => ['i' => ['p' => 1]]]
 ```
 
 **See also:**

src/Map.php

@@ -1360,11 +1360,13 @@ public function dump( ?callable $callback = null ) : self
 	 *  Map::from( [1, 2, '1', 3] )->duplicates()
 	 *  Map::from( [['p' => '1'], ['p' => 1], ['p' => 2]] )->duplicates( 'p' )
 	 *  Map::from( [['i' => ['p' => '1']], ['i' => ['p' => 1]]] )->duplicates( 'i/p' )
+	 *  Map::from( [['i' => ['p' => '1']], ['i' => ['p' => 1]]] )->duplicates( fn( $item, $key ) => $item['i']['p'] )
 	 *
 	 * Results:
 	 *  [2 => '1']
 	 *  [1 => ['p' => 1]]
-	 *  [1 => ['i' => ['p' => '1']]]
+	 *  [1 => ['i' => ['p' => 1]]]
+	 *  [1 => ['i' => ['p' => 1]]]
 	 *
 	 * This does also work for multi-dimensional arrays by passing the keys
 	 * of the arrays separated by the delimiter ("/" by default), e.g. "key1/key2/key3"
@@ -1373,13 +1375,27 @@ public function dump( ?callable $callback = null ) : self
 	 *
 	 * The keys are preserved using this method.
 	 *
-	 * @param string|null $key Key or path of the nested array or object to check for
+	 * @param \Closure|string|null $col Key, path of the nested array or anonymous function with ($item, $key) parameters returning the value for comparison
 	 * @return self<int|string,mixed> New map
 	 */
-	public function duplicates( ?string $key = null ) : self
+	public function duplicates( $col = null ) : self
 	{
-		$list = $this->list();
-		$items = ( $key !== null ? $this->col( $key )->toArray() : $list );
+		$items = $list = $this->list();
+
+		if( $col instanceof \Closure )
+		{
+			$items = [];
+
+			foreach( $this->list() as $key => $item )
+			{
+				$value = (string) $col( $item, $key );
+				$items[$key] = $value;
+			}
+		}
+		elseif( $col !== null )
+		{
+			$items = $this->col( $col )->toArray();
+		}
 
 		return new static( array_diff_key( $list, array_unique( $items ) ) );
 	}

tests/MapTest.php

@@ -733,6 +733,16 @@ public function testDuplicatesPath()
 	}
 
 
+	public function testDuplicatesClosure()
+	{
+		$m = new Map( [['i' => ['p' => '1']], ['i' => ['p' => 1]]] );
+		$r = $m->duplicates( fn( $item, $key ) => $item['i']['p'] );
+
+		$this->assertInstanceOf( Map::class, $r );
+		$this->assertSame( [1 => ['i' => ['p' => 1]]], $r->toArray() );
+	}
+
+
 	public function testEach()
 	{
 		$m = new Map( $original = [1, 2, 'foo' => 'bar', 'bam' => 'baz'] );