Simplified processing nested events to a single pass.

src/Events/Recursive_Event_Iterator.php

@@ -8,39 +8,30 @@ class Recursive_Event_Iterator extends \ArrayIterator implements \RecursiveItera
 
 	public function __construct( array $events, $flags = 0 ) {
 
+		usort( $events, [ $this, 'sort_origin' ] );
+		$end = 0;
+
 		foreach ( $events as $key => $event ) {
 
-			foreach ( $events as $check_key => $check_event ) {
-
-				if ( $check_key <= $key ) {
-					continue;
-				}
-
-				if ( $this->overlaps( $event, $check_event ) ) {
-
-					unset( $events[ $check_key ] );
-					$this->children[] = $check_event;
-				}
-
+			if ( $event['origin'] < $end ) {
+				unset( $events[ $key ] );
+				$this->children[] = $event;
+				continue;
 			}
+
+			$end = $event['origin'] + $event['duration'];
 		}
 
 		parent::__construct( $events, $flags );
 	}
 
-	/**
-	 * @param array $event_a
-	 * @param array $event_b
-	 *
-	 * @return bool True if event B starts after A and before it finishes.
-	 */
-	protected function overlaps( $event_a, $event_b ) {
+	protected function sort_origin( $event_a, $event_b ) {
 
-		if ( $event_a['origin'] > $event_b['origin'] ) {
-			return false;
+		if ( $event_a['origin'] === $event_b['origin'] ) {
+			return 0;
 		}
 
-		return $event_b['origin'] < ( $event_a['origin'] + $event_a['duration'] );
+		return ( $event_a['origin'] < $event_b['origin'] ) ? - 1 : 1;
 	}
 
 	public function hasChildren() {