Implemented initial handling of arbitrary nesting events.

See #11

src/Events/Recursive_Event_Iterator.php

@@ -0,0 +1,55 @@
+<?php
+
+namespace Rarst\Laps\Events;
+
+class Recursive_Event_Iterator extends \RecursiveArrayIterator {
+
+	protected $children = [];
+
+	public function __construct( array $events, $flags = 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;
+				}
+
+			}
+		}
+
+		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 ) {
+
+		if ( $event_a['origin'] > $event_b['origin'] ) {
+			return false;
+		}
+
+		return $event_b['origin'] < ( $event_a['origin'] + $event_a['duration'] );
+	}
+
+	public function hasChildren() {
+
+		return ! empty( $this->children );
+	}
+
+	public function getChildren() {
+
+		return new static( $this->children );
+	}
+}