Merge pull request #7 from dc-ag/mb/early-traversal-termination

Mb/early traversal termination
dc-ag · Jan 25, 2022 · 8c072eb · 8c072eb
2 parents 15169f5 + b824734
commit 8c072eb
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Showing 3 changed files with 77 additions and 1 deletion.
diff --git a/src/EarlyTraversalTerminationException.php b/src/EarlyTraversalTerminationException.php
@@ -0,0 +1,8 @@
+<?php
+declare(strict_types=1);
+
+namespace TreeNodes;
+
+use Exception;
+
+class EarlyTraversalTerminationException extends Exception {}
diff --git a/src/GenericTreeNodeVisitor.php b/src/GenericTreeNodeVisitor.php
@@ -38,6 +38,7 @@ public function visitPreOrder(?SortableTreeNode $node, bool $atRoot = true): voi
         }
         ($this->visitorCallable)($node);
         $this->visitPreOrder($leftmostChild, false);
+
         if (!$atRoot) {
             $this->visitPreOrder($node->getRightSibling(), false);
         }
@@ -67,6 +68,7 @@ public function visitPostOrder(?SortableTreeNode $node, bool $atRoot = true): vo
         if (!$atRoot) {
             $this->visitPostOrder($node->getRightSibling(), false);
         }
+
     }
 
             /**
@@ -88,7 +90,6 @@ public function visitLevelOrder(?SortableTreeNode $node, bool $atRoot = true): v
         $collectNextLevelNodes = static function(SortableTreeNode $treeNode) use (&$nextLevelNodes) { 
              $nextLevelNodes = [...$nextLevelNodes, ...$treeNode->getChildren()];
         };
-
         do {
             while (!empty($currlevelNodes)) {
                 $currNode = \array_shift($currlevelNodes);
@@ -98,5 +99,6 @@ public function visitLevelOrder(?SortableTreeNode $node, bool $atRoot = true): v
             $currlevelNodes = $nextLevelNodes;
             $nextLevelNodes = [];
         } while (!empty($currlevelNodes));
+
     }
 }
diff --git a/tests/Unit/GenericTreeNodeVisitorTest.php b/tests/Unit/GenericTreeNodeVisitorTest.php
@@ -11,6 +11,7 @@
 use TreeNodes\TreeNodeVisitor;
 use TreeNodes\GenericTreeNodeVisitor;
 use TreeNodes\SortableTreeNode;
+use TreeNodes\EarlyTraversalTerminationException;
 
 final class GenericTreeNodeVisitorTest extends TestCase
 {
@@ -105,4 +106,69 @@ public function testVisitLevelOrder(): void
         $errMsg = 'Expected order: [' . $expectedOrder . '] - actual order [' . $this->orderString . '].';
         $this->assertEquals($expectedOrder, $this->orderString, $errMsg);
     }
+
+
+    public function testEarlyPreOrderTraversalTermination(): void
+    {
+        $sortableTreeNode = $this->demoTree;
+        $this->orderString = "";
+        $expectedOrder = "root, 1, 2, 2.1";
+        $visitFn = function(SortableTreeNode $treeNode) {
+            $separator = '' === $this->orderString ? '' : ', ';
+            $id = $treeNode->getId();
+            $this->orderString .= $separator . $id;
+            if ('2.1' === $id) {
+                throw new EarlyTraversalTerminationException();
+            }
+        };
+        $visitor = new GenericTreeNodeVisitor($visitFn);
+        try {
+            $visitor->visitPreOrder($sortableTreeNode);
+        } catch (EarlyTraversalTerminationException) {}
+        $errMsg = 'Expected order: [' . $expectedOrder . '] - actual order [' . $this->orderString . '].';
+        $this->assertEquals($expectedOrder, $this->orderString, $errMsg);
+    }
+
+    public function testEarlyPostOrderTraversalTermination(): void
+    {
+        $sortableTreeNode = $this->demoTree;
+        $this->orderString = "";
+        $expectedOrder = "1, 2.1.1, 2.1.2, 2.1";
+        $visitFn = function(SortableTreeNode $treeNode) {
+            $separator = '' === $this->orderString ? '' : ', ';
+            $id = $treeNode->getId();
+            $this->orderString .= $separator . $id;
+            if ('2.1' === $id) {
+                throw new EarlyTraversalTerminationException();
+            }
+        };
+        $visitor = new GenericTreeNodeVisitor($visitFn);
+        try {
+            $visitor->visitPostOrder($sortableTreeNode);
+        } catch (EarlyTraversalTerminationException) {}
+
+        $errMsg = 'Expected order: [' . $expectedOrder . '] - actual order [' . $this->orderString . '].';
+        $this->assertEquals($expectedOrder, $this->orderString, $errMsg);
+    }
+
+    public function testEarlyLevelOrderTraversalTermination(): void
+    {
+        $sortableTreeNode = $this->demoTree;
+        $this->orderString = "";
+        $expectedOrder = "root, 1, 2, 3, 4, 5, 2.1";
+        $visitFn = function(SortableTreeNode $treeNode) {
+            $separator = '' === $this->orderString ? '' : ', ';
+            $id = $treeNode->getId();
+            $this->orderString .= $separator . $id;
+            if ('2.1' === $id) {
+                throw new EarlyTraversalTerminationException();
+            }
+        };
+        $visitor = new GenericTreeNodeVisitor($visitFn);
+        try {
+            $visitor->visitLevelOrder($sortableTreeNode);
+        } catch (EarlyTraversalTerminationException) {}
+        $errMsg = 'Expected order: [' . $expectedOrder . '] - actual order [' . $this->orderString . '].';
+        $this->assertEquals($expectedOrder, $this->orderString, $errMsg);
+    }
 }