README upd

Author: Smoren

README.md

@@ -13,6 +13,108 @@ Library for working with trees.
 composer require smoren/tree-tools
 ```
 
+## Quick reference
+
+#### Tree Walker
+| Reducer                                           | Description                                | Code Snippet                                                     |
+|---------------------------------------------------|--------------------------------------------|------------------------------------------------------------------|
+| [`traverseDepthFirst`](#Traverse-Depth-First)     | Iterates a tree using depth-first search   | `TreeWalker::traverseDepthFirst($data, $childrenContainerKey)`   |
+| [`traverseBreadthFirst`](#Traverse-Breadth-First) | Iterates a tree using breadth-first search | `TreeWalker::traverseBreadthFirst($data, $childrenContainerKey)` |
+
+## Usage
+
+### Tree Walker
+
+#### Traverse-Depth-First
+
+Iterates a tree like a flat collection using depth-first traversal.
+
+If `$childrenContainerKey` is not null looks for children items using by this key only.
+
+Otherwise, considers any subarray to contain children.
+
+```TreeWalker::traverseDepthFirst(iterable $data, ?string $childrenContainerKey = null): Generator```
+
+```php
+use Smoren\TreeTools\TreeWalker;
+
+$tree = [
+    [
+        'id' => 1,
+        'children' => [
+            ['id' => 11],
+            [
+                'id' => 12,
+                'children' => [
+                    ['id' => 121],
+                    ['id' => 122],
+                ],
+            ],
+        ],
+    ],
+    [
+        'id' => 2,
+        'children' => [
+            ['id' => 21],
+        ],
+    ],
+    ['id' => 3],
+];
+
+$result = [];
+
+foreach(TreeWalker::traverseDepthFirst($tree) as $item) {
+    $result[] = $item['id'];
+}
+var_dump($result);
+// [1, 11, 12, 121, 122, 2, 21, 3]
+```
+
+#### Traverse-Breadth-First
+
+Iterates a tree like a flat collection using depth-breadth traversal.
+
+If `$childrenContainerKey` is not null looks for children items using by this key only.
+
+Otherwise, considers any subarray to contain children.
+
+```TreeWalker::traverseBreadthFirst(iterable $data, ?string $childrenContainerKey = null): Generator```
+
+```php
+use Smoren\TreeTools\TreeWalker;
+
+$tree = [
+    [
+        'id' => 1,
+        'children' => [
+            ['id' => 11],
+            [
+                'id' => 12,
+                'children' => [
+                    ['id' => 121],
+                    ['id' => 122],
+                ],
+            ],
+        ],
+    ],
+    [
+        'id' => 2,
+        'children' => [
+            ['id' => 21],
+        ],
+    ],
+    ['id' => 3],
+];
+
+$result = [];
+
+foreach(TreeWalker::traverseBreadthFirst($tree) as $item) {
+    $result[] = $item['id'];
+}
+var_dump($result);
+// [1, 2, 3, 11, 12, 21, 121, 122]
+```
+
 ## Unit testing
 ```
 composer install

src/TreeWalker.php

@@ -14,7 +14,7 @@
 class TreeWalker
 {
     /**
-     * Iterates a tree like a flat collection using deep traversal.
+     * Iterates a tree like a flat collection using depth-first traversal.
      *
      * If $childrenContainerKey is not null looks for children items using by this key only.
      *
@@ -31,7 +31,7 @@ public static function traverseDepthFirst(iterable $data, ?string $childrenConta
     }
 
     /**
-     * Iterates a tree like a flat collection using wide traversal.
+     * Iterates a tree like a flat collection using breadth-first traversal.
      *
      * If $childrenContainerKey is not null looks for children items using by this key only.
      *