分页类增加each方法

library/think/Paginator.php

@@ -273,6 +273,23 @@ abstract class Paginator implements ArrayAccess, Countable, IteratorAggregate, J
         return $this->items->isEmpty();
     }
 
+    /**
+     * 给每个元素执行个回调
+     *
+     * @param  callable $callback
+     * @return $this
+     */
+    public function each(callable $callback)
+    {
+        foreach ($this->items as $key => $item) {
+            if ($callback($item, $key) === false) {
+                break;
+            }
+        }
+
+        return $this;
+    }
+
     /**
      * Retrieve an external iterator
      * @return Traversable An instance of an object implementing <b>Iterator</b> or