chain() supports both static and OO-style calls

test/ChainingTest.php

@@ -26,15 +26,21 @@ public function testMapFlattenReduce() {
   }
 
   public function testSelectRejectSortBy() {
+    // from js
+    $numbers = array(1,2,3,4,5,6,7,8,9,10);
+    $numbers = __($numbers)->chain()
+                           ->select(function($n) { return $n % 2 === 0; })
+                           ->reject(function($n) { return $n % 4 === 0; })
+                           ->sortBy(function($n) { return -$n; })
+                           ->value();
+    $this->assertEquals(array(10, 6, 2), $numbers, 'filtered and reversed the numbers in OO-style call');
+
     $numbers = array(1,2,3,4,5,6,7,8,9,10);
-    $numbers = __($numbers)->chain()->select(function($n) {
-      return $n % 2 === 0;
-    })->reject(function($n) {
-      return $n % 4 === 0;
-    })->sortBy(function($n) {
-      return -$n;
-    })->value();
-    $this->assertEquals(array(10, 6, 2), $numbers, 'filtered and reversed the numbers');
+    $numbers = __::chain($numbers)->select(function($n) { return $n % 2 === 0; })
+                                  ->reject(function($n) { return $n % 4 === 0; })
+                                  ->sortBy(function($n) { return -$n; })
+                                  ->value();
+    $this->assertEquals(array(10, 6, 2), $numbers, 'filtered and reversed the numbers in static call');
   }
 
   public function testChain() {

underscore.php

@@ -20,9 +20,12 @@ class __ {
 
   // Start the chain
   private $_chained = false; // Are we in a chain?
-  public function chain() {
-    $this->_chained = true;
-    return $this;
+  public function chain($item=null) {
+    list($item) = self::_wrapArgs(func_get_args(), 1);
+
+    $__ = (isset($this) && isset($this->_chained) && $this->_chained) ? $this : __($item);
+    $__->_chained = true;
+    return $__;
   }