X-Git-Url: http://git.polytechnique.org/?a=blobdiff_plain;f=classes%2Fpliteratorutils.php;h=875aac70cd4707747e4d1a3c5f71d61d69db66fc;hb=504647c51aac2a34a4c3f11f33cc4fa6eecdb64f;hp=a77244b50fc101504cc74ecaf77f32908cfe10b1;hpb=c291ca5486bce705cd3dfd81065cbd2d92b96da5;p=platal.git

diff --git a/classes/pliteratorutils.php b/classes/pliteratorutils.php
index a77244b..875aac7 100644
--- a/classes/pliteratorutils.php
+++ b/classes/pliteratorutils.php
@@ -135,6 +135,13 @@ class PlIteratorUtils
         $callback = new _GetObjectPropertyCallback($property);
         return array($callback, 'get');
     }
+
+    /** Returns a wrapper around the PlIterator suitable for foreach() iterations
+     */
+    public static function foreachIterator(PlIterator $iterator)
+    {
+        return new SPLIterator($iterator);
+    }
 }
 
 /** Empty iterator
@@ -665,7 +672,8 @@ class PlParallelIterator implements PlIterator
     private $master_id;
     private $master;
 
-    private $stepped;
+    private $over = array();
+    private $stepped = array();
     private $current_elts = array();
     private $callback_res = array();
 
@@ -689,6 +697,7 @@ class PlParallelIterator implements PlIterator
 
         foreach ($this->ids as $id) {
             $this->stepped[$id] = false;
+            $this->over[$id] = false;
             $this->current_elts[$id] = null;
             $this->callback_res[$id] = null;
         }
@@ -700,12 +709,24 @@ class PlParallelIterator implements PlIterator
             return;
         }
 
+        // Don't do anything if the iterator is at its end
+        if ($this->over[$id]) {
+            $this->stepped[$id] = true;
+            return;
+        }
+
         $it = $this->iterators[$id];
         $nxt = $it->next();
+        $this->stepped[$id] = true;
+        if ($nxt === null) {
+            $this->over[$id] = true;
+            $this->current_elts[$id] = null;
+            $this->callback_res[$id] = null;
+            return;
+        }
         $res = call_user_func($this->callbacks[$id], $nxt);
         $this->current_elts[$id] = $nxt;
         $this->callback_res[$id] = $res;
-        $this->stepped[$id] = true;
     }
 
     private function stepAll()
@@ -718,7 +739,7 @@ class PlParallelIterator implements PlIterator
     public function next()
     {
         $this->stepAll();
-        if ($this->current_elts[$this->master_id] == null) {
+        if ($this->current_elts[$this->master_id] === null) {
             return null;
         }
 
@@ -789,5 +810,48 @@ class _GetObjectPropertyCallback
     }
 }
 
+// Wrapper class to build a SPL iterator from a PlIterator
+class SPLIterator implements Iterator
+{
+    private $it;
+    private $pos;
+    private $value;
+
+    public function __construct(PlIterator $it)
+    {
+        $this->it = $it;
+        $this->pos = 0;
+        $this->value = $this->it->next();
+    }
+
+    public function rewind()
+    {
+        if ($this->pos != 0) {
+            throw new Exception("Rewind not supported on this iterator");
+        }
+    }
+
+    public function current()
+    {
+        return $this->value;
+    }
+
+    public function key()
+    {
+        return $this->pos;
+    }
+
+    public function next()
+    {
+        ++$this->pos;
+        $this->value = $this->it->next();
+    }
+
+    public function valid()
+    {
+        return !!$this->value;
+    }
+}
+
 // vim:set et sw=4 sts=4 sws=4 foldmethod=marker enc=utf-8:
 ?>