Merge pull request #21 from fusonic/generator_support

Generator support

Author: davidroth

src/Fusonic/Linq/Helper/LinqHelper.php

@@ -43,13 +43,20 @@ public static function assertArgumentIsIterable($param, $argumentName)
         }
     }
 
+    public static function assertValueIsIterable($param)
+    {
+        if (!self::isIterable($param)) {
+            throw new \UnexpectedValueException("Value must be an array, or implement either the \IteratorAggregate or \Iterator interface");
+        }
+    }
+
     public static function getIteratorOrThrow($value)
     {
         if (is_array($value)) {
             return new ArrayIterator($value);
         }
         else if($value instanceof \IteratorAggregate) {
-            return $value->getIterator();
+            return $value;
         }
         else if($value instanceof \Iterator) {
             return $value;

src/Fusonic/Linq/Helper/Set.php

@@ -0,0 +1,79 @@
+<?php
+/*
+ * This file is part of Fusonic-linq.
+ * https://github.com/fusonic/fusonic-linq
+ *
+ * (c) Fusonic GmbH
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Fusonic\Linq\Helper;
+
+
+class Set
+{
+    private $objects = array();
+
+    /**
+     * If the value is not in the set, it will be added and true is returned. otherwise false is returned.
+     * @return bool
+     */
+    public function add($value)
+    {
+        return !$this->find($value, true);
+    }
+
+    /**
+     * If the value is in the set, it will be removed and true is returned. otherwise false is returned.
+     * @param $value
+     * @return bool
+     */
+    public function remove($value)
+    {
+        $hash = self::hash($value);
+        if(array_key_exists($hash, $this->objects)) {
+            unset($this->objects[$hash]);
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Returns true if the value exist in the set. Otherwise false.
+     * @return bool
+     */
+    public function contains($value)
+    {
+        $hash = self::hash($value);
+        return array_key_exists($hash, $this->objects);
+    }
+
+    // Finds the given value and returns true if it was found. Otherwise return false.
+    private function find($value, $add = false)
+    {
+        $hash = self::hash($value);
+        if(array_key_exists($hash, $this->objects)) {
+            return true;
+        }
+        else if($add) {
+            $this->objects[$hash] = $value;
+        }
+        return false;
+    }
+
+    private static function hash($value)
+    {
+        if (is_object($value)) {
+            return spl_object_hash($value);
+        } elseif (is_scalar($value)) {
+            return "s_$value";
+        } elseif (is_array($value)) {
+            return 'a_' . md5(json_encode($value));
+        } else if($value === null) {
+            return null;
+        }
+        else throw new \InvalidArgumentException("Value type is not supported.");
+    }
+}

src/Fusonic/Linq/Iterator/ChunkIterator.php

@@ -13,84 +13,38 @@
 namespace Fusonic\Linq\Iterator;
 
 use Fusonic\Linq\Linq;
-use Iterator;
+use Traversable;
 
 /**
  * Iterates over an iterator, returning Linq objects of the given chunk size.
  */
-class ChunkIterator implements Iterator
+class ChunkIterator implements \IteratorAggregate
 {
-    /**
-     * @var Iterator
-     */
     private $iterator;
-
-    /**
-     * @var array
-     */
-    private $chunk;
-
-    /**
-     * @var int
-     */
-    private $i = 0;
-
-    /**
-     * @var int
-     */
     private $chunkSize;
 
-    public function __construct(Iterator $iterator, $chunkSize)
+    public function __construct(Traversable $iterator, $chunkSize)
     {
         $this->iterator = $iterator;
         $this->chunkSize = $chunkSize;
     }
 
-    /**
-     * @return Linq
-     */
-    public function current()
-    {
-        return new Linq($this->chunk);
-    }
-
-    public function next()
-    {
-        $this->iterator->next();
-        $this->chunk = $this->getNextChunk();
-        $this->i++;
-    }
-
-    private function getNextChunk()
+    public function getIterator()
     {
         $chunk = [];
-        while ($this->iterator->valid()) {
-            $chunk[] = $this->iterator->current();
-
-            if (count($chunk) < $this->chunkSize) {
-                $this->iterator->next();
-            } else {
-                break;
+        $current = 0;
+        foreach ($this->iterator as $d) {
+            $current++;
+            $chunk[] = $d;
+
+            if ($current >= $this->chunkSize) {
+                yield Linq::from($chunk);
+                $chunk = [];
+                $current = 0;
             }
         }
-
-        return $chunk;
-    }
-
-    public function key()
-    {
-        return $this->i;
-    }
-
-    public function valid()
-    {
-        return !empty($this->chunk);
-    }
-
-    public function rewind()
-    {
-        $this->iterator->rewind();
-        $this->i = 0;
-        $this->chunk = $this->getNextChunk();
+        if(count($chunk) > 0) {
+            yield Linq::from($chunk);
+        }
     }
-}
+}

src/Fusonic/Linq/Iterator/DistinctIterator.php

@@ -12,51 +12,25 @@
 
 namespace Fusonic\Linq\Iterator;
 
-use Iterator;
+use Fusonic\Linq\Helper\Set;
+use Traversable;
 
-class DistinctIterator extends \IteratorIterator
+final class DistinctIterator implements \IteratorAggregate
 {
     private $iterator;
-    private $distinct;
 
-    public function __construct(Iterator $iterator)
+    public function __construct(Traversable $iterator)
     {
         $this->iterator = $iterator;
     }
 
-    public function current()
+    public function getIterator()
     {
-        return $this->distinct->current();
-    }
-
-    public function next()
-    {
-        $this->distinct->next();
-    }
-
-    public function key()
-    {
-        return $this->distinct->key();
-    }
-
-    public function valid()
-    {
-        return $this->distinct->valid();
-    }
-
-    public function rewind()
-    {
-        if ($this->distinct === null) {
-            $this->getDistincts();
+        $set = new Set();
+        foreach($this->iterator as $value) {
+            if($set->add($value)) {
+                yield $value;
+            }
         }
-
-        $this->distinct->rewind();
-    }
-
-    private function getDistincts()
-    {
-        $data = iterator_to_array($this->iterator);
-        $distinct = array_unique($data);
-        $this->distinct = new \ArrayIterator($distinct);
     }
-}
+}

src/Fusonic/Linq/Iterator/ExceptIterator.php

@@ -12,54 +12,30 @@
 
 namespace Fusonic\Linq\Iterator;
 
-use ArrayIterator;
-use Iterator;
+use Fusonic\Linq\Helper\Set;
+use Traversable;
 
-class ExceptIterator implements Iterator
+final class ExceptIterator implements \IteratorAggregate
 {
     private $first;
     private $second;
-    private $result;
 
-    public function __construct(Iterator $first, Iterator $second)
+    public function __construct(Traversable $first, Traversable $second)
     {
         $this->first = $first;
         $this->second = $second;
     }
 
-    public function current()
+    public function getIterator()
     {
-        return $this->result->current();
-    }
-
-    public function next()
-    {
-        $this->result->next();
-    }
-
-    public function key()
-    {
-        return $this->result->key();
-    }
-
-    public function valid()
-    {
-        return $this->result->valid();
-    }
-
-    public function rewind()
-    {
-        if ($this->result === null) {
-            $this->getResult();
+        $set = new Set();
+        foreach($this->second as $second) {
+            $set->add($second);
+        }
+        foreach($this->first as $first) {
+            if(!$set->contains($first)) {
+                yield $first;
+            }
         }
-
-        $this->result->rewind();
-    }
-
-    private function getResult()
-    {
-        $firstArray = iterator_to_array($this->first);
-        $secondArray = iterator_to_array($this->second);
-        $this->result = new ArrayIterator(array_diff($firstArray, $secondArray));
     }
-}
+}