vendor/symfony/src/Symfony/Component/CssSelector/TokenStream.php
changeset 0 7f95f8617b0b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/vendor/symfony/src/Symfony/Component/CssSelector/TokenStream.php	Sat Sep 24 15:40:41 2011 +0200
@@ -0,0 +1,105 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\CssSelector;
+
+/**
+ * TokenStream represents a stream of CSS Selector tokens.
+ *
+ * This component is a port of the Python lxml library,
+ * which is copyright Infrae and distributed under the BSD license.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class TokenStream
+{
+    private $used;
+    private $tokens;
+    private $source;
+    private $peeked;
+    private $peeking;
+
+    /**
+     * Constructor.
+     *
+     * @param array $tokens The tokens that make the stream.
+     * @param mixed $source The source of the stream.
+     */
+    public function __construct($tokens, $source = null)
+    {
+        $this->used = array();
+        $this->tokens = $tokens;
+        $this->source = $source;
+        $this->peeked = null;
+        $this->peeking = false;
+    }
+
+    /**
+     * Gets the tokens that have already been visited in this stream.
+     *
+     * @return array
+     */
+    public function getUsed()
+    {
+        return $this->used;
+    }
+
+    /**
+     * Gets the next token in the stream or null if there is none.
+     * Note that if this stream was set to be peeking its behavior
+     * will be restored to not peeking after this operation.
+     *
+     * @return mixed
+     */
+    public function next()
+    {
+        if ($this->peeking) {
+            $this->peeking = false;
+            $this->used[] = $this->peeked;
+
+            return $this->peeked;
+        }
+
+        if (!count($this->tokens)) {
+            return null;
+        }
+
+        $next = array_shift($this->tokens);
+        $this->used[] = $next;
+
+        return $next;
+    }
+
+    /**
+     * Peeks for the next token in this stream. This means that the next token
+     * will be returned but it won't be considered as used (visited) until the
+     * next() method is invoked.
+     * If there are no remaining tokens null will be returned.
+     *
+     * @see next()
+     *
+     * @return mixed
+     */
+    public function peek()
+    {
+        if (!$this->peeking) {
+            if (!count($this->tokens)) {
+                return null;
+            }
+
+            $this->peeked = array_shift($this->tokens);
+
+            $this->peeking = true;
+        }
+
+        return $this->peeked;
+    }
+}