--- /dev/null
+<?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\XPath;
+
+/**
+ * XPath expression translator interface.
+ *
+ * This component is a port of the Python cssselect library,
+ * which is copyright Ian Bicking, @see https://github.com/SimonSapin/cssselect.
+ *
+ * @author Jean-François Simon <jeanfrancois.simon@sensiolabs.com>
+ *
+ * @internal
+ */
+class XPathExpr
+{
+ /**
+ * @var string
+ */
+ private $path;
+
+ /**
+ * @var string
+ */
+ private $element;
+
+ /**
+ * @var string
+ */
+ private $condition;
+
+ /**
+ * @param string $path
+ * @param string $element
+ * @param string $condition
+ * @param bool $starPrefix
+ */
+ public function __construct($path = '', $element = '*', $condition = '', $starPrefix = false)
+ {
+ $this->path = $path;
+ $this->element = $element;
+ $this->condition = $condition;
+
+ if ($starPrefix) {
+ $this->addStarPrefix();
+ }
+ }
+
+ /**
+ * @return string
+ */
+ public function getElement()
+ {
+ return $this->element;
+ }
+
+ /**
+ * @param $condition
+ *
+ * @return $this
+ */
+ public function addCondition($condition)
+ {
+ $this->condition = $this->condition ? sprintf('%s and (%s)', $this->condition, $condition) : $condition;
+
+ return $this;
+ }
+
+ /**
+ * @return string
+ */
+ public function getCondition()
+ {
+ return $this->condition;
+ }
+
+ /**
+ * @return $this
+ */
+ public function addNameTest()
+ {
+ if ('*' !== $this->element) {
+ $this->addCondition('name() = '.Translator::getXpathLiteral($this->element));
+ $this->element = '*';
+ }
+
+ return $this;
+ }
+
+ /**
+ * @return $this
+ */
+ public function addStarPrefix()
+ {
+ $this->path .= '*/';
+
+ return $this;
+ }
+
+ /**
+ * Joins another XPathExpr with a combiner.
+ *
+ * @param string $combiner
+ * @param XPathExpr $expr
+ *
+ * @return $this
+ */
+ public function join($combiner, XPathExpr $expr)
+ {
+ $path = $this->__toString().$combiner;
+
+ if ('*/' !== $expr->path) {
+ $path .= $expr->path;
+ }
+
+ $this->path = $path;
+ $this->element = $expr->element;
+ $this->condition = $expr->condition;
+
+ return $this;
+ }
+
+ /**
+ * @return string
+ */
+ public function __toString()
+ {
+ $path = $this->path.$this->element;
+ $condition = null === $this->condition || '' === $this->condition ? '' : '['.$this->condition.']';
+
+ return $path.$condition;
+ }
+}