--- /dev/null
+<?php
+
+/*
+ * This file is part of the Behat.
+ * (c) Konstantin Kudryashov <ever.zet@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Behat\Behat\Transformation\Transformer;
+
+use Behat\Behat\Definition\Call\DefinitionCall;
+
+/**
+ * Transforms a single argument value.
+ *
+ * @author Konstantin Kudryashov <ever.zet@gmail.com>
+ */
+interface ArgumentTransformer
+{
+ /**
+ * Checks if transformer supports argument.
+ *
+ * @param DefinitionCall $definitionCall
+ * @param integer|string $argumentIndex
+ * @param mixed $argumentValue
+ *
+ * @return Boolean
+ */
+ public function supportsDefinitionAndArgument(DefinitionCall $definitionCall, $argumentIndex, $argumentValue);
+
+ /**
+ * Transforms argument value using transformation and returns a new one.
+ *
+ * @param DefinitionCall $definitionCall
+ * @param integer|string $argumentIndex
+ * @param mixed $argumentValue
+ *
+ * @return mixed
+ */
+ public function transformArgument(DefinitionCall $definitionCall, $argumentIndex, $argumentValue);
+}