--- /dev/null
+<?php
+/**
+ * Markdown - A text-to-HTML conversion tool for web writers
+ *
+ * @package php-markdown
+ * @author Michel Fortin <michel.fortin@michelf.com>
+ * @copyright 2004-2016 Michel Fortin <https://michelf.com/projects/php-markdown/>
+ * @copyright (Original Markdown) 2004-2006 John Gruber <https://daringfireball.net/projects/markdown/>
+ */
+
+namespace Michelf;
+
+/**
+ * Markdown Parser Interface
+ */
+interface MarkdownInterface {
+ /**
+ * Initialize the parser and return the result of its transform method.
+ * This will work fine for derived classes too.
+ *
+ * @api
+ *
+ * @param string $text
+ * @return string
+ */
+ public static function defaultTransform($text);
+
+ /**
+ * Main function. Performs some preprocessing on the input text
+ * and pass it through the document gamut.
+ *
+ * @api
+ *
+ * @param string $text
+ * @return string
+ */
+ public function transform($text);
+}