--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/3rdparty/maddy/horizontallineparser.h	Tue Aug 17 11:19:54 2021 +0200
@@ -0,0 +1,106 @@
+/*
+ * This project is licensed under the MIT license. For more information see the
+ * LICENSE file.
+ */
+#pragma once
+
+// -----------------------------------------------------------------------------
+
+#include <functional>
+#include <string>
+#include <regex>
+
+#include "maddy/blockparser.h"
+
+// -----------------------------------------------------------------------------
+
+namespace maddy {
+
+// -----------------------------------------------------------------------------
+
+/**
+ * HorizontalLineParser
+ *
+ * From Markdown: `---`
+ *
+ * To HTML: `<hr/>`
+ *
+ * @class
+ */
+class HorizontalLineParser : public BlockParser
+{
+public:
+  /**
+   * ctor
+   *
+   * @method
+   * @param {std::function<void(std::string&)>} parseLineCallback
+   * @param {std::function<std::shared_ptr<BlockParser>(const std::string& line)>} getBlockParserForLineCallback
+   */
+  HorizontalLineParser(
+    std::function<void(std::string&)> parseLineCallback,
+    std::function<std::shared_ptr<BlockParser>(const std::string& line)> getBlockParserForLineCallback
+  )
+    : BlockParser(parseLineCallback, getBlockParserForLineCallback)
+    , lineRegex("^---$")
+  {}
+
+  /**
+   * IsStartingLine
+   *
+   * If the line has exact three dashes `---`, then it is a horizontal line.
+   *
+   * @method
+   * @param {const std::string&} line
+   * @return {bool}
+   */
+  static bool
+  IsStartingLine(const std::string& line)
+  {
+    static std::regex re("^---$");
+    return std::regex_match(line, re);
+  }
+
+  /**
+   * IsFinished
+   *
+   * The horizontal line is always only one line long, so this method always
+   * returns true.
+   *
+   * @method
+   * @return {bool}
+   */
+  bool
+  IsFinished() const override
+  {
+    return true;
+  }
+
+protected:
+  bool
+  isInlineBlockAllowed() const override
+  {
+    return false;
+  }
+
+  bool
+  isLineParserAllowed() const override
+  {
+    return false;
+  }
+
+  void
+  parseBlock(std::string& line) override
+  {
+    static std::string replacement = "<hr/>";
+
+    line = std::regex_replace(line, lineRegex, replacement);
+  }
+
+private:
+  std::regex lineRegex;
+}; // class HorizontalLineParser
+
+// -----------------------------------------------------------------------------
+
+} // namespace maddy