--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/3rdparty/maddy/headlineparser.h	Tue Aug 17 11:19:54 2021 +0200
@@ -0,0 +1,138 @@
+/*
+ * 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 {
+
+// -----------------------------------------------------------------------------
+
+/**
+ * HeadlineParser
+ *
+ * From Markdown:
+ *
+ * ```
+ * # Headline 1
+ * ## Headline 2
+ * ### Headline 3
+ * #### Headline 4
+ * ##### Headline 5
+ * ###### Headline 6
+ * ```
+ *
+ * To HTML:
+ *
+ * ```
+ * <h1>Headline 1</h1>
+ * <h2>Headline 2</h2>
+ * <h3>Headline 3</h3>
+ * <h4>Headline 4</h4>
+ * <h5>Headline 5</h5>
+ * <h6>Headline 6</h6>
+ * ```
+ *
+ * @class
+ */
+class HeadlineParser : public BlockParser
+{
+public:
+  /**
+   * ctor
+   *
+   * @method
+   * @param {std::function<void(std::string&)>} parseLineCallback
+   * @param {std::function<std::shared_ptr<BlockParser>(const std::string& line)>} getBlockParserForLineCallback
+   */
+  HeadlineParser(
+    std::function<void(std::string&)> parseLineCallback,
+    std::function<std::shared_ptr<BlockParser>(const std::string& line)> getBlockParserForLineCallback
+  )
+    : BlockParser(parseLineCallback, getBlockParserForLineCallback)
+  {}
+
+  /**
+   * IsStartingLine
+   *
+   * If the line starts with 1 - 6 `#`, then it is a headline.
+   *
+   * @method
+   * @param {const std::string&} line
+   * @return {bool}
+   */
+  static bool
+  IsStartingLine(const std::string& line)
+  {
+    static std::regex re("^(?:#){1,6} (.*)");
+    return std::regex_match(line, re);
+  }
+
+  /**
+   * IsFinished
+   *
+   * The headline 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::vector<std::regex> hlRegex = {
+      std::regex("^# (.*)")
+      , std::regex("^(?:#){2} (.*)")
+      , std::regex("^(?:#){3} (.*)")
+      , std::regex("^(?:#){4} (.*)")
+      , std::regex("^(?:#){5} (.*)")
+      , std::regex("^(?:#){6} (.*)")
+    };
+    static std::vector<std::string> hlReplacement = {
+      "<h1>$1</h1>"
+      , "<h2>$1</h2>"
+      , "<h3>$1</h3>"
+      , "<h4>$1</h4>"
+      , "<h5>$1</h5>"
+      , "<h6>$1</h6>"
+    };
+
+    for (uint8_t i = 0; i < 6; ++i)
+    {
+      line = std::regex_replace(line, hlRegex[i], hlReplacement[i]);
+    }
+  }
+}; // class HeadlineParser
+
+// -----------------------------------------------------------------------------
+
+} // namespace maddy