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diff --git a/src/plugins/plain/PlainFormatStreamReader.hpp b/src/plugins/plain/PlainFormatStreamReader.hpp
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+/*
+    Ousía
+    Copyright (C) 2014  Benjamin Paaßen, Andreas Stöckel
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef _OUSIA_PLAIN_FORMAT_STREAM_READER_HPP_
+#define _OUSIA_PLAIN_FORMAT_STREAM_READER_HPP_
+
+/**
+ * @file PlainFormatStreamReader.hpp
+ *
+ * Provides classes for low-level classes for reading the plain TeX-esque
+ * format. The class provided here do not build any model objects and does not
+ * implement the Parser interfaces.
+ *
+ * @author Andreas Stöckel (astoecke@techfak.uni-bielefeld.de)
+ */
+
+#include <core/common/Variant.hpp>
+
+namespace ousia {
+
+// Forward declarations
+class CharReader;
+class Logger;
+
+/**
+ * The PlainFormatStreamReader class provides a low-level reader for the plain
+ * TeX-esque format. The parser is constructed around a "parse" function, which
+ * reads data from the underlying CharReader until a new state is reached and
+ * indicates this state in a return value. The calling code then has to pull
+ * corresponding data from the stream reader. The reader already handles some
+ * invalid cases, but recovers from most errors and happily continues parsing.
+ */
+class PlainFormatStreamReader {
+public:
+	/**
+	 * Enum used to indicate which state the PlainFormatStreamReader class is in
+	 * after calling the "parse" function.
+	 */
+	enum class State {
+		/**
+	     * State returned if a fully featured command has been read. A command
+	     * consists of the command name and its arguments (which optionally
+	     * includes the name).
+	     */
+		COMMAND,
+
+		/**
+	     * State returned if data is given. The reader must decide which field
+	     * or command this should be routed to. Trailing or leading whitespace
+	     * has been removed. Only called if the data is non-empty.
+	     */
+		DATA,
+
+		/**
+		 * State returned if a linebreak has been reached (outside of comments).
+		 */
+		LINEBREAK,
+
+		/**
+	     * A user-defined entity has been found. The entity sequence is stored
+	     * in the command name.
+	     */
+		ENTITY,
+
+		/**
+	     * State returned if an annotation was started. An annotation consists
+	     * of the command name and its arguments (which optionally include the
+	     * name).
+	     */
+		ANNOTATION_START,
+
+		/**
+	     * State returned if an annotation ends. The reader indicates which
+	     * annotation ends.
+	     */
+		ANNOTATION_END,
+
+		/**
+	     * State returned if a new field started. The reader assures that the
+	     * current field ends before a new field is started and that the field
+	     * is not started if data has been given outside of a field. The
+	     * field number is set to the current field index.
+	     */
+		FIELD_START,
+
+		/**
+	     * State returned if the current field ends. The reader assures that a
+	     * field was actually open.
+	     */
+		FIELD_END,
+
+		/**
+	     * The end of the stream has been reached.
+	     */
+		END
+	};
+
+private:
+	/**
+	 * Reference to the CharReader instance from which the incomming bytes are
+	 * read.
+	 */
+	CharReader &reader;
+
+	/**
+	 * Reference at the logger instance to which all error messages are sent.
+	 */
+	Logger &logger;
+
+	/**
+	 * Variant containing the current command name (always is a string variant,
+	 * but additionally contains the correct locatino of the name).
+	 */
+	Variant commandName;
+
+	/**
+	 * Variant containing the command arguments (always is a map or array
+	 * variant, but additionally contains the source location of the arguments).
+	 */
+	Variant commandArguments;
+
+	/**
+	 * Variant containing the data that has been read (always is a string,
+	 * contains the exact location of the data in the source file).
+	 */
+	Variant data;
+
+	/**
+	 * Contains the field index of the current command.
+	 */
+	size_t fieldIdx;
+
+	/**
+	 * Function used internally to parse a block comment.
+	 */
+	void parseBlockComment();
+
+	/**
+	 * Function used internally to parse a generic comment.
+	 */
+	void parseComment();
+
+public:
+	/**
+	 * Constructor of the PlainFormatStreamReader class. Attaches the new
+	 * PlainFormatStreamReader to the given CharReader and Logger instances.
+	 *
+	 * @param reader is the reader instance from which incomming characters
+	 * should be read.
+	 * @param logger is the logger instance to which errors should be written.
+	 */
+	PlainFormatStreamReader(CharReader &reader, Logger &logger);
+
+	/**
+	 * Continues parsing. Returns one of the states defined in the State enum.
+	 * Callers should stop once the State::END state is reached. Use the getter
+	 * functions to get more information about the current state, such as the
+	 * command name or the data or the current field index.
+	 *
+	 * @return the new state the parser has reached.
+	 */
+	State parse();
+
+	/**
+	 * Returns a reference at the internally stored data.
+	 */
+	const Variant& getData() {return data;}
+};
+}
+
+#endif /* _OUSIA_PLAIN_FORMAT_STREAM_READER_HPP_ */
+