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diff --git a/src/core/common/Location.hpp b/src/core/common/Location.hpp
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+/*
+    Ousía
+    Copyright (C) 2014, 2015  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_LOCATION_HPP_
+#define _OUSIA_LOCATION_HPP_
+
+namespace ousia {
+
+/**
+ * Struct representing a location within a source file. A position is defined by
+ * a byte offset (which is always reproducable), a line number and a column
+ * number (which may differ depending on the encoding used).
+ */
+struct SourceLocation {
+	/**
+	 * Current line, starting with one.
+	 */
+	int line;
+
+	/**
+	 * Current column, starting with one.
+	 */
+	int column;
+
+	/**
+	 * Current byte offset.
+	 */
+	size_t offs;
+
+	/**
+	 * Default constructor of the SourceLocation struct, initializes all
+	 * memebers with zero.
+	 */
+	SourceLocation() : line(0), column(0), offs(0) {}
+
+	/**
+	 * Creates a new SourceLocation struct with only a line and no column.
+	 *
+	 * @param line is the line number.
+	 * @param column is the column number.
+	 */
+	SourceLocation(int line) : line(line), column(0), offs(0) {}
+
+	/**
+	 * Creates a new SourceLocation struct with a line and column.
+	 *
+	 * @param line is the line number.
+	 * @param column is the column number.
+	 */
+	SourceLocation(int line, int column) : line(line), column(column), offs(0)
+	{
+	}
+
+	/**
+	 * Creates a new SourceLocation struct with a line, column and byte offset.
+	 *
+	 * @param line is the line number.
+	 * @param column is the column number.
+	 * @param offs is the byte offset.
+	 */
+	SourceLocation(int line, int column, size_t offs)
+	    : line(line), column(column), offs(offs)
+	{
+	}
+
+	/**
+	 * Returns true, if the line number is valid, false otherwise.
+	 *
+	 * @return true for valid line numbers.
+	 */
+	bool hasLine() const { return line > 0; }
+
+	/**
+	 * Returns true, if the column number is valid, false otherwise.
+	 *
+	 * @return true for valid column numbers.
+	 */
+	bool hasColumn() const { return column > 0; }
+
+	/**
+	 * Returns true, if the position is valid, false otherwise. This function is
+	 * equivalent to the hasLine() function.
+	 *
+	 * @return true if the Position struct is valid.
+	 */
+	bool valid() const { return hasLine(); }
+};
+
+/**
+ * Represents the context of a SourceLocation instance. Used to build error
+ * messages.
+ */
+struct SourceContext {
+	/**
+	 * Set to the content of the current line.
+	 */
+	std::string text;
+
+	/**
+	 * Relative position (in characters) within that line. May point to
+	 * locations beyond the text content.
+	 */
+	int relPos;
+
+	/**
+	 * Set to true if the beginning of the line has been truncated (because
+	 * the reader position is too far away from the actual position of the
+	 * line).
+	 */
+	bool truncatedStart;
+
+	/**
+	 * Set to true if the end of the line has been truncated (because the
+	 * reader position is too far away from the actual end position of the
+	 * line.
+	 */
+	bool truncatedEnd;
+
+	/**
+	 * Default constructor, initializes all members with zero values.
+	 */
+	SourceContext()
+	    : text(), relPos(0), truncatedStart(false), truncatedEnd(false)
+	{
+	}
+
+	/**
+	 * Constructor of the SourceContext class.
+	 *
+	 * @param text is the current line the text cursor is at.
+	 * @param relPos is the relative position of the text cursor within that
+	 * line.
+	 * @param truncatedStart specifies whether the text was truncated at the
+	 * beginning.
+	 * @param truncatedEnd specifies whether the text was truncated at the
+	 * end.
+	 */
+	SourceContext(std::string text, size_t relPos, bool truncatedStart,
+	              bool truncatedEnd)
+	    : text(std::move(text)),
+	      relPos(relPos),
+	      truncatedStart(truncatedStart),
+	      truncatedEnd(truncatedEnd)
+	{
+	}
+
+	/**
+	 * Returns true the context text is not empty.
+	 *
+	 * @return true if the context is valid and e.g. should be printed.
+	 */
+	bool valid() const { return !text.empty(); }
+};
+
+/**
+ * Callback used to lookup the context corresponding to the given source
+ * location.
+ *
+ * @param location is the location for which the context should be looked up.
+ * @param data is used defined data associated with the callback.
+ */
+using SourceContextCallback = SourceContext (*)(const SourceLocation &location,
+                                                void *data);
+}
+
+#endif /* _OUSIA_LOCATION_HPP_ */
+