11 files changed, 1074 insertions, 0 deletions
diff --git a/logo/src/xlogo/kernel/grammar/LogoException.java b/logo/src/xlogo/kernel/grammar/LogoException.java
new file mode 100644
index 0000000..225a677
--- /dev/null
+++ b/logo/src/xlogo/kernel/grammar/LogoException.java
@@ -0,0 +1,69 @@
+/* XLogo4Schools - A Logo Interpreter specialized for use in schools, based on XLogo by Lo�c Le Coq
+ * Copyright (C) 2013 Marko Zivkovic
+ * 
+ * Contact Information: marko88zivkovic at gmail dot com
+ * 
+ * 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 2 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, write to the Free 
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 
+ * MA 02110-1301, USA.
+ * 
+ * 
+ * This Java source code belongs to XLogo4Schools, written by Marko Zivkovic
+ * during his Bachelor thesis at the computer science department of ETH Z�rich,
+ * in the year 2013 and/or during future work.
+ * 
+ * It is a reengineered version of XLogo written by Lo�c Le Coq, published
+ * under the GPL License at http://xlogo.tuxfamily.org/
+ * 
+ * Contents of this file were initially written by Lo�c Le Coq,
+ * modifications, extensions, refactorings might have been applied by Marko Zivkovic 
+ */
+
+/**
+ * Title : XLogo
+ * Description : XLogo is an interpreter for the Logo
+ * programming language
+ * Licence : GPL
+ * 
+ * @author Loïc Le Coq
+ */
+package xlogo.kernel.grammar;
+
+/**
+ * @author loic
+ * 
+ */
+public class LogoException extends LogoType
+{
+	
+	private String	message;
+	
+	public LogoException(String message)
+	{
+		this.message = message;
+	}
+	
+	public boolean isException()
+	{
+		return true;
+	}
+	
+	public String toString()
+	{
+		return message;
+	}
+	
+	@Override
+	public String toDebug()
+	{
+		return "(EXCEPTION) " + message;
+	}
+	
+}
diff --git a/logo/src/xlogo/kernel/grammar/LogoList.java b/logo/src/xlogo/kernel/grammar/LogoList.java
new file mode 100644
index 0000000..1cd6ea5
--- /dev/null
+++ b/logo/src/xlogo/kernel/grammar/LogoList.java
@@ -0,0 +1,93 @@
+/* XLogo4Schools - A Logo Interpreter specialized for use in schools, based on XLogo by Lo�c Le Coq
+ * Copyright (C) 2013 Marko Zivkovic
+ * 
+ * Contact Information: marko88zivkovic at gmail dot com
+ * 
+ * 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 2 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, write to the Free 
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 
+ * MA 02110-1301, USA.
+ * 
+ * 
+ * This Java source code belongs to XLogo4Schools, written by Marko Zivkovic
+ * during his Bachelor thesis at the computer science department of ETH Z�rich,
+ * in the year 2013 and/or during future work.
+ * 
+ * It is a reengineered version of XLogo written by Lo�c Le Coq, published
+ * under the GPL License at http://xlogo.tuxfamily.org/
+ * 
+ * Contents of this file were initially written by Lo�c Le Coq,
+ * modifications, extensions, refactorings might have been applied by Marko Zivkovic 
+ */
+
+/**
+ * Title : XLogo
+ * Description : XLogo is an interpreter for the Logo
+ * programming language
+ * Licence : GPL
+ * 
+ * @author Loïc Le Coq
+ */
+package xlogo.kernel.grammar;
+
+import java.util.Vector;
+
+public class LogoList extends LogoType
+{
+	private Vector<LogoType>	vector;
+	
+	LogoList(Vector<LogoType> vector)
+	{
+		this.vector = vector;
+	}
+	
+	LogoList()
+	{
+		vector = new Vector<LogoType>();
+	}
+	
+	public boolean isList()
+	{
+		return true;
+	}
+	
+	public void add(LogoType type)
+	{
+		vector.add(type);
+	}
+	
+	public Vector<LogoType> getVector()
+	{
+		return vector;
+	}
+	
+	public String toString()
+	{
+		StringBuffer sb = new StringBuffer();
+		sb.append("[ ");
+		for (int i = 0; i < vector.size(); i++)
+		{
+			sb.append(vector.get(i).toString());
+			sb.append(" ");
+		}
+		sb.append("]");
+		return sb.toString();
+	}
+	
+	@Override
+	public String toDebug()
+	{
+		StringBuffer sb = new StringBuffer();
+		sb.append("(LIST) ");
+		sb.append(toString());
+		return sb.toString();
+		
+	}
+	
+}
diff --git a/logo/src/xlogo/kernel/grammar/LogoNumber.java b/logo/src/xlogo/kernel/grammar/LogoNumber.java
new file mode 100644
index 0000000..fd367bb
--- /dev/null
+++ b/logo/src/xlogo/kernel/grammar/LogoNumber.java
@@ -0,0 +1,76 @@
+/* XLogo4Schools - A Logo Interpreter specialized for use in schools, based on XLogo by Lo�c Le Coq
+ * Copyright (C) 2013 Marko Zivkovic
+ * 
+ * Contact Information: marko88zivkovic at gmail dot com
+ * 
+ * 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 2 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, write to the Free 
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 
+ * MA 02110-1301, USA.
+ * 
+ * 
+ * This Java source code belongs to XLogo4Schools, written by Marko Zivkovic
+ * during his Bachelor thesis at the computer science department of ETH Z�rich,
+ * in the year 2013 and/or during future work.
+ * 
+ * It is a reengineered version of XLogo written by Lo�c Le Coq, published
+ * under the GPL License at http://xlogo.tuxfamily.org/
+ * 
+ * Contents of this file were initially written by Lo�c Le Coq,
+ * modifications, extensions, refactorings might have been applied by Marko Zivkovic 
+ */
+
+/**
+ * Title : XLogo
+ * Description : XLogo is an interpreter for the Logo
+ * programming language
+ * Licence : GPL
+ * 
+ * @author Loïc Le Coq
+ */
+package xlogo.kernel.grammar;
+
+/**
+ * @author loic
+ * 
+ */
+public class LogoNumber extends LogoType
+{
+	private double	value;
+	
+	LogoNumber(double value)
+	{
+		this.value = value;
+	}
+	public double getValue()
+	{
+		return value;
+	}
+	
+	public boolean isWord()
+	{
+		return true;
+	}
+	
+	public boolean isNumber()
+	{
+		return true;
+	}
+	
+	public String toString()
+	{
+		return String.valueOf(value);
+	}
+	
+	@Override
+	public String toDebug()
+	{
+		return "(NUMBER) " + String.valueOf(value);
+	}
+}
diff --git a/logo/src/xlogo/kernel/grammar/LogoParser.java b/logo/src/xlogo/kernel/grammar/LogoParser.java
new file mode 100644
index 0000000..ccf3436
--- /dev/null
+++ b/logo/src/xlogo/kernel/grammar/LogoParser.java
@@ -0,0 +1,289 @@
+/* XLogo4Schools - A Logo Interpreter specialized for use in schools, based on XLogo by Lo�c Le Coq
+ * Copyright (C) 2013 Marko Zivkovic
+ * 
+ * Contact Information: marko88zivkovic at gmail dot com
+ * 
+ * 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 2 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, write to the Free 
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 
+ * MA 02110-1301, USA.
+ * 
+ * 
+ * This Java source code belongs to XLogo4Schools, written by Marko Zivkovic
+ * during his Bachelor thesis at the computer science department of ETH Z�rich,
+ * in the year 2013 and/or during future work.
+ * 
+ * It is a reengineered version of XLogo written by Lo�c Le Coq, published
+ * under the GPL License at http://xlogo.tuxfamily.org/
+ * 
+ * Contents of this file were initially written by Lo�c Le Coq,
+ * modifications, extensions, refactorings might have been applied by Marko Zivkovic 
+ */
+
+/**
+ * Title : XLogo
+ * Description : XLogo is an interpreter for the Logo
+ * programming language
+ * 
+ * @author Loïc Le Coq
+ */
+
+package xlogo.kernel.grammar;
+
+import xlogo.Logo;
+import xlogo.kernel.DrawPanel;
+import xlogo.kernel.Primitive;
+import xlogo.storage.global.GlobalConfig;
+
+public class LogoParser
+{
+	private char	c;
+	private int		cursor;
+	private String	text;
+	
+	/**
+	 * 
+	 * @param sr
+	 *            The String input reader
+	 */
+	public LogoParser(String text)
+	{
+		this.text = text;
+		cursor = 0;
+		while (cursor < text.length())
+		{
+			LogoType lt = getToken();
+			if (GlobalConfig.DEBUG)
+				System.out.println("[DEBUG] Token " + lt.toDebug() + " cursor " + cursor);
+		}
+	}
+	
+	private LogoType getToken()
+	{
+		boolean isQuotedWord = false;
+		boolean isVariable = false;
+		
+		StringBuffer sb = new StringBuffer();
+		boolean start = false;
+		boolean backslash = false;
+		do
+		{
+			c = text.charAt(cursor);
+			// Skip White Spaces
+			if (c == ' ' || c == '\t')
+			{
+				if (start)
+					break;
+				else
+					cursor++;
+			}
+			else
+			{
+				if (backslash)
+				{
+					if (c == ' ')
+						sb.append(" ");
+					else if (c == '#')
+						sb.append("#");
+					else if (c == '\\')
+						sb.append("\\");
+					else if (c == '(')
+						sb.append("(");
+					else if (c == ')')
+						sb.append(")");
+					else if (c == '[')
+						sb.append("[");
+					else if (c == ']')
+						sb.append("]");
+					else if (c == 'n')
+						sb.append("\n");
+					else
+						sb.append(c);
+					cursor++;
+				}
+				else
+				{
+					// If it's the first character, check for type
+					if (!start)
+					{
+						if (c == ':')
+							isVariable = true;
+						else if (c == '\"')
+							isQuotedWord = true;
+					}
+					if (c == '\\')
+						backslash = true;
+					
+					else if (c == '[')
+					{
+						if (start)
+							break;
+						else
+						{
+							cursor++;
+							return extractList();
+						}
+					}
+					else if (c == '(')
+					{
+						if (start)
+							break;
+					}
+					else if (c == '*' || c == '/' || c == '+' || c == '-' || c == '|' || c == '&' || c == '=')
+					{
+						if (!isQuotedWord)
+						{
+							if (!start)
+							{
+								sb.append(c);
+								cursor++;
+							}
+							break;
+							
+						}
+						else
+							cursor++;
+					}
+					else if (c == ')')
+						return new LogoException(Logo.messages.getString("parenthese_ouvrante"));
+					else if (c == ']')
+						return new LogoException(Logo.messages.getString("error.whattodo") + " ]");
+					else
+					{
+						sb.append(c);
+						cursor++;
+					}
+				}
+				start = true;
+			}
+		} while (cursor < text.length());
+		if (sb.length() == 0)
+			return DrawPanel.nullType;
+		else if (isQuotedWord)
+			return new LogoWord(sb.substring(1));
+		else if (isVariable)
+			return new LogoVariable(sb.substring(1));
+		try
+		{
+			double d = Double.parseDouble(sb.toString());
+			return new LogoNumber(d);
+		}
+		catch (NumberFormatException e)
+		{
+			int id = Primitive.isPrimitive(sb.toString());
+			if (id != -1) { return new LogoPrimitive(id, sb.toString()); }
+			return new LogoException(Logo.messages.getString("je_ne_sais_pas") + " " + sb.toString());
+		}
+		
+	}
+	
+	/**
+	 * This method extracts a list.
+	 * 
+	 * @return a LogoList if operation succeed,
+	 *         a LogoException otherwise
+	 */
+	
+	private LogoType extractList()
+	{
+		LogoList list = new LogoList();
+		while (cursor < text.length())
+		{
+			LogoType lt = getListToken();
+			if (lt.isNull())
+			{
+				return new LogoException(Logo.messages.getString("erreur_crochet"));
+			}
+			else if (lt.isRightDelimiter())
+				return list;
+			else
+			{
+				list.add(lt);
+			}
+		}
+		return new LogoException(Logo.messages.getString("erreur_crochet"));
+	}
+	
+	private LogoType getListToken()
+	{
+		StringBuffer sb = new StringBuffer();
+		boolean start = false;
+		boolean backslash = false;
+		for (int i = cursor; i < text.length(); i++)
+		{
+			cursor = i;
+			c = text.charAt(i);
+			// Skip White Spaces
+			if (c == ' ' || c == '\t')
+			{
+				if (start)
+					break;
+			}
+			else
+			{
+				if (backslash)
+				{
+					if (c == ' ')
+						sb.append(" ");
+					else if (c == '#')
+						sb.append("#");
+					else if (c == '\\')
+						sb.append("\\");
+					else if (c == '(')
+						sb.append("(");
+					else if (c == ')')
+						sb.append(")");
+					else if (c == '[')
+						sb.append("[");
+					else if (c == ']')
+						sb.append("]");
+					else if (c == 'n')
+						sb.append("\n");
+					else
+						sb.append(c);
+				}
+				else
+				{
+					if (c == '\\')
+					{
+						backslash = true;
+					}
+					else if (c == '[')
+					{
+						if (start)
+							break;
+						else
+						{
+							cursor++;
+							return extractList();
+						}
+					}
+					else if (c == ']')
+					{
+						if (start)
+							break;
+						else
+						{
+							System.out.println("coucou");
+							cursor++;
+							return new LogoRightDelimiter();
+						}
+					}
+					else
+						sb.append(c);
+				}
+				start = true;
+			}
+		}
+		if (sb.length() == 0)
+			return DrawPanel.nullType;
+		return new LogoWord(sb.toString());
+	}
+	
+}
diff --git a/logo/src/xlogo/kernel/grammar/LogoPrimitive.java b/logo/src/xlogo/kernel/grammar/LogoPrimitive.java
new file mode 100644
index 0000000..52044a3
--- /dev/null
+++ b/logo/src/xlogo/kernel/grammar/LogoPrimitive.java
@@ -0,0 +1,74 @@
+/* XLogo4Schools - A Logo Interpreter specialized for use in schools, based on XLogo by Lo�c Le Coq
+ * Copyright (C) 2013 Marko Zivkovic
+ * 
+ * Contact Information: marko88zivkovic at gmail dot com
+ * 
+ * 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 2 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, write to the Free 
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 
+ * MA 02110-1301, USA.
+ * 
+ * 
+ * This Java source code belongs to XLogo4Schools, written by Marko Zivkovic
+ * during his Bachelor thesis at the computer science department of ETH Z�rich,
+ * in the year 2013 and/or during future work.
+ * 
+ * It is a reengineered version of XLogo written by Lo�c Le Coq, published
+ * under the GPL License at http://xlogo.tuxfamily.org/
+ * 
+ * Contents of this file were initially written by Lo�c Le Coq,
+ * modifications, extensions, refactorings might have been applied by Marko Zivkovic 
+ */
+
+/**
+ * Title : XLogo
+ * Description : XLogo is an interpreter for the Logo
+ * programming language
+ * Licence : GPL
+ * 
+ * @author Loïc Le Coq
+ */
+package xlogo.kernel.grammar;
+
+public class LogoPrimitive extends LogoType
+{
+	private int		id;
+	private String	name;
+	
+	LogoPrimitive(int id, String name)
+	{
+		this.id = id;
+		this.name = name;
+	}
+	
+	public boolean isPrimitive()
+	{
+		return true;
+	}
+	
+	/**
+	 * @return
+	 * @uml.property name="id"
+	 */
+	public int getId()
+	{
+		return id;
+	}
+	
+	public String toString()
+	{
+		return name;
+	}
+	
+	@Override
+	public String toDebug()
+	{
+		return "(PRIMITIVE id=" + id + ") " + name;
+	}
+}
diff --git a/logo/src/xlogo/kernel/grammar/LogoRightDelimiter.java b/logo/src/xlogo/kernel/grammar/LogoRightDelimiter.java
new file mode 100644
index 0000000..fb46026
--- /dev/null
+++ b/logo/src/xlogo/kernel/grammar/LogoRightDelimiter.java
@@ -0,0 +1,56 @@
+/* XLogo4Schools - A Logo Interpreter specialized for use in schools, based on XLogo by Lo�c Le Coq
+ * Copyright (C) 2013 Marko Zivkovic
+ * 
+ * Contact Information: marko88zivkovic at gmail dot com
+ * 
+ * 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 2 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, write to the Free 
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 
+ * MA 02110-1301, USA.
+ * 
+ * 
+ * This Java source code belongs to XLogo4Schools, written by Marko Zivkovic
+ * during his Bachelor thesis at the computer science department of ETH Z�rich,
+ * in the year 2013 and/or during future work.
+ * 
+ * It is a reengineered version of XLogo written by Lo�c Le Coq, published
+ * under the GPL License at http://xlogo.tuxfamily.org/
+ * 
+ * Contents of this file were initially written by Lo�c Le Coq,
+ * modifications, extensions, refactorings might have been applied by Marko Zivkovic 
+ */
+
+/**
+ * Title : XLogo
+ * Description : XLogo is an interpreter for the Logo
+ * programming language
+ * Licence : GPL
+ * 
+ * @author Loïc Le Coq
+ */
+package xlogo.kernel.grammar;
+
+/**
+ * @author loic
+ * 
+ */
+public class LogoRightDelimiter extends LogoType
+{
+	public boolean isRightDelimiter()
+	{
+		return true;
+	}
+	
+	@Override
+	public String toDebug()
+	{
+		return null;
+	}
+	
+}
diff --git a/logo/src/xlogo/kernel/grammar/LogoTree.java b/logo/src/xlogo/kernel/grammar/LogoTree.java
new file mode 100644
index 0000000..4e6b66e
--- /dev/null
+++ b/logo/src/xlogo/kernel/grammar/LogoTree.java
@@ -0,0 +1,96 @@
+/* XLogo4Schools - A Logo Interpreter specialized for use in schools, based on XLogo by Lo�c Le Coq
+ * Copyright (C) 2013 Marko Zivkovic
+ * 
+ * Contact Information: marko88zivkovic at gmail dot com
+ * 
+ * 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 2 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, write to the Free 
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 
+ * MA 02110-1301, USA.
+ * 
+ * 
+ * This Java source code belongs to XLogo4Schools, written by Marko Zivkovic
+ * during his Bachelor thesis at the computer science department of ETH Z�rich,
+ * in the year 2013 and/or during future work.
+ * 
+ * It is a reengineered version of XLogo written by Lo�c Le Coq, published
+ * under the GPL License at http://xlogo.tuxfamily.org/
+ * 
+ * Contents of this file were initially written by Lo�c Le Coq,
+ * modifications, extensions, refactorings might have been applied by Marko Zivkovic 
+ */
+
+package xlogo.kernel.grammar;
+
+import java.util.Vector;
+
+public class LogoTree
+{
+	private Vector<LogoTree>	children;
+	private LogoTree			parent;
+	private LogoType			value;
+	private boolean				isRoot		= false;
+	private boolean				isProcedure	= false;
+	private boolean				isPrimitive	= false;
+	private boolean				isLeaf		= false;
+	
+	LogoTree()
+	{
+		children = new Vector<LogoTree>();
+	}
+	
+	protected void setParent(LogoTree lt)
+	{
+		this.parent = lt;
+	}
+	
+	protected LogoTree getParent()
+	{
+		return parent;
+	}
+	
+	protected boolean isRoot()
+	{
+		return isRoot;
+	}
+	
+	protected void addChild(LogoTree child)
+	{
+		children.add(child);
+	}
+	
+	protected void setValue(LogoType value)
+	{
+		this.value = value;
+	}
+	
+	protected LogoType getValue()
+	{
+		return value;
+	}
+	
+	protected boolean isLeaf()
+	{
+		return isLeaf;
+	}
+	
+	LogoType evaluate()
+	{
+		Vector<LogoType> args = new Vector<LogoType>();
+		for (int i = 0; i < children.size(); i++)
+		{
+			LogoTree child = children.get(i);
+			if (child.isLeaf())
+				args.add(child.getValue());
+			else
+				args.add(child.evaluate());
+		}
+		return null;
+	}
+}
diff --git a/logo/src/xlogo/kernel/grammar/LogoType.java b/logo/src/xlogo/kernel/grammar/LogoType.java
new file mode 100644
index 0000000..d407431
--- /dev/null
+++ b/logo/src/xlogo/kernel/grammar/LogoType.java
@@ -0,0 +1,129 @@
+/* XLogo4Schools - A Logo Interpreter specialized for use in schools, based on XLogo by Lo�c Le Coq
+ * Copyright (C) 2013 Marko Zivkovic
+ * 
+ * Contact Information: marko88zivkovic at gmail dot com
+ * 
+ * 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 2 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, write to the Free 
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 
+ * MA 02110-1301, USA.
+ * 
+ * 
+ * This Java source code belongs to XLogo4Schools, written by Marko Zivkovic
+ * during his Bachelor thesis at the computer science department of ETH Z�rich,
+ * in the year 2013 and/or during future work.
+ * 
+ * It is a reengineered version of XLogo written by Lo�c Le Coq, published
+ * under the GPL License at http://xlogo.tuxfamily.org/
+ * 
+ * Contents of this file were initially written by Lo�c Le Coq,
+ * modifications, extensions, refactorings might have been applied by Marko Zivkovic 
+ */
+
+/**
+ * Title : XLogo
+ * Description : XLogo is an interpreter for the Logo
+ * programming language
+ * Licence : GPL
+ * 
+ * @author Loïc Le Coq
+ */
+
+package xlogo.kernel.grammar;
+
+public abstract class LogoType
+{
+	
+	/**
+	 * If this token is a word ?
+	 * 
+	 * @return true for a word, false otherwise
+	 */
+	public boolean isWord()
+	{
+		return false;
+	}
+	
+	/**
+	 * If this token is a list?
+	 * 
+	 * @return true for a list, false otherwise
+	 */
+	public boolean isList()
+	{
+		return false;
+	}
+	
+	/**
+	 * If this token is a number?
+	 * 
+	 * @return true for a number, false otherwise
+	 */
+	public boolean isNumber()
+	{
+		return false;
+	}
+	
+	/**
+	 * If this token is a variable?
+	 * 
+	 * @return true for a variable, false otherwise
+	 */
+	public boolean isVariable()
+	{
+		return false;
+	}
+	
+	/**
+	 * If this token is a primitive?
+	 * 
+	 * @return true for a primitive, false otherwise
+	 */
+	public boolean isPrimitive()
+	{
+		return false;
+	}
+	
+	/**
+	 * If this token is a procedure?
+	 * 
+	 * @return true for a procedure, false otherwise
+	 */
+	public boolean isProcedure()
+	{
+		return false;
+	}
+	
+	/**
+	 * If this token is an exception?
+	 * 
+	 * @return true for an exception, false otherwise
+	 */
+	public boolean isException()
+	{
+		return false;
+	}
+	
+	public boolean isNull()
+	{
+		return false;
+	}
+	
+	public boolean isRightDelimiter()
+	{
+		return false;
+	}
+	
+	/**
+	 * Util for debugging
+	 * 
+	 * @return the type and value for LogoType
+	 */
+	abstract public String toDebug();
+}
diff --git a/logo/src/xlogo/kernel/grammar/LogoTypeNull.java b/logo/src/xlogo/kernel/grammar/LogoTypeNull.java
new file mode 100644
index 0000000..b764063
--- /dev/null
+++ b/logo/src/xlogo/kernel/grammar/LogoTypeNull.java
@@ -0,0 +1,56 @@
+/* XLogo4Schools - A Logo Interpreter specialized for use in schools, based on XLogo by Lo�c Le Coq
+ * Copyright (C) 2013 Marko Zivkovic
+ * 
+ * Contact Information: marko88zivkovic at gmail dot com
+ * 
+ * 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 2 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, write to the Free 
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 
+ * MA 02110-1301, USA.
+ * 
+ * 
+ * This Java source code belongs to XLogo4Schools, written by Marko Zivkovic
+ * during his Bachelor thesis at the computer science department of ETH Z�rich,
+ * in the year 2013 and/or during future work.
+ * 
+ * It is a reengineered version of XLogo written by Lo�c Le Coq, published
+ * under the GPL License at http://xlogo.tuxfamily.org/
+ * 
+ * Contents of this file were initially written by Lo�c Le Coq,
+ * modifications, extensions, refactorings might have been applied by Marko Zivkovic 
+ */
+
+/**
+ * Title : XLogo
+ * Description : XLogo is an interpreter for the Logo
+ * programming language
+ * Licence : GPL
+ * 
+ * @author Loïc Le Coq
+ */
+package xlogo.kernel.grammar;
+
+/**
+ * @author loic
+ * 
+ */
+public class LogoTypeNull extends LogoType
+{
+	public boolean isNull()
+	{
+		return true;
+	}
+	
+	@Override
+	public String toDebug()
+	{
+		return "(LogoTypeNull)";
+	}
+	
+}
diff --git a/logo/src/xlogo/kernel/grammar/LogoVariable.java b/logo/src/xlogo/kernel/grammar/LogoVariable.java
new file mode 100644
index 0000000..d2a7e91
--- /dev/null
+++ b/logo/src/xlogo/kernel/grammar/LogoVariable.java
@@ -0,0 +1,68 @@
+/* XLogo4Schools - A Logo Interpreter specialized for use in schools, based on XLogo by Lo�c Le Coq
+ * Copyright (C) 2013 Marko Zivkovic
+ * 
+ * Contact Information: marko88zivkovic at gmail dot com
+ * 
+ * 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 2 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, write to the Free 
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 
+ * MA 02110-1301, USA.
+ * 
+ * 
+ * This Java source code belongs to XLogo4Schools, written by Marko Zivkovic
+ * during his Bachelor thesis at the computer science department of ETH Z�rich,
+ * in the year 2013 and/or during future work.
+ * 
+ * It is a reengineered version of XLogo written by Lo�c Le Coq, published
+ * under the GPL License at http://xlogo.tuxfamily.org/
+ * 
+ * Contents of this file were initially written by Lo�c Le Coq,
+ * modifications, extensions, refactorings might have been applied by Marko Zivkovic 
+ */
+
+package xlogo.kernel.grammar;
+
+/**
+ * Title : XLogo
+ * Description : XLogo is an interpreter for the Logo
+ * programming language
+ * Licence : GPL
+ * 
+ * @author Loïc Le Coq
+ */
+public class LogoVariable extends LogoType
+{
+	String	name;
+	
+	LogoVariable(String name)
+	{
+		this.name = name;
+	}
+	
+	public boolean isVariable()
+	{
+		return true;
+	}
+
+	public String getName()
+	{
+		return name;
+	}
+	
+	public String toString()
+	{
+		return ":" + name;
+	}
+	
+	@Override
+	public String toDebug()
+	{
+		return "(VARIABLE) :" + name;
+	}
+}
diff --git a/logo/src/xlogo/kernel/grammar/LogoWord.java b/logo/src/xlogo/kernel/grammar/LogoWord.java
new file mode 100644
index 0000000..e155180
--- /dev/null
+++ b/logo/src/xlogo/kernel/grammar/LogoWord.java
@@ -0,0 +1,68 @@
+/* XLogo4Schools - A Logo Interpreter specialized for use in schools, based on XLogo by Lo�c Le Coq
+ * Copyright (C) 2013 Marko Zivkovic
+ * 
+ * Contact Information: marko88zivkovic at gmail dot com
+ * 
+ * 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 2 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, write to the Free 
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 
+ * MA 02110-1301, USA.
+ * 
+ * 
+ * This Java source code belongs to XLogo4Schools, written by Marko Zivkovic
+ * during his Bachelor thesis at the computer science department of ETH Z�rich,
+ * in the year 2013 and/or during future work.
+ * 
+ * It is a reengineered version of XLogo written by Lo�c Le Coq, published
+ * under the GPL License at http://xlogo.tuxfamily.org/
+ * 
+ * Contents of this file were initially written by Lo�c Le Coq,
+ * modifications, extensions, refactorings might have been applied by Marko Zivkovic 
+ */
+
+/**
+ * Title : XLogo
+ * Description : XLogo is an interpreter for the Logo
+ * programming language
+ * Licence : GPL
+ * 
+ * @author Loïc Le Coq
+ */
+package xlogo.kernel.grammar;
+
+public class LogoWord extends LogoType
+{
+	private String	value;
+	
+	LogoWord(String value)
+	{
+		this.value = value;
+	}
+	
+	public String getQuotedValue()
+	{
+		return "\"" + value;
+	}
+	
+	public String toString()
+	{
+		return value;
+	}
+	
+	public boolean isWord()
+	{
+		return true;
+	}
+	
+	@Override
+	public String toDebug()
+	{
+		return "(WORD) " + value;
+	}
+}