moved ptg classes to org.apache.poi.ss.formula.ptg

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1038688 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/poi/ss/formula/EvaluationName.java

@@ -17,8 +17,8 @@
 
 package org.apache.poi.ss.formula;
 
-import org.apache.poi.hssf.record.formula.NamePtg;
+import org.apache.poi.ss.formula.ptg.NamePtg;
-import org.apache.poi.hssf.record.formula.Ptg;
+import org.apache.poi.ss.formula.ptg.Ptg;
 /**
  * Abstracts a name record for formula evaluation.<br/>
  *

src/java/org/apache/poi/ss/formula/EvaluationWorkbook.java

@@ -17,9 +17,9 @@
 
 package org.apache.poi.ss.formula;
 
-import org.apache.poi.hssf.record.formula.NamePtg;
+import org.apache.poi.ss.formula.ptg.NamePtg;
-import org.apache.poi.hssf.record.formula.NameXPtg;
+import org.apache.poi.ss.formula.ptg.NameXPtg;
-import org.apache.poi.hssf.record.formula.Ptg;
+import org.apache.poi.ss.formula.ptg.Ptg;
 
 /**
  * Abstracts a workbook for the purpose of formula evaluation.<br/>

src/java/org/apache/poi/ss/formula/ExternSheetReferenceToken.java

@@ -18,7 +18,7 @@
 package org.apache.poi.ss.formula;
 
 /**
- * Should be implemented by any {@link org.apache.poi.hssf.record.formula.Ptg} subclass that needs has an extern sheet index <br/>
+ * Should be implemented by any {@link org.apache.poi.ss.formula.ptg.Ptg} subclass that needs has an extern sheet index <br/>
  *
  * For POI internal use only
  *

src/java/org/apache/poi/ss/formula/Formula.java

@@ -19,10 +19,10 @@ package org.apache.poi.ss.formula;
 
 import java.util.Arrays;
 
-import org.apache.poi.hssf.record.formula.ExpPtg;
+import org.apache.poi.ss.formula.ptg.ExpPtg;
-import org.apache.poi.hssf.record.formula.Ptg;
+import org.apache.poi.ss.formula.ptg.Ptg;
-import org.apache.poi.hssf.record.formula.TblPtg;
+import org.apache.poi.ss.formula.ptg.TblPtg;
-import org.apache.poi.hssf.util.CellReference;
+import org.apache.poi.ss.util.CellReference;
 import org.apache.poi.util.LittleEndian;
 import org.apache.poi.util.LittleEndianByteArrayInputStream;
 import org.apache.poi.util.LittleEndianInput;

src/java/org/apache/poi/ss/formula/FormulaParser.java

@@ -21,8 +21,8 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.regex.Pattern;
 
-import org.apache.poi.hssf.record.constant.ErrorConstant;
+import org.apache.poi.ss.formula.constant.ErrorConstant;
-import org.apache.poi.hssf.record.formula.*;
+import org.apache.poi.ss.formula.ptg.*;
 import org.apache.poi.ss.formula.function.FunctionMetadata;
 import org.apache.poi.ss.formula.function.FunctionMetadataRegistry;
 import org.apache.poi.ss.usermodel.ErrorConstants;

src/java/org/apache/poi/ss/formula/FormulaParsingWorkbook.java

@@ -17,7 +17,7 @@
 
 package org.apache.poi.ss.formula;
 
-import org.apache.poi.hssf.record.formula.NameXPtg;
+import org.apache.poi.ss.formula.ptg.NameXPtg;
 import org.apache.poi.ss.SpreadsheetVersion;
 
 /**

src/java/org/apache/poi/ss/formula/FormulaRenderer.java

@@ -19,13 +19,13 @@ package org.apache.poi.ss.formula;
 
 import java.util.Stack;
 
-import org.apache.poi.hssf.record.formula.AttrPtg;
+import org.apache.poi.ss.formula.ptg.AttrPtg;
-import org.apache.poi.hssf.record.formula.MemAreaPtg;
+import org.apache.poi.ss.formula.ptg.MemAreaPtg;
-import org.apache.poi.hssf.record.formula.MemErrPtg;
+import org.apache.poi.ss.formula.ptg.MemErrPtg;
-import org.apache.poi.hssf.record.formula.MemFuncPtg;
+import org.apache.poi.ss.formula.ptg.MemFuncPtg;
-import org.apache.poi.hssf.record.formula.OperationPtg;
+import org.apache.poi.ss.formula.ptg.OperationPtg;
-import org.apache.poi.hssf.record.formula.ParenthesisPtg;
+import org.apache.poi.ss.formula.ptg.ParenthesisPtg;
-import org.apache.poi.hssf.record.formula.Ptg;
+import org.apache.poi.ss.formula.ptg.Ptg;
 
 /**
  * Common logic for rendering formulas.<br/>

src/java/org/apache/poi/ss/formula/FormulaRenderingWorkbook.java

@@ -17,8 +17,8 @@
 
 package org.apache.poi.ss.formula;
 
-import org.apache.poi.hssf.record.formula.NamePtg;
+import org.apache.poi.ss.formula.ptg.NamePtg;
-import org.apache.poi.hssf.record.formula.NameXPtg;
+import org.apache.poi.ss.formula.ptg.NameXPtg;
 import org.apache.poi.ss.formula.EvaluationWorkbook.ExternalSheet;
 
 /**

src/java/org/apache/poi/ss/formula/FormulaShifter.java

@@ -17,7 +17,7 @@
 
 package org.apache.poi.ss.formula;
 
-import org.apache.poi.hssf.record.formula.*;
+import org.apache.poi.ss.formula.ptg.*;
 
 
 /**

src/java/org/apache/poi/ss/formula/FormulaUsedBlankCellSet.java

@@ -22,7 +22,7 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
-import org.apache.poi.hssf.util.CellReference;
+import org.apache.poi.ss.util.CellReference;
 
 /**
  * Optimisation - compacts many blank cell references used by a single formula.

src/java/org/apache/poi/ss/formula/LazyAreaEval.java

@@ -17,12 +17,12 @@
 
 package org.apache.poi.ss.formula;
 
-import org.apache.poi.hssf.record.formula.AreaI;
+import org.apache.poi.ss.formula.ptg.AreaI;
-import org.apache.poi.hssf.record.formula.AreaI.OffsetArea;
+import org.apache.poi.ss.formula.ptg.AreaI.OffsetArea;
 import org.apache.poi.ss.formula.eval.AreaEval;
 import org.apache.poi.ss.formula.eval.AreaEvalBase;
 import org.apache.poi.ss.formula.eval.ValueEval;
-import org.apache.poi.hssf.util.CellReference;
+import org.apache.poi.ss.util.CellReference;
 
 /**
  *

src/java/org/apache/poi/ss/formula/LazyRefEval.java

@@ -17,12 +17,12 @@
 
 package org.apache.poi.ss.formula;
 
-import org.apache.poi.hssf.record.formula.AreaI;
+import org.apache.poi.ss.formula.ptg.AreaI;
-import org.apache.poi.hssf.record.formula.AreaI.OffsetArea;
+import org.apache.poi.ss.formula.ptg.AreaI.OffsetArea;
 import org.apache.poi.ss.formula.eval.AreaEval;
 import org.apache.poi.ss.formula.eval.RefEvalBase;
 import org.apache.poi.ss.formula.eval.ValueEval;
-import org.apache.poi.hssf.util.CellReference;
+import org.apache.poi.ss.util.CellReference;
 
 /**
 *

src/java/org/apache/poi/ss/formula/OperandClassTransformer.java

@@ -17,16 +17,16 @@
 
 package org.apache.poi.ss.formula;
 
-import org.apache.poi.hssf.record.formula.AbstractFunctionPtg;
+import org.apache.poi.ss.formula.ptg.AbstractFunctionPtg;
-import org.apache.poi.hssf.record.formula.AttrPtg;
+import org.apache.poi.ss.formula.ptg.AttrPtg;
-import org.apache.poi.hssf.record.formula.ControlPtg;
+import org.apache.poi.ss.formula.ptg.ControlPtg;
-import org.apache.poi.hssf.record.formula.FuncVarPtg;
+import org.apache.poi.ss.formula.ptg.FuncVarPtg;
-import org.apache.poi.hssf.record.formula.MemAreaPtg;
+import org.apache.poi.ss.formula.ptg.MemAreaPtg;
-import org.apache.poi.hssf.record.formula.MemFuncPtg;
+import org.apache.poi.ss.formula.ptg.MemFuncPtg;
-import org.apache.poi.hssf.record.formula.Ptg;
+import org.apache.poi.ss.formula.ptg.Ptg;
-import org.apache.poi.hssf.record.formula.RangePtg;
+import org.apache.poi.ss.formula.ptg.RangePtg;
-import org.apache.poi.hssf.record.formula.UnionPtg;
+import org.apache.poi.ss.formula.ptg.UnionPtg;
-import org.apache.poi.hssf.record.formula.ValueOperatorPtg;
+import org.apache.poi.ss.formula.ptg.ValueOperatorPtg;
 
 /**
  * This class performs 'operand class' transformation. Non-base tokens are classified into three

src/java/org/apache/poi/ss/formula/OperationEvaluationContext.java

@@ -17,10 +17,10 @@
 
 package org.apache.poi.ss.formula;
 
-import org.apache.poi.hssf.record.formula.Area3DPtg;
+import org.apache.poi.ss.formula.ptg.Area3DPtg;
-import org.apache.poi.hssf.record.formula.NameXPtg;
+import org.apache.poi.ss.formula.ptg.NameXPtg;
-import org.apache.poi.hssf.record.formula.Ptg;
+import org.apache.poi.ss.formula.ptg.Ptg;
-import org.apache.poi.hssf.record.formula.Ref3DPtg;
+import org.apache.poi.ss.formula.ptg.Ref3DPtg;
 import org.apache.poi.ss.formula.eval.*;
 import org.apache.poi.ss.formula.functions.FreeRefFunction;
 import org.apache.poi.ss.SpreadsheetVersion;

src/java/org/apache/poi/ss/formula/OperationEvaluatorFactory.java

@@ -22,25 +22,25 @@ import java.lang.reflect.Modifier;
 import java.util.HashMap;
 import java.util.Map;
 
-import org.apache.poi.hssf.record.formula.AbstractFunctionPtg;
+import org.apache.poi.ss.formula.ptg.AbstractFunctionPtg;
-import org.apache.poi.hssf.record.formula.AddPtg;
+import org.apache.poi.ss.formula.ptg.AddPtg;
-import org.apache.poi.hssf.record.formula.ConcatPtg;
+import org.apache.poi.ss.formula.ptg.ConcatPtg;
-import org.apache.poi.hssf.record.formula.DividePtg;
+import org.apache.poi.ss.formula.ptg.DividePtg;
-import org.apache.poi.hssf.record.formula.EqualPtg;
+import org.apache.poi.ss.formula.ptg.EqualPtg;
-import org.apache.poi.hssf.record.formula.GreaterEqualPtg;
+import org.apache.poi.ss.formula.ptg.GreaterEqualPtg;
-import org.apache.poi.hssf.record.formula.GreaterThanPtg;
+import org.apache.poi.ss.formula.ptg.GreaterThanPtg;
-import org.apache.poi.hssf.record.formula.IntersectionPtg;
+import org.apache.poi.ss.formula.ptg.IntersectionPtg;
-import org.apache.poi.hssf.record.formula.LessEqualPtg;
+import org.apache.poi.ss.formula.ptg.LessEqualPtg;
-import org.apache.poi.hssf.record.formula.LessThanPtg;
+import org.apache.poi.ss.formula.ptg.LessThanPtg;
-import org.apache.poi.hssf.record.formula.MultiplyPtg;
+import org.apache.poi.ss.formula.ptg.MultiplyPtg;
-import org.apache.poi.hssf.record.formula.NotEqualPtg;
+import org.apache.poi.ss.formula.ptg.NotEqualPtg;
-import org.apache.poi.hssf.record.formula.OperationPtg;
+import org.apache.poi.ss.formula.ptg.OperationPtg;
-import org.apache.poi.hssf.record.formula.PercentPtg;
+import org.apache.poi.ss.formula.ptg.PercentPtg;
-import org.apache.poi.hssf.record.formula.PowerPtg;
+import org.apache.poi.ss.formula.ptg.PowerPtg;
-import org.apache.poi.hssf.record.formula.RangePtg;
+import org.apache.poi.ss.formula.ptg.RangePtg;
-import org.apache.poi.hssf.record.formula.SubtractPtg;
+import org.apache.poi.ss.formula.ptg.SubtractPtg;
-import org.apache.poi.hssf.record.formula.UnaryMinusPtg;
+import org.apache.poi.ss.formula.ptg.UnaryMinusPtg;
-import org.apache.poi.hssf.record.formula.UnaryPlusPtg;
+import org.apache.poi.ss.formula.ptg.UnaryPlusPtg;
 import org.apache.poi.ss.formula.eval.ConcatEval;
 import org.apache.poi.ss.formula.eval.FunctionEval;
 import org.apache.poi.ss.formula.eval.IntersectionEval;

src/java/org/apache/poi/ss/formula/ParseNode.java

@@ -17,12 +17,12 @@
 
 package org.apache.poi.ss.formula;
 
-import org.apache.poi.hssf.record.formula.ArrayPtg;
+import org.apache.poi.ss.formula.ptg.ArrayPtg;
-import org.apache.poi.hssf.record.formula.AttrPtg;
+import org.apache.poi.ss.formula.ptg.AttrPtg;
-import org.apache.poi.hssf.record.formula.FuncVarPtg;
+import org.apache.poi.ss.formula.ptg.FuncVarPtg;
-import org.apache.poi.hssf.record.formula.MemAreaPtg;
+import org.apache.poi.ss.formula.ptg.MemAreaPtg;
-import org.apache.poi.hssf.record.formula.MemFuncPtg;
+import org.apache.poi.ss.formula.ptg.MemFuncPtg;
-import org.apache.poi.hssf.record.formula.Ptg;
+import org.apache.poi.ss.formula.ptg.Ptg;
 import org.apache.poi.ss.formula.function.FunctionMetadataRegistry;
 /**
  * Represents a syntactic element from a formula by encapsulating the corresponding <tt>Ptg</tt>

src/java/org/apache/poi/ss/formula/SharedFormula.java

@@ -16,7 +16,7 @@
 ==================================================================== */
 package org.apache.poi.ss.formula;
 
-import org.apache.poi.hssf.record.formula.*;
+import org.apache.poi.ss.formula.ptg.*;
 import org.apache.poi.ss.SpreadsheetVersion;
 
 /**
@@ -34,7 +34,7 @@ public class SharedFormula {
 
     /**
      * Creates a non shared formula from the shared formula counterpart, i.e.
-     * Converts the shared formula into the equivalent {@link org.apache.poi.hssf.record.formula.Ptg} array that it would have,
+     * Converts the shared formula into the equivalent {@link org.apache.poi.ss.formula.ptg.Ptg} array that it would have,
      * were it not shared.
      *
      * @param ptgs parsed tokens of the shared formula

src/java/org/apache/poi/ss/formula/WorkbookDependentFormula.java

@@ -18,7 +18,7 @@
 package org.apache.poi.ss.formula;
 
 /**
- * Should be implemented by any {@link org.apache.poi.hssf.record.formula.Ptg} subclass that needs a workbook to render its formula.
+ * Should be implemented by any {@link org.apache.poi.ss.formula.ptg.Ptg} subclass that needs a workbook to render its formula.
  * <br/>
  *
  * For POI internal use only

src/java/org/apache/poi/ss/formula/WorkbookEvaluator.java

@@ -21,33 +21,33 @@ import java.util.IdentityHashMap;
 import java.util.Map;
 import java.util.Stack;
 
-import org.apache.poi.hssf.record.formula.Area3DPtg;
+import org.apache.poi.ss.formula.ptg.Area3DPtg;
-import org.apache.poi.hssf.record.formula.AreaErrPtg;
+import org.apache.poi.ss.formula.ptg.AreaErrPtg;
-import org.apache.poi.hssf.record.formula.AreaPtg;
+import org.apache.poi.ss.formula.ptg.AreaPtg;
-import org.apache.poi.hssf.record.formula.AttrPtg;
+import org.apache.poi.ss.formula.ptg.AttrPtg;
-import org.apache.poi.hssf.record.formula.BoolPtg;
+import org.apache.poi.ss.formula.ptg.BoolPtg;
-import org.apache.poi.hssf.record.formula.ControlPtg;
+import org.apache.poi.ss.formula.ptg.ControlPtg;
-import org.apache.poi.hssf.record.formula.DeletedArea3DPtg;
+import org.apache.poi.ss.formula.ptg.DeletedArea3DPtg;
-import org.apache.poi.hssf.record.formula.DeletedRef3DPtg;
+import org.apache.poi.ss.formula.ptg.DeletedRef3DPtg;
-import org.apache.poi.hssf.record.formula.ErrPtg;
+import org.apache.poi.ss.formula.ptg.ErrPtg;
-import org.apache.poi.hssf.record.formula.ExpPtg;
+import org.apache.poi.ss.formula.ptg.ExpPtg;
-import org.apache.poi.hssf.record.formula.FuncVarPtg;
+import org.apache.poi.ss.formula.ptg.FuncVarPtg;
-import org.apache.poi.hssf.record.formula.IntPtg;
+import org.apache.poi.ss.formula.ptg.IntPtg;
-import org.apache.poi.hssf.record.formula.MemAreaPtg;
+import org.apache.poi.ss.formula.ptg.MemAreaPtg;
-import org.apache.poi.hssf.record.formula.MemErrPtg;
+import org.apache.poi.ss.formula.ptg.MemErrPtg;
-import org.apache.poi.hssf.record.formula.MemFuncPtg;
+import org.apache.poi.ss.formula.ptg.MemFuncPtg;
-import org.apache.poi.hssf.record.formula.MissingArgPtg;
+import org.apache.poi.ss.formula.ptg.MissingArgPtg;
-import org.apache.poi.hssf.record.formula.NamePtg;
+import org.apache.poi.ss.formula.ptg.NamePtg;
-import org.apache.poi.hssf.record.formula.NameXPtg;
+import org.apache.poi.ss.formula.ptg.NameXPtg;
-import org.apache.poi.hssf.record.formula.NumberPtg;
+import org.apache.poi.ss.formula.ptg.NumberPtg;
-import org.apache.poi.hssf.record.formula.OperationPtg;
+import org.apache.poi.ss.formula.ptg.OperationPtg;
-import org.apache.poi.hssf.record.formula.Ptg;
+import org.apache.poi.ss.formula.ptg.Ptg;
-import org.apache.poi.hssf.record.formula.Ref3DPtg;
+import org.apache.poi.ss.formula.ptg.Ref3DPtg;
-import org.apache.poi.hssf.record.formula.RefErrorPtg;
+import org.apache.poi.ss.formula.ptg.RefErrorPtg;
-import org.apache.poi.hssf.record.formula.RefPtg;
+import org.apache.poi.ss.formula.ptg.RefPtg;
-import org.apache.poi.hssf.record.formula.StringPtg;
+import org.apache.poi.ss.formula.ptg.StringPtg;
-import org.apache.poi.hssf.record.formula.UnionPtg;
+import org.apache.poi.ss.formula.ptg.UnionPtg;
-import org.apache.poi.hssf.record.formula.UnknownPtg;
+import org.apache.poi.ss.formula.ptg.UnknownPtg;
 import org.apache.poi.ss.formula.eval.BlankEval;
 import org.apache.poi.ss.formula.eval.BoolEval;
 import org.apache.poi.ss.formula.eval.ErrorEval;
@@ -63,7 +63,7 @@ import org.apache.poi.ss.formula.functions.FreeRefFunction;
 import org.apache.poi.ss.formula.functions.IfFunc;
 import org.apache.poi.ss.formula.udf.UDFFinder;
 import org.apache.poi.hssf.usermodel.HSSFEvaluationWorkbook;
-import org.apache.poi.hssf.util.CellReference;
+import org.apache.poi.ss.util.CellReference;
 import org.apache.poi.ss.formula.CollaboratingWorkbooksEnvironment.WorkbookNotFoundException;
 import org.apache.poi.ss.formula.eval.NotImplementedException;
 import org.apache.poi.ss.usermodel.Cell;

src/java/org/apache/poi/ss/formula/constant/ConstantValueParser.java

@@ -0,0 +1,157 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.constant;
+
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+import org.apache.poi.util.StringUtil;
+
+/**
+ * To support Constant Values (2.5.7) as required by the CRN record.
+ * This class is also used for two dimensional arrays which are encoded by 
+ * EXTERNALNAME (5.39) records and Array tokens.<p/>
+ * 
+ * @author Josh Micich
+ */
+public final class ConstantValueParser {
+	// note - these (non-combinable) enum values are sparse.
+	private static final int TYPE_EMPTY = 0;
+	private static final int TYPE_NUMBER = 1;
+	private static final int TYPE_STRING = 2;
+	private static final int TYPE_BOOLEAN = 4; 
+	private static final int TYPE_ERROR_CODE = 16; // TODO - update OOO document to include this value
+	
+	private static final int TRUE_ENCODING = 1; 
+	private static final int FALSE_ENCODING = 0;
+	
+	// TODO - is this the best way to represent 'EMPTY'?
+	private static final Object EMPTY_REPRESENTATION = null;
+
+	private ConstantValueParser() {
+		// no instances of this class
+	}
+
+	public static Object[] parse(LittleEndianInput in, int nValues) {
+		Object[] result = new Object[nValues];
+		for (int i = 0; i < result.length; i++) {
+			result[i] = readAConstantValue(in);
+		}
+		return result;
+	}
+
+	private static Object readAConstantValue(LittleEndianInput in) {
+		byte grbit = in.readByte();
+		switch(grbit) {
+			case TYPE_EMPTY:
+				in.readLong(); // 8 byte 'not used' field
+				return EMPTY_REPRESENTATION; 
+			case TYPE_NUMBER:
+				return new Double(in.readDouble());
+			case TYPE_STRING:
+				return StringUtil.readUnicodeString(in);
+			case TYPE_BOOLEAN:
+				return readBoolean(in);
+			case TYPE_ERROR_CODE:
+				int errCode = in.readUShort();
+				// next 6 bytes are unused
+				in.readUShort();
+				in.readInt();
+				return ErrorConstant.valueOf(errCode);
+		}
+		throw new RuntimeException("Unknown grbit value (" + grbit + ")");
+	}
+
+	private static Object readBoolean(LittleEndianInput in) {
+		byte val = (byte)in.readLong(); // 7 bytes 'not used'
+		switch(val) {
+			case FALSE_ENCODING:
+				return Boolean.FALSE;
+			case TRUE_ENCODING:
+				return Boolean.TRUE;
+		}
+		// Don't tolerate unusual boolean encoded values (unless it becomes evident that they occur)
+		throw new RuntimeException("unexpected boolean encoding (" + val + ")");
+	}
+
+	public static int getEncodedSize(Object[] values) {
+		// start with one byte 'type' code for each value
+		int result = values.length * 1;
+		for (int i = 0; i < values.length; i++) {
+			result += getEncodedSize(values[i]);
+		}
+		return result;
+	}
+
+	/**
+	 * @return encoded size without the 'type' code byte
+	 */
+	private static int getEncodedSize(Object object) {
+		if(object == EMPTY_REPRESENTATION) {
+			return 8;
+		}
+		Class cls = object.getClass();
+		
+		if(cls == Boolean.class || cls == Double.class || cls == ErrorConstant.class) {
+			return 8;
+		}
+		String strVal = (String)object;
+		return StringUtil.getEncodedSize(strVal);
+	}
+
+	public static void encode(LittleEndianOutput out, Object[] values) {
+		for (int i = 0; i < values.length; i++) {
+			encodeSingleValue(out, values[i]);
+		}
+	}
+
+	private static void encodeSingleValue(LittleEndianOutput out, Object value) {
+		if (value == EMPTY_REPRESENTATION) {
+			out.writeByte(TYPE_EMPTY);
+			out.writeLong(0L);
+			return;
+		}
+		if (value instanceof Boolean) {
+			Boolean bVal = ((Boolean)value);
+			out.writeByte(TYPE_BOOLEAN);
+			long longVal = bVal.booleanValue() ? 1L : 0L;
+			out.writeLong(longVal);
+			return;
+		}
+		if (value instanceof Double) {
+			Double dVal = (Double) value;
+			out.writeByte(TYPE_NUMBER);
+			out.writeDouble(dVal.doubleValue());
+			return;
+		}
+		if (value instanceof String) {
+			String val = (String) value;
+			out.writeByte(TYPE_STRING);
+			StringUtil.writeUnicodeString(out, val);
+			return;
+		}
+		if (value instanceof ErrorConstant) {
+			ErrorConstant ecVal = (ErrorConstant) value;
+			out.writeByte(TYPE_ERROR_CODE);
+			long longVal = ecVal.getErrorCode();
+			out.writeLong(longVal);
+			return;
+		}
+
+		throw new IllegalStateException("Unexpected value type (" + value.getClass().getName() + "'");
+	}
+}

src/java/org/apache/poi/ss/formula/constant/ErrorConstant.java

@@ -0,0 +1,77 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.constant;
+
+import org.apache.poi.ss.usermodel.ErrorConstants;
+/**
+ * Represents a constant error code value as encoded in a constant values array. <p/>
+ * 
+ * This class is a type-safe wrapper for a 16-bit int value performing a similar job to 
+ * <tt>ErrorEval</tt>.
+ * 
+ * @author Josh Micich
+ */
+public class ErrorConstant {
+	// convenient access to name space
+	private static final ErrorConstants EC = null;
+
+	private static final ErrorConstant NULL = new ErrorConstant(EC.ERROR_NULL);
+	private static final ErrorConstant DIV_0 = new ErrorConstant(EC.ERROR_DIV_0);
+	private static final ErrorConstant VALUE = new ErrorConstant(EC.ERROR_VALUE);
+	private static final ErrorConstant REF = new ErrorConstant(EC.ERROR_REF);
+	private static final ErrorConstant NAME = new ErrorConstant(EC.ERROR_NAME);
+	private static final ErrorConstant NUM = new ErrorConstant(EC.ERROR_NUM);
+	private static final ErrorConstant NA = new ErrorConstant(EC.ERROR_NA);
+
+	private final int _errorCode;
+
+	private ErrorConstant(int errorCode) {
+		_errorCode = errorCode;
+	}
+	
+	public int getErrorCode() {
+		return _errorCode;
+	}
+	public String getText() {
+		if(ErrorConstants.isValidCode(_errorCode)) {
+			return ErrorConstants.getText(_errorCode);
+		}
+		return "unknown error code (" + _errorCode + ")";
+	}
+
+	public static ErrorConstant valueOf(int errorCode) {
+		switch (errorCode) {
+			case ErrorConstants.ERROR_NULL:  return NULL;
+			case ErrorConstants.ERROR_DIV_0: return DIV_0;
+			case ErrorConstants.ERROR_VALUE: return VALUE;
+			case ErrorConstants.ERROR_REF:   return REF;
+			case ErrorConstants.ERROR_NAME:  return NAME;
+			case ErrorConstants.ERROR_NUM:   return NUM;
+			case ErrorConstants.ERROR_NA:	return NA;
+		}
+		System.err.println("Warning - unexpected error code (" + errorCode + ")");
+		return new ErrorConstant(errorCode);
+	}
+	public String toString() {
+		StringBuffer sb = new StringBuffer(64);
+		sb.append(getClass().getName()).append(" [");
+		sb.append(getText());
+		sb.append("]");
+		return sb.toString();
+	}
+}

src/java/org/apache/poi/ss/formula/eval/AreaEvalBase.java

@@ -17,7 +17,7 @@
 
 package org.apache.poi.ss.formula.eval;
 
-import org.apache.poi.hssf.record.formula.AreaI;
+import org.apache.poi.ss.formula.ptg.AreaI;
 
 /**
  * @author Josh Micich

src/java/org/apache/poi/ss/formula/eval/NameXEval.java

@@ -17,7 +17,7 @@
 
 package org.apache.poi.ss.formula.eval;
 
-import org.apache.poi.hssf.record.formula.NameXPtg;
+import org.apache.poi.ss.formula.ptg.NameXPtg;
 
 /**
  * @author Josh Micich

src/java/org/apache/poi/ss/formula/eval/NumberEval.java

@@ -20,9 +20,9 @@
  */
 package org.apache.poi.ss.formula.eval;
 
-import org.apache.poi.hssf.record.formula.IntPtg;
+import org.apache.poi.ss.formula.ptg.IntPtg;
-import org.apache.poi.hssf.record.formula.NumberPtg;
+import org.apache.poi.ss.formula.ptg.NumberPtg;
-import org.apache.poi.hssf.record.formula.Ptg;
+import org.apache.poi.ss.formula.ptg.Ptg;
 import org.apache.poi.ss.util.NumberToTextConverter;
 
 /**

src/java/org/apache/poi/ss/formula/eval/StringEval.java

@@ -17,8 +17,8 @@
 
 package org.apache.poi.ss.formula.eval;
 
-import org.apache.poi.hssf.record.formula.Ptg;
+import org.apache.poi.ss.formula.ptg.Ptg;
-import org.apache.poi.hssf.record.formula.StringPtg;
+import org.apache.poi.ss.formula.ptg.StringPtg;
 
 /**
  * @author Amol S. Deshmukh < amolweb at ya hoo dot com >

src/java/org/apache/poi/ss/formula/eval/forked/ForkedEvaluationWorkbook.java

@@ -20,9 +20,9 @@ package org.apache.poi.ss.formula.eval.forked;
 import java.util.HashMap;
 import java.util.Map;
 
-import org.apache.poi.hssf.record.formula.NamePtg;
+import org.apache.poi.ss.formula.ptg.NamePtg;
-import org.apache.poi.hssf.record.formula.NameXPtg;
+import org.apache.poi.ss.formula.ptg.NameXPtg;
-import org.apache.poi.hssf.record.formula.Ptg;
+import org.apache.poi.ss.formula.ptg.Ptg;
 import org.apache.poi.ss.formula.EvaluationCell;
 import org.apache.poi.ss.formula.EvaluationName;
 import org.apache.poi.ss.formula.EvaluationSheet;

src/java/org/apache/poi/ss/formula/function/FunctionMetadataReader.java

@@ -27,7 +27,7 @@ import java.util.HashSet;
 import java.util.Set;
 import java.util.regex.Pattern;
 
-import org.apache.poi.hssf.record.formula.Ptg;
+import org.apache.poi.ss.formula.ptg.Ptg;
 
 /**
  * Converts the text meta-data file into a <tt>FunctionMetadataRegistry</tt>

src/java/org/apache/poi/ss/formula/ptg/AbstractFunctionPtg.java

@@ -0,0 +1,164 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.formula.function.FunctionMetadata;
+import org.apache.poi.ss.formula.function.FunctionMetadataRegistry;
+
+
+/**
+ * This class provides the base functionality for Excel sheet functions
+ * There are two kinds of function Ptgs - tFunc and tFuncVar
+ * Therefore, this class will have ONLY two subclasses
+ * @author  Avik Sengupta
+ * @author Andrew C. Oliver (acoliver at apache dot org)
+ */
+public abstract class AbstractFunctionPtg extends OperationPtg {
+
+    /**
+     * The name of the IF function (i.e. "IF").  Extracted as a constant for clarity.
+     */
+    public static final String FUNCTION_NAME_IF = "IF";
+    /** All external functions have function index 255 */
+    private static final short FUNCTION_INDEX_EXTERNAL = 255;
+
+    private final byte returnClass;
+    private final byte[] paramClass;
+
+    private final byte _numberOfArgs;
+    private final short _functionIndex;
+
+    protected AbstractFunctionPtg(int functionIndex, int pReturnClass, byte[] paramTypes, int nParams) {
+        _numberOfArgs = (byte) nParams;
+        _functionIndex = (short) functionIndex;
+        returnClass = (byte) pReturnClass;
+        paramClass = paramTypes;
+    }
+    public final boolean isBaseToken() {
+        return false;
+    }
+
+    public final String toString() {
+        StringBuilder sb = new StringBuilder(64);
+        sb.append(getClass().getName()).append(" [");
+        sb.append(lookupName(_functionIndex));
+        sb.append(" nArgs=").append(_numberOfArgs);
+        sb.append("]");
+        return sb.toString();
+    }
+
+    public final short getFunctionIndex() {
+        return _functionIndex;
+    }
+    public final int getNumberOfOperands() {
+        return _numberOfArgs;
+    }
+
+    public final String getName() {
+        return lookupName(_functionIndex);
+    }
+    /**
+     * external functions get some special processing
+     * @return <code>true</code> if this is an external function
+     */
+    public final boolean isExternalFunction() {
+        return _functionIndex == FUNCTION_INDEX_EXTERNAL;
+    }
+
+    public final String toFormulaString() {
+        return getName();
+    }
+
+    public String toFormulaString(String[] operands) {
+        StringBuilder buf = new StringBuilder();
+
+        if(isExternalFunction()) {
+            buf.append(operands[0]); // first operand is actually the function name
+            appendArgs(buf, 1, operands);
+        } else {
+            buf.append(getName());
+            appendArgs(buf, 0, operands);
+        }
+        return buf.toString();
+    }
+
+    private static void appendArgs(StringBuilder buf, int firstArgIx, String[] operands) {
+        buf.append('(');
+        for (int i=firstArgIx;i<operands.length;i++) {
+            if (i>firstArgIx) {
+                buf.append(',');
+            }
+            buf.append(operands[i]);
+        }
+        buf.append(")");
+    }
+
+    public abstract int getSize();
+
+
+    /**
+     * Used to detect whether a function name found in a formula is one of the standard excel functions
+     * <p>
+     * The name matching is case insensitive.
+     * @return <code>true</code> if the name specifies a standard worksheet function,
+     *  <code>false</code> if the name should be assumed to be an external function.
+     */
+    public static final boolean isBuiltInFunctionName(String name) {
+        short ix = FunctionMetadataRegistry.lookupIndexByName(name.toUpperCase());
+        return ix >= 0;
+    }
+
+    protected final String lookupName(short index) {
+        if(index == FunctionMetadataRegistry.FUNCTION_INDEX_EXTERNAL) {
+            return "#external#";
+        }
+        FunctionMetadata fm = FunctionMetadataRegistry.getFunctionByIndex(index);
+        if(fm == null) {
+            throw new RuntimeException("bad function index (" + index + ")");
+        }
+        return fm.getName();
+    }
+
+    /**
+     * Resolves internal function names into function indexes.
+     * <p>
+     * The name matching is case insensitive.
+     * @return the standard worksheet function index if found, otherwise <tt>FUNCTION_INDEX_EXTERNAL</tt>
+     */
+    protected static short lookupIndex(String name) {
+        short ix = FunctionMetadataRegistry.lookupIndexByName(name.toUpperCase());
+        if (ix < 0) {
+            return FUNCTION_INDEX_EXTERNAL;
+        }
+        return ix;
+    }
+
+    public byte getDefaultOperandClass() {
+        return returnClass;
+    }
+
+    public final byte getParameterClass(int index) {
+        if (index >= paramClass.length) {
+            // For var-arg (and other?) functions, the metadata does not list all the parameter
+            // operand classes.  In these cases, all extra parameters are assumed to have the
+            // same operand class as the last one specified.
+            return paramClass[paramClass.length - 1];
+        }
+        return paramClass[index];
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/AddPtg.java

@@ -0,0 +1,54 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+/**
+ * Addition operator PTG the "+" binomial operator.  If you need more 
+ * explanation than that then well...We really can't help you here.
+ * @author  Andrew C. Oliver (acoliver@apache.org)
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class AddPtg extends ValueOperatorPtg {
+    public final static byte sid  = 0x03;
+    
+    private final static String ADD = "+";
+
+    public static final ValueOperatorPtg instance = new AddPtg();
+
+    private AddPtg() {
+    	// enforce singleton
+    }
+    
+    protected byte getSid() {
+    	return sid;
+    }
+
+    public int getNumberOfOperands() {
+        return 2;
+    }
+       
+   /** implementation of method from OperationsPtg*/  
+    public String toFormulaString(String[] operands) {
+        StringBuffer buffer = new StringBuffer();
+
+        buffer.append(operands[ 0 ]);
+        buffer.append(ADD);
+        buffer.append(operands[ 1 ]);
+        return buffer.toString();
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/Area2DPtgBase.java

@@ -0,0 +1,64 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.util.AreaReference;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * Common superclass of 2-D area refs
+ */
+public abstract class Area2DPtgBase extends AreaPtgBase {
+	private final static int SIZE = 9;
+
+	protected Area2DPtgBase(int firstRow, int lastRow, int firstColumn, int lastColumn, boolean firstRowRelative, boolean lastRowRelative, boolean firstColRelative, boolean lastColRelative) {
+		super(firstRow, lastRow, firstColumn, lastColumn, firstRowRelative, lastRowRelative, firstColRelative, lastColRelative);
+	}
+	protected Area2DPtgBase(AreaReference ar) {
+		super(ar);
+	}
+
+	protected Area2DPtgBase(LittleEndianInput in)  {
+		readCoordinates(in);
+	}
+
+	protected abstract byte getSid();
+
+	public final void write(LittleEndianOutput out) {
+		out.writeByte(getSid() + getPtgClass());
+		writeCoordinates(out);
+	}
+
+	public final int getSize() {
+		return SIZE;
+	}
+
+	public final String toFormulaString() {
+		return formatReferenceAsString();
+	}
+
+	public final String toString() {
+		StringBuffer sb = new StringBuffer();
+		sb.append(getClass().getName());
+		sb.append(" [");
+		sb.append(formatReferenceAsString());
+		sb.append("]");
+		return sb.toString();
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/Area3DPtg.java

@@ -0,0 +1,105 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.util.AreaReference;
+import org.apache.poi.ss.formula.ExternSheetReferenceToken;
+import org.apache.poi.ss.formula.FormulaRenderingWorkbook;
+import org.apache.poi.ss.formula.WorkbookDependentFormula;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * Title:        Area 3D Ptg - 3D reference (Sheet + Area)<P>
+ * Description:  Defined a area in Extern Sheet. <P>
+ * REFERENCE:  <P>
+ * @author Libin Roman (Vista Portal LDT. Developer)
+ * @author avik
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class Area3DPtg extends AreaPtgBase implements WorkbookDependentFormula, ExternSheetReferenceToken {
+	public final static byte sid = 0x3b;
+	private final static int SIZE = 11; // 10 + 1 for Ptg
+
+	private int field_1_index_extern_sheet;
+
+
+	public Area3DPtg(String arearef, int externIdx) {
+		super(new AreaReference(arearef));
+		setExternSheetIndex(externIdx);
+	}
+
+	public Area3DPtg(LittleEndianInput in)  {
+		field_1_index_extern_sheet = in.readShort();
+		readCoordinates(in);
+	}
+
+	public Area3DPtg(int firstRow, int lastRow, int firstColumn, int lastColumn,
+			boolean firstRowRelative, boolean lastRowRelative, boolean firstColRelative, boolean lastColRelative,
+			int externalSheetIndex) {
+		super(firstRow, lastRow, firstColumn, lastColumn, firstRowRelative, lastRowRelative, firstColRelative, lastColRelative);
+		setExternSheetIndex(externalSheetIndex);
+	}
+
+	public Area3DPtg(AreaReference arearef, int externIdx) {
+		super(arearef);
+		setExternSheetIndex(externIdx);
+	}
+
+	public String toString() {
+		StringBuffer sb = new StringBuffer();
+		sb.append(getClass().getName());
+		sb.append(" [");
+		sb.append("sheetIx=").append(getExternSheetIndex());
+		sb.append(" ! ");
+		sb.append(formatReferenceAsString());
+		sb.append("]");
+		return sb.toString();
+	}
+
+	public void write(LittleEndianOutput out) {
+		out.writeByte(sid + getPtgClass());
+		out.writeShort(field_1_index_extern_sheet);
+		writeCoordinates(out);
+	}
+
+	public int getSize() {
+		return SIZE;
+	}
+
+	public int getExternSheetIndex() {
+		return field_1_index_extern_sheet;
+	}
+
+	public void setExternSheetIndex(int index) {
+		field_1_index_extern_sheet = index;
+	}
+	public String format2DRefAsString() {
+		return formatReferenceAsString();
+	}
+	/**
+	 * @return text representation of this area reference that can be used in text
+	 *  formulas. The sheet name will get properly delimited if required.
+	 */
+	public String toFormulaString(FormulaRenderingWorkbook book) {
+		return ExternSheetNameResolver.prependSheetName(book, field_1_index_extern_sheet, formatReferenceAsString());
+	}
+	public String toFormulaString() {
+		throw new RuntimeException("3D references need a workbook to determine formula text");
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/AreaErrPtg.java

@@ -0,0 +1,63 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.usermodel.ErrorConstants;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * AreaErr - handles deleted cell area references.
+ *
+ * @author Daniel Noll (daniel at nuix dot com dot au)
+ */
+public final class AreaErrPtg extends OperandPtg {
+	public final static byte sid = 0x2B;
+	private final int unused1;
+	private final int unused2;
+
+	public AreaErrPtg() {
+		unused1 = 0;
+		unused2 = 0;
+	}
+
+	public AreaErrPtg(LittleEndianInput in)  {
+		// 8 bytes unused:
+		unused1 = in.readInt();
+		unused2 = in.readInt();
+	}
+
+	public void write(LittleEndianOutput out) {
+		out.writeByte(sid + getPtgClass());
+		out.writeInt(unused1);
+		out.writeInt(unused2);
+	}
+
+	public String toFormulaString() {
+		return ErrorConstants.getText(ErrorConstants.ERROR_REF);
+	}
+
+	public byte getDefaultOperandClass() {
+		return Ptg.CLASS_REF;
+	}
+
+	public int getSize() {
+		return 9;
+	}
+}
+

src/java/org/apache/poi/ss/formula/ptg/AreaI.java

@@ -0,0 +1,75 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+/**
+ * Common interface for AreaPtg and Area3DPtg, and their child classes.
+ */
+public interface AreaI {
+	/**
+	 * @return the first row in the area
+	 */
+	public int getFirstRow();
+
+	/**
+	 * @return last row in the range (x2 in x1,y1-x2,y2)
+	 */
+	public int getLastRow();
+
+	/**
+	 * @return the first column number in the area.
+	 */
+	public int getFirstColumn();
+
+	/**
+	 * @return lastcolumn in the area
+	 */
+	public int getLastColumn();
+
+	class OffsetArea implements AreaI {
+
+		private final int _firstColumn;
+		private final int _firstRow;
+		private final int _lastColumn;
+		private final int _lastRow;
+
+		public OffsetArea(int baseRow, int baseColumn, int relFirstRowIx, int relLastRowIx,
+				int relFirstColIx, int relLastColIx) {
+			_firstRow = baseRow + Math.min(relFirstRowIx, relLastRowIx);
+			_lastRow = baseRow + Math.max(relFirstRowIx, relLastRowIx);
+			_firstColumn = baseColumn + Math.min(relFirstColIx, relLastColIx);
+			_lastColumn = baseColumn + Math.max(relFirstColIx, relLastColIx);
+		}
+
+		public int getFirstColumn() {
+			return _firstColumn;
+		}
+
+		public int getFirstRow() {
+			return _firstRow;
+		}
+
+		public int getLastColumn() {
+			return _lastColumn;
+		}
+
+		public int getLastRow() {
+			return _lastRow;
+		}
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/AreaNPtg.java

@@ -0,0 +1,36 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.util.LittleEndianInput;
+
+/**
+ * Specifies a rectangular area of cells A1:A4 for instance.
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class AreaNPtg extends Area2DPtgBase {
+	public final static short sid = 0x2D;
+
+	public AreaNPtg(LittleEndianInput in)  {
+		super(in);
+	}
+
+	protected byte getSid() {
+		return sid;
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/AreaPtg.java

@@ -0,0 +1,45 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.util.AreaReference;
+import org.apache.poi.util.LittleEndianInput;
+
+/**
+ * Specifies a rectangular area of cells A1:A4 for instance.
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class AreaPtg extends Area2DPtgBase {
+	public final static short sid  = 0x25;
+
+	public AreaPtg(int firstRow, int lastRow, int firstColumn, int lastColumn, boolean firstRowRelative, boolean lastRowRelative, boolean firstColRelative, boolean lastColRelative) {
+		super(firstRow, lastRow, firstColumn, lastColumn, firstRowRelative, lastRowRelative, firstColRelative, lastColRelative);
+	}
+	public AreaPtg(LittleEndianInput in)  {
+		super(in);
+	}
+	public AreaPtg(String arearef) {
+		super(new AreaReference(arearef));
+	}
+	public AreaPtg(AreaReference areaRef) {
+		super(areaRef);
+	}
+	protected byte getSid() {
+		return sid;
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/AreaPtgBase.java

@@ -0,0 +1,272 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.util.AreaReference;
+import org.apache.poi.ss.util.CellReference;
+import org.apache.poi.util.BitField;
+import org.apache.poi.util.BitFieldFactory;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * Specifies a rectangular area of cells A1:A4 for instance.
+ * @author  andy
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public abstract class AreaPtgBase extends OperandPtg implements AreaI {
+	/**
+	 * TODO - (May-2008) fix subclasses of AreaPtg 'AreaN~' which are used in shared formulas.
+	 * see similar comment in ReferencePtg
+	 */
+	protected final RuntimeException notImplemented() {
+		return new RuntimeException("Coding Error: This method should never be called. This ptg should be converted");
+	}
+
+	/** zero based, unsigned 16 bit */
+	private int             field_1_first_row;
+	/** zero based, unsigned 16 bit */
+	private int             field_2_last_row;
+	/** zero based, unsigned 8 bit */
+	private int             field_3_first_column;
+	/** zero based, unsigned 8 bit */
+	private int             field_4_last_column;
+
+	private final static BitField   rowRelative = BitFieldFactory.getInstance(0x8000);
+	private final static BitField   colRelative = BitFieldFactory.getInstance(0x4000);
+	private final static BitField   columnMask      = BitFieldFactory.getInstance(0x3FFF);
+
+	protected AreaPtgBase() {
+		// do nothing
+	}
+
+	protected AreaPtgBase(AreaReference ar) {
+		CellReference firstCell = ar.getFirstCell();
+		CellReference lastCell = ar.getLastCell();
+		setFirstRow(firstCell.getRow());
+		setFirstColumn(firstCell.getCol() == -1 ? 0 : firstCell.getCol());
+		setLastRow(lastCell.getRow());
+		setLastColumn(lastCell.getCol() == -1 ? 0xFF : lastCell.getCol());
+		setFirstColRelative(!firstCell.isColAbsolute());
+		setLastColRelative(!lastCell.isColAbsolute());
+		setFirstRowRelative(!firstCell.isRowAbsolute());
+		setLastRowRelative(!lastCell.isRowAbsolute());
+	}
+
+	protected AreaPtgBase(int firstRow, int lastRow, int firstColumn, int lastColumn,
+			boolean firstRowRelative, boolean lastRowRelative, boolean firstColRelative, boolean lastColRelative) {
+
+		if (lastRow > firstRow) {
+			setFirstRow(firstRow);
+			setLastRow(lastRow);
+			setFirstRowRelative(firstRowRelative);
+			setLastRowRelative(lastRowRelative);
+		} else {
+			setFirstRow(lastRow);
+			setLastRow(firstRow);
+			setFirstRowRelative(lastRowRelative);
+			setLastRowRelative(firstRowRelative);
+		}
+
+		if (lastColumn > firstColumn) {
+			setFirstColumn(firstColumn);
+			setLastColumn(lastColumn);
+			setFirstColRelative(firstColRelative);
+			setLastColRelative(lastColRelative);
+		} else {
+			setFirstColumn(lastColumn);
+			setLastColumn(firstColumn);
+			setFirstColRelative(lastColRelative);
+			setLastColRelative(firstColRelative);
+		}
+	}
+
+	protected final void readCoordinates(LittleEndianInput in)  {
+		field_1_first_row = in.readUShort();
+		field_2_last_row = in.readUShort();
+		field_3_first_column = in.readUShort();
+		field_4_last_column = in.readUShort();
+	}
+	protected final void writeCoordinates(LittleEndianOutput out) {
+		out.writeShort(field_1_first_row);
+		out.writeShort(field_2_last_row);
+		out.writeShort(field_3_first_column);
+		out.writeShort(field_4_last_column);
+	}
+
+	/**
+	 * @return the first row in the area
+	 */
+	public final int getFirstRow() {
+		return field_1_first_row;
+	}
+
+	/**
+	 * sets the first row
+	 * @param rowIx number (0-based)
+	 */
+	public final void setFirstRow(int rowIx) {
+		field_1_first_row = rowIx;
+	}
+
+	/**
+	 * @return last row in the range (x2 in x1,y1-x2,y2)
+	 */
+	public final int getLastRow() {
+		return field_2_last_row;
+	}
+
+	/**
+	 * @param rowIx last row number in the area
+	 */
+	public final void setLastRow(int rowIx) {
+		field_2_last_row = rowIx;
+	}
+
+	/**
+	 * @return the first column number in the area.
+	 */
+	public final int getFirstColumn() {
+		return columnMask.getValue(field_3_first_column);
+	}
+
+	/**
+	 * @return the first column number + the options bit settings unstripped
+	 */
+	public final short getFirstColumnRaw() {
+		return (short) field_3_first_column; // TODO
+	}
+
+	/**
+	 * @return whether or not the first row is a relative reference or not.
+	 */
+	public final boolean isFirstRowRelative() {
+		return rowRelative.isSet(field_3_first_column);
+	}
+
+	/**
+	 * sets the first row to relative or not
+	 * @param rel is relative or not.
+	 */
+	public final void setFirstRowRelative(boolean rel) {
+		field_3_first_column=rowRelative.setBoolean(field_3_first_column,rel);
+	}
+
+	/**
+	 * @return isrelative first column to relative or not
+	 */
+	public final boolean isFirstColRelative() {
+		return colRelative.isSet(field_3_first_column);
+	}
+
+	/**
+	 * set whether the first column is relative
+	 */
+	public final void setFirstColRelative(boolean rel) {
+		field_3_first_column=colRelative.setBoolean(field_3_first_column,rel);
+	}
+
+	/**
+	 * set the first column in the area
+	 */
+	public final void setFirstColumn(int colIx) {
+		field_3_first_column=columnMask.setValue(field_3_first_column, colIx);
+	}
+
+	/**
+	 * set the first column irrespective of the bitmasks
+	 */
+	public final void setFirstColumnRaw(int column) {
+		field_3_first_column = column;
+	}
+
+	/**
+	 * @return lastcolumn in the area
+	 */
+	public final int getLastColumn() {
+		return columnMask.getValue(field_4_last_column);
+	}
+
+	/**
+	 * @return last column and bitmask (the raw field)
+	 */
+	public final short getLastColumnRaw() {
+		return (short) field_4_last_column;
+	}
+
+	/**
+	 * @return last row relative or not
+	 */
+	public final boolean isLastRowRelative() {
+		return rowRelative.isSet(field_4_last_column);
+	}
+
+	/**
+	 * set whether the last row is relative or not
+	 * @param rel <code>true</code> if the last row relative, else
+	 * <code>false</code>
+	 */
+	public final void setLastRowRelative(boolean rel) {
+		field_4_last_column=rowRelative.setBoolean(field_4_last_column,rel);
+	}
+
+	/**
+	 * @return lastcol relative or not
+	 */
+	public final boolean isLastColRelative() {
+		return colRelative.isSet(field_4_last_column);
+	}
+
+	/**
+	 * set whether the last column should be relative or not
+	 */
+	public final void setLastColRelative(boolean rel) {
+		field_4_last_column=colRelative.setBoolean(field_4_last_column,rel);
+	}
+
+	/**
+	 * set the last column in the area
+	 */
+	public final void setLastColumn(int colIx) {
+		field_4_last_column=columnMask.setValue(field_4_last_column, colIx);
+	}
+
+	/**
+	 * set the last column irrespective of the bitmasks
+	 */
+	public final void setLastColumnRaw(short column) {
+		field_4_last_column = column;
+	}
+	protected final String formatReferenceAsString() {
+		CellReference topLeft = new CellReference(getFirstRow(),getFirstColumn(),!isFirstRowRelative(),!isFirstColRelative());
+		CellReference botRight = new CellReference(getLastRow(),getLastColumn(),!isLastRowRelative(),!isLastColRelative());
+
+		if(AreaReference.isWholeColumnReference(topLeft, botRight)) {
+			return (new AreaReference(topLeft, botRight)).formatAsString();
+		}
+		return topLeft.formatAsString() + ":" + botRight.formatAsString();
+	}
+
+	public String toFormulaString() {
+		return formatReferenceAsString();
+	}
+
+	public byte getDefaultOperandClass() {
+		return Ptg.CLASS_REF;
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/ArrayPtg.java

@@ -0,0 +1,268 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.formula.constant.ConstantValueParser;
+import org.apache.poi.ss.formula.constant.ErrorConstant;
+import org.apache.poi.ss.util.NumberToTextConverter;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * ArrayPtg - handles arrays
+ *
+ * The ArrayPtg is a little weird, the size of the Ptg when parsing initially only
+ * includes the Ptg sid and the reserved bytes. The next Ptg in the expression then follows.
+ * It is only after the "size" of all the Ptgs is met, that the ArrayPtg data is actually
+ * held after this. So Ptg.createParsedExpression keeps track of the number of
+ * ArrayPtg elements and need to parse the data upto the FORMULA record size.
+ *
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class ArrayPtg extends Ptg {
+	public static final byte sid  = 0x20;
+
+	private static final int RESERVED_FIELD_LEN = 7;
+	/**
+	 * The size of the plain tArray token written within the standard formula tokens
+	 * (not including the data which comes after all formula tokens)
+	 */
+	public static final int PLAIN_TOKEN_SIZE = 1+RESERVED_FIELD_LEN;
+
+	// 7 bytes of data (stored as an int, short and byte here)
+	private final int _reserved0Int;
+	private final int _reserved1Short;
+	private final int _reserved2Byte;
+
+	// data from these fields comes after the Ptg data of all tokens in current formula
+	private final int  _nColumns;
+	private final int _nRows;
+	private final Object[] _arrayValues;
+
+	ArrayPtg(int reserved0, int reserved1, int reserved2, int nColumns, int nRows, Object[] arrayValues) {
+		_reserved0Int = reserved0;
+		_reserved1Short = reserved1;
+		_reserved2Byte = reserved2;
+		_nColumns = nColumns;
+		_nRows = nRows;
+		_arrayValues = arrayValues;
+	}
+	/**
+	 * @param values2d array values arranged in rows
+	 */
+	public ArrayPtg(Object[][] values2d) {
+		int nColumns = values2d[0].length;
+		int nRows = values2d.length;
+		// convert 2-d to 1-d array (row by row according to getValueIndex())
+		_nColumns = (short) nColumns;
+		_nRows = (short) nRows;
+
+		Object[] vv = new Object[_nColumns * _nRows];
+		for (int r=0; r<nRows; r++) {
+			Object[] rowData = values2d[r];
+			for (int c=0; c<nColumns; c++) {
+				vv[getValueIndex(c, r)] = rowData[c];
+			}
+		}
+
+		_arrayValues = vv;
+		_reserved0Int = 0;
+		_reserved1Short = 0;
+		_reserved2Byte = 0;
+	}
+	/**
+	 * @return 2-d array (inner index is rowIx, outer index is colIx)
+	 */
+	public Object[][] getTokenArrayValues() {
+		if (_arrayValues == null) {
+			throw new IllegalStateException("array values not read yet");
+		}
+		Object[][] result = new Object[_nRows][_nColumns];
+		for (int r = 0; r < _nRows; r++) {
+			Object[] rowData = result[r];
+			for (int c = 0; c < _nColumns; c++) {
+				rowData[c] = _arrayValues[getValueIndex(c, r)];
+			}
+		}
+		return result;
+	}
+
+	public boolean isBaseToken() {
+		return false;
+	}
+
+	public String toString() {
+		StringBuffer sb = new StringBuffer("[ArrayPtg]\n");
+
+		sb.append("nRows = ").append(getRowCount()).append("\n");
+		sb.append("nCols = ").append(getColumnCount()).append("\n");
+		if (_arrayValues == null) {
+			sb.append("  #values#uninitialised#\n");
+		} else {
+			sb.append("  ").append(toFormulaString());
+		}
+		return sb.toString();
+	}
+
+	/**
+	 * Note - (2D) array elements are stored row by row
+	 * @return the index into the internal 1D array for the specified column and row
+	 */
+	/* package */ int getValueIndex(int colIx, int rowIx) {
+		if(colIx < 0 || colIx >= _nColumns) {
+			throw new IllegalArgumentException("Specified colIx (" + colIx
+					+ ") is outside the allowed range (0.." + (_nColumns-1) + ")");
+		}
+		if(rowIx < 0 || rowIx >= _nRows) {
+			throw new IllegalArgumentException("Specified rowIx (" + rowIx
+					+ ") is outside the allowed range (0.." + (_nRows-1) + ")");
+		}
+		return rowIx * _nColumns + colIx;
+	}
+
+	public void write(LittleEndianOutput out) {
+		out.writeByte(sid + getPtgClass());
+		out.writeInt(_reserved0Int);
+		out.writeShort(_reserved1Short);
+		out.writeByte(_reserved2Byte);
+	}
+
+	public int writeTokenValueBytes(LittleEndianOutput out) {
+
+		out.writeByte(_nColumns-1);
+		out.writeShort(_nRows-1);
+		ConstantValueParser.encode(out, _arrayValues);
+		return 3 + ConstantValueParser.getEncodedSize(_arrayValues);
+	}
+
+	public int getRowCount() {
+		return _nRows;
+	}
+
+	public int getColumnCount() {
+		return _nColumns;
+	}
+
+	/** This size includes the size of the array Ptg plus the Array Ptg Token value size*/
+	public int getSize() {
+		return PLAIN_TOKEN_SIZE
+			// data written after the all tokens:
+			+ 1 + 2 // column, row
+			+ ConstantValueParser.getEncodedSize(_arrayValues);
+	}
+
+	public String toFormulaString() {
+		StringBuffer b = new StringBuffer();
+		b.append("{");
+	  	for (int y=0;y<getRowCount();y++) {
+			if (y > 0) {
+				b.append(";");
+			}
+			for (int x=0;x<getColumnCount();x++) {
+			  	if (x > 0) {
+					b.append(",");
+				}
+		  		Object o = _arrayValues[getValueIndex(x, y)];
+		  		b.append(getConstantText(o));
+		  	}
+		  }
+		b.append("}");
+		return b.toString();
+	}
+
+	private static String getConstantText(Object o) {
+
+		if (o == null) {
+			throw new RuntimeException("Array item cannot be null");
+		}
+		if (o instanceof String) {
+			return "\"" + (String)o + "\"";
+		}
+		if (o instanceof Double) {
+			return NumberToTextConverter.toText(((Double)o).doubleValue());
+		}
+		if (o instanceof Boolean) {
+			return ((Boolean)o).booleanValue() ? "TRUE" : "FALSE";
+		}
+		if (o instanceof ErrorConstant) {
+			return ((ErrorConstant)o).getText();
+		}
+		throw new IllegalArgumentException("Unexpected constant class (" + o.getClass().getName() + ")");
+	}
+
+	public byte getDefaultOperandClass() {
+		return Ptg.CLASS_ARRAY;
+	}
+
+	/**
+	 * Represents the initial plain tArray token (without the constant data that trails the whole
+	 * formula).  Objects of this class are only temporary and cannot be used as {@link Ptg}s.
+	 * These temporary objects get converted to {@link ArrayPtg} by the
+	 * {@link #finishReading(LittleEndianInput)} method.
+	 */
+	static final class Initial extends Ptg {
+		private final int _reserved0;
+		private final int _reserved1;
+		private final int _reserved2;
+
+		public Initial(LittleEndianInput in) {
+			_reserved0 = in.readInt();
+			_reserved1 = in.readUShort();
+			_reserved2 = in.readUByte();
+		}
+		private static RuntimeException invalid() {
+			throw new IllegalStateException("This object is a partially initialised tArray, and cannot be used as a Ptg");
+		}
+		public byte getDefaultOperandClass() {
+			throw invalid();
+		}
+		public int getSize() {
+			return PLAIN_TOKEN_SIZE;
+		}
+		public boolean isBaseToken() {
+			return false;
+		}
+		public String toFormulaString() {
+			throw invalid();
+		}
+		public void write(LittleEndianOutput out) {
+			throw invalid();
+		}
+		/**
+		 * Read in the actual token (array) values. This occurs
+		 * AFTER the last Ptg in the expression.
+		 * See page 304-305 of Excel97-2007BinaryFileFormat(xls)Specification.pdf
+		 */
+		public ArrayPtg finishReading(LittleEndianInput in) {
+			int nColumns = in.readUByte();
+			short nRows = in.readShort();
+			//The token_1_columns and token_2_rows do not follow the documentation.
+			//The number of physical rows and columns is actually +1 of these values.
+			//Which is not explicitly documented.
+			nColumns++;
+			nRows++;
+
+			int totalCount = nRows * nColumns;
+			Object[] arrayValues = ConstantValueParser.parse(in, totalCount);
+
+			ArrayPtg result = new ArrayPtg(_reserved0, _reserved1, _reserved2, nColumns, nRows, arrayValues);
+			result.setClass(getPtgClass());
+			return result;
+		}
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/AttrPtg.java

@@ -0,0 +1,263 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.util.BitField;
+import org.apache.poi.util.BitFieldFactory;
+import org.apache.poi.util.LittleEndian;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * "Special Attributes"
+ * This seems to be a Misc Stuff and Junk record.  One function it serves is
+ * in SUM functions (i.e. SUM(A1:A3) causes an area PTG then an ATTR with the SUM option set)
+ * @author  andy
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class AttrPtg extends ControlPtg {
+    public final static byte sid  = 0x19;
+    private final static int  SIZE = 4;
+    private final byte _options;
+    private final short _data;
+
+    /** only used for tAttrChoose: table of offsets to starts of args */
+    private final int[] _jumpTable;
+    /** only used for tAttrChoose: offset to the tFuncVar for CHOOSE() */
+    private final int   _chooseFuncOffset;
+
+    // flags 'volatile' and 'space', can be combined.
+    // OOO spec says other combinations are theoretically possible but not likely to occur.
+    private static final BitField semiVolatile = BitFieldFactory.getInstance(0x01);
+    private static final BitField optiIf       = BitFieldFactory.getInstance(0x02);
+    private static final BitField optiChoose   = BitFieldFactory.getInstance(0x04);
+    private static final BitField optiSkip     = BitFieldFactory.getInstance(0x08);
+    private static final BitField optiSum      = BitFieldFactory.getInstance(0x10);
+    private static final BitField baxcel       = BitFieldFactory.getInstance(0x20); // 'assignment-style formula in a macro sheet'
+    private static final BitField space        = BitFieldFactory.getInstance(0x40);
+
+    public static final AttrPtg SUM = new AttrPtg(0x0010, 0, null, -1);
+
+    public static final class SpaceType {
+        private SpaceType() {
+            // no instances of this class
+        }
+
+        /** 00H = Spaces before the next token (not allowed before tParen token) */
+        public static final int SPACE_BEFORE = 0x00;
+        /** 01H = Carriage returns before the next token (not allowed before tParen token) */
+        public static final int CR_BEFORE = 0x01;
+        /** 02H = Spaces before opening parenthesis (only allowed before tParen token) */
+        public static final int SPACE_BEFORE_OPEN_PAREN = 0x02;
+        /** 03H = Carriage returns before opening parenthesis (only allowed before tParen token) */
+        public static final int CR_BEFORE_OPEN_PAREN = 0x03;
+        /** 04H = Spaces before closing parenthesis (only allowed before tParen, tFunc, and tFuncVar tokens) */
+        public static final int SPACE_BEFORE_CLOSE_PAREN = 0x04;
+        /** 05H = Carriage returns before closing parenthesis (only allowed before tParen, tFunc, and tFuncVar tokens) */
+        public static final int CR_BEFORE_CLOSE_PAREN = 0x05;
+        /** 06H = Spaces following the equality sign (only in macro sheets) */
+        public static final int SPACE_AFTER_EQUALITY = 0x06;
+    }
+
+    public AttrPtg(LittleEndianInput in) {
+        _options = in.readByte();
+        _data    = in.readShort();
+        if (isOptimizedChoose()) {
+            int nCases = _data;
+            int[] jumpTable = new int[nCases];
+            for (int i = 0; i < jumpTable.length; i++) {
+                jumpTable[i] = in.readUShort();
+            }
+            _jumpTable = jumpTable;
+            _chooseFuncOffset = in.readUShort();
+        } else {
+            _jumpTable = null;
+            _chooseFuncOffset = -1;
+        }
+
+    }
+    private AttrPtg(int options, int data, int[] jt, int chooseFuncOffset) {
+        _options = (byte) options;
+        _data = (short) data;
+        _jumpTable = jt;
+        _chooseFuncOffset = chooseFuncOffset;
+    }
+
+    /**
+     * @param type a constant from <tt>SpaceType</tt>
+     * @param count the number of space characters
+     */
+    public static AttrPtg createSpace(int type, int count) {
+        int data = type & 0x00FF | (count << 8) & 0x00FFFF;
+        return new AttrPtg(space.set(0), data, null, -1);
+    }
+
+    /**
+     * @param dist distance (in bytes) to start of either <ul><li>false parameter</li>
+     * <li>tFuncVar(IF) token (when false parameter is not present)</li></ul>
+     */
+    public static AttrPtg createIf(int dist) {
+        return new AttrPtg(optiIf.set(0), dist, null, -1);
+    }
+
+    /**
+     * @param dist distance (in bytes) to position behind tFuncVar(IF) token (minus 1)
+     */
+    public static AttrPtg createSkip(int dist) {
+        return new AttrPtg(optiSkip.set(0), dist, null, -1);
+    }
+
+    public static AttrPtg getSumSingle() {
+        return new AttrPtg(optiSum.set(0), 0, null, -1);
+    }
+
+
+    public boolean isSemiVolatile() {
+        return semiVolatile.isSet(_options);
+    }
+
+    public boolean isOptimizedIf() {
+        return optiIf.isSet(_options);
+    }
+
+    public boolean isOptimizedChoose() {
+        return optiChoose.isSet(_options);
+    }
+
+    public boolean isSum() {
+        return optiSum.isSet(_options);
+    }
+    public boolean isSkip() {
+        return optiSkip.isSet(_options);
+    }
+
+    // lets hope no one uses this anymore
+    private boolean isBaxcel() {
+        return baxcel.isSet(_options);
+    }
+
+    public boolean isSpace() {
+        return space.isSet(_options);
+    }
+
+    public short getData() {
+        return _data;
+    }
+    public int[] getJumpTable() {
+        return _jumpTable.clone();
+    }
+    public int getChooseFuncOffset() {
+        if (_jumpTable == null) {
+            throw new IllegalStateException("Not tAttrChoose");
+        }
+        return _chooseFuncOffset;
+    }
+
+    public String toString() {
+        StringBuffer sb = new StringBuffer(64);
+        sb.append(getClass().getName()).append(" [");
+
+        if(isSemiVolatile()) {
+            sb.append("volatile ");
+        }
+        if(isSpace()) {
+            sb.append("space count=").append((_data >> 8) & 0x00FF);
+            sb.append(" type=").append(_data & 0x00FF).append(" ");
+        }
+        // the rest seem to be mutually exclusive
+        if(isOptimizedIf()) {
+            sb.append("if dist=").append(_data);
+        } else if(isOptimizedChoose()) {
+            sb.append("choose nCases=").append(_data);
+        } else if(isSkip()) {
+            sb.append("skip dist=").append(_data);
+        } else if(isSum()) {
+            sb.append("sum ");
+        } else if(isBaxcel()) {
+            sb.append("assign ");
+        }
+        sb.append("]");
+        return sb.toString();
+    }
+
+    public void write(LittleEndianOutput out) {
+        out.writeByte(sid + getPtgClass());
+        out.writeByte(_options);
+        out.writeShort(_data);
+        int[] jt = _jumpTable;
+        if (jt != null) {
+            for (int i = 0; i < jt.length; i++) {
+                out.writeShort(jt[i]);
+            }
+            out.writeShort(_chooseFuncOffset);
+        }
+    }
+
+    public int getSize() {
+        if (_jumpTable != null) {
+            return SIZE + (_jumpTable.length + 1) * LittleEndian.SHORT_SIZE;
+        }
+        return SIZE;
+    }
+
+    public String toFormulaString(String[] operands) {
+        if(space.isSet(_options)) {
+            return operands[ 0 ];
+        } else if (optiIf.isSet(_options)) {
+            return toFormulaString() + "(" + operands[0] + ")";
+        } else if (optiSkip.isSet(_options)) {
+            return toFormulaString() + operands[0];   //goto isn't a real formula element should not show up
+        } else {
+            return toFormulaString() + "(" + operands[0] + ")";
+        }
+    }
+
+
+    public int getNumberOfOperands() {
+        return 1;
+    }
+
+    public int getType() {
+        return -1;
+    }
+
+   public String toFormulaString() {
+      if(semiVolatile.isSet(_options)) {
+        return "ATTR(semiVolatile)";
+      }
+      if(optiIf.isSet(_options)) {
+        return "IF";
+      }
+      if( optiChoose.isSet(_options)) {
+        return "CHOOSE";
+      }
+      if(optiSkip.isSet(_options)) {
+        return "";
+      }
+      if(optiSum.isSet(_options)) {
+        return "SUM";
+      }
+      if(baxcel.isSet(_options)) {
+        return "ATTR(baxcel)";
+      }
+      if(space.isSet(_options)) {
+        return "";
+      }
+      return "UNKNOWN ATTRIBUTE";
+     }
+}

src/java/org/apache/poi/ss/formula/ptg/BoolPtg.java

@@ -0,0 +1,66 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * Boolean (boolean) Stores a (java) boolean value in a formula.
+ *
+ * @author Paul Krause (pkrause at soundbite dot com)
+ * @author Andrew C. Oliver (acoliver at apache dot org)
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class BoolPtg extends ScalarConstantPtg {
+	public static final int SIZE = 2;
+	public static final byte sid = 0x1D;
+
+	private static final BoolPtg FALSE = new BoolPtg(false);
+	private static final BoolPtg TRUE = new BoolPtg(true);
+
+	private final boolean _value;
+
+	private BoolPtg(boolean b) {
+		_value = b;
+	}
+
+	public static BoolPtg valueOf(boolean b) {
+		return b ? TRUE : FALSE;
+	}
+	public static BoolPtg read(LittleEndianInput in)  {
+		return valueOf(in.readByte() == 1);
+	}
+
+	public boolean getValue() {
+		return _value;
+	}
+
+	public void write(LittleEndianOutput out) {
+		out.writeByte(sid + getPtgClass());
+		out.writeByte(_value ? 1 : 0);
+	}
+
+	public int getSize() {
+		return SIZE;
+	}
+
+	public String toFormulaString() {
+		return _value ? "TRUE" : "FALSE";
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/ConcatPtg.java

@@ -0,0 +1,52 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+/**
+ *
+ * @author  andy
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class ConcatPtg extends ValueOperatorPtg {
+    public final static byte sid  = 0x08;
+    
+    private final static String CONCAT = "&";
+    
+    public static final ValueOperatorPtg instance = new ConcatPtg();
+
+    private ConcatPtg() {
+    	// enforce singleton
+    }
+    
+    protected byte getSid() {
+    	return sid;
+    }
+
+    public int getNumberOfOperands() {
+        return 2;
+    }
+       
+    public String toFormulaString(String[] operands) {
+        StringBuffer buffer = new StringBuffer();
+
+        buffer.append(operands[ 0 ]);
+        buffer.append(CONCAT);
+        buffer.append(operands[ 1 ]);
+        return buffer.toString();
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/ControlPtg.java

@@ -0,0 +1,38 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+/**
+ * Common superclass for 
+ * tExp
+ * tTbl
+ * tParen
+ * tNlr
+ * tAttr
+ * tSheet
+ * tEndSheet
+ */
+public abstract class ControlPtg extends Ptg {
+
+	public boolean isBaseToken() {
+		return true;
+	}
+	public final byte getDefaultOperandClass() {
+		throw new IllegalStateException("Control tokens are not classified");
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/DeletedArea3DPtg.java

@@ -0,0 +1,69 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.usermodel.ErrorConstants;
+import org.apache.poi.ss.formula.FormulaRenderingWorkbook;
+import org.apache.poi.ss.formula.WorkbookDependentFormula;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * Title:        Deleted Area 3D Ptg - 3D referecnce (Sheet + Area)<P>
+ * Description:  Defined a area in Extern Sheet. <P>
+ * REFERENCE:  <P>
+ * @author Patrick Luby
+ * @version 1.0-pre
+ */
+public final class DeletedArea3DPtg extends OperandPtg implements WorkbookDependentFormula {
+	public final static byte sid = 0x3d;
+	private final int field_1_index_extern_sheet;
+	private final int unused1;
+	private final int unused2;
+
+	public DeletedArea3DPtg(int externSheetIndex) {
+		field_1_index_extern_sheet = externSheetIndex;
+		unused1 = 0;
+		unused2 = 0;
+	}
+	
+	public DeletedArea3DPtg(LittleEndianInput in)  {
+		field_1_index_extern_sheet = in.readUShort();
+		unused1 = in.readInt();
+		unused2 = in.readInt();
+	}
+	public String toFormulaString(FormulaRenderingWorkbook book) {
+		return ExternSheetNameResolver.prependSheetName(book, field_1_index_extern_sheet, 
+				ErrorConstants.getText(ErrorConstants.ERROR_REF));
+	}
+	public String toFormulaString() {
+		throw new RuntimeException("3D references need a workbook to determine formula text");
+	}
+	public byte getDefaultOperandClass() {
+		return Ptg.CLASS_REF;
+	}
+	public int getSize() {
+		return 11;
+	}
+	public void write(LittleEndianOutput out) {
+		out.writeByte(sid + getPtgClass());
+		out.writeShort(field_1_index_extern_sheet);
+		out.writeInt(unused1);
+		out.writeInt(unused2);
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/DeletedRef3DPtg.java

@@ -0,0 +1,68 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+
+import org.apache.poi.ss.usermodel.ErrorConstants;
+import org.apache.poi.ss.formula.FormulaRenderingWorkbook;
+import org.apache.poi.ss.formula.WorkbookDependentFormula;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * Title:        Deleted Reference 3D Ptg <P>
+ * Description:  Defined a cell in extern sheet. <P>
+ * REFERENCE:  <P>
+ * @author Patrick Luby
+ * @version 1.0-pre
+ */
+public final class DeletedRef3DPtg extends OperandPtg implements WorkbookDependentFormula {
+	public final static byte sid  = 0x3c;
+	private final int field_1_index_extern_sheet;
+	private final int unused1;
+
+	/** Creates new DeletedRef3DPtg */
+	public DeletedRef3DPtg(LittleEndianInput in)  {
+		field_1_index_extern_sheet = in.readUShort();
+		unused1 = in.readInt();
+	}
+
+	public DeletedRef3DPtg(int externSheetIndex) {
+		field_1_index_extern_sheet = externSheetIndex;
+		unused1 = 0;
+	}
+
+	public String toFormulaString(FormulaRenderingWorkbook book) {
+		return ExternSheetNameResolver.prependSheetName(book, field_1_index_extern_sheet, 
+				ErrorConstants.getText(ErrorConstants.ERROR_REF));
+	}
+	public String toFormulaString() {
+		throw new RuntimeException("3D references need a workbook to determine formula text");
+	}
+	public byte getDefaultOperandClass() {
+		return Ptg.CLASS_REF;
+	}
+	public int getSize() {
+		return 7;
+	}
+	public void write(LittleEndianOutput out) {
+		out.writeByte(sid + getPtgClass());
+		out.writeShort(field_1_index_extern_sheet);
+		out.writeInt(unused1);
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/DividePtg.java

@@ -0,0 +1,50 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+/**
+ * This PTG implements the standard binomial divide "/"
+ * @author  Andrew C. Oliver acoliver at apache dot org
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class DividePtg extends ValueOperatorPtg {
+    public final static byte sid  = 0x06;
+
+    public static final ValueOperatorPtg instance = new DividePtg();
+
+    private DividePtg() {
+    	// enforce singleton
+    }
+    
+    protected byte getSid() {
+    	return sid;
+    }
+
+    public int getNumberOfOperands() {
+        return 2;
+    }
+
+     public String toFormulaString(String[] operands) {
+        StringBuffer buffer = new StringBuffer();
+
+        buffer.append(operands[ 0 ]);
+        buffer.append("/");
+        buffer.append(operands[ 1 ]);
+        return buffer.toString();
+    }      
+}

src/java/org/apache/poi/ss/formula/ptg/EqualPtg.java

@@ -0,0 +1,50 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+/**
+ *
+ * @author  andy
+ */
+public final class EqualPtg extends ValueOperatorPtg {
+    public final static byte sid  = 0x0b;
+
+    public static final ValueOperatorPtg instance = new EqualPtg();
+
+    private EqualPtg() {
+    	// enforce singleton
+    }
+    
+    protected byte getSid() {
+    	return sid;
+    }
+
+    public int getNumberOfOperands() {
+        return 2;
+    }
+ 
+    public String toFormulaString(String[] operands) {
+         StringBuffer buffer = new StringBuffer();
+
+        
+        buffer.append(operands[ 0 ]);
+        buffer.append("=");
+        buffer.append(operands[ 1 ]);
+        return buffer.toString();
+    }       
+}

src/java/org/apache/poi/ss/formula/ptg/ErrPtg.java

@@ -0,0 +1,94 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.usermodel.ErrorConstants;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * @author Daniel Noll (daniel at nuix dot com dot au)
+ */
+public final class ErrPtg extends ScalarConstantPtg {
+
+    // convenient access to namespace
+    private static final ErrorConstants EC = null;
+
+    /** <b>#NULL!</b>  - Intersection of two cell ranges is empty */
+    public static final ErrPtg NULL_INTERSECTION = new ErrPtg(EC.ERROR_NULL);
+    /** <b>#DIV/0!</b> - Division by zero */
+    public static final ErrPtg DIV_ZERO = new ErrPtg(EC.ERROR_DIV_0);
+    /** <b>#VALUE!</b> - Wrong type of operand */
+    public static final ErrPtg VALUE_INVALID = new ErrPtg(EC.ERROR_VALUE);
+    /** <b>#REF!</b> - Illegal or deleted cell reference */
+    public static final ErrPtg REF_INVALID = new ErrPtg(EC.ERROR_REF);
+    /** <b>#NAME?</b> - Wrong function or range name */
+    public static final ErrPtg NAME_INVALID = new ErrPtg(EC.ERROR_NAME);
+    /** <b>#NUM!</b> - Value range overflow */
+    public static final ErrPtg NUM_ERROR = new ErrPtg(EC.ERROR_NUM);
+    /** <b>#N/A</b> - Argument or function not available */
+    public static final ErrPtg N_A = new ErrPtg(EC.ERROR_NA);
+
+
+    public static final short sid  = 0x1c;
+    private static final int  SIZE = 2;
+    private final int field_1_error_code;
+
+    /** Creates new ErrPtg */
+
+    private ErrPtg(int errorCode) {
+        if(!ErrorConstants.isValidCode(errorCode)) {
+            throw new IllegalArgumentException("Invalid error code (" + errorCode + ")");
+        }
+        field_1_error_code = errorCode;
+    }
+
+    public static ErrPtg read(LittleEndianInput in)  {
+        return valueOf(in.readByte());
+    }
+
+    public void write(LittleEndianOutput out) {
+        out.writeByte(sid + getPtgClass());
+        out.writeByte(field_1_error_code);
+    }
+
+    public String toFormulaString() {
+        return ErrorConstants.getText(field_1_error_code);
+    }
+
+    public int getSize() {
+        return SIZE;
+    }
+
+    public int getErrorCode() {
+        return field_1_error_code;
+    }
+
+    public static ErrPtg valueOf(int code) {
+        switch(code) {
+            case ErrorConstants.ERROR_DIV_0: return DIV_ZERO;
+            case ErrorConstants.ERROR_NA: return N_A;
+            case ErrorConstants.ERROR_NAME: return NAME_INVALID;
+            case ErrorConstants.ERROR_NULL: return NULL_INTERSECTION;
+            case ErrorConstants.ERROR_NUM: return NUM_ERROR;
+            case ErrorConstants.ERROR_REF: return REF_INVALID;
+            case ErrorConstants.ERROR_VALUE: return VALUE_INVALID;
+        }
+        throw new RuntimeException("Unexpected error code (" + code + ")");
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/ExpPtg.java

@@ -0,0 +1,73 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ *
+ * @author  andy
+ * @author Jason Height (jheight at chariot dot net dot au)
+ * @author dmui (save existing implementation)
+ */
+public final class ExpPtg extends ControlPtg {
+    private final static int  SIZE = 5;
+    public final static short sid  = 0x1;
+    private final int field_1_first_row;
+    private final int field_2_first_col;
+
+    public ExpPtg(LittleEndianInput in) {
+      field_1_first_row = in.readShort();
+      field_2_first_col = in.readShort();
+    }
+
+    public ExpPtg(int firstRow, int firstCol) {
+      this.field_1_first_row = firstRow;
+      this.field_2_first_col = firstCol;
+    }
+
+    public void write(LittleEndianOutput out) {
+        out.writeByte(sid + getPtgClass());
+        out.writeShort(field_1_first_row);
+        out.writeShort(field_2_first_col);
+    }
+
+    public int getSize() {
+        return SIZE;
+    }
+
+    public int getRow() {
+      return field_1_first_row;
+    }
+
+    public int getColumn() {
+      return field_2_first_col;
+    }
+
+    public String toFormulaString() {
+        throw new RuntimeException("Coding Error: Expected ExpPtg to be converted from Shared to Non-Shared Formula by ValueRecordsAggregate, but it wasn't");
+    }
+
+    public String toString() {
+        StringBuffer buffer = new StringBuffer("[Array Formula or Shared Formula]\n");
+        buffer.append("row = ").append(getRow()).append("\n");
+        buffer.append("col = ").append(getColumn()).append("\n");
+        return buffer.toString();
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/ExternSheetNameResolver.java

@@ -0,0 +1,55 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.formula.FormulaRenderingWorkbook;
+import org.apache.poi.ss.formula.EvaluationWorkbook.ExternalSheet;
+import org.apache.poi.ss.formula.SheetNameFormatter;
+
+/**
+ * @author Josh Micich
+ */
+final class ExternSheetNameResolver {
+
+	private ExternSheetNameResolver() {
+		// no instances of this class
+	}
+
+	public static String prependSheetName(FormulaRenderingWorkbook book, int field_1_index_extern_sheet, String cellRefText) {
+		ExternalSheet externalSheet = book.getExternalSheet(field_1_index_extern_sheet);
+		StringBuffer sb;
+		if (externalSheet != null) {
+			String wbName = externalSheet.getWorkbookName();
+			String sheetName = externalSheet.getSheetName();
+			sb = new StringBuffer(wbName.length() + sheetName.length() + cellRefText.length() + 4);
+			SheetNameFormatter.appendFormat(sb, wbName, sheetName);
+		} else {
+			String sheetName = book.getSheetNameByExternSheet(field_1_index_extern_sheet);
+			sb = new StringBuffer(sheetName.length() + cellRefText.length() + 4);
+			if (sheetName.length() < 1) {
+				// What excel does if sheet has been deleted
+				sb.append("#REF"); // note - '!' added just once below
+			} else {
+				SheetNameFormatter.appendFormat(sb, sheetName);
+			}
+		}
+   		sb.append('!');
+		sb.append(cellRefText);
+		return sb.toString();
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/FuncPtg.java

@@ -0,0 +1,60 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.formula.function.FunctionMetadata;
+import org.apache.poi.ss.formula.function.FunctionMetadataRegistry;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * @author aviks
+ * @author Jason Height (jheight at chariot dot net dot au)
+ * @author Danny Mui (dmui at apache dot org) (Leftover handling)
+ */
+public final class FuncPtg extends AbstractFunctionPtg {
+
+    public final static byte sid  = 0x21;
+    public final static int  SIZE = 3;
+
+    public static FuncPtg create(LittleEndianInput in) {
+        return create(in.readUShort());
+    }
+
+    private FuncPtg(int funcIndex, FunctionMetadata fm) {
+        super(funcIndex, fm.getReturnClassCode(), fm.getParameterClassCodes(), fm.getMinParams());  // minParams same as max since these are not var-arg funcs
+    }
+
+    public static FuncPtg create(int functionIndex) {
+        FunctionMetadata fm = FunctionMetadataRegistry.getFunctionByIndex(functionIndex);
+        if(fm == null) {
+            throw new RuntimeException("Invalid built-in function index (" + functionIndex + ")");
+        }
+        return new FuncPtg(functionIndex, fm);
+    }
+
+
+    public void write(LittleEndianOutput out) {
+        out.writeByte(sid + getPtgClass());
+        out.writeShort(getFunctionIndex());
+    }
+
+    public int getSize() {
+        return SIZE;
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/FuncVarPtg.java

@@ -0,0 +1,73 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+import org.apache.poi.ss.formula.function.FunctionMetadata;
+import org.apache.poi.ss.formula.function.FunctionMetadataRegistry;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class FuncVarPtg extends AbstractFunctionPtg{
+
+    public final static byte sid  = 0x22;
+    private final static int  SIZE = 4;
+
+    /**
+     * Single instance of this token for 'sum() taking a single argument'
+     */
+    public static final OperationPtg SUM = FuncVarPtg.create("SUM", 1);
+
+    private FuncVarPtg(int functionIndex, int returnClass, byte[] paramClasses, int numArgs) {
+        super(functionIndex, returnClass, paramClasses, numArgs);
+    }
+
+    /**Creates new function pointer from a byte array
+     * usually called while reading an excel file.
+     */
+    public static FuncVarPtg create(LittleEndianInput in)  {
+        return create(in.readByte(), in.readShort());
+    }
+
+    /**
+     * Create a function ptg from a string tokenised by the parser
+     */
+    public static FuncVarPtg create(String pName, int numArgs) {
+        return create(numArgs, lookupIndex(pName));
+    }
+
+    private static FuncVarPtg create(int numArgs, int functionIndex) {
+        FunctionMetadata fm = FunctionMetadataRegistry.getFunctionByIndex(functionIndex);
+        if(fm == null) {
+            // Happens only as a result of a call to FormulaParser.parse(), with a non-built-in function name
+            return new FuncVarPtg(functionIndex, Ptg.CLASS_VALUE, new byte[] {Ptg.CLASS_VALUE}, numArgs);
+        }
+        return new FuncVarPtg(functionIndex, fm.getReturnClassCode(), fm.getParameterClassCodes(), numArgs);
+    }
+
+    public void write(LittleEndianOutput out) {
+        out.writeByte(sid + getPtgClass());
+        out.writeByte(getNumberOfOperands());
+        out.writeShort(getFunctionIndex());
+    }
+
+    public int getSize() {
+        return SIZE;
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/GreaterEqualPtg.java

@@ -0,0 +1,54 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+
+/**
+ * PTG class to implement greater or equal to
+ *
+ * @author  fred at stsci dot edu
+ */
+public final class GreaterEqualPtg extends ValueOperatorPtg {
+    public final static int  SIZE = 1;
+    public final static byte sid  = 0x0c;
+
+    public static final ValueOperatorPtg instance = new GreaterEqualPtg();
+
+    private GreaterEqualPtg() {
+    	// enforce singleton
+    }
+    
+    protected byte getSid() {
+    	return sid;
+    }
+
+    public int getNumberOfOperands() {
+        return 2;
+    }
+
+    public String toFormulaString(String[] operands) {
+         StringBuffer buffer = new StringBuffer();
+
+        buffer.append(operands[ 0 ]);
+
+        buffer.append(">=");
+        buffer.append(operands[ 1 ]);
+
+        return buffer.toString();
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/GreaterThanPtg.java

@@ -0,0 +1,61 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+
+/**
+ * Greater than operator PTG ">"
+ * @author  Cameron Riley (criley at ekmail.com)
+ */
+public final class GreaterThanPtg extends ValueOperatorPtg {
+    public final static byte sid  = 0x0D;    
+    private final static String GREATERTHAN = ">";
+
+    public static final ValueOperatorPtg instance = new GreaterThanPtg();
+
+    private GreaterThanPtg() {
+    	// enforce singleton
+    }
+    
+    protected byte getSid() {
+    	return sid;
+    }
+
+    /**
+     * Get the number of operands for the Less than operator
+     * @return int the number of operands
+     */
+    public int getNumberOfOperands() {
+        return 2;
+    }
+    
+    /** 
+     * Implementation of method from OperationsPtg
+     * @param operands a String array of operands
+     * @return String the Formula as a String
+     */  
+    public String toFormulaString(String[] operands) 
+    {
+        StringBuffer buffer = new StringBuffer();
+
+        buffer.append(operands[ 0 ]);
+        buffer.append(GREATERTHAN);
+        buffer.append(operands[ 1 ]);
+        return buffer.toString();
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/IntPtg.java

@@ -0,0 +1,76 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * Integer (unsigned short integer) Stores an unsigned short value (java int) in
+ * a formula
+ * 
+ * @author Andrew C. Oliver (acoliver at apache dot org)
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class IntPtg extends ScalarConstantPtg {
+	// 16 bit unsigned integer
+	private static final int MIN_VALUE = 0x0000;
+	private static final int MAX_VALUE = 0xFFFF;
+
+	/**
+	 * Excel represents integers 0..65535 with the tInt token.
+	 * 
+	 * @return <code>true</code> if the specified value is within the range of values 
+	 * <tt>IntPtg</tt> can represent.
+	 */
+	public static boolean isInRange(int i) {
+		return i >= MIN_VALUE && i <= MAX_VALUE;
+	}
+
+	public final static int SIZE = 3;
+	public final static byte sid = 0x1e;
+	private final int field_1_value;
+
+	public IntPtg(LittleEndianInput in)  {
+		this(in.readUShort());
+	}
+
+	public IntPtg(int value) {
+		if (!isInRange(value)) {
+			throw new IllegalArgumentException("value is out of range: " + value);
+		}
+		field_1_value = value;
+	}
+
+	public int getValue() {
+		return field_1_value;
+	}
+
+	public void write(LittleEndianOutput out) {
+		out.writeByte(sid + getPtgClass());
+		out.writeShort(getValue());
+	}
+
+	public int getSize() {
+		return SIZE;
+	}
+
+	public String toFormulaString() {
+		return String.valueOf(getValue());
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/IntersectionPtg.java

@@ -0,0 +1,62 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * @author Daniel Noll (daniel at nuix dot com dot au)
+ */
+public final class IntersectionPtg extends OperationPtg {
+	public final static byte sid = 0x0f;
+
+	public static final OperationPtg instance = new IntersectionPtg();
+
+	private IntersectionPtg() {
+		// enforce singleton
+	}
+
+	public final boolean isBaseToken() {
+		return true;
+	}
+
+	public int getSize() {
+		return 1;
+	}
+
+	public void write(LittleEndianOutput out) {
+		out.writeByte(sid + getPtgClass());
+	}
+
+	public String toFormulaString() {
+		return " ";
+	}
+
+	public String toFormulaString(String[] operands) {
+		StringBuffer buffer = new StringBuffer();
+
+		buffer.append(operands[0]);
+		buffer.append(" ");
+		buffer.append(operands[1]);
+		return buffer.toString();
+	}
+
+	public int getNumberOfOperands() {
+		return 2;
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/LessEqualPtg.java

@@ -0,0 +1,53 @@
+        
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+
+
+
+/**
+ * Ptg class to implement less than or equal
+ *
+ * @author fred at stsci dot edu
+ */
+public final class LessEqualPtg extends ValueOperatorPtg {
+    public final static byte sid = 0x0a;
+
+    public static final ValueOperatorPtg instance = new LessEqualPtg();
+
+    private LessEqualPtg() {
+    	// enforce singleton
+    }
+    
+    protected byte getSid() {
+    	return sid;
+    }
+
+    public int getNumberOfOperands() {
+        return 2;
+    }
+
+    public String toFormulaString(String[] operands) {
+        StringBuffer buffer = new StringBuffer();
+        buffer.append( operands[0] );
+        buffer.append("<=");
+        buffer.append( operands[1] );
+        return buffer.toString();
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/LessThanPtg.java

@@ -0,0 +1,64 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+/**
+ * Less than operator PTG "<". The SID is taken from the 
+ * Openoffice.orgs Documentation of the Excel File Format,
+ * Table 3.5.7
+ * @author Cameron Riley (criley at ekmail.com)
+ */
+public final class LessThanPtg extends ValueOperatorPtg {
+    /** the sid for the less than operator as hex */
+    public final static byte sid  = 0x09;    
+
+    /** identifier for LESS THAN char */
+    private final static String LESSTHAN = "<";
+
+    public static final ValueOperatorPtg instance = new LessThanPtg();
+
+    private LessThanPtg() {
+    	// enforce singleton
+    }
+    
+    protected byte getSid() {
+    	return sid;
+    }
+
+    /**
+     * Get the number of operands for the Less than operator
+     * @return int the number of operands
+     */
+    public int getNumberOfOperands() {
+        return 2;
+    }
+    
+     /** 
+     * Implementation of method from OperationsPtg
+     * @param operands a String array of operands
+     * @return String the Formula as a String
+     */  
+    public String toFormulaString(String[] operands) 
+    {
+        StringBuffer buffer = new StringBuffer();
+        buffer.append(operands[ 0 ]);
+        buffer.append(LESSTHAN);
+        buffer.append(operands[ 1 ]);
+        return buffer.toString();
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/MemAreaPtg.java

@@ -0,0 +1,74 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * @author Daniel Noll (daniel at nuix dot com dot au)
+ */
+public final class MemAreaPtg extends OperandPtg {
+	public final static short sid = 0x26;
+	private final static int SIZE = 7;
+	private final int field_1_reserved;
+	private final int field_2_subex_len;
+
+	/** Creates new MemAreaPtg */
+
+	public MemAreaPtg(int subexLen) {
+		field_1_reserved = 0;
+		field_2_subex_len = subexLen;
+	}
+
+	public MemAreaPtg(LittleEndianInput in)  {
+		field_1_reserved = in.readInt();
+		field_2_subex_len = in.readShort();
+	}
+
+	public int getLenRefSubexpression() {
+		return field_2_subex_len;
+	}
+
+	public void write(LittleEndianOutput out) {
+		out.writeByte(sid + getPtgClass());
+		out.writeInt(field_1_reserved);
+		out.writeShort(field_2_subex_len);
+	}
+
+	public int getSize() {
+		return SIZE;
+	}
+
+	public String toFormulaString() {
+		return ""; // TODO: Not sure how to format this. -- DN
+	}
+
+	public byte getDefaultOperandClass() {
+		return Ptg.CLASS_VALUE;
+	}
+
+	@Override
+	public final String toString() {
+		StringBuffer sb = new StringBuffer(64);
+		sb.append(getClass().getName()).append(" [len=");
+		sb.append(field_2_subex_len);
+		sb.append("]");
+		return sb.toString();
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/MemErrPtg.java

@@ -0,0 +1,57 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * 
+ * @author andy
+ * @author Jason Height (jheight at chariot dot net dot au)
+ * @author Daniel Noll (daniel at nuix dot com dot au)
+ */
+public final class MemErrPtg extends OperandPtg {
+	public final static short sid = 0x27;
+	private final static int SIZE = 7;
+	private int field_1_reserved;
+	private short field_2_subex_len;
+
+	public MemErrPtg(LittleEndianInput in)  {
+		field_1_reserved = in.readInt();
+		field_2_subex_len = in.readShort();
+	}
+
+	public void write(LittleEndianOutput out) {
+		out.writeByte(sid + getPtgClass());
+		out.writeInt(field_1_reserved);
+		out.writeShort(field_2_subex_len);
+	}
+
+	public int getSize() {
+		return SIZE;
+	}
+
+	public String toFormulaString() {
+		return "ERR#";
+	}
+
+	public byte getDefaultOperandClass() {
+		return Ptg.CLASS_VALUE;
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/MemFuncPtg.java

@@ -0,0 +1,75 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * @author Glen Stampoultzis (glens at apache.org)
+ */
+public final class MemFuncPtg extends OperandPtg {
+
+	public final static byte sid = 0x29;
+	private final int field_1_len_ref_subexpression;
+
+	/**
+	 * Creates new function pointer from a byte array usually called while
+	 * reading an excel file.
+	 */
+	public MemFuncPtg(LittleEndianInput in)  {
+		this(in.readUShort());
+	}
+
+	public MemFuncPtg(int subExprLen) {
+		field_1_len_ref_subexpression = subExprLen;
+	}
+
+	public int getSize() {
+		return 3;
+	}
+
+	public void write(LittleEndianOutput out) {
+		out.writeByte(sid + getPtgClass());
+		out.writeShort(field_1_len_ref_subexpression);
+	}
+
+	public String toFormulaString() {
+		return "";
+	}
+
+	public byte getDefaultOperandClass() {
+		return Ptg.CLASS_REF;
+	}
+
+	public int getNumberOfOperands() {
+		return field_1_len_ref_subexpression;
+	}
+
+	public int getLenRefSubexpression() {
+		return field_1_len_ref_subexpression;
+	}
+	@Override
+	public final String toString() {
+		StringBuffer sb = new StringBuffer(64);
+		sb.append(getClass().getName()).append(" [len=");
+		sb.append(field_1_len_ref_subexpression);
+		sb.append("]");
+		return sb.toString();
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/MissingArgPtg.java

@@ -0,0 +1,51 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * Missing Function Arguments
+ * 
+ * Avik Sengupta <avik at apache.org>
+ * 
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class MissingArgPtg extends ScalarConstantPtg {
+
+	private final static int SIZE = 1;
+	public final static byte sid = 0x16;
+
+	public static final Ptg instance = new MissingArgPtg();
+
+	private MissingArgPtg() {
+		// enforce singleton
+	}
+
+	public void write(LittleEndianOutput out) {
+		out.writeByte(sid + getPtgClass());
+	}
+
+	public int getSize() {
+		return SIZE;
+	}
+
+	public String toFormulaString() {
+		return " ";
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/MultiplyPtg.java

@@ -0,0 +1,50 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+/**
+ * Implements the standard mathmatical multiplication - *
+ * @author  Andrew C. Oliver (acoliver at apache dot org)
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class MultiplyPtg extends ValueOperatorPtg {
+    public final static byte sid  = 0x05;
+
+    public static final ValueOperatorPtg instance = new MultiplyPtg();
+
+    private MultiplyPtg() {
+    	// enforce singleton
+    }
+    
+    protected byte getSid() {
+    	return sid;
+    }
+
+    public int getNumberOfOperands() {
+        return 2;
+    }
+    
+    public String toFormulaString(String[] operands) {
+        StringBuffer buffer = new StringBuffer();
+
+        buffer.append(operands[ 0 ]);
+        buffer.append("*");
+        buffer.append(operands[ 1 ]);
+        return buffer.toString();
+    }                  
+}

src/java/org/apache/poi/ss/formula/ptg/NamePtg.java

@@ -0,0 +1,79 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.formula.FormulaRenderingWorkbook;
+import org.apache.poi.ss.formula.WorkbookDependentFormula;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * 
+ * @author andy
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class NamePtg extends OperandPtg implements WorkbookDependentFormula {
+	public final static short sid = 0x23;
+	private final static int SIZE = 5;
+	/** one-based index to defined name record */
+	private int field_1_label_index;
+	private short field_2_zero; // reserved must be 0
+
+	/**
+	 * @param nameIndex zero-based index to name within workbook
+	 */
+	public NamePtg(int nameIndex) {
+		field_1_label_index = 1 + nameIndex; // convert to 1-based
+	}
+
+	/** Creates new NamePtg */
+
+	public NamePtg(LittleEndianInput in)  {
+		field_1_label_index = in.readShort();
+		field_2_zero = in.readShort();
+	}
+
+	/**
+	 * @return zero based index to a defined name record in the LinkTable
+	 */
+	public int getIndex() {
+		return field_1_label_index - 1; // convert to zero based
+	}
+
+	public void write(LittleEndianOutput out) {
+		out.writeByte(sid + getPtgClass());
+		out.writeShort(field_1_label_index);
+		out.writeShort(field_2_zero);
+	}
+
+	public int getSize() {
+		return SIZE;
+	}
+
+	public String toFormulaString(FormulaRenderingWorkbook book) {
+		return book.getNameText(this);
+	}
+
+	public String toFormulaString() {
+		throw new RuntimeException("3D references need a workbook to determine formula text");
+	}
+
+	public byte getDefaultOperandClass() {
+		return Ptg.CLASS_REF;
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/NameXPtg.java

@@ -0,0 +1,93 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.formula.FormulaRenderingWorkbook;
+import org.apache.poi.ss.formula.WorkbookDependentFormula;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * 
+ * @author aviks
+ */
+public final class NameXPtg extends OperandPtg implements WorkbookDependentFormula {
+	public final static short sid = 0x39;
+	private final static int SIZE = 7;
+
+	/** index to REF entry in externsheet record */
+	private final int _sheetRefIndex;
+	/** index to defined name or externname table(1 based) */
+	private final int _nameNumber;
+	/** reserved must be 0 */
+	private final int _reserved;
+
+	private NameXPtg(int sheetRefIndex, int nameNumber, int reserved) {
+		_sheetRefIndex = sheetRefIndex;
+		_nameNumber = nameNumber;
+		_reserved = reserved;
+	}
+
+	/**
+	 * @param sheetRefIndex index to REF entry in externsheet record
+	 * @param nameIndex index to defined name or externname table
+	 */
+	public NameXPtg(int sheetRefIndex, int nameIndex) {
+		this(sheetRefIndex, nameIndex + 1, 0);
+	}
+
+	public NameXPtg(LittleEndianInput in)  {
+		this(in.readUShort(), in.readUShort(), in.readUShort());
+	}
+
+	public void write(LittleEndianOutput out) {
+		out.writeByte(sid + getPtgClass());
+		out.writeShort(_sheetRefIndex);
+		out.writeShort(_nameNumber);
+		out.writeShort(_reserved);
+	}
+
+	public int getSize() {
+		return SIZE;
+	}
+
+	public String toFormulaString(FormulaRenderingWorkbook book) {
+		// -1 to convert definedNameIndex from 1-based to zero-based
+		return book.resolveNameXText(this);
+	}
+	public String toFormulaString() {
+		throw new RuntimeException("3D references need a workbook to determine formula text");
+	}
+	
+	public String toString(){
+	   String retValue = "NameXPtg:[sheetRefIndex:" + _sheetRefIndex + 
+	      " , nameNumber:" + _nameNumber + "]" ;
+	   return retValue;
+	}
+	
+	public byte getDefaultOperandClass() {
+		return Ptg.CLASS_VALUE;
+	}
+
+	public int getSheetRefIndex() {
+		return _sheetRefIndex;
+	}
+	public int getNameIndex() {
+		return _nameNumber - 1;
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/NotEqualPtg.java

@@ -0,0 +1,52 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+/**
+ * Ptg class to implement not equal
+ *
+ * @author fred at stsci dot edu
+ */
+public final class NotEqualPtg extends ValueOperatorPtg {
+    public final static byte sid = 0x0e;
+
+    public static final ValueOperatorPtg instance = new NotEqualPtg();
+
+    private NotEqualPtg() {
+    	// enforce singleton
+    }
+    
+    protected byte getSid() {
+    	return sid;
+    }
+
+    public int getNumberOfOperands() {
+        return 2;
+    }
+
+    public String toFormulaString(String[] operands) {
+        StringBuffer buffer = new StringBuffer();
+
+        buffer.append( operands[0] );
+
+        buffer.append("<>");
+        buffer.append( operands[1] );
+
+        return buffer.toString();
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/NumberPtg.java

@@ -0,0 +1,71 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.util.NumberToTextConverter;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * Number Stores a floating point value in a formula value stored in a 8 byte
+ * field using IEEE notation
+ * 
+ * @author Avik Sengupta
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class NumberPtg extends ScalarConstantPtg {
+	public final static int SIZE = 9;
+	public final static byte sid = 0x1f;
+	private final double field_1_value;
+
+	public NumberPtg(LittleEndianInput in)  {
+		this(in.readDouble());
+	}
+
+	/**
+	 * Create a NumberPtg from a string representation of the number Number
+	 * format is not checked, it is expected to be validated in the parser that
+	 * calls this method.
+	 * 
+	 * @param value String representation of a floating point number
+	 */
+	public NumberPtg(String value) {
+		this(Double.parseDouble(value));
+	}
+
+	public NumberPtg(double value) {
+		field_1_value = value;
+	}
+
+	public double getValue() {
+		return field_1_value;
+	}
+
+	public void write(LittleEndianOutput out) {
+		out.writeByte(sid + getPtgClass());
+		out.writeDouble(getValue());
+	}
+
+	public int getSize() {
+		return SIZE;
+	}
+
+	public String toFormulaString() {
+		return NumberToTextConverter.toText(field_1_value);
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/OperandPtg.java

@@ -0,0 +1,38 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+/**
+ * @author Josh Micich
+ */
+public abstract class OperandPtg extends Ptg implements Cloneable {
+
+	/**
+	 * All Operand {@link Ptg}s are classified ('relative', 'value', 'array')
+	 */
+	public final boolean isBaseToken() {
+		return false;
+	}
+	public final OperandPtg copy() {
+		try {
+			return (OperandPtg) clone();
+		} catch (CloneNotSupportedException e) {
+			throw new RuntimeException(e);
+		}
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/OperationPtg.java

@@ -0,0 +1,45 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+/**
+ * defines a Ptg that is an operation instead of an operand
+ * @author  andy
+ */
+public abstract class OperationPtg extends Ptg {
+    public final static int TYPE_UNARY    = 0;
+    public final static int TYPE_BINARY   = 1;
+    public final static int TYPE_FUNCTION = 2;
+
+    /**
+     *  returns a string representation of the operations
+     *  the length of the input array should equal the number returned by 
+     *  @see #getNumberOfOperands
+     *  
+     */
+    public abstract String toFormulaString(String[] operands);
+    
+    /**
+     * The number of operands expected by the operations
+     */
+    public abstract int getNumberOfOperands();
+    
+    public byte getDefaultOperandClass() {
+        return Ptg.CLASS_VALUE;
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/ParenthesisPtg.java

@@ -0,0 +1,58 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * While formula tokens are stored in RPN order and thus do not need parenthesis
+ * for precedence reasons, Parenthesis tokens ARE written to ensure that user
+ * entered parenthesis are displayed as-is on reading back
+ * 
+ * Avik Sengupta <lists@aviksengupta.com> Andrew C. Oliver (acoliver at
+ * apache dot org)
+ * 
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class ParenthesisPtg extends ControlPtg {
+
+	private final static int SIZE = 1;
+	public final static byte sid = 0x15;
+
+	public static final ControlPtg instance = new ParenthesisPtg();
+
+	private ParenthesisPtg() {
+		// enforce singleton
+	}
+
+	public void write(LittleEndianOutput out) {
+		out.writeByte(sid + getPtgClass());
+	}
+
+	public int getSize() {
+		return SIZE;
+	}
+
+	public String toFormulaString() {
+		return "()";
+	}
+
+	public String toFormulaString(String[] operands) {
+		return "(" + operands[0] + ")";
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/PercentPtg.java

@@ -0,0 +1,52 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+/**
+ * Percent PTG.
+ *
+ * @author Daniel Noll (daniel at nuix.com.au)
+ */
+public final class PercentPtg extends ValueOperatorPtg {
+    public final static int  SIZE = 1;
+    public final static byte sid  = 0x14;
+    
+    private final static String PERCENT = "%";
+
+    public static final ValueOperatorPtg instance = new PercentPtg();
+
+    private PercentPtg() {
+    	// enforce singleton
+    }
+    
+    protected byte getSid() {
+    	return sid;
+    }
+
+    public int getNumberOfOperands() {
+        return 1;
+    }
+       
+    public String toFormulaString(String[] operands) {
+        StringBuffer buffer = new StringBuffer();
+
+        buffer.append(operands[ 0 ]);
+        buffer.append(PERCENT);
+        return buffer.toString();
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/PowerPtg.java

@@ -0,0 +1,51 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+/**
+ *
+ * @author  andy
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class PowerPtg extends ValueOperatorPtg {
+    public final static byte sid  = 0x07;
+
+    public static final ValueOperatorPtg instance = new PowerPtg();
+
+    private PowerPtg() {
+    	// enforce singleton
+    }
+    
+    protected byte getSid() {
+    	return sid;
+    }
+
+    public int getNumberOfOperands() {
+        return 2; // TODO - 2 seems wrong (Jun 2008).  Maybe this method is not relevant
+    }
+ 
+    public String toFormulaString(String[] operands) {
+         StringBuffer buffer = new StringBuffer();
+
+        
+        buffer.append(operands[ 0 ]);
+        buffer.append("^");
+        buffer.append(operands[ 1 ]);
+        return buffer.toString();
+    }       
+}

src/java/org/apache/poi/ss/formula/ptg/Ptg.java

@@ -0,0 +1,321 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.poi.util.LittleEndianByteArrayOutputStream;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * <tt>Ptg</tt> represents a syntactic token in a formula.  'PTG' is an acronym for
+ * '<b>p</b>arse <b>t</b>hin<b>g</b>'.  Originally, the name referred to the single
+ * byte identifier at the start of the token, but in POI, <tt>Ptg</tt> encapsulates
+ * the whole formula token (initial byte + value data).
+ * <p/>
+ *
+ * <tt>Ptg</tt>s are logically arranged in a tree representing the structure of the
+ * parsed formula.  However, in BIFF files <tt>Ptg</tt>s are written/read in
+ * <em>Reverse-Polish Notation</em> order. The RPN ordering also simplifies formula
+ * evaluation logic, so POI mostly accesses <tt>Ptg</tt>s in the same way.
+ *
+ * @author  andy
+ * @author avik
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public abstract class Ptg {
+	public static final Ptg[] EMPTY_PTG_ARRAY = { };
+
+
+	/**
+	 * Reads <tt>size</tt> bytes of the input stream, to create an array of <tt>Ptg</tt>s.
+	 * Extra data (beyond <tt>size</tt>) may be read if and <tt>ArrayPtg</tt>s are present.
+	 */
+	public static Ptg[] readTokens(int size, LittleEndianInput in) {
+		List<Ptg> temp = new ArrayList<Ptg>(4 + size / 2);
+		int pos = 0;
+		boolean hasArrayPtgs = false;
+		while (pos < size) {
+			Ptg ptg = Ptg.createPtg(in);
+			if (ptg instanceof ArrayPtg.Initial) {
+				hasArrayPtgs = true;
+			}
+			pos += ptg.getSize();
+			temp.add(ptg);
+		}
+		if(pos != size) {
+			throw new RuntimeException("Ptg array size mismatch");
+		}
+		if (hasArrayPtgs) {
+			Ptg[] result = toPtgArray(temp);
+			for (int i=0;i<result.length;i++) {
+				if (result[i] instanceof ArrayPtg.Initial) {
+					result[i] = ((ArrayPtg.Initial) result[i]).finishReading(in);
+				}
+			}
+			return result;
+		}
+		return toPtgArray(temp);
+	}
+
+	public static Ptg createPtg(LittleEndianInput in) {
+		byte id = in.readByte();
+
+		if (id < 0x20) {
+			return createBasePtg(id, in);
+		}
+
+		Ptg  retval = createClassifiedPtg(id, in);
+
+		if (id >= 0x60) {
+			retval.setClass(CLASS_ARRAY);
+		} else if (id >= 0x40) {
+			retval.setClass(CLASS_VALUE);
+		} else {
+			retval.setClass(CLASS_REF);
+		}
+		return retval;
+	}
+
+	private static Ptg createClassifiedPtg(byte id, LittleEndianInput in) {
+
+		int baseId = id & 0x1F | 0x20;
+
+		switch (baseId) {
+			case ArrayPtg.sid:    return new ArrayPtg.Initial(in);//0x20, 0x40, 0x60
+			case FuncPtg.sid:     return FuncPtg.create(in);  // 0x21, 0x41, 0x61
+			case FuncVarPtg.sid:  return FuncVarPtg.create(in);//0x22, 0x42, 0x62
+			case NamePtg.sid:     return new NamePtg(in);     // 0x23, 0x43, 0x63
+			case RefPtg.sid:      return new RefPtg(in);      // 0x24, 0x44, 0x64
+			case AreaPtg.sid:     return new AreaPtg(in);     // 0x25, 0x45, 0x65
+			case MemAreaPtg.sid:  return new MemAreaPtg(in);  // 0x26, 0x46, 0x66
+			case MemErrPtg.sid:   return new MemErrPtg(in);   // 0x27, 0x47, 0x67
+			case MemFuncPtg.sid:  return new MemFuncPtg(in);  // 0x29, 0x49, 0x69
+			case RefErrorPtg.sid: return new RefErrorPtg(in); // 0x2a, 0x4a, 0x6a
+			case AreaErrPtg.sid:  return new AreaErrPtg(in);  // 0x2b, 0x4b, 0x6b
+			case RefNPtg.sid:     return new RefNPtg(in);     // 0x2c, 0x4c, 0x6c
+			case AreaNPtg.sid:    return new AreaNPtg(in);    // 0x2d, 0x4d, 0x6d
+
+			case NameXPtg.sid:    return new NameXPtg(in);    // 0x39, 0x49, 0x79
+			case Ref3DPtg.sid:    return new Ref3DPtg(in);    // 0x3a, 0x5a, 0x7a
+			case Area3DPtg.sid:   return new Area3DPtg(in);   // 0x3b, 0x5b, 0x7b
+			case DeletedRef3DPtg.sid:  return new DeletedRef3DPtg(in);   // 0x3c, 0x5c, 0x7c
+			case DeletedArea3DPtg.sid: return  new DeletedArea3DPtg(in); // 0x3d, 0x5d, 0x7d
+		}
+		throw new UnsupportedOperationException(" Unknown Ptg in Formula: 0x"+
+					Integer.toHexString(id) + " (" + ( int ) id + ")");
+	}
+
+	private static Ptg createBasePtg(byte id, LittleEndianInput in) {
+		switch(id) {
+			case 0x00:                return new UnknownPtg(id); // TODO - not a real Ptg
+			case ExpPtg.sid:          return new ExpPtg(in);          // 0x01
+			case TblPtg.sid:          return new TblPtg(in);          // 0x02
+			case AddPtg.sid:          return AddPtg.instance;         // 0x03
+			case SubtractPtg.sid:     return SubtractPtg.instance;    // 0x04
+			case MultiplyPtg.sid:     return MultiplyPtg.instance;    // 0x05
+			case DividePtg.sid:       return DividePtg.instance;      // 0x06
+			case PowerPtg.sid:        return PowerPtg.instance;       // 0x07
+			case ConcatPtg.sid:       return ConcatPtg.instance;      // 0x08
+			case LessThanPtg.sid:     return LessThanPtg.instance;    // 0x09
+			case LessEqualPtg.sid:    return LessEqualPtg.instance;   // 0x0a
+			case EqualPtg.sid:        return EqualPtg.instance;       // 0x0b
+			case GreaterEqualPtg.sid: return GreaterEqualPtg.instance;// 0x0c
+			case GreaterThanPtg.sid:  return GreaterThanPtg.instance; // 0x0d
+			case NotEqualPtg.sid:     return NotEqualPtg.instance;    // 0x0e
+			case IntersectionPtg.sid: return IntersectionPtg.instance;// 0x0f
+			case UnionPtg.sid:        return UnionPtg.instance;       // 0x10
+			case RangePtg.sid:        return RangePtg.instance;       // 0x11
+			case UnaryPlusPtg.sid:    return UnaryPlusPtg.instance;   // 0x12
+			case UnaryMinusPtg.sid:   return UnaryMinusPtg.instance;  // 0x13
+			case PercentPtg.sid:      return PercentPtg.instance;     // 0x14
+			case ParenthesisPtg.sid:  return ParenthesisPtg.instance; // 0x15
+			case MissingArgPtg.sid:   return MissingArgPtg.instance;  // 0x16
+
+			case StringPtg.sid:       return new StringPtg(in);       // 0x17
+			case AttrPtg.sid:         return new AttrPtg(in);         // 0x19
+			case ErrPtg.sid:          return ErrPtg.read(in);         // 0x1c
+			case BoolPtg.sid:         return BoolPtg.read(in);        // 0x1d
+			case IntPtg.sid:          return new IntPtg(in);          // 0x1e
+			case NumberPtg.sid:       return new NumberPtg(in);       // 0x1f
+		}
+		throw new RuntimeException("Unexpected base token id (" + id + ")");
+	}
+
+	private static Ptg[] toPtgArray(List<Ptg> l) {
+		if (l.isEmpty()) {
+			return EMPTY_PTG_ARRAY;
+		}
+		Ptg[] result = new Ptg[l.size()];
+		l.toArray(result);
+		return result;
+	}
+	/**
+	 * This method will return the same result as {@link #getEncodedSizeWithoutArrayData(Ptg[])}
+	 * if there are no array tokens present.
+	 * @return the full size taken to encode the specified <tt>Ptg</tt>s
+	 */
+	public static int getEncodedSize(Ptg[] ptgs) {
+		int result = 0;
+		for (int i = 0; i < ptgs.length; i++) {
+			result += ptgs[i].getSize();
+		}
+		return result;
+	}
+	/**
+	 * Used to calculate value that should be encoded at the start of the encoded Ptg token array;
+	 * @return the size of the encoded Ptg tokens not including any trailing array data.
+	 */
+	public static int getEncodedSizeWithoutArrayData(Ptg[] ptgs) {
+		int result = 0;
+		for (int i = 0; i < ptgs.length; i++) {
+			Ptg ptg = ptgs[i];
+			if (ptg instanceof ArrayPtg) {
+				result += ArrayPtg.PLAIN_TOKEN_SIZE;
+			} else {
+				result += ptg.getSize();
+			}
+		}
+		return result;
+	}
+	/**
+	 * Writes the ptgs to the data buffer, starting at the specified offset.
+	 *
+	 * <br/>
+	 * The 2 byte encode length field is <b>not</b> written by this method.
+	 * @return number of bytes written
+	 */
+	public static int serializePtgs(Ptg[] ptgs, byte[] array, int offset) {
+		int nTokens = ptgs.length;
+
+		LittleEndianByteArrayOutputStream out = new LittleEndianByteArrayOutputStream(array, offset);
+
+		List<Ptg> arrayPtgs = null;
+
+		for (int k = 0; k < nTokens; k++) {
+			Ptg ptg = ptgs[k];
+
+			ptg.write(out);
+			if (ptg instanceof ArrayPtg) {
+				if (arrayPtgs == null) {
+					arrayPtgs = new ArrayList<Ptg>(5);
+				}
+				arrayPtgs.add(ptg);
+			}
+		}
+		if (arrayPtgs != null) {
+			for (int i=0;i<arrayPtgs.size();i++) {
+				ArrayPtg p = (ArrayPtg)arrayPtgs.get(i);
+				p.writeTokenValueBytes(out);
+			}
+		}
+		return out.getWriteIndex() - offset;
+	}
+
+	/**
+	 * @return the encoded length of this Ptg, including the initial Ptg type identifier byte.
+	 */
+	public abstract int getSize();
+
+	public abstract void write(LittleEndianOutput out);
+
+	/**
+	 * return a string representation of this token alone
+	 */
+	public abstract String toFormulaString();
+
+	/** Overridden toString method to ensure object hash is not printed.
+	 * This helps get rid of gratuitous diffs when comparing two dumps
+	 * Subclasses may output more relevant information by overriding this method
+	 **/
+	public String toString(){
+		return this.getClass().toString();
+	}
+
+	public static final byte CLASS_REF = 0x00;
+	public static final byte CLASS_VALUE = 0x20;
+	public static final byte CLASS_ARRAY = 0x40;
+
+	private byte ptgClass = CLASS_REF; //base ptg
+
+	public final void setClass(byte thePtgClass) {
+		if (isBaseToken()) {
+			throw new RuntimeException("setClass should not be called on a base token");
+		}
+		ptgClass = thePtgClass;
+	}
+
+	/**
+	 *  @return the 'operand class' (REF/VALUE/ARRAY) for this Ptg
+	 */
+	public final byte getPtgClass() {
+		return ptgClass;
+	}
+
+	/**
+	 * Debug / diagnostic method to get this token's 'operand class' type.
+	 * @return 'R' for 'reference', 'V' for 'value', 'A' for 'array' and '.' for base tokens
+	 */
+	public final char getRVAType() {
+		if (isBaseToken()) {
+			return '.';
+		}
+		switch (ptgClass) {
+			case Ptg.CLASS_REF:   return 'R';
+			case Ptg.CLASS_VALUE: return 'V';
+			case Ptg.CLASS_ARRAY: return 'A';
+		}
+		throw new RuntimeException("Unknown operand class (" + ptgClass + ")");
+	}
+
+	public abstract byte getDefaultOperandClass();
+
+	/**
+	 * @return <code>false</code> if this token is classified as 'reference', 'value', or 'array'
+	 */
+	public abstract boolean isBaseToken();
+
+	public static boolean doesFormulaReferToDeletedCell(Ptg[] ptgs) {
+		for (int i = 0; i < ptgs.length; i++) {
+			if (isDeletedCellRef(ptgs[i])) {
+				return true;
+			}
+		}
+		return false;
+	}
+	private static boolean isDeletedCellRef(Ptg ptg) {
+		if (ptg == ErrPtg.REF_INVALID) {
+			return true;
+		}
+		if (ptg instanceof DeletedArea3DPtg) {
+			return true;
+		}
+		if (ptg instanceof DeletedRef3DPtg) {
+			return true;
+		}
+		if (ptg instanceof AreaErrPtg) {
+			return true;
+		}
+		if (ptg instanceof RefErrorPtg) {
+			return true;
+		}
+		return false;
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/RangePtg.java

@@ -0,0 +1,71 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.util.LittleEndianOutput;
+
+
+/**
+ * @author Daniel Noll (daniel at nuix dot com dot au)
+ */
+public final class RangePtg  extends OperationPtg {
+    public final static int  SIZE = 1;
+    public final static byte sid  = 0x11;
+
+    public static final OperationPtg instance = new RangePtg();
+
+    private RangePtg() {
+    	// enforce singleton
+    }
+
+    public final boolean isBaseToken() {
+        return true;
+    }
+
+    public int getSize()
+    {
+        return SIZE;
+    }
+
+    public void write(LittleEndianOutput out) {
+        out.writeByte(sid + getPtgClass());
+    }
+
+    public String toFormulaString()
+    {
+        return ":";
+    }
+
+
+    /** implementation of method from OperationsPtg*/
+    public String toFormulaString(String[] operands)
+    {
+         StringBuffer buffer = new StringBuffer();
+
+         buffer.append(operands[ 0 ]);
+         buffer.append(":");
+         buffer.append(operands[ 1 ]);
+         return buffer.toString();
+     }
+
+    public int getNumberOfOperands()
+    {
+        return 2;
+    }
+
+}

src/java/org/apache/poi/ss/formula/ptg/Ref2DPtgBase.java

@@ -0,0 +1,69 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.util.CellReference;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * @author Josh Micich
+ */
+abstract class Ref2DPtgBase extends RefPtgBase {
+	private final static int SIZE = 5;
+
+
+	protected Ref2DPtgBase(int row, int column, boolean isRowRelative, boolean isColumnRelative) {
+		setRow(row);
+		setColumn(column);
+		setRowRelative(isRowRelative);
+		setColRelative(isColumnRelative);
+	}
+
+	protected Ref2DPtgBase(LittleEndianInput in)  {
+		readCoordinates(in);
+	}
+
+	protected Ref2DPtgBase(CellReference cr) {
+		super(cr);
+	}
+
+	public void write(LittleEndianOutput out) {
+		out.writeByte(getSid() + getPtgClass());
+		writeCoordinates(out);
+	}
+
+	public final String toFormulaString() {
+		return formatReferenceAsString();
+	}
+
+	protected abstract byte getSid();
+
+	public final int getSize() {
+		return SIZE;
+	}
+
+	public final String toString() {
+		StringBuffer sb = new StringBuffer();
+		sb.append(getClass().getName());
+		sb.append(" [");
+		sb.append(formatReferenceAsString());
+		sb.append("]");
+		return sb.toString();
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/Ref3DPtg.java

@@ -0,0 +1,96 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.util.CellReference;
+import org.apache.poi.ss.formula.ExternSheetReferenceToken;
+import org.apache.poi.ss.formula.FormulaRenderingWorkbook;
+import org.apache.poi.ss.formula.WorkbookDependentFormula;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * Title:        Reference 3D Ptg <P>
+ * Description:  Defined a cell in extern sheet. <P>
+ * REFERENCE:  <P>
+ * @author Libin Roman (Vista Portal LDT. Developer)
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class Ref3DPtg extends RefPtgBase implements WorkbookDependentFormula, ExternSheetReferenceToken {
+    public final static byte sid  = 0x3a;
+
+    private final static int  SIZE = 7; // 6 + 1 for Ptg
+    private int             field_1_index_extern_sheet;
+
+
+    public Ref3DPtg(LittleEndianInput in)  {
+        field_1_index_extern_sheet = in.readShort();
+        readCoordinates(in);
+    }
+
+    public Ref3DPtg(String cellref, int externIdx ) {
+        this(new CellReference(cellref), externIdx);
+    }
+
+    public Ref3DPtg(CellReference c, int externIdx) {
+        super(c);
+        setExternSheetIndex(externIdx);
+    }
+
+    public String toString() {
+        StringBuffer sb = new StringBuffer();
+        sb.append(getClass().getName());
+        sb.append(" [");
+        sb.append("sheetIx=").append(getExternSheetIndex());
+        sb.append(" ! ");
+        sb.append(formatReferenceAsString());
+        sb.append("]");
+        return sb.toString();
+    }
+
+    public void write(LittleEndianOutput out) {
+        out.writeByte(sid + getPtgClass());
+        out.writeShort(getExternSheetIndex());
+        writeCoordinates(out);
+    }
+
+    public int getSize() {
+        return SIZE;
+    }
+
+    public int getExternSheetIndex() {
+        return field_1_index_extern_sheet;
+    }
+
+    public void setExternSheetIndex(int index) {
+        field_1_index_extern_sheet = index;
+    }
+    public String format2DRefAsString() {
+        return formatReferenceAsString();
+    }
+    /**
+     * @return text representation of this cell reference that can be used in text
+     * formulas. The sheet name will get properly delimited if required.
+     */
+    public String toFormulaString(FormulaRenderingWorkbook book) {
+        return ExternSheetNameResolver.prependSheetName(book, field_1_index_extern_sheet, formatReferenceAsString());
+    }
+    public String toFormulaString() {
+        throw new RuntimeException("3D references need a workbook to determine formula text");
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/RefErrorPtg.java

@@ -0,0 +1,62 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.usermodel.ErrorConstants;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * RefError - handles deleted cell reference
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class RefErrorPtg extends OperandPtg {
+
+    private final static int SIZE = 5;
+    public final static byte sid  = 0x2A;
+    private int              field_1_reserved;
+
+    public RefErrorPtg() {
+        field_1_reserved = 0;
+    }
+    public RefErrorPtg(LittleEndianInput in)  {
+        field_1_reserved = in.readInt();
+    }
+
+    public String toString() {
+        return getClass().getName();
+    }
+
+    public void write(LittleEndianOutput out) {
+        out.writeByte(sid + getPtgClass());
+        out.writeInt(field_1_reserved);
+    }
+
+    public int getSize()
+    {
+        return SIZE;
+    }
+
+    public String toFormulaString() {
+        return ErrorConstants.getText(ErrorConstants.ERROR_REF);
+    }
+    
+    public byte getDefaultOperandClass() {
+        return Ptg.CLASS_REF;
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/RefNPtg.java

@@ -0,0 +1,36 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.util.LittleEndianInput;
+
+/**
+ * RefNPtg
+ * @author Jason Height (jheight at apache dot com)
+ */
+public final class RefNPtg extends Ref2DPtgBase {
+	public final static byte sid = 0x2C;
+
+	public RefNPtg(LittleEndianInput in)  {
+		super(in);
+	}
+
+	protected byte getSid() {
+		return sid;
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/RefPtg.java

@@ -0,0 +1,54 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.util.CellReference;
+import org.apache.poi.util.LittleEndianInput;
+
+/**
+ * ReferencePtg - handles references (such as A1, A2, IA4)
+ * @author  Andrew C. Oliver (acoliver@apache.org)
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class RefPtg extends Ref2DPtgBase {
+	public final static byte sid = 0x24;
+
+	/**
+	 * Takes in a String representation of a cell reference and fills out the
+	 * numeric fields.
+	 */
+	public RefPtg(String cellref) {
+		super(new CellReference(cellref));
+	}
+
+	public RefPtg(int row, int column, boolean isRowRelative, boolean isColumnRelative) {
+		super(row, column, isRowRelative, isColumnRelative);
+	}
+
+	public RefPtg(LittleEndianInput in)  {
+		super(in);
+	}
+
+	public RefPtg(CellReference cr) {
+		super(cr);
+	}
+
+	protected byte getSid() {
+		return sid;
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/RefPtgBase.java

@@ -0,0 +1,117 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.util.CellReference;
+import org.apache.poi.util.BitField;
+import org.apache.poi.util.BitFieldFactory;
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * ReferencePtgBase - handles references (such as A1, A2, IA4)
+ *
+ * @author Andrew C. Oliver (acoliver@apache.org)
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public abstract class RefPtgBase extends OperandPtg {
+
+	/** The row index - zero based unsigned 16 bit value */
+	private int field_1_row;
+	/**
+	 * Field 2 - lower 8 bits is the zero based unsigned byte column index - bit
+	 * 16 - isRowRelative - bit 15 - isColumnRelative
+	 */
+	private int field_2_col;
+	private static final BitField rowRelative = BitFieldFactory.getInstance(0x8000);
+	private static final BitField colRelative = BitFieldFactory.getInstance(0x4000);
+
+    /**
+     * YK: subclasses of RefPtgBase are used by the FormulaParser and FormulaEvaluator accross HSSF and XSSF.
+     * The bit mask should accomodate the maximum number of avaiable columns, i.e. 0x3FFF.
+     *
+     * @see org.apache.poi.ss.SpreadsheetVersion
+     */
+    private static final BitField column = BitFieldFactory.getInstance(0x3FFF);
+
+	protected RefPtgBase() {
+		// Required for clone methods
+	}
+
+	protected RefPtgBase(CellReference c) {
+		setRow(c.getRow());
+		setColumn(c.getCol());
+		setColRelative(!c.isColAbsolute());
+		setRowRelative(!c.isRowAbsolute());
+	}
+
+	protected final void readCoordinates(LittleEndianInput in) {
+		field_1_row = in.readUShort();
+		field_2_col = in.readUShort();
+	}
+
+	protected final void writeCoordinates(LittleEndianOutput out) {
+		out.writeShort(field_1_row);
+		out.writeShort(field_2_col);
+	}
+
+	public final void setRow(int rowIndex) {
+		field_1_row = rowIndex;
+	}
+
+	/**
+	 * @return the row number as an int
+	 */
+	public final int getRow() {
+		return field_1_row;
+	}
+
+	public final boolean isRowRelative() {
+		return rowRelative.isSet(field_2_col);
+	}
+
+	public final void setRowRelative(boolean rel) {
+		field_2_col = rowRelative.setBoolean(field_2_col, rel);
+	}
+
+	public final boolean isColRelative() {
+		return colRelative.isSet(field_2_col);
+	}
+
+	public final void setColRelative(boolean rel) {
+		field_2_col = colRelative.setBoolean(field_2_col, rel);
+	}
+
+	public final void setColumn(int col) {
+		field_2_col = column.setValue(field_2_col, col);
+	}
+
+	public final int getColumn() {
+		return column.getValue(field_2_col);
+	}
+
+	protected final String formatReferenceAsString() {
+		// Only make cell references as needed. Memory is an issue
+		CellReference cr = new CellReference(getRow(), getColumn(), !isRowRelative(), !isColRelative());
+		return cr.formatAsString();
+	}
+
+	public final byte getDefaultOperandClass() {
+		return Ptg.CLASS_REF;
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/ScalarConstantPtg.java

@@ -0,0 +1,42 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+
+/**
+ * Common superclass of all {@link Ptg}s that represent simple constant values.
+ *
+ * @author Josh Micich
+ */
+public abstract class ScalarConstantPtg extends Ptg {
+	public final boolean isBaseToken() {
+		return true;
+	}
+
+	public final byte getDefaultOperandClass() {
+		return Ptg.CLASS_VALUE;
+	}
+
+	public final String toString() {
+		StringBuffer sb = new StringBuffer(64);
+		sb.append(getClass().getName()).append(" [");
+		sb.append(toFormulaString());
+		sb.append("]");
+		return sb.toString();
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/StringPtg.java

@@ -0,0 +1,108 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+import org.apache.poi.util.StringUtil;
+
+/**
+ * String Stores a String value in a formula value stored in the format
+ * <length 2 bytes>char[]
+ * 
+ * @author Werner Froidevaux
+ * @author Jason Height (jheight at chariot dot net dot au)
+ * @author Bernard Chesnoy
+ */
+public final class StringPtg extends ScalarConstantPtg {
+     public final static byte sid = 0x17;
+    /** the character (") used in formulas to delimit string literals */
+    private static final char FORMULA_DELIMITER = '"';
+
+    private final boolean _is16bitUnicode;
+    /**
+     * NOTE: OO doc says 16bit length, but BiffViewer says 8 Book says something
+     * totally different, so don't look there!
+     */
+    private final String field_3_string;
+
+    /** Create a StringPtg from a stream */
+    public StringPtg(LittleEndianInput in)  {
+    	int nChars = in.readUByte(); // Note - nChars is 8-bit
+    	_is16bitUnicode = (in.readByte() & 0x01) != 0;
+    	if (_is16bitUnicode) {
+    		field_3_string = StringUtil.readUnicodeLE(in, nChars);
+    	} else {
+    		field_3_string = StringUtil.readCompressedUnicode(in, nChars);
+    	}
+    }
+
+    /**
+     * Create a StringPtg from a string representation of the number Number
+     * format is not checked, it is expected to be validated in the parser that
+     * calls this method.
+     * 
+     * @param value :
+     *            String representation of a floating point number
+     */
+    public StringPtg(String value) {
+        if (value.length() > 255) {
+            throw new IllegalArgumentException(
+                    "String literals in formulas can't be bigger than 255 characters ASCII");
+        }
+        _is16bitUnicode = StringUtil.hasMultibyte(value);
+        field_3_string = value;
+    }
+
+    public String getValue() {
+        return field_3_string;
+    }
+
+    public void write(LittleEndianOutput out) {
+        out.writeByte(sid + getPtgClass());
+        out.writeByte(field_3_string.length()); // Note - nChars is 8-bit
+        out.writeByte(_is16bitUnicode ? 0x01 : 0x00);
+        if (_is16bitUnicode) {
+        	StringUtil.putUnicodeLE(field_3_string, out);
+        } else {
+        	StringUtil.putCompressedUnicode(field_3_string, out);
+        }
+    }
+
+    public int getSize() {
+    	return 3 +  field_3_string.length() * (_is16bitUnicode ? 2 : 1);
+    }
+
+    public String toFormulaString() {
+        String value = field_3_string;
+        int len = value.length();
+        StringBuffer sb = new StringBuffer(len + 4);
+        sb.append(FORMULA_DELIMITER);
+
+        for (int i = 0; i < len; i++) {
+            char c = value.charAt(i);
+            if (c == FORMULA_DELIMITER) {
+                sb.append(FORMULA_DELIMITER);
+            }
+            sb.append(c);
+        }
+
+        sb.append(FORMULA_DELIMITER);
+        return sb.toString();
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/SubtractPtg.java

@@ -0,0 +1,50 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+/**
+ *
+ * @author  andy
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public final class SubtractPtg extends ValueOperatorPtg {
+    public final static byte sid  = 0x04;
+
+    public static final ValueOperatorPtg instance = new SubtractPtg();
+
+    private SubtractPtg() {
+    	// enforce singleton
+    }
+    
+    protected byte getSid() {
+    	return sid;
+    }
+
+    public int getNumberOfOperands() {
+        return 2;
+    }
+       
+    public String toFormulaString(String[] operands) {
+        StringBuffer buffer = new StringBuffer();
+
+        buffer.append(operands[ 0 ]);
+        buffer.append("-");
+        buffer.append(operands[ 1 ]);
+        return buffer.toString();
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/TblPtg.java

@@ -0,0 +1,80 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.util.LittleEndianInput;
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * This ptg indicates a data table.
+ * It only occurs in a FORMULA record, never in an
+ *  ARRAY or NAME record.  When ptgTbl occurs in a
+ *  formula, it is the only token in the formula.
+ *
+ * This indicates that the cell containing the
+ *  formula is an interior cell in a data table;
+ *  the table description is found in a TABLE
+ *  record. Rows and columns which contain input
+ *  values to be substituted in the table do
+ *  not contain ptgTbl.
+ * See page 811 of the june 08 binary docs.
+ */
+public final class TblPtg extends ControlPtg {
+    private final static int  SIZE = 5;
+    public final static short sid  = 0x02;
+    /** The row number of the upper left corner */
+    private final int field_1_first_row;
+    /** The column number of the upper left corner */
+    private final int field_2_first_col;
+
+    public TblPtg(LittleEndianInput in)  {
+      field_1_first_row = in.readUShort();
+      field_2_first_col = in.readUShort();
+    }
+
+    public void write(LittleEndianOutput out) {
+        out.writeByte(sid + getPtgClass());
+        out.writeShort(field_1_first_row);
+        out.writeShort(field_2_first_col);
+    }
+
+    public int getSize() {
+        return SIZE;
+    }
+
+    public int getRow() {
+      return field_1_first_row;
+    }
+
+    public int getColumn() {
+      return field_2_first_col;
+    }
+
+    public String toFormulaString()
+    {
+        // table(....)[][]
+        throw new RuntimeException("Table and Arrays are not yet supported");
+    }
+
+    public String toString() {
+        StringBuffer buffer = new StringBuffer("[Data Table - Parent cell is an interior cell in a data table]\n");
+        buffer.append("top left row = ").append(getRow()).append("\n");
+        buffer.append("top left col = ").append(getColumn()).append("\n");
+        return buffer.toString();
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/UnaryMinusPtg.java

@@ -0,0 +1,51 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+/**
+ * Unary Plus operator
+ * does not have any effect on the operand
+ * @author Avik Sengupta
+ */
+public final class UnaryMinusPtg extends ValueOperatorPtg {
+    public final static byte sid  = 0x13;
+    
+    private final static String MINUS = "-";
+
+    public static final ValueOperatorPtg instance = new UnaryMinusPtg();
+
+    private UnaryMinusPtg() {
+    	// enforce singleton
+    }
+    
+    protected byte getSid() {
+    	return sid;
+    }
+
+    public int getNumberOfOperands() {
+        return 1;
+    }
+    
+   /** implementation of method from OperationsPtg*/  
+    public String toFormulaString(String[] operands) {
+        StringBuffer buffer = new StringBuffer();
+        buffer.append(MINUS);
+        buffer.append(operands[ 0]);
+        return buffer.toString();
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/UnaryPlusPtg.java

@@ -0,0 +1,51 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+/**
+ * Unary Plus operator
+ * does not have any effect on the operand
+ * @author Avik Sengupta
+ */
+public final class UnaryPlusPtg extends ValueOperatorPtg {
+    public final static byte sid  = 0x12;
+    
+    private final static String ADD = "+";
+
+    public static final ValueOperatorPtg instance = new UnaryPlusPtg();
+
+    private UnaryPlusPtg() {
+    	// enforce singleton
+    }
+    
+    protected byte getSid() {
+    	return sid;
+    }
+
+    public int getNumberOfOperands() {
+        return 1;
+    }
+    
+   /** implementation of method from OperationsPtg*/  
+    public String toFormulaString(String[] operands) {
+        StringBuffer buffer = new StringBuffer();
+        buffer.append(ADD);
+        buffer.append(operands[ 0]);
+        return buffer.toString();
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/UnionPtg.java

@@ -0,0 +1,70 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.util.LittleEndianOutput;
+
+
+/**
+ * @author Glen Stampoultzis (glens at apache.org)
+ */
+public final class UnionPtg extends OperationPtg {
+    public final static byte sid  = 0x10;
+
+    public static final OperationPtg instance = new UnionPtg();
+
+    private UnionPtg() {
+    	// enforce singleton
+    }
+
+    public final boolean isBaseToken() {
+        return true;
+    }
+
+    public int getSize()
+    {
+        return 1;
+    }
+
+    public void write(LittleEndianOutput out) {
+        out.writeByte(sid + getPtgClass());
+    }
+
+    public String toFormulaString()
+    {
+        return ",";
+    }
+
+
+    /** implementation of method from OperationsPtg*/
+    public String toFormulaString(String[] operands)
+    {
+         StringBuffer buffer = new StringBuffer();
+
+         buffer.append(operands[ 0 ]);
+         buffer.append(",");
+         buffer.append(operands[ 1 ]);
+         return buffer.toString();
+     }
+
+    public int getNumberOfOperands()
+    {
+        return 2;
+    }
+
+}

src/java/org/apache/poi/ss/formula/ptg/UnknownPtg.java

@@ -0,0 +1,50 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * @author andy
+ * @author Jason Height (jheight at chariot dot net dot au)
+ */
+public class UnknownPtg extends Ptg {
+    private short size = 1;
+    private final int _sid;
+
+    public UnknownPtg(int sid) {
+        _sid = sid;
+    }
+
+    public boolean isBaseToken() {
+        return true;
+    }
+    public void write(LittleEndianOutput out) {
+        out.writeByte(_sid);
+    }
+
+    public int getSize() {
+        return size;
+    }
+
+    public String toFormulaString() {
+        return "UNKNOWN";
+    }
+    public byte getDefaultOperandClass() {
+        return Ptg.CLASS_VALUE;
+    }
+}

src/java/org/apache/poi/ss/formula/ptg/ValueOperatorPtg.java

@@ -0,0 +1,56 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.util.LittleEndianOutput;
+
+/**
+ * Common superclass of all value operators. Subclasses include all unary and
+ * binary operators except for the reference operators (IntersectionPtg,
+ * RangePtg, UnionPtg)
+ * 
+ * @author Josh Micich
+ */
+public abstract class ValueOperatorPtg extends OperationPtg {
+
+	/**
+	 * All Operator <tt>Ptg</tt>s are base tokens (i.e. are not RVA classified)
+	 */
+	public final boolean isBaseToken() {
+		return true;
+	}
+
+	public final byte getDefaultOperandClass() {
+		return Ptg.CLASS_VALUE;
+	}
+
+	public void write(LittleEndianOutput out) {
+		out.writeByte(getSid());
+	}
+
+	protected abstract byte getSid();
+
+	public final int getSize() {
+		return 1;
+	}
+
+	public final String toFormulaString() {
+		// TODO - prune this method out of the hierarchy
+		throw new RuntimeException("toFormulaString(String[] operands) should be used for subclasses of OperationPtgs");
+	}
+}

src/java/org/apache/poi/ss/formula/ptg/package.html

@@ -0,0 +1,38 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
+<!--
+   ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+   ====================================================================
+-->
+<html>
+<head>
+</head>
+<body bgcolor="white">
+
+formula package contains binary PTG structures used in Formulas 
+
+<h2>Related Documentation</h2>
+
+For overviews, tutorials, examples, guides, and tool documentation, please see:
+<ul>
+<li><a href="http://poi.apache.org">Apache POI Project</a>
+</ul>
+
+<!-- Put @see and @since tags down here. -->
+@see org.apache.poi.hssf.record
+@see org.apache.poi.hssf.record.FormulaRecord
+</body>
+</html>

src/java/org/apache/poi/ss/usermodel/Footer.java

@@ -22,7 +22,7 @@ package org.apache.poi.ss.usermodel;
  * For a list of all the different fields that can be
  *  placed into a footer, such as page number,
  *  bold, underline etc, see 
- *  {@link org.apache.poi.hssf.usermodel.HeaderFooter}.
+ *  {@link org.apache.poi.ss.usermodel.HeaderFooter}.
  */
 public interface Footer extends HeaderFooter {
     /**

src/java/org/apache/poi/ss/usermodel/Header.java

@@ -22,7 +22,7 @@ package org.apache.poi.ss.usermodel;
  * For a list of all the different fields that can be
  *  placed into a header, such as page number,
  *  bold, underline etc, see 
- *  {@link org.apache.poi.hssf.usermodel.HeaderFooter}.
+ *  {@link org.apache.poi.ss.usermodel.HeaderFooter}.
  */
 public interface Header extends HeaderFooter {
     /**