Replaced obsolete Eval with ValueEval in signature of Function.evaluate()

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@805119 13f79535-47bb-0310-9956-ffa450edef68

50 files changed, 200 insertions, 329 deletions

diff --git a/src/java/org/apache/poi/hssf/record/formula/atp/AnalysisToolPak.java b/src/java/org/apache/poi/hssf/record/formula/atp/AnalysisToolPak.java
index 96a43170e7..af56041521 100644
--- a/src/java/org/apache/poi/hssf/record/formula/atp/AnalysisToolPak.java
+++ b/src/java/org/apache/poi/hssf/record/formula/atp/AnalysisToolPak.java
@@ -20,7 +20,6 @@ package org.apache.poi.hssf.record.formula.atp;
 import java.util.HashMap;
 import java.util.Map;
 
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.ValueEval;
 import org.apache.poi.hssf.record.formula.functions.FreeRefFunction;
 import org.apache.poi.ss.formula.EvaluationWorkbook;
diff --git a/src/java/org/apache/poi/hssf/record/formula/eval/FunctionEval.java b/src/java/org/apache/poi/hssf/record/formula/eval/FunctionEval.java
index 5928fe40fe..5d04de0fc3 100644
--- a/src/java/org/apache/poi/hssf/record/formula/eval/FunctionEval.java
+++ b/src/java/org/apache/poi/hssf/record/formula/eval/FunctionEval.java
@@ -20,7 +20,63 @@ package org.apache.poi.hssf.record.formula.eval;
 import org.apache.poi.hssf.record.formula.AbstractFunctionPtg;
 import org.apache.poi.hssf.record.formula.function.FunctionMetadata;
 import org.apache.poi.hssf.record.formula.function.FunctionMetadataRegistry;
-import org.apache.poi.hssf.record.formula.functions.*;
+import org.apache.poi.hssf.record.formula.functions.AggregateFunction;
+import org.apache.poi.hssf.record.formula.functions.And;
+import org.apache.poi.hssf.record.formula.functions.CalendarFieldFunction;
+import org.apache.poi.hssf.record.formula.functions.Choose;
+import org.apache.poi.hssf.record.formula.functions.Column;
+import org.apache.poi.hssf.record.formula.functions.Columns;
+import org.apache.poi.hssf.record.formula.functions.Count;
+import org.apache.poi.hssf.record.formula.functions.Counta;
+import org.apache.poi.hssf.record.formula.functions.Countif;
+import org.apache.poi.hssf.record.formula.functions.DateFunc;
+import org.apache.poi.hssf.record.formula.functions.Errortype;
+import org.apache.poi.hssf.record.formula.functions.Even;
+import org.apache.poi.hssf.record.formula.functions.False;
+import org.apache.poi.hssf.record.formula.functions.FinanceFunction;
+import org.apache.poi.hssf.record.formula.functions.Find;
+import org.apache.poi.hssf.record.formula.functions.FreeRefFunction;
+import org.apache.poi.hssf.record.formula.functions.Function;
+import org.apache.poi.hssf.record.formula.functions.Hlookup;
+import org.apache.poi.hssf.record.formula.functions.Hyperlink;
+import org.apache.poi.hssf.record.formula.functions.If;
+import org.apache.poi.hssf.record.formula.functions.Index;
+import org.apache.poi.hssf.record.formula.functions.Indirect;
+import org.apache.poi.hssf.record.formula.functions.IsError;
+import org.apache.poi.hssf.record.formula.functions.IsNa;
+import org.apache.poi.hssf.record.formula.functions.Isblank;
+import org.apache.poi.hssf.record.formula.functions.Isref;
+import org.apache.poi.hssf.record.formula.functions.LogicalFunction;
+import org.apache.poi.hssf.record.formula.functions.Lookup;
+import org.apache.poi.hssf.record.formula.functions.Match;
+import org.apache.poi.hssf.record.formula.functions.MinaMaxa;
+import org.apache.poi.hssf.record.formula.functions.Mode;
+import org.apache.poi.hssf.record.formula.functions.Na;
+import org.apache.poi.hssf.record.formula.functions.Not;
+import org.apache.poi.hssf.record.formula.functions.NotImplementedFunction;
+import org.apache.poi.hssf.record.formula.functions.Now;
+import org.apache.poi.hssf.record.formula.functions.NumericFunction;
+import org.apache.poi.hssf.record.formula.functions.Odd;
+import org.apache.poi.hssf.record.formula.functions.Offset;
+import org.apache.poi.hssf.record.formula.functions.Or;
+import org.apache.poi.hssf.record.formula.functions.Pi;
+import org.apache.poi.hssf.record.formula.functions.Rand;
+import org.apache.poi.hssf.record.formula.functions.Replace;
+import org.apache.poi.hssf.record.formula.functions.Row;
+import org.apache.poi.hssf.record.formula.functions.Rows;
+import org.apache.poi.hssf.record.formula.functions.Substitute;
+import org.apache.poi.hssf.record.formula.functions.Sumif;
+import org.apache.poi.hssf.record.formula.functions.Sumproduct;
+import org.apache.poi.hssf.record.formula.functions.Sumx2my2;
+import org.apache.poi.hssf.record.formula.functions.Sumx2py2;
+import org.apache.poi.hssf.record.formula.functions.Sumxmy2;
+import org.apache.poi.hssf.record.formula.functions.T;
+import org.apache.poi.hssf.record.formula.functions.TextFunction;
+import org.apache.poi.hssf.record.formula.functions.Time;
+import org.apache.poi.hssf.record.formula.functions.Today;
+import org.apache.poi.hssf.record.formula.functions.True;
+import org.apache.poi.hssf.record.formula.functions.Value;
+import org.apache.poi.hssf.record.formula.functions.Vlookup;
 import org.apache.poi.ss.formula.eval.NotImplementedException;
 
 /**
@@ -151,8 +207,8 @@ public final class FunctionEval implements OperationEval {
 
 		retval[124] = new Find();
 
-		retval[127] = new Istext();
-		retval[128] = new Isnumber();
+		retval[127] = LogicalFunction.IsText;
+		retval[128] = LogicalFunction.IsNumber;
 		retval[129] = new Isblank();
 		retval[130] = new T();
 
@@ -163,9 +219,9 @@ public final class FunctionEval implements OperationEval {
 		retval[183] = AggregateFunction.PRODUCT;
 		retval[184] = NumericFunction.FACT;
 
-		retval[190] = new Isnontext();
+		retval[190] = LogicalFunction.IsNonText;
 
-		retval[198] = new Islogical();
+		retval[198] = LogicalFunction.IsLogical;
 
 		retval[212] = NumericFunction.ROUNDUP;
 		retval[213] = NumericFunction.ROUNDDOWN;
@@ -248,7 +304,7 @@ public final class FunctionEval implements OperationEval {
 		if (f == null) {
 			throw new NotImplementedException("FuncIx=" + getFunctionIndex());
 		}
-		return (ValueEval) f.evaluate(operands, srcRow, srcCol);
+		return f.evaluate(operands, srcRow, srcCol);
 	}
 
 	public int getNumberOfOperands() {
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/BooleanFunction.java b/src/java/org/apache/poi/hssf/record/formula/functions/BooleanFunction.java
index 4995599ea5..76be216f2f 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/BooleanFunction.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/BooleanFunction.java
@@ -39,7 +39,7 @@ import org.apache.poi.hssf.record.formula.eval.ValueEval;
  */
 public abstract class BooleanFunction implements Function {
 
-	public final Eval evaluate(Eval[] args, int srcRow, short srcCol) {
+	public final ValueEval evaluate(ValueEval[] args, int srcRow, short srcCol) {
 		if (args.length < 1) {
 			return ErrorEval.VALUE_INVALID;
 		}
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/CalendarFieldFunction.java b/src/java/org/apache/poi/hssf/record/formula/functions/CalendarFieldFunction.java
index ce6c2b4285..90e8c16675 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/CalendarFieldFunction.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/CalendarFieldFunction.java
@@ -22,7 +22,6 @@ import java.util.Date;
 import java.util.GregorianCalendar;
 
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.EvaluationException;
 import org.apache.poi.hssf.record.formula.eval.NumberEval;
 import org.apache.poi.hssf.record.formula.eval.OperandResolver;
@@ -49,7 +48,7 @@ public final class CalendarFieldFunction implements Function {
 		_needsOneBaseAdjustment = needsOneBaseAdjustment;
 	}
 
-	public Eval evaluate(Eval[] operands, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] operands, int srcCellRow, short srcCellCol) {
 		if (operands.length != 1) {
 			return ErrorEval.VALUE_INVALID;
 		}
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Choose.java b/src/java/org/apache/poi/hssf/record/formula/functions/Choose.java
index dbe0aa7a9b..e7a827f4bd 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Choose.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Choose.java
@@ -18,7 +18,6 @@
 package org.apache.poi.hssf.record.formula.functions;
 
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.EvaluationException;
 import org.apache.poi.hssf.record.formula.eval.OperandResolver;
 import org.apache.poi.hssf.record.formula.eval.ValueEval;
@@ -29,7 +28,7 @@ import org.apache.poi.hssf.record.formula.eval.ValueEval;
  */
 public final class Choose implements Function {
 
-	public Eval evaluate(Eval[] args, int srcRowIndex, short srcColumnIndex) {
+	public ValueEval evaluate(ValueEval[] args, int srcRowIndex, short srcColumnIndex) {
 		if (args.length < 2) {
 			return ErrorEval.VALUE_INVALID;
 		}
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Column.java b/src/java/org/apache/poi/hssf/record/formula/functions/Column.java
index 5b04836123..e329abe3de 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Column.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Column.java
@@ -19,13 +19,12 @@ package org.apache.poi.hssf.record.formula.functions;
 
 import org.apache.poi.hssf.record.formula.eval.AreaEval;
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.NumberEval;
 import org.apache.poi.hssf.record.formula.eval.RefEval;
 import org.apache.poi.hssf.record.formula.eval.ValueEval;
 
 public final class Column implements Function {
-    public Eval evaluate(Eval[] evals, int srcCellRow, short srcCellCol) {
+    public ValueEval evaluate(ValueEval[] evals, int srcCellRow, short srcCellCol) {
         ValueEval retval = null;
         int cnum = -1;
 
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Columns.java b/src/java/org/apache/poi/hssf/record/formula/functions/Columns.java
index 2a57bedb2d..2871c63410 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Columns.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Columns.java
@@ -22,6 +22,7 @@ import org.apache.poi.hssf.record.formula.eval.ErrorEval;
 import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.NumberEval;
 import org.apache.poi.hssf.record.formula.eval.RefEval;
+import org.apache.poi.hssf.record.formula.eval.ValueEval;
 
 /**
  * Implementation for Excel COLUMNS function.
@@ -30,7 +31,7 @@ import org.apache.poi.hssf.record.formula.eval.RefEval;
  */
 public final class Columns implements Function {
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		switch(args.length) {
 			case 1:
 				// expected
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Count.java b/src/java/org/apache/poi/hssf/record/formula/functions/Count.java
index 4b8b217f4d..827fc0449f 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Count.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Count.java
@@ -21,6 +21,7 @@ import org.apache.poi.hssf.record.formula.eval.ErrorEval;
 import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.MissingArgEval;
 import org.apache.poi.hssf.record.formula.eval.NumberEval;
+import org.apache.poi.hssf.record.formula.eval.ValueEval;
 import org.apache.poi.hssf.record.formula.functions.CountUtils.I_MatchPredicate;
 
 /**
@@ -36,7 +37,7 @@ import org.apache.poi.hssf.record.formula.functions.CountUtils.I_MatchPredicate;
  */
 public final class Count implements Function {
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		int nArgs = args.length;
 		if (nArgs < 1) {
 			// too few arguments
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Counta.java b/src/java/org/apache/poi/hssf/record/formula/functions/Counta.java
index 7ce7eadcb5..609301db6d 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Counta.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Counta.java
@@ -21,6 +21,7 @@ import org.apache.poi.hssf.record.formula.eval.BlankEval;
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
 import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.NumberEval;
+import org.apache.poi.hssf.record.formula.eval.ValueEval;
 import org.apache.poi.hssf.record.formula.functions.CountUtils.I_MatchPredicate;
 
 /**
@@ -34,7 +35,7 @@ import org.apache.poi.hssf.record.formula.functions.CountUtils.I_MatchPredicate;
  */
 public final class Counta implements Function {
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		int nArgs = args.length;
 		if (nArgs < 1) {
 			// too few arguments
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Countif.java b/src/java/org/apache/poi/hssf/record/formula/functions/Countif.java
index 5b9debc28d..e1de081d8b 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Countif.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Countif.java
@@ -29,6 +29,7 @@ import org.apache.poi.hssf.record.formula.eval.NumberEval;
 import org.apache.poi.hssf.record.formula.eval.OperandResolver;
 import org.apache.poi.hssf.record.formula.eval.RefEval;
 import org.apache.poi.hssf.record.formula.eval.StringEval;
+import org.apache.poi.hssf.record.formula.eval.ValueEval;
 import org.apache.poi.hssf.record.formula.functions.CountUtils.I_MatchPredicate;
 import org.apache.poi.ss.usermodel.ErrorConstants;
 
@@ -400,7 +401,7 @@ public final class Countif implements Function {
 		}
 	}
 
-	public Eval evaluate(Eval[] args, int srcRowIndex, short srcColumnIndex) {
+	public ValueEval evaluate(ValueEval[] args, int srcRowIndex, short srcColumnIndex) {
 		switch(args.length) {
 			case 2:
 				// expected
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Errortype.java b/src/java/org/apache/poi/hssf/record/formula/functions/Errortype.java
index 0240f817e7..a2a2572587 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Errortype.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Errortype.java
@@ -18,10 +18,10 @@
 package org.apache.poi.hssf.record.formula.functions;
 
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.EvaluationException;
 import org.apache.poi.hssf.record.formula.eval.NumberEval;
 import org.apache.poi.hssf.record.formula.eval.OperandResolver;
+import org.apache.poi.hssf.record.formula.eval.ValueEval;
 import org.apache.poi.hssf.usermodel.HSSFErrorConstants;
 
 /**
@@ -52,7 +52,7 @@ import org.apache.poi.hssf.usermodel.HSSFErrorConstants;
  */
 public final class Errortype implements Function {
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 
 		try {
 			OperandResolver.getSingleValue(args[0], srcCellRow, srcCellCol);
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/False.java b/src/java/org/apache/poi/hssf/record/formula/functions/False.java
index b94686bb9e..c5ddc266ac 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/False.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/False.java
@@ -19,7 +19,6 @@ package org.apache.poi.hssf.record.formula.functions;
 
 import org.apache.poi.hssf.record.formula.eval.BoolEval;
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.ValueEval;
 
 /**
@@ -28,7 +27,7 @@ import org.apache.poi.hssf.record.formula.eval.ValueEval;
  */
 public final class False implements Function {
 
-    public Eval evaluate(Eval[] operands, int srcRow, short srcCol) {
+    public ValueEval evaluate(ValueEval[] operands, int srcRow, short srcCol) {
         ValueEval retval;
         switch (operands.length) {
         default:
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Function.java b/src/java/org/apache/poi/hssf/record/formula/functions/Function.java
index 90e6afe05f..1aff51cf4f 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Function.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Function.java
@@ -19,7 +19,6 @@ package org.apache.poi.hssf.record.formula.functions;
 
 import org.apache.poi.hssf.record.formula.eval.BlankEval;
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.MissingArgEval;
 import org.apache.poi.hssf.record.formula.eval.ValueEval;
 
@@ -31,16 +30,14 @@ import org.apache.poi.hssf.record.formula.eval.ValueEval;
 public interface Function {
 
 	/**
-	 * @param args the evaluated function arguments. Elements of this array typically implement
-	 * {@link ValueEval}.  Empty values are represented with {@link BlankEval} or {@link
-	 * MissingArgEval}, never <code>null</code>.
+	 * @param args the evaluated function arguments.  Empty values are represented with
+	 * {@link BlankEval} or {@link MissingArgEval}, never <code>null</code>.
 	 * @param srcRowIndex row index of the cell containing the formula under evaluation
 	 * @param srcColumnIndex column index of the cell containing the formula under evaluation
 	 * @return The evaluated result, possibly an {@link ErrorEval}, never <code>null</code>.
 	 * <b>Note</b> - Excel uses the error code <i>#NUM!</i> instead of IEEE <i>NaN</i>, so when
 	 * numeric functions evaluate to {@link Double#NaN} be sure to translate the result to {@link
 	 * ErrorEval#NUM_ERROR}.
-	 *
 	 */
-	Eval evaluate(Eval[] args, int srcRowIndex, short srcColumnIndex);
+	ValueEval evaluate(ValueEval[] args, int srcRowIndex, short srcColumnIndex);
 }
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Hlookup.java b/src/java/org/apache/poi/hssf/record/formula/functions/Hlookup.java
index 8230fb01f9..35a0b3ae34 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Hlookup.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Hlookup.java
@@ -42,7 +42,7 @@ import org.apache.poi.hssf.record.formula.functions.LookupUtils.ValueVector;
  */
 public final class Hlookup implements Function {
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		Eval arg3 = null;
 		switch(args.length) {
 			case 4:
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Hyperlink.java b/src/java/org/apache/poi/hssf/record/formula/functions/Hyperlink.java
index ecfdebf26f..19659081ec 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Hyperlink.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Hyperlink.java
@@ -18,10 +18,10 @@
 package org.apache.poi.hssf.record.formula.functions;
 
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.EvaluationException;
 import org.apache.poi.hssf.record.formula.eval.OperandResolver;
 import org.apache.poi.hssf.record.formula.eval.StringEval;
+import org.apache.poi.hssf.record.formula.eval.ValueEval;
 
 /**
  * Implementation of Excel HYPERLINK function.<p/>
@@ -41,7 +41,7 @@ import org.apache.poi.hssf.record.formula.eval.StringEval;
  */
 public final class Hyperlink implements Function {
 
-	public Eval evaluate(Eval[] operands, int srcRow, short srcCol) {
+	public ValueEval evaluate(ValueEval[] operands, int srcRow, short srcCol) {
 		int lastArgIx = operands.length - 1;
 		if (lastArgIx < 0 || lastArgIx > 1) {
 			return ErrorEval.VALUE_INVALID;
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/If.java b/src/java/org/apache/poi/hssf/record/formula/functions/If.java
index 450a96834b..f8d3c03ee3 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/If.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/If.java
@@ -19,7 +19,6 @@ package org.apache.poi.hssf.record.formula.functions;
 
 import org.apache.poi.hssf.record.formula.eval.BoolEval;
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.EvaluationException;
 import org.apache.poi.hssf.record.formula.eval.OperandResolver;
 import org.apache.poi.hssf.record.formula.eval.ValueEval;
@@ -30,8 +29,8 @@ import org.apache.poi.hssf.record.formula.eval.ValueEval;
  */
 public final class If implements Function {
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
-		Eval falseResult;
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
+		ValueEval falseResult;
 		switch (args.length) {
 			case 3:
 				falseResult = args[2];
@@ -54,7 +53,7 @@ public final class If implements Function {
 		return falseResult;
 	}
 
-	private static boolean evaluateFirstArg(Eval arg, int srcCellRow, short srcCellCol)
+	private static boolean evaluateFirstArg(ValueEval arg, int srcCellRow, short srcCellCol)
 			throws EvaluationException {
 		ValueEval ve = OperandResolver.getSingleValue(arg, srcCellRow, srcCellCol);
 		Boolean b = OperandResolver.coerceValueToBoolean(ve, false);
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Index.java b/src/java/org/apache/poi/hssf/record/formula/functions/Index.java
index b4eca2b9b5..acdd6adde8 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Index.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Index.java
@@ -47,7 +47,7 @@ import org.apache.poi.hssf.record.formula.eval.ValueEval;
  */
 public final class Index implements Function {
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		int nArgs = args.length;
 		if(nArgs < 2) {
 			// too few arguments
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/IsError.java b/src/java/org/apache/poi/hssf/record/formula/functions/IsError.java
index 818a463d95..55919a3a84 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/IsError.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/IsError.java
@@ -20,7 +20,6 @@ package org.apache.poi.hssf.record.formula.functions;
 import org.apache.poi.hssf.record.formula.eval.AreaEval;
 import org.apache.poi.hssf.record.formula.eval.BoolEval;
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.RefEval;
 import org.apache.poi.hssf.record.formula.eval.ValueEval;
 
@@ -30,7 +29,7 @@ import org.apache.poi.hssf.record.formula.eval.ValueEval;
  */
 public final class IsError implements Function {
 
-    public Eval evaluate(Eval[] operands, int srcCellRow, short srcCellCol) {
+    public ValueEval evaluate(ValueEval[] operands, int srcCellRow, short srcCellCol) {
         ValueEval retval = null;
         boolean b = false;
 
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/IsNa.java b/src/java/org/apache/poi/hssf/record/formula/functions/IsNa.java
index 0c9cf4f200..d8f9ac9ecb 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/IsNa.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/IsNa.java
@@ -22,6 +22,7 @@ import org.apache.poi.hssf.record.formula.eval.ErrorEval;
 import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.EvaluationException;
 import org.apache.poi.hssf.record.formula.eval.OperandResolver;
+import org.apache.poi.hssf.record.formula.eval.ValueEval;
 import org.apache.poi.ss.usermodel.ErrorConstants;
 
 /**
@@ -38,7 +39,7 @@ import org.apache.poi.ss.usermodel.ErrorConstants;
  */
 public final class IsNa implements Function {
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		if(args.length != 1) {
 			return ErrorEval.VALUE_INVALID;
 		}
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Isblank.java b/src/java/org/apache/poi/hssf/record/formula/functions/Isblank.java
index 655d296c39..51e8ee441f 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Isblank.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Isblank.java
@@ -31,7 +31,7 @@ import org.apache.poi.hssf.record.formula.eval.ValueEval;
  */
 public final class Isblank implements Function {
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		if(args.length != 1) {
 			return ErrorEval.VALUE_INVALID;
 		}
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Islogical.java b/src/java/org/apache/poi/hssf/record/formula/functions/Islogical.java
deleted file mode 100644
index 666c89ee04..0000000000
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Islogical.java
+++ /dev/null
@@ -1,53 +0,0 @@
-/* ====================================================================
-   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.hssf.record.formula.functions;
-
-import org.apache.poi.hssf.record.formula.eval.BoolEval;
-import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
-import org.apache.poi.hssf.record.formula.eval.RefEval;
-
-/**
- * @author Amol S. Deshmukh &lt; amolweb at ya hoo dot com &gt;
- *
- */
-public final class Islogical extends LogicalFunction {
-
-    public Eval evaluate(Eval[] operands, int srcCellRow, short srcCellCol) {
-        Eval retval = BoolEval.FALSE;
-
-        switch (operands.length) {
-        default:
-            retval = ErrorEval.VALUE_INVALID;
-            break;
-        case 1:
-            Eval eval = operands[0];
-            if (eval instanceof BoolEval) {
-                retval = BoolEval.TRUE;
-            }
-            else if (eval instanceof RefEval) {
-                Eval xlatedEval = xlateRefEval((RefEval) eval);
-                if (xlatedEval instanceof BoolEval) {
-                    retval = BoolEval.TRUE;
-                }
-            }
-        }
-
-        return retval;
-    }
-}
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Isnontext.java b/src/java/org/apache/poi/hssf/record/formula/functions/Isnontext.java
deleted file mode 100644
index e62dc69019..0000000000
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Isnontext.java
+++ /dev/null
@@ -1,53 +0,0 @@
-/* ====================================================================
-   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.hssf.record.formula.functions;
-
-import org.apache.poi.hssf.record.formula.eval.BoolEval;
-import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
-import org.apache.poi.hssf.record.formula.eval.RefEval;
-import org.apache.poi.hssf.record.formula.eval.StringEval;
-
-/**
- * @author Amol S. Deshmukh &lt; amolweb at ya hoo dot com &gt;
- *
- */
-public final class Isnontext extends LogicalFunction {
-    public Eval evaluate(Eval[] operands, int srcCellRow, short srcCellCol) {
-        Eval retval = BoolEval.TRUE;
-
-        switch (operands.length) {
-        default:
-            retval = ErrorEval.VALUE_INVALID;
-            break;
-        case 1:
-            Eval eval = operands[0];
-            if (eval instanceof StringEval) {
-                retval = BoolEval.FALSE;
-            }
-            else if (eval instanceof RefEval) {
-                Eval xlatedEval = xlateRefEval((RefEval) eval);
-                if (xlatedEval instanceof StringEval) {
-                    retval = BoolEval.FALSE;
-                }
-            }
-        }
-
-        return retval;
-    }
-}
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Isnumber.java b/src/java/org/apache/poi/hssf/record/formula/functions/Isnumber.java
deleted file mode 100644
index f00fd05c24..0000000000
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Isnumber.java
+++ /dev/null
@@ -1,53 +0,0 @@
-/* ====================================================================
-   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.hssf.record.formula.functions;
-
-import org.apache.poi.hssf.record.formula.eval.BoolEval;
-import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
-import org.apache.poi.hssf.record.formula.eval.NumberEval;
-import org.apache.poi.hssf.record.formula.eval.RefEval;
-
-/**
- * @author Amol S. Deshmukh &lt; amolweb at ya hoo dot com &gt;
- *
- */
-public final class Isnumber extends LogicalFunction {
-    public Eval evaluate(Eval[] operands, int srcCellRow, short srcCellCol) {
-        Eval retval = BoolEval.FALSE;
-
-        switch (operands.length) {
-        default:
-            retval = ErrorEval.VALUE_INVALID;
-            break;
-        case 1:
-            Eval eval = operands[0];
-            if (eval instanceof NumberEval) {
-                retval = BoolEval.TRUE;
-            }
-            else if (eval instanceof RefEval) {
-                Eval xlatedEval = xlateRefEval((RefEval) eval);
-                if (xlatedEval instanceof NumberEval) {
-                    retval = BoolEval.TRUE;
-                }
-            }
-        }
-
-        return retval;
-    }
-}
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Isref.java b/src/java/org/apache/poi/hssf/record/formula/functions/Isref.java
index 565d5e4989..f5d8ac7e38 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Isref.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Isref.java
@@ -22,26 +22,22 @@ import org.apache.poi.hssf.record.formula.eval.BoolEval;
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
 import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.RefEval;
+import org.apache.poi.hssf.record.formula.eval.ValueEval;
 
 /**
  * @author Amol S. Deshmukh &lt; amolweb at ya hoo dot com &gt;
- *
  */
 public final class Isref implements Function {
-    public Eval evaluate(Eval[] operands, int srcCellRow, short srcCellCol) {
-        Eval retval = BoolEval.FALSE;
+	public ValueEval evaluate(ValueEval[] operands, int srcCellRow, short srcCellCol) {
+		if (operands.length != 1) {
+			return ErrorEval.VALUE_INVALID;
+		}
 
-        switch (operands.length) {
-        default:
-            retval = ErrorEval.VALUE_INVALID;
-            break;
-        case 1:
-            Eval eval = operands[0];
-            if (eval instanceof RefEval || eval instanceof AreaEval) {
-                retval = BoolEval.TRUE;
-            }
-        }
+		Eval eval = operands[0];
+		if (eval instanceof RefEval || eval instanceof AreaEval) {
+			return BoolEval.TRUE;
+		}
 
-        return retval;
-    }
+		return BoolEval.FALSE;
+	}
 }
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Istext.java b/src/java/org/apache/poi/hssf/record/formula/functions/Istext.java
deleted file mode 100644
index f669d7f497..0000000000
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Istext.java
+++ /dev/null
@@ -1,53 +0,0 @@
-/* ====================================================================
-   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.hssf.record.formula.functions;
-
-import org.apache.poi.hssf.record.formula.eval.BoolEval;
-import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
-import org.apache.poi.hssf.record.formula.eval.RefEval;
-import org.apache.poi.hssf.record.formula.eval.StringEval;
-
-/**
- * @author Amol S. Deshmukh &lt; amolweb at ya hoo dot com &gt;
- *
- */
-public final class Istext extends LogicalFunction {
-    public Eval evaluate(Eval[] operands, int srcCellRow, short srcCellCol) {
-        Eval retval = BoolEval.FALSE;
-
-        switch (operands.length) {
-        default:
-            retval = ErrorEval.VALUE_INVALID;
-            break;
-        case 1:
-            Eval eval = operands[0];
-            if (eval instanceof StringEval) {
-                retval = BoolEval.TRUE;
-            }
-            else if (eval instanceof RefEval) {
-                Eval xlatedEval = xlateRefEval((RefEval) eval);
-                if (xlatedEval instanceof StringEval) {
-                    retval = BoolEval.TRUE;
-                }
-            }
-        }
-
-        return retval;
-    }
-}
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/LogicalFunction.java b/src/java/org/apache/poi/hssf/record/formula/functions/LogicalFunction.java
index ae5a0ebf6b..fadad2ca7c 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/LogicalFunction.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/LogicalFunction.java
@@ -17,28 +17,76 @@
 
 package org.apache.poi.hssf.record.formula.functions;
 
+import org.apache.poi.hssf.record.formula.eval.BoolEval;
+import org.apache.poi.hssf.record.formula.eval.ErrorEval;
+import org.apache.poi.hssf.record.formula.eval.EvaluationException;
+import org.apache.poi.hssf.record.formula.eval.NumberEval;
 import org.apache.poi.hssf.record.formula.eval.OperandResolver;
 import org.apache.poi.hssf.record.formula.eval.RefEval;
+import org.apache.poi.hssf.record.formula.eval.StringEval;
 import org.apache.poi.hssf.record.formula.eval.ValueEval;
 
 /**
  * @author Amol S. Deshmukh &lt; amolweb at ya hoo dot com &gt;
- *
  */
 public abstract class LogicalFunction implements Function {
 
-    /**
-     * recursively evaluate any RefEvals
-     * TODO - use {@link OperandResolver}
-     */
-    protected ValueEval xlateRefEval(RefEval reval) {
-        ValueEval retval = reval.getInnerValueEval();
+	/**
+	 * recursively evaluate any RefEvals TODO - use {@link OperandResolver}
+	 */
+	private static ValueEval xlateRefEval(RefEval reval) {
+		ValueEval retval = reval.getInnerValueEval();
 
-        if (retval instanceof RefEval) {
-            RefEval re = (RefEval) retval;
-            retval = xlateRefEval(re);
-        }
+		if (retval instanceof RefEval) {
+			RefEval re = (RefEval) retval;
+			retval = xlateRefEval(re);
+		}
 
-        return retval;
-    }
+		return retval;
+	}
+
+	public final ValueEval evaluate(ValueEval[] operands, int srcCellRow, short srcCellCol) {
+		if (operands.length != 1) {
+			return ErrorEval.VALUE_INVALID;
+		}
+		ValueEval ve;
+		try {
+			ve = OperandResolver.getSingleValue(operands[0], srcCellRow, srcCellCol);
+		} catch (EvaluationException e) {
+			if (false) {
+				// Note - it is more usual to propagate error codes straight to the result like this:
+				return e.getErrorEval();
+				// but logical functions behave a little differently
+			}
+			// this will usually cause a 'FALSE' result except for ISNONTEXT()
+			ve = e.getErrorEval();
+		}
+		if (ve instanceof RefEval) {
+			ve = xlateRefEval((RefEval) ve);
+		}
+		return BoolEval.valueOf(evaluate(ve));
+
+	}
+	protected abstract boolean evaluate(ValueEval arg);
+
+	public static final Function IsLogical = new LogicalFunction() {
+		protected boolean evaluate(ValueEval arg) {
+			return arg instanceof BoolEval;
+		}
+	};
+	public static final Function IsNonText = new LogicalFunction() {
+		protected boolean evaluate(ValueEval arg) {
+			return !(arg instanceof StringEval);
+		}
+	};
+	public static final Function IsNumber = new LogicalFunction() {
+		protected boolean evaluate(ValueEval arg) {
+			return arg instanceof NumberEval;
+		}
+	};
+	public static final Function IsText = new LogicalFunction() {
+		protected boolean evaluate(ValueEval arg) {
+			return arg instanceof StringEval;
+		}
+	};
 }
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Lookup.java b/src/java/org/apache/poi/hssf/record/formula/functions/Lookup.java
index 0cbae7fb88..7bb3326d4e 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Lookup.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Lookup.java
@@ -19,7 +19,6 @@ package org.apache.poi.hssf.record.formula.functions;
 
 import org.apache.poi.hssf.record.formula.eval.AreaEval;
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.EvaluationException;
 import org.apache.poi.hssf.record.formula.eval.OperandResolver;
 import org.apache.poi.hssf.record.formula.eval.ValueEval;
@@ -41,7 +40,7 @@ import org.apache.poi.hssf.record.formula.functions.LookupUtils.ValueVector;
  */
 public final class Lookup implements Function {
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		switch(args.length) {
 			case 3:
 				break;
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Match.java b/src/java/org/apache/poi/hssf/record/formula/functions/Match.java
index 7a8cc6cc24..9f61937440 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Match.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Match.java
@@ -67,7 +67,7 @@ import org.apache.poi.hssf.record.formula.functions.LookupUtils.ValueVector;
 public final class Match implements Function {
 
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 
 		double match_type = 1; // default
 
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Mode.java b/src/java/org/apache/poi/hssf/record/formula/functions/Mode.java
index 767e980c1c..4c6295615d 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Mode.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Mode.java
@@ -74,7 +74,7 @@ public final class Mode implements Function {
 
 	}
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		double result;
 		try {
 			List<Double> temp = new ArrayList<Double>();
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/MultiOperandNumericFunction.java b/src/java/org/apache/poi/hssf/record/formula/functions/MultiOperandNumericFunction.java
index 30b72ee74f..67bfaa038b 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/MultiOperandNumericFunction.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/MultiOperandNumericFunction.java
@@ -83,7 +83,7 @@ public abstract class MultiOperandNumericFunction implements Function {
 
 	private static final int DEFAULT_MAX_NUM_OPERANDS = 30;
 
-	public final Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public final ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 
 		double d;
 		try {
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Na.java b/src/java/org/apache/poi/hssf/record/formula/functions/Na.java
index 720b0c661f..d24a5994a9 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Na.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Na.java
@@ -18,7 +18,7 @@
 package org.apache.poi.hssf.record.formula.functions;
 
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
+import org.apache.poi.hssf.record.formula.eval.ValueEval;
 
 /**
  * Implementation of Excel function NA()
@@ -27,7 +27,7 @@ import org.apache.poi.hssf.record.formula.eval.Eval;
  */
 public final class Na implements Function {
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		return ErrorEval.NA;
 	}
 
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Not.java b/src/java/org/apache/poi/hssf/record/formula/functions/Not.java
index 46d1e7142a..4e89ac3096 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Not.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Not.java
@@ -19,7 +19,6 @@ package org.apache.poi.hssf.record.formula.functions;
 
 import org.apache.poi.hssf.record.formula.eval.BoolEval;
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.EvaluationException;
 import org.apache.poi.hssf.record.formula.eval.OperandResolver;
 import org.apache.poi.hssf.record.formula.eval.ValueEval;
@@ -33,7 +32,7 @@ import org.apache.poi.hssf.record.formula.eval.ValueEval;
  */
 public final class Not implements Function {
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		if (args.length != 1) {
 			return ErrorEval.VALUE_INVALID;
 		}
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/NotImplementedFunction.java b/src/java/org/apache/poi/hssf/record/formula/functions/NotImplementedFunction.java
index 9c685d0f51..e243e87289 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/NotImplementedFunction.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/NotImplementedFunction.java
@@ -17,7 +17,7 @@
 
 package org.apache.poi.hssf.record.formula.functions;
 
-import org.apache.poi.hssf.record.formula.eval.Eval;
+import org.apache.poi.hssf.record.formula.eval.ValueEval;
 import org.apache.poi.ss.formula.eval.NotImplementedException;
 
 /**
@@ -38,7 +38,7 @@ public final class NotImplementedFunction implements Function {
 		_functionName = name;
 	}
 
-	public Eval evaluate(Eval[] operands, int srcRow, short srcCol) {
+	public ValueEval evaluate(ValueEval[] operands, int srcRow, short srcCol) {
 		throw new NotImplementedException(_functionName);
 	}
 	public String getFunctionName() {
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Now.java b/src/java/org/apache/poi/hssf/record/formula/functions/Now.java
index 528d7f98ab..cb9687654b 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Now.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Now.java
@@ -20,8 +20,8 @@ package org.apache.poi.hssf.record.formula.functions;
 import java.util.Date;
 
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.NumberEval;
+import org.apache.poi.hssf.record.formula.eval.ValueEval;
 import org.apache.poi.hssf.usermodel.HSSFDateUtil;
 
 /**
@@ -31,7 +31,7 @@ import org.apache.poi.hssf.usermodel.HSSFDateUtil;
  */
 public final class Now implements Function {
 
-	public Eval evaluate(Eval[] evals, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] evals, int srcCellRow, short srcCellCol) {
 		if (evals.length > 0) {
 			return ErrorEval.VALUE_INVALID;
 		}
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/NumericFunction.java b/src/java/org/apache/poi/hssf/record/formula/functions/NumericFunction.java
index 136cf36630..310be7bb15 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/NumericFunction.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/NumericFunction.java
@@ -46,7 +46,7 @@ public abstract class NumericFunction implements Function {
 		}
 	}
 
-	public final Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public final ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		double result;
 		try {
 			result = eval(args, srcCellRow, srcCellCol);
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Offset.java b/src/java/org/apache/poi/hssf/record/formula/functions/Offset.java
index 0fda540e3a..c83e1b8f57 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Offset.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Offset.java
@@ -164,7 +164,7 @@ public final class Offset implements Function {
 		}
 	}
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		if(args.length < 3 || args.length > 5) {
 			return ErrorEval.VALUE_INVALID;
 		}
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Pi.java b/src/java/org/apache/poi/hssf/record/formula/functions/Pi.java
index d69015b148..3282c7d786 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Pi.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Pi.java
@@ -18,7 +18,6 @@
 package org.apache.poi.hssf.record.formula.functions;
 
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.NumberEval;
 import org.apache.poi.hssf.record.formula.eval.ValueEval;
 
@@ -30,7 +29,7 @@ public final class Pi implements Function {
 
     private static final NumberEval PI_EVAL = new NumberEval(Math.PI);
 
-    public Eval evaluate(Eval[] operands, int srcRow, short srcCol) {
+    public ValueEval evaluate(ValueEval[] operands, int srcRow, short srcCol) {
         ValueEval retval;
         switch (operands.length) {
         default:
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Rand.java b/src/java/org/apache/poi/hssf/record/formula/functions/Rand.java
index c9940fffed..5f5173e856 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Rand.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Rand.java
@@ -18,7 +18,6 @@
 package org.apache.poi.hssf.record.formula.functions;
 
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.NumberEval;
 import org.apache.poi.hssf.record.formula.eval.ValueEval;
 
@@ -28,7 +27,7 @@ import org.apache.poi.hssf.record.formula.eval.ValueEval;
  */
 public final class Rand implements Function {
 
-    public Eval evaluate(Eval[] operands, int srcRow, short srcCol) {
+    public ValueEval evaluate(ValueEval[] operands, int srcRow, short srcCol) {
         ValueEval retval;
         switch (operands.length) {
         default:
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Row.java b/src/java/org/apache/poi/hssf/record/formula/functions/Row.java
index ac16401262..59c1203b75 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Row.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Row.java
@@ -19,14 +19,13 @@ package org.apache.poi.hssf.record.formula.functions;
 
 import org.apache.poi.hssf.record.formula.eval.AreaEval;
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.NumberEval;
 import org.apache.poi.hssf.record.formula.eval.RefEval;
 import org.apache.poi.hssf.record.formula.eval.ValueEval;
 
 public final class Row implements Function {
 
-    public Eval evaluate(Eval[] evals, int srcCellRow, short srcCellCol) {
+    public ValueEval evaluate(ValueEval[] evals, int srcCellRow, short srcCellCol) {
         ValueEval retval = null;
         int rnum = -1;
 
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Rows.java b/src/java/org/apache/poi/hssf/record/formula/functions/Rows.java
index 9f331f47d7..7272a07c5d 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Rows.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Rows.java
@@ -22,6 +22,7 @@ import org.apache.poi.hssf.record.formula.eval.ErrorEval;
 import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.NumberEval;
 import org.apache.poi.hssf.record.formula.eval.RefEval;
+import org.apache.poi.hssf.record.formula.eval.ValueEval;
 
 /**
  * Implementation for Excel ROWS function.
@@ -30,7 +31,7 @@ import org.apache.poi.hssf.record.formula.eval.RefEval;
  */
 public final class Rows implements Function {
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		switch(args.length) {
 			case 1:
 				// expected
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Sumif.java b/src/java/org/apache/poi/hssf/record/formula/functions/Sumif.java
index 8eb2565d89..97ba463d92 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Sumif.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Sumif.java
@@ -41,7 +41,7 @@ import org.apache.poi.hssf.record.formula.functions.CountUtils.I_MatchPredicate;
  */
 public final class Sumif implements Function {
 
-	public Eval evaluate(Eval[] args, int srcRowIndex, short srcColumnIndex) {
+	public ValueEval evaluate(ValueEval[] args, int srcRowIndex, short srcColumnIndex) {
 		if (args.length < 2) {
 			return ErrorEval.VALUE_INVALID;
 		}
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Sumproduct.java b/src/java/org/apache/poi/hssf/record/formula/functions/Sumproduct.java
index 572c67f926..bc743e7197 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Sumproduct.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Sumproduct.java
@@ -20,7 +20,6 @@ package org.apache.poi.hssf.record.formula.functions;
 import org.apache.poi.hssf.record.formula.eval.AreaEval;
 import org.apache.poi.hssf.record.formula.eval.BlankEval;
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.EvaluationException;
 import org.apache.poi.hssf.record.formula.eval.NumberEval;
 import org.apache.poi.hssf.record.formula.eval.NumericValueEval;
@@ -54,14 +53,14 @@ import org.apache.poi.hssf.record.formula.eval.ValueEval;
 public final class Sumproduct implements Function {
 
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 
 		int maxN = args.length;
 
 		if(maxN < 1) {
 			return ErrorEval.VALUE_INVALID;
 		}
-		Eval firstArg = args[0];
+		ValueEval firstArg = args[0];
 		try {
 			if(firstArg instanceof NumericValueEval) {
 				return evaluateSingleProduct(args);
@@ -83,7 +82,7 @@ public final class Sumproduct implements Function {
 				+ firstArg.getClass().getName() + ")");
 	}
 
-	private static Eval evaluateSingleProduct(Eval[] evalArgs) throws EvaluationException {
+	private static ValueEval evaluateSingleProduct(ValueEval[] evalArgs) throws EvaluationException {
 		int maxN = evalArgs.length;
 
 		double term = 1D;
@@ -94,9 +93,9 @@ public final class Sumproduct implements Function {
 		return new NumberEval(term);
 	}
 
-	private static double getScalarValue(Eval arg) throws EvaluationException {
+	private static double getScalarValue(ValueEval arg) throws EvaluationException {
 
-		Eval eval;
+		ValueEval eval;
 		if (arg instanceof RefEval) {
 			RefEval re = (RefEval) arg;
 			eval = re.getInnerValueEval();
@@ -116,15 +115,10 @@ public final class Sumproduct implements Function {
 			eval = ae.getRelativeValue(0, 0);
 		}
 
-		if (!(eval instanceof ValueEval)) {
-			throw new RuntimeException("Unexpected value eval class ("
-					+ eval.getClass().getName() + ")");
-		}
-
-		return getProductTerm((ValueEval) eval, true);
+		return getProductTerm(eval, true);
 	}
 
-	private static Eval evaluateAreaSumProduct(Eval[] evalArgs) throws EvaluationException {
+	private static ValueEval evaluateAreaSumProduct(ValueEval[] evalArgs) throws EvaluationException {
 		int maxN = evalArgs.length;
 		AreaEval[] args = new AreaEval[maxN];
 		try {
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/T.java b/src/java/org/apache/poi/hssf/record/formula/functions/T.java
index 9d764c33bc..6f13d4c5ee 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/T.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/T.java
@@ -18,20 +18,20 @@
 package org.apache.poi.hssf.record.formula.functions;
 
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.RefEval;
 import org.apache.poi.hssf.record.formula.eval.StringEval;
+import org.apache.poi.hssf.record.formula.eval.ValueEval;
 
 public final class T implements Function {
 
-    public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+    public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
         switch (args.length) {
             default:
                 return ErrorEval.VALUE_INVALID;
             case 1:
                  break;
         }
-        Eval arg = args[0];
+        ValueEval arg = args[0];
         if (arg instanceof RefEval) {
             RefEval re = (RefEval) arg;
             arg = re.getInnerValueEval();
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/TextFunction.java b/src/java/org/apache/poi/hssf/record/formula/functions/TextFunction.java
index 5fd758962d..ff55e1921f 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/TextFunction.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/TextFunction.java
@@ -43,7 +43,7 @@ public abstract class TextFunction implements Function {
 		return OperandResolver.coerceValueToInt(ve);
 	}
 
-	public final Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public final ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		try {
 			return evaluateFunc(args, srcCellRow, srcCellCol);
 		} catch (EvaluationException e) {
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Time.java b/src/java/org/apache/poi/hssf/record/formula/functions/Time.java
index 1ddb8516ff..6d1ef146ca 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Time.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Time.java
@@ -38,7 +38,7 @@ public final class Time implements Function {
 	private static final int SECONDS_PER_DAY = HOURS_PER_DAY * SECONDS_PER_HOUR;
 
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		if (args.length != 3) {
 			return ErrorEval.VALUE_INVALID;
 		}
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Today.java b/src/java/org/apache/poi/hssf/record/formula/functions/Today.java
index b71fce4611..434653c12c 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Today.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Today.java
@@ -21,8 +21,8 @@ import java.util.Calendar;
 import java.util.GregorianCalendar;
 
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.NumberEval;
+import org.apache.poi.hssf.record.formula.eval.ValueEval;
 import org.apache.poi.hssf.usermodel.HSSFDateUtil;
 
 /**
@@ -32,7 +32,7 @@ import org.apache.poi.hssf.usermodel.HSSFDateUtil;
  */
 public final class Today implements Function {
 
-	public Eval evaluate(Eval[] evals, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] evals, int srcCellRow, short srcCellCol) {
 		if (evals.length > 0) {
 			return ErrorEval.VALUE_INVALID;
 		}
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/True.java b/src/java/org/apache/poi/hssf/record/formula/functions/True.java
index 429cc5f0d5..9a80c8d479 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/True.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/True.java
@@ -19,7 +19,6 @@ package org.apache.poi.hssf.record.formula.functions;
 
 import org.apache.poi.hssf.record.formula.eval.BoolEval;
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.ValueEval;
 
 /**
@@ -28,7 +27,7 @@ import org.apache.poi.hssf.record.formula.eval.ValueEval;
  */
 public final class True implements Function {
 
-    public Eval evaluate(Eval[] operands, int srcRow, short srcCol) {
+    public ValueEval evaluate(ValueEval[] operands, int srcRow, short srcCol) {
         ValueEval retval;
         switch (operands.length) {
         default:
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Value.java b/src/java/org/apache/poi/hssf/record/formula/functions/Value.java
index 0dbfdb52de..cfa6dff4c9 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Value.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Value.java
@@ -18,7 +18,6 @@
 package org.apache.poi.hssf.record.formula.functions;
 
 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
-import org.apache.poi.hssf.record.formula.eval.Eval;
 import org.apache.poi.hssf.record.formula.eval.EvaluationException;
 import org.apache.poi.hssf.record.formula.eval.NumberEval;
 import org.apache.poi.hssf.record.formula.eval.OperandResolver;
@@ -42,7 +41,7 @@ public final class Value implements Function {
 	private static final int MIN_DISTANCE_BETWEEN_THOUSANDS_SEPARATOR = 4;
 	private static final Double ZERO = new Double(0.0);
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		if (args.length != 1) {
 			return ErrorEval.VALUE_INVALID;
 		}
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/Vlookup.java b/src/java/org/apache/poi/hssf/record/formula/functions/Vlookup.java
index 27d16ee867..9887f69c33 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/Vlookup.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/Vlookup.java
@@ -42,7 +42,7 @@ import org.apache.poi.hssf.record.formula.functions.LookupUtils.ValueVector;
  */
 public final class Vlookup implements Function {
 
-	public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		Eval arg3 = null;
 		switch(args.length) {
 			case 4:
diff --git a/src/java/org/apache/poi/hssf/record/formula/functions/XYNumericFunction.java b/src/java/org/apache/poi/hssf/record/formula/functions/XYNumericFunction.java
index 5c80068fff..c43cca0adf 100644
--- a/src/java/org/apache/poi/hssf/record/formula/functions/XYNumericFunction.java
+++ b/src/java/org/apache/poi/hssf/record/formula/functions/XYNumericFunction.java
@@ -97,7 +97,7 @@ public abstract class XYNumericFunction implements Function {
 	 */
 	protected abstract Accumulator createAccumulator();
 
-	public final Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
+	public final ValueEval evaluate(ValueEval[] args, int srcCellRow, short srcCellCol) {
 		if (args.length != 2) {
 			return ErrorEval.VALUE_INVALID;
 		}