Improvements to patch 47809 (support for UDFs)

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@816016 13f79535-47bb-0310-9956-ffa450edef68

23 files changed, 392 insertions, 576 deletions

diff --git a/src/java/org/apache/poi/hssf/record/NameRecord.java b/src/java/org/apache/poi/hssf/record/NameRecord.java
index 6b38e36d4e..9084f12369 100644
--- a/src/java/org/apache/poi/hssf/record/NameRecord.java
+++ b/src/java/org/apache/poi/hssf/record/NameRecord.java
@@ -33,9 +33,7 @@ import org.apache.poi.util.StringUtil;
  * @author Libin Roman (Vista Portal LDT. Developer)
  * @author  Sergei Kozello (sergeikozello at mail.ru)
  * @author Glen Stampoultzis (glens at apache.org)
- * @version 1.0-pre
- *  
- * Modified 8/31/09 by Petr Udalau - added method setFunction(boolean)
+ * @author Petr Udalau - added method setFunction(boolean)
  */
 public final class NameRecord extends StandardRecord {
     public final static short sid = 0x0018;
@@ -135,7 +133,7 @@ public final class NameRecord extends StandardRecord {
 
 	/**
 	 * For named ranges, and built-in names
-	 * @return the 1-based sheet number. 
+	 * @return the 1-based sheet number.
 	 */
 	public int getSheetNumber()
 	{
@@ -239,13 +237,13 @@ public final class NameRecord extends StandardRecord {
 	public boolean isFunctionName() {
 		return (field_1_option_flag & Option.OPT_FUNCTION_NAME) != 0;
 	}
-	
-    /**
-     * Indicates that the defined name refers to a user-defined function.
-     * This attribute is used when there is an add-in or other code project associated with the file.
-     *
-     * @param value <code>true</code> indicates the name refers to a function.
-     */
+
+	/**
+	 * Indicates that the defined name refers to a user-defined function.
+	 * This attribute is used when there is an add-in or other code project associated with the file.
+	 *
+	 * @param value <code>true</code> indicates the name refers to a function.
+	 */
 	public void setFunction(boolean function){
 		if (function) {
 			field_1_option_flag |= Option.OPT_FUNCTION_NAME;
@@ -351,7 +349,7 @@ public final class NameRecord extends StandardRecord {
 		int field_8_length_description_text = field_15_description_text.length();
 		int field_9_length_help_topic_text = field_16_help_topic_text.length();
 		int field_10_length_status_bar_text = field_17_status_bar_text.length();
-		
+
 		// size defined below
 		out.writeShort(getOptionFlag());
 		out.writeByte(getKeyboardShortcut());
@@ -379,7 +377,7 @@ public final class NameRecord extends StandardRecord {
 		}
 		field_13_name_definition.serializeTokens(out);
 		field_13_name_definition.serializeArrayConstantData(out);
-		
+
 		StringUtil.putCompressedUnicode( getCustomMenuText(), out);
 		StringUtil.putCompressedUnicode( getDescriptionText(), out);
 		StringUtil.putCompressedUnicode( getHelpTopicText(), out);
@@ -388,14 +386,14 @@ public final class NameRecord extends StandardRecord {
 	private int getNameRawSize() {
 		if (isBuiltInName()) {
 			return 1;
-		} 
+		}
 		int nChars = field_12_name_text.length();
 		if(field_11_nameIsMultibyte) {
 			return 2 * nChars;
-		} 
+		}
 		return nChars;
 	}
-	
+
 	protected int getDataSize() {
 		return 13 // 3 shorts + 7 bytes
 			+ getNameRawSize()
@@ -456,7 +454,7 @@ public final class NameRecord extends StandardRecord {
 			}
 		}
 
-		int nBytesAvailable = in.available() - (f7_customMenuLen 
+		int nBytesAvailable = in.available() - (f7_customMenuLen
 				+ f8_descriptionTextLen + f9_helpTopicTextLen + f10_statusBarTextLen);
 		field_13_name_definition = Formula.read(field_4_length_name_definition, in, nBytesAvailable);
 
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 acfb306242..61f108b674 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
@@ -22,14 +22,17 @@ import java.util.Map;
 
 import org.apache.poi.hssf.record.formula.eval.ValueEval;
 import org.apache.poi.hssf.record.formula.functions.FreeRefFunction;
-import org.apache.poi.hssf.record.formula.toolpack.ToolPack;
+import org.apache.poi.hssf.record.formula.udf.UDFFinder;
 import org.apache.poi.ss.formula.OperationEvaluationContext;
 import org.apache.poi.ss.formula.eval.NotImplementedException;
 
 /**
- * Modified 09/07/09 by Petr Udalau - systematized work of ToolPacks. 
+ * @author Josh Micich
+ * @author Petr Udalau - systematized work of add-in libraries and user defined functions.
  */
-public final class AnalysisToolPak implements ToolPack {
+public final class AnalysisToolPak implements UDFFinder {
+
+	public static final UDFFinder instance = new AnalysisToolPak();
 
 	private static final class NotImplemented implements FreeRefFunction {
 		private final String _functionName;
@@ -42,13 +45,18 @@ public final class AnalysisToolPak implements ToolPack {
 			throw new NotImplementedException(_functionName);
 		}
 	};
-	
-	private Map<String, FreeRefFunction> _functionsByName = createFunctionsMap();
+
+	private final Map<String, FreeRefFunction> _functionsByName = createFunctionsMap();
+
+
+	private AnalysisToolPak() {
+		// enforce singleton
+	}
 
 	public FreeRefFunction findFunction(String name) {
 		return _functionsByName.get(name);
 	}
-	
+
 	private Map<String, FreeRefFunction> createFunctionsMap() {
 		Map<String, FreeRefFunction> m = new HashMap<String, FreeRefFunction>(100);
 
@@ -153,16 +161,4 @@ public final class AnalysisToolPak implements ToolPack {
 		FreeRefFunction func = pFunc == null ? new NotImplemented(functionName) : pFunc;
 		m.put(functionName, func);
 	}
-
-    public void addFunction(String name, FreeRefFunction evaluator) {
-        r(_functionsByName, name, evaluator);
-    }
-
-    public boolean containsFunction(String name) {
-        return _functionsByName.containsKey(name);
-    }
-
-    public void removeFunction(String name) {
-        _functionsByName.remove(name);
-    }
 }
diff --git a/src/java/org/apache/poi/hssf/record/formula/eval/UserDefinedFunction.java b/src/java/org/apache/poi/hssf/record/formula/eval/UserDefinedFunction.java
index bf390141ee..223f13378e 100644
--- a/src/java/org/apache/poi/hssf/record/formula/eval/UserDefinedFunction.java
+++ b/src/java/org/apache/poi/hssf/record/formula/eval/UserDefinedFunction.java
@@ -18,8 +18,6 @@
 package org.apache.poi.hssf.record.formula.eval;
 
 import org.apache.poi.hssf.record.formula.functions.FreeRefFunction;
-import org.apache.poi.hssf.record.formula.toolpack.MainToolPacksHandler;
-import org.apache.poi.ss.formula.EvaluationWorkbook;
 import org.apache.poi.ss.formula.OperationEvaluationContext;
 import org.apache.poi.ss.formula.eval.NotImplementedException;
 /**
@@ -28,8 +26,7 @@ import org.apache.poi.ss.formula.eval.NotImplementedException;
  * <tt>AbstractFunctionPtg.field_2_fnc_index</tt> == 255)
  *
  * @author Josh Micich
- * 
- * Modified 09/07/09 by Petr Udalau - Improved resolving of UDFs through the ToolPacks. 
+ * @author Petr Udalau - Improved resolving of UDFs through the ToolPacks.
  */
 final class UserDefinedFunction implements FreeRefFunction {
 
@@ -40,60 +37,28 @@ final class UserDefinedFunction implements FreeRefFunction {
 	}
 
 	public ValueEval evaluate(ValueEval[] args, OperationEvaluationContext ec) {
-		EvaluationWorkbook workbook = ec.getWorkbook();
 		int nIncomingArgs = args.length;
 		if(nIncomingArgs < 1) {
 			throw new RuntimeException("function name argument missing");
 		}
 
 		ValueEval nameArg = args[0];
-		FreeRefFunction targetFunc;
+		String functionName;
 		if (nameArg instanceof NameEval) {
-			targetFunc = findInternalUserDefinedFunction(workbook, (NameEval) nameArg);
+			functionName = ((NameEval) nameArg).getFunctionName();
 		} else if (nameArg instanceof NameXEval) {
-			targetFunc = findExternalUserDefinedFunction(workbook, (NameXEval) nameArg);
+			functionName = ec.getWorkbook().resolveNameXText(((NameXEval) nameArg).getPtg());
 		} else {
 			throw new RuntimeException("First argument should be a NameEval, but got ("
 					+ nameArg.getClass().getName() + ")");
 		}
+		FreeRefFunction targetFunc = ec.findUserDefinedFunction(functionName);
+		if (targetFunc == null) {
+			throw new NotImplementedException(functionName);
+		}
 		int nOutGoingArgs = nIncomingArgs -1;
 		ValueEval[] outGoingArgs = new ValueEval[nOutGoingArgs];
 		System.arraycopy(args, 1, outGoingArgs, 0, nOutGoingArgs);
 		return targetFunc.evaluate(outGoingArgs, ec);
 	}
-
-	private static FreeRefFunction findExternalUserDefinedFunction(EvaluationWorkbook workbook,
-			NameXEval n) {
-		String functionName = workbook.resolveNameXText(n.getPtg());
-
-		if(false) {
-			System.out.println("received call to external user defined function (" + functionName + ")");
-		}
-		// currently only looking for functions from the 'Analysis TookPak'(contained in MainToolPacksHandler)  e.g. "YEARFRAC" or "ISEVEN"
-		// not sure how much this logic would need to change to support other or multiple add-ins.
-		FreeRefFunction result = MainToolPacksHandler.instance().findFunction(functionName);
-		if (result != null) {
-			return result;
-		}
-		throw new NotImplementedException(functionName);
-	}
-
-	private static FreeRefFunction findInternalUserDefinedFunction(EvaluationWorkbook workbook,
-			NameEval functionNameEval) {
-
-		String functionName = functionNameEval.getFunctionName();
-		if(false) {
-			System.out.println("received call to internal user defined function  (" + functionName + ")");
-		}
-		FreeRefFunction functionEvaluator = workbook.findUserDefinedFunction(functionName); 
-		if (functionEvaluator == null) {
-		    functionEvaluator = MainToolPacksHandler.instance().findFunction(functionName);
-		}
-		if (functionEvaluator != null) {
-            return functionEvaluator;
-        }
-		// TODO find the implementation for the user defined function
-
-		throw new NotImplementedException(functionName);
-	}
 }
diff --git a/src/java/org/apache/poi/hssf/record/formula/toolpack/MainToolPacksHandler.java b/src/java/org/apache/poi/hssf/record/formula/toolpack/MainToolPacksHandler.java
deleted file mode 100755
index 9bb0c07888..0000000000
--- a/src/java/org/apache/poi/hssf/record/formula/toolpack/MainToolPacksHandler.java
+++ /dev/null
@@ -1,102 +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.toolpack;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import org.apache.poi.hssf.record.formula.atp.AnalysisToolPak;
-import org.apache.poi.hssf.record.formula.functions.FreeRefFunction;
-
-/**
- * Contains all tool packs. Processing of UDF is through this class.
- * 
- * @author PUdalau
- */
-public class MainToolPacksHandler{
-
-    private DefaultToolPack defaultToolPack;
-
-    private List<ToolPack> usedToolPacks = new ArrayList<ToolPack>();
-
-    private static MainToolPacksHandler instance;
-
-    /**
-     * @return Unique instance of handler.
-     */
-    public static MainToolPacksHandler instance() {
-        if (instance == null) {
-            instance = new MainToolPacksHandler();
-        }
-        return instance;
-    }
-
-    /**
-     * @return Default tool pack(which is obligatory exists in handler).
-     */
-    public DefaultToolPack getDefaultToolPack() {
-        return defaultToolPack;
-    }
-
-    private MainToolPacksHandler() {
-        defaultToolPack = new DefaultToolPack();
-        usedToolPacks.add(defaultToolPack);
-        usedToolPacks.add(new AnalysisToolPak());
-    }
-
-    /**
-	 * Checks if such function exists in any registered tool pack. 
-	 * @param name Name of function.
-	 * @return true if some tool pack contains such function.
-     */
-    public boolean containsFunction(String name) {
-        for (ToolPack pack : usedToolPacks) {
-            if (pack.containsFunction(name)) {
-                return true;
-            }
-        }
-        return false;
-    }
-
-    /**
-	 * Returns executor by specified name. Returns <code>null</code> if
-	 * function isn't contained by any registered tool pack.
-	 * 
-	 * @param name
-	 *            Name of function.
-	 * @return Function executor.
-	 */
-    public FreeRefFunction findFunction(String name) {
-        FreeRefFunction evaluatorForFunction;
-        for (ToolPack pack : usedToolPacks) {
-            evaluatorForFunction = pack.findFunction(name);
-            if (evaluatorForFunction != null) {
-                return evaluatorForFunction;
-            }
-        }
-        return null;
-    }
-
-    /**
-     * Registers new tool pack in handler.
-     * @param pack Tool pack to add.
-     */
-    public void addToolPack(ToolPack pack) {
-        usedToolPacks.add(pack);
-    }
-}
diff --git a/src/java/org/apache/poi/hssf/record/formula/udf/AggregatingUDFFinder.java b/src/java/org/apache/poi/hssf/record/formula/udf/AggregatingUDFFinder.java
new file mode 100755
index 0000000000..2dedf7b9d3
--- /dev/null
+++ b/src/java/org/apache/poi/hssf/record/formula/udf/AggregatingUDFFinder.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.hssf.record.formula.udf;
+
+import org.apache.poi.hssf.record.formula.functions.FreeRefFunction;
+
+/**
+ * Collects add-in libraries and VB macro functions together into one UDF finder
+ *
+ * @author PUdalau
+ */
+public final class AggregatingUDFFinder implements UDFFinder {
+
+	private final UDFFinder[] _usedToolPacks;
+
+	public AggregatingUDFFinder(UDFFinder ... usedToolPacks) {
+		_usedToolPacks = usedToolPacks.clone();
+	}
+
+	/**
+	 * Returns executor by specified name. Returns <code>null</code> if
+	 * function isn't contained by any registered tool pack.
+	 *
+	 * @param name Name of function.
+	 * @return Function executor. <code>null</code> if not found
+	 */
+	public FreeRefFunction findFunction(String name) {
+		FreeRefFunction evaluatorForFunction;
+		for (UDFFinder pack : _usedToolPacks) {
+			evaluatorForFunction = pack.findFunction(name);
+			if (evaluatorForFunction != null) {
+				return evaluatorForFunction;
+			}
+		}
+		return null;
+	}
+}
diff --git a/src/java/org/apache/poi/hssf/record/formula/toolpack/DefaultToolPack.java b/src/java/org/apache/poi/hssf/record/formula/udf/DefaultUDFFinder.java
index 39d2c47ca9..f87027aeb7 100755
--- a/src/java/org/apache/poi/hssf/record/formula/toolpack/DefaultToolPack.java
+++ b/src/java/org/apache/poi/hssf/record/formula/udf/DefaultUDFFinder.java
@@ -15,7 +15,7 @@
    limitations under the License.
 ==================================================================== */
 
-package org.apache.poi.hssf.record.formula.toolpack;
+package org.apache.poi.hssf.record.formula.udf;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -23,29 +23,27 @@ import java.util.Map;
 import org.apache.poi.hssf.record.formula.functions.FreeRefFunction;
 
 /**
- * Default tool pack.
- * If you want to add some UDF, but you don't want to create new tool pack, use this.
- * 
+ * Default UDF finder - for adding your own user defined functions.
+ *
  * @author PUdalau
  */
-public class DefaultToolPack implements ToolPack {
-    private Map<String, FreeRefFunction> functionsByName = new HashMap<String, FreeRefFunction>();
-
-    public void addFunction(String name, FreeRefFunction evaluator) {
-        if (evaluator != null){
-            functionsByName.put(name, evaluator);
-        }
-    }
-
-    public boolean containsFunction(String name) {
-        return functionsByName.containsKey(name);
-    }
-
-    public FreeRefFunction findFunction(String name) {
-        return functionsByName.get(name);
-    }
-
-    public void removeFunction(String name) {
-        functionsByName.remove(name);
-    }
+public final class DefaultUDFFinder implements UDFFinder {
+	private final Map<String, FreeRefFunction> _functionsByName;
+
+	public DefaultUDFFinder(String[] functionNames, FreeRefFunction[] functionImpls) {
+		int nFuncs = functionNames.length;
+		if (functionImpls.length != nFuncs) {
+			throw new IllegalArgumentException(
+					"Mismatch in number of function names and implementations");
+		}
+		HashMap<String, FreeRefFunction> m = new HashMap<String, FreeRefFunction>(nFuncs * 3 / 2);
+		for (int i = 0; i < functionImpls.length; i++) {
+			m.put(functionNames[i], functionImpls[i]);
+		}
+		_functionsByName = m;
+	}
+
+	public FreeRefFunction findFunction(String name) {
+		return _functionsByName.get(name);
+	}
 }
diff --git a/src/java/org/apache/poi/hssf/record/formula/toolpack/ToolPack.java b/src/java/org/apache/poi/hssf/record/formula/udf/UDFFinder.java
index d2e58da9e3..ba2882664f 100755
--- a/src/java/org/apache/poi/hssf/record/formula/toolpack/ToolPack.java
+++ b/src/java/org/apache/poi/hssf/record/formula/udf/UDFFinder.java
@@ -15,42 +15,24 @@
    limitations under the License.
 ==================================================================== */
 
-package org.apache.poi.hssf.record.formula.toolpack;
+package org.apache.poi.hssf.record.formula.udf;
 
+import org.apache.poi.hssf.record.formula.atp.AnalysisToolPak;
 import org.apache.poi.hssf.record.formula.functions.FreeRefFunction;
 
 /**
- * Common interface for any new tool pack with executors for functions.
- * 
+ * Common interface for "Add-in" libraries and user defined function libraries.
+ *
  * @author PUdalau
  */
-public interface ToolPack {
+public interface UDFFinder {
+	public static final UDFFinder DEFAULT = new AggregatingUDFFinder(AnalysisToolPak.instance);
+
 	/**
-	 * Returns executor by specified name. Returns <code>null</code> if tool
-	 * pack doesn't contains such function.
-	 * 
+	 * Returns executor by specified name. Returns <code>null</code> if the function name is unknown.
+	 *
 	 * @param name Name of function.
 	 * @return Function executor.
 	 */
 	FreeRefFunction findFunction(String name);
-
-	/**
-	 * Add new function with executor.
-	 * @param name Name of function.
-	 * @param evaluator Function executor.
-	 */
-	void addFunction(String name, FreeRefFunction evaluator);
-
-	/**
-	 * Returns executor by specified name if it exists.
-	 * @param name Name of function.
-	 */
-	void removeFunction(String name);
-
-	/**
-	 * Checks if such function exists in tool pack. 
-	 * @param name Name of function.
-	 * @return true if tool pack contains such function.
-	 */
-	boolean containsFunction(String name);
 }
diff --git a/src/java/org/apache/poi/hssf/usermodel/HSSFEvaluationWorkbook.java b/src/java/org/apache/poi/hssf/usermodel/HSSFEvaluationWorkbook.java
index b0f18bcda9..0184d1639b 100644
--- a/src/java/org/apache/poi/hssf/usermodel/HSSFEvaluationWorkbook.java
+++ b/src/java/org/apache/poi/hssf/usermodel/HSSFEvaluationWorkbook.java
@@ -6,7 +6,7 @@
    (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
+	   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,
@@ -24,146 +24,145 @@ import org.apache.poi.hssf.record.aggregates.FormulaRecordAggregate;
 import org.apache.poi.hssf.record.formula.NamePtg;
 import org.apache.poi.hssf.record.formula.NameXPtg;
 import org.apache.poi.hssf.record.formula.Ptg;
-import org.apache.poi.hssf.record.formula.functions.FreeRefFunction;
-import org.apache.poi.ss.formula.*;
 import org.apache.poi.ss.SpreadsheetVersion;
+import org.apache.poi.ss.formula.EvaluationCell;
+import org.apache.poi.ss.formula.EvaluationName;
+import org.apache.poi.ss.formula.EvaluationSheet;
+import org.apache.poi.ss.formula.EvaluationWorkbook;
+import org.apache.poi.ss.formula.FormulaParsingWorkbook;
+import org.apache.poi.ss.formula.FormulaRenderingWorkbook;
+import org.apache.poi.ss.formula.FormulaType;
 
 /**
  * Internal POI use only
  *
  * @author Josh Micich
- * 
- * Modified 09/07/09 by Petr Udalau - added methods for searching for UDFs of this Workbook. 
  */
 public final class HSSFEvaluationWorkbook implements FormulaRenderingWorkbook, EvaluationWorkbook, FormulaParsingWorkbook {
 
-    private final HSSFWorkbook _uBook;
-    private final Workbook _iBook;
-
-    public static HSSFEvaluationWorkbook create(HSSFWorkbook book) {
-        if (book == null) {
-            return null;
-        }
-        return new HSSFEvaluationWorkbook(book);
-    }
-
-    private HSSFEvaluationWorkbook(HSSFWorkbook book) {
-        _uBook = book;
-        _iBook = book.getWorkbook();
-    }
-
-    public int getExternalSheetIndex(String sheetName) {
-        int sheetIndex = _uBook.getSheetIndex(sheetName);
-        return _iBook.checkExternSheet(sheetIndex);
-    }
-    public int getExternalSheetIndex(String workbookName, String sheetName) {
-        return _iBook.getExternalSheetIndex(workbookName, sheetName);
-    }
-
-    public NameXPtg getNameXPtg(String name) {
-        return _iBook.getNameXPtg(name);
-    }
-
-    /**
-     * Lookup a named range by its name.
-     *
-     * @param name the name to search
-     * @param sheetIndex  the 0-based index of the sheet this formula belongs to.
-     * The sheet index is required to resolve sheet-level names. <code>-1</code> means workbook-global names
-      */
-    public EvaluationName getName(String name, int sheetIndex) {
-        for(int i=0; i < _iBook.getNumNames(); i++) {
-            NameRecord nr = _iBook.getNameRecord(i);
-            if (nr.getSheetNumber() == sheetIndex+1 && name.equalsIgnoreCase(nr.getNameText())) {
-                return new Name(nr, i);
-            }
-        }
-        return sheetIndex == -1 ? null : getName(name, -1);
-    }
-
-    public int getSheetIndex(EvaluationSheet evalSheet) {
-        HSSFSheet sheet = ((HSSFEvaluationSheet)evalSheet).getHSSFSheet();
-        return _uBook.getSheetIndex(sheet);
-    }
-    public int getSheetIndex(String sheetName) {
-        return _uBook.getSheetIndex(sheetName);
-    }
-
-    public String getSheetName(int sheetIndex) {
-        return _uBook.getSheetName(sheetIndex);
-    }
-
-    public EvaluationSheet getSheet(int sheetIndex) {
-        return new HSSFEvaluationSheet(_uBook.getSheetAt(sheetIndex));
-    }
-    public int convertFromExternSheetIndex(int externSheetIndex) {
-        return _iBook.getSheetIndexFromExternSheetIndex(externSheetIndex);
-    }
-
-    public ExternalSheet getExternalSheet(int externSheetIndex) {
-        return _iBook.getExternalSheet(externSheetIndex);
-    }
-
-    public String resolveNameXText(NameXPtg n) {
-        return _iBook.resolveNameXText(n.getSheetRefIndex(), n.getNameIndex());
-    }
-
-    public String getSheetNameByExternSheet(int externSheetIndex) {
-        return _iBook.findSheetNameFromExternSheet(externSheetIndex);
-    }
-    public String getNameText(NamePtg namePtg) {
-        return _iBook.getNameRecord(namePtg.getIndex()).getNameText();
-    }
-    public EvaluationName getName(NamePtg namePtg) {
-        int ix = namePtg.getIndex();
-        return new Name(_iBook.getNameRecord(ix), ix);
-    }
-    public Ptg[] getFormulaTokens(EvaluationCell evalCell) {
-        HSSFCell cell = ((HSSFEvaluationCell)evalCell).getHSSFCell();
-        if (false) {
-            // re-parsing the formula text also works, but is a waste of time
-            // It is useful from time to time to run all unit tests with this code
-            // to make sure that all formulas POI can evaluate can also be parsed.
-            return HSSFFormulaParser.parse(cell.getCellFormula(), _uBook, FormulaType.CELL, _uBook.getSheetIndex(cell.getSheet()));
-        }
-        FormulaRecordAggregate fra = (FormulaRecordAggregate) cell.getCellValueRecord();
-        return fra.getFormulaTokens();
-    }
-
-    private static final class Name implements EvaluationName {
-
-        private final NameRecord _nameRecord;
-        private final int _index;
-
-        public Name(NameRecord nameRecord, int index) {
-            _nameRecord = nameRecord;
-            _index = index;
-        }
-        public Ptg[] getNameDefinition() {
-            return _nameRecord.getNameDefinition();
-        }
-        public String getNameText() {
-            return _nameRecord.getNameText();
-        }
-        public boolean hasFormula() {
-            return _nameRecord.hasFormula();
-        }
-        public boolean isFunctionName() {
-            return _nameRecord.isFunctionName();
-        }
-        public boolean isRange() {
-            return _nameRecord.hasFormula(); // TODO - is this right?
-        }
-        public NamePtg createPtg() {
-            return new NamePtg(_index);
-        }
-    }
-
-    public SpreadsheetVersion getSpreadsheetVersion(){
-        return SpreadsheetVersion.EXCEL97;
-    }
-    
-    public FreeRefFunction findUserDefinedFunction(String functionName) {
-        return _uBook.getUserDefinedFunction(functionName);
-    }
+	private final HSSFWorkbook _uBook;
+	private final Workbook _iBook;
+
+	public static HSSFEvaluationWorkbook create(HSSFWorkbook book) {
+		if (book == null) {
+			return null;
+		}
+		return new HSSFEvaluationWorkbook(book);
+	}
+
+	private HSSFEvaluationWorkbook(HSSFWorkbook book) {
+		_uBook = book;
+		_iBook = book.getWorkbook();
+	}
+
+	public int getExternalSheetIndex(String sheetName) {
+		int sheetIndex = _uBook.getSheetIndex(sheetName);
+		return _iBook.checkExternSheet(sheetIndex);
+	}
+	public int getExternalSheetIndex(String workbookName, String sheetName) {
+		return _iBook.getExternalSheetIndex(workbookName, sheetName);
+	}
+
+	public NameXPtg getNameXPtg(String name) {
+		return _iBook.getNameXPtg(name);
+	}
+
+	/**
+	 * Lookup a named range by its name.
+	 *
+	 * @param name the name to search
+	 * @param sheetIndex  the 0-based index of the sheet this formula belongs to.
+	 * The sheet index is required to resolve sheet-level names. <code>-1</code> means workbook-global names
+	  */
+	public EvaluationName getName(String name, int sheetIndex) {
+		for(int i=0; i < _iBook.getNumNames(); i++) {
+			NameRecord nr = _iBook.getNameRecord(i);
+			if (nr.getSheetNumber() == sheetIndex+1 && name.equalsIgnoreCase(nr.getNameText())) {
+				return new Name(nr, i);
+			}
+		}
+		return sheetIndex == -1 ? null : getName(name, -1);
+	}
+
+	public int getSheetIndex(EvaluationSheet evalSheet) {
+		HSSFSheet sheet = ((HSSFEvaluationSheet)evalSheet).getHSSFSheet();
+		return _uBook.getSheetIndex(sheet);
+	}
+	public int getSheetIndex(String sheetName) {
+		return _uBook.getSheetIndex(sheetName);
+	}
+
+	public String getSheetName(int sheetIndex) {
+		return _uBook.getSheetName(sheetIndex);
+	}
+
+	public EvaluationSheet getSheet(int sheetIndex) {
+		return new HSSFEvaluationSheet(_uBook.getSheetAt(sheetIndex));
+	}
+	public int convertFromExternSheetIndex(int externSheetIndex) {
+		return _iBook.getSheetIndexFromExternSheetIndex(externSheetIndex);
+	}
+
+	public ExternalSheet getExternalSheet(int externSheetIndex) {
+		return _iBook.getExternalSheet(externSheetIndex);
+	}
+
+	public String resolveNameXText(NameXPtg n) {
+		return _iBook.resolveNameXText(n.getSheetRefIndex(), n.getNameIndex());
+	}
+
+	public String getSheetNameByExternSheet(int externSheetIndex) {
+		return _iBook.findSheetNameFromExternSheet(externSheetIndex);
+	}
+	public String getNameText(NamePtg namePtg) {
+		return _iBook.getNameRecord(namePtg.getIndex()).getNameText();
+	}
+	public EvaluationName getName(NamePtg namePtg) {
+		int ix = namePtg.getIndex();
+		return new Name(_iBook.getNameRecord(ix), ix);
+	}
+	public Ptg[] getFormulaTokens(EvaluationCell evalCell) {
+		HSSFCell cell = ((HSSFEvaluationCell)evalCell).getHSSFCell();
+		if (false) {
+			// re-parsing the formula text also works, but is a waste of time
+			// It is useful from time to time to run all unit tests with this code
+			// to make sure that all formulas POI can evaluate can also be parsed.
+			return HSSFFormulaParser.parse(cell.getCellFormula(), _uBook, FormulaType.CELL, _uBook.getSheetIndex(cell.getSheet()));
+		}
+		FormulaRecordAggregate fra = (FormulaRecordAggregate) cell.getCellValueRecord();
+		return fra.getFormulaTokens();
+	}
+
+	private static final class Name implements EvaluationName {
+
+		private final NameRecord _nameRecord;
+		private final int _index;
+
+		public Name(NameRecord nameRecord, int index) {
+			_nameRecord = nameRecord;
+			_index = index;
+		}
+		public Ptg[] getNameDefinition() {
+			return _nameRecord.getNameDefinition();
+		}
+		public String getNameText() {
+			return _nameRecord.getNameText();
+		}
+		public boolean hasFormula() {
+			return _nameRecord.hasFormula();
+		}
+		public boolean isFunctionName() {
+			return _nameRecord.isFunctionName();
+		}
+		public boolean isRange() {
+			return _nameRecord.hasFormula(); // TODO - is this right?
+		}
+		public NamePtg createPtg() {
+			return new NamePtg(_index);
+		}
+	}
+
+	public SpreadsheetVersion getSpreadsheetVersion(){
+		return SpreadsheetVersion.EXCEL97;
+	}
 }
diff --git a/src/java/org/apache/poi/hssf/usermodel/HSSFFormulaEvaluator.java b/src/java/org/apache/poi/hssf/usermodel/HSSFFormulaEvaluator.java
index a49fb9c684..16b5a5a0dc 100644
--- a/src/java/org/apache/poi/hssf/usermodel/HSSFFormulaEvaluator.java
+++ b/src/java/org/apache/poi/hssf/usermodel/HSSFFormulaEvaluator.java
@@ -24,6 +24,7 @@ import org.apache.poi.hssf.record.formula.eval.ErrorEval;
 import org.apache.poi.hssf.record.formula.eval.NumberEval;
 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.udf.UDFFinder;
 import org.apache.poi.ss.formula.CollaboratingWorkbooksEnvironment;
 import org.apache.poi.ss.formula.IStabilityClassifier;
 import org.apache.poi.ss.formula.WorkbookEvaluator;
@@ -64,10 +65,28 @@ public class HSSFFormulaEvaluator implements FormulaEvaluator  {
 	 * evaluation begins.
 	 */
 	public HSSFFormulaEvaluator(HSSFWorkbook workbook, IStabilityClassifier stabilityClassifier) {
-		_bookEvaluator = new WorkbookEvaluator(HSSFEvaluationWorkbook.create(workbook), stabilityClassifier);
+		this(workbook, stabilityClassifier, null);
 	}
 
 	/**
+	 * @param udfFinder pass <code>null</code> for default (AnalysisToolPak only)
+	 */
+	private HSSFFormulaEvaluator(HSSFWorkbook workbook, IStabilityClassifier stabilityClassifier, UDFFinder udfFinder) {
+		_bookEvaluator = new WorkbookEvaluator(HSSFEvaluationWorkbook.create(workbook), stabilityClassifier, udfFinder);
+	}
+
+	/**
+	 * @param stabilityClassifier used to optimise caching performance. Pass <code>null</code>
+	 * for the (conservative) assumption that any cell may have its definition changed after
+	 * evaluation begins.
+	 * @param udfFinder pass <code>null</code> for default (AnalysisToolPak only)
+	 */
+	public static HSSFFormulaEvaluator create(HSSFWorkbook workbook, IStabilityClassifier stabilityClassifier, UDFFinder udfFinder) {
+		return new HSSFFormulaEvaluator(workbook, stabilityClassifier, udfFinder);
+	}
+
+
+	/**
 	 * Coordinates several formula evaluators together so that formulas that involve external
 	 * references can be evaluated.
 	 * @param workbookNames the simple file names used to identify the workbooks in formulas
diff --git a/src/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java b/src/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java
index b9a732bc32..cb772c9b84 100644
--- a/src/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java
+++ b/src/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java
@@ -24,11 +24,9 @@ import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.PrintWriter;
 import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.Hashtable;
 import java.util.Iterator;
 import java.util.List;
-import java.util.Map;
 import java.util.regex.Pattern;
 
 import org.apache.poi.POIDocument;
@@ -64,12 +62,10 @@ import org.apache.poi.hssf.record.formula.Ptg;
 import org.apache.poi.hssf.record.formula.Ref3DPtg;
 import org.apache.poi.hssf.record.formula.SheetNameFormatter;
 import org.apache.poi.hssf.record.formula.UnionPtg;
-import org.apache.poi.hssf.record.formula.functions.FreeRefFunction;
 import org.apache.poi.hssf.util.CellReference;
 import org.apache.poi.poifs.filesystem.DirectoryNode;
 import org.apache.poi.poifs.filesystem.POIFSFileSystem;
 import org.apache.poi.ss.usermodel.CreationHelper;
-import org.apache.poi.ss.usermodel.Name;
 import org.apache.poi.ss.usermodel.Row.MissingCellPolicy;
 import org.apache.poi.ss.formula.FormulaType;
 import org.apache.poi.util.POILogFactory;
@@ -86,9 +82,6 @@ import org.apache.poi.util.POILogger;
  * @author  Andrew C. Oliver (acoliver at apache dot org)
  * @author  Glen Stampoultzis (glens at apache.org)
  * @author  Shawn Laubach (slaubach at apache dot org)
- *
- * 
- * Modified 09/07/09 by Petr Udalau - added methods for work with UDFs of this Workbook. 
  */
 public class HSSFWorkbook extends POIDocument implements org.apache.poi.ss.usermodel.Workbook {
     private static final Pattern COMMA_PATTERN = Pattern.compile(",");
@@ -167,9 +160,6 @@ public class HSSFWorkbook extends POIDocument implements org.apache.poi.ss.userm
 
 
     private static POILogger log = POILogFactory.getLogger(HSSFWorkbook.class);
-    
-    /** Map of user defined functions, key - function name, value - instance of FreeRefFunctions */
-	private Map<String, FreeRefFunction> udfFunctions;
 
     /**
      * Creates new HSSFWorkbook from scratch (start here!)
@@ -186,7 +176,6 @@ public class HSSFWorkbook extends POIDocument implements org.apache.poi.ss.userm
         workbook = book;
         _sheets = new ArrayList( INITIAL_CAPACITY );
         names = new ArrayList( INITIAL_CAPACITY );
-        udfFunctions = new HashMap<String, FreeRefFunction>(); 
     }
 
     public HSSFWorkbook(POIFSFileSystem fs) throws IOException {
@@ -278,7 +267,6 @@ public class HSSFWorkbook extends POIDocument implements org.apache.poi.ss.userm
 
         _sheets = new ArrayList(INITIAL_CAPACITY);
         names  = new ArrayList(INITIAL_CAPACITY);
-        udfFunctions = new HashMap<String, FreeRefFunction>();
 
         // Grab the data from the workbook stream, however
         //  it happens to be spelled.
@@ -1627,25 +1615,6 @@ public class HSSFWorkbook extends POIDocument implements org.apache.poi.ss.userm
             }
         }
     }
-    
-    public FreeRefFunction getUserDefinedFunction(String functionName) {
-    	return udfFunctions.get(functionName);
-    }
-    
-    public void registerUserDefinedFunction(String functionName, FreeRefFunction freeRefFunction) {
-    	Name udfDeclaration = getName(functionName);
-        if (udfDeclaration == null) {
-            udfDeclaration = createName();
-        }
-        udfDeclaration.setNameName(functionName);
-        udfDeclaration.setFunction(true);
-        udfFunctions.put(functionName, freeRefFunction);
-    	
-    }
-
-	public List<String> getUserDefinedFunctionNames() {
-		return new ArrayList<String>(udfFunctions.keySet());
-	}
 
     /**
      * Is the workbook protected with a password (not encrypted)?
@@ -1729,5 +1698,4 @@ public class HSSFWorkbook extends POIDocument implements org.apache.poi.ss.userm
     public NameXPtg getNameXPtg(String name) {
         return workbook.getNameXPtg(name);
     }
-
 }
diff --git a/src/java/org/apache/poi/ss/formula/EvaluationWorkbook.java b/src/java/org/apache/poi/ss/formula/EvaluationWorkbook.java
index 0d65af92df..a3b2325719 100644
--- a/src/java/org/apache/poi/ss/formula/EvaluationWorkbook.java
+++ b/src/java/org/apache/poi/ss/formula/EvaluationWorkbook.java
@@ -20,7 +20,6 @@ package org.apache.poi.ss.formula;
 import org.apache.poi.hssf.record.formula.NamePtg;
 import org.apache.poi.hssf.record.formula.NameXPtg;
 import org.apache.poi.hssf.record.formula.Ptg;
-import org.apache.poi.hssf.record.formula.functions.FreeRefFunction;
 
 /**
  * Abstracts a workbook for the purpose of formula evaluation.<br/>
@@ -28,8 +27,6 @@ import org.apache.poi.hssf.record.formula.functions.FreeRefFunction;
  * For POI internal use only
  *
  * @author Josh Micich
- * 
- * Modified 09/07/09 by Petr Udalau - added methods for searching for UDFs of this Workbook. 
  */
 public interface EvaluationWorkbook {
 	String getSheetName(int sheetIndex);
@@ -54,17 +51,6 @@ public interface EvaluationWorkbook {
 	String resolveNameXText(NameXPtg ptg);
 	Ptg[] getFormulaTokens(EvaluationCell cell);
 
-	/**
-     * Find and return user defined function (UDF) contained by workbook with
-     * specified name.
-     * 
-     * @param functionName UDF name
-     * @return instance of FreeRefFunction or null if no UDF with the specified
-     *         name exists.
-     */
-	FreeRefFunction findUserDefinedFunction(String functionName);
-
-
 	class ExternalSheet {
 		private final String _workbookName;
 		private final String _sheetName;
diff --git a/src/java/org/apache/poi/ss/formula/OperationEvaluationContext.java b/src/java/org/apache/poi/ss/formula/OperationEvaluationContext.java
index 2ec5f5791c..e1a28a6fee 100644
--- a/src/java/org/apache/poi/ss/formula/OperationEvaluationContext.java
+++ b/src/java/org/apache/poi/ss/formula/OperationEvaluationContext.java
@@ -22,6 +22,7 @@ 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.RefEval;
 import org.apache.poi.hssf.record.formula.eval.ValueEval;
+import org.apache.poi.hssf.record.formula.functions.FreeRefFunction;
 import org.apache.poi.ss.SpreadsheetVersion;
 import org.apache.poi.ss.formula.CollaboratingWorkbooksEnvironment.WorkbookNotFoundException;
 import org.apache.poi.ss.formula.EvaluationWorkbook.ExternalSheet;
@@ -256,4 +257,8 @@ public final class OperationEvaluationContext {
 		}
 		return CellReference.classifyCellReference(str, ssVersion);
 	}
+
+	public FreeRefFunction findUserDefinedFunction(String functionName) {
+		return _bookEvaluator.findUserDefinedFunction(functionName);
+	}
 }
diff --git a/src/java/org/apache/poi/ss/formula/WorkbookEvaluator.java b/src/java/org/apache/poi/ss/formula/WorkbookEvaluator.java
index 806c002bb1..ed8abb7dfa 100644
--- a/src/java/org/apache/poi/ss/formula/WorkbookEvaluator.java
+++ b/src/java/org/apache/poi/ss/formula/WorkbookEvaluator.java
@@ -59,6 +59,8 @@ import org.apache.poi.hssf.record.formula.eval.OperationEval;
 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.FreeRefFunction;
+import org.apache.poi.hssf.record.formula.udf.UDFFinder;
 import org.apache.poi.hssf.util.CellReference;
 import org.apache.poi.ss.formula.CollaboratingWorkbooksEnvironment.WorkbookNotFoundException;
 import org.apache.poi.ss.formula.eval.NotImplementedException;
@@ -87,12 +89,16 @@ public final class WorkbookEvaluator {
 	private final Map<String, Integer> _sheetIndexesByName;
 	private CollaboratingWorkbooksEnvironment _collaboratingWorkbookEnvironment;
 	private final IStabilityClassifier _stabilityClassifier;
+	private final UDFFinder _udfFinder;
 
-	public WorkbookEvaluator(EvaluationWorkbook workbook, IStabilityClassifier stabilityClassifier) {
-		this (workbook, null, stabilityClassifier);
+	/**
+	 * @param udfFinder pass <code>null</code> for default (AnalysisToolPak only)
+	 */
+	public WorkbookEvaluator(EvaluationWorkbook workbook, IStabilityClassifier stabilityClassifier, UDFFinder udfFinder) {
+		this (workbook, null, stabilityClassifier, udfFinder);
 	}
 	/* package */ WorkbookEvaluator(EvaluationWorkbook workbook, IEvaluationListener evaluationListener,
-			IStabilityClassifier stabilityClassifier) {
+			IStabilityClassifier stabilityClassifier, UDFFinder udfFinder) {
 		_workbook = workbook;
 		_evaluationListener = evaluationListener;
 		_cache = new EvaluationCache(evaluationListener);
@@ -101,6 +107,7 @@ public final class WorkbookEvaluator {
 		_collaboratingWorkbookEnvironment = CollaboratingWorkbooksEnvironment.EMPTY;
 		_workbookIx = 0;
 		_stabilityClassifier = stabilityClassifier;
+		_udfFinder = udfFinder == null ? UDFFinder.DEFAULT : udfFinder;
 	}
 
 	/**
@@ -516,4 +523,7 @@ public final class WorkbookEvaluator {
 		EvaluationCell cell = sheet.getCell(rowIndex, columnIndex);
 		return evaluateAny(cell, sheetIndex, rowIndex, columnIndex, tracker);
 	}
+	public FreeRefFunction findUserDefinedFunction(String functionName) {
+		return _udfFinder.findFunction(functionName);
+	}
 }
diff --git a/src/java/org/apache/poi/ss/formula/eval/forked/ForkedEvaluationWorkbook.java b/src/java/org/apache/poi/ss/formula/eval/forked/ForkedEvaluationWorkbook.java
index 1525708f31..08ed7f5346 100644
--- a/src/java/org/apache/poi/ss/formula/eval/forked/ForkedEvaluationWorkbook.java
+++ b/src/java/org/apache/poi/ss/formula/eval/forked/ForkedEvaluationWorkbook.java
@@ -36,8 +36,6 @@ import org.apache.poi.ss.usermodel.Workbook;
  * updated after a call to {@link #getOrCreateUpdatableCell(String, int, int)}.
  *
  * @author Josh Micich
- * 
- * Modified 09/07/09 by Petr Udalau - added methods for searching for UDFs of this Workbook. 
  */
 final class ForkedEvaluationWorkbook implements EvaluationWorkbook {
 
@@ -144,8 +142,4 @@ final class ForkedEvaluationWorkbook implements EvaluationWorkbook {
 			return _index - o._index;
 		}
 	}
-
-    public FreeRefFunction findUserDefinedFunction(String functionName) {
-        return _masterBook.findUserDefinedFunction(functionName);
-    }
 }
diff --git a/src/java/org/apache/poi/ss/formula/eval/forked/ForkedEvaluator.java b/src/java/org/apache/poi/ss/formula/eval/forked/ForkedEvaluator.java
index e89d2a6104..7985603748 100644
--- a/src/java/org/apache/poi/ss/formula/eval/forked/ForkedEvaluator.java
+++ b/src/java/org/apache/poi/ss/formula/eval/forked/ForkedEvaluator.java
@@ -22,6 +22,7 @@ import org.apache.poi.hssf.record.formula.eval.ErrorEval;
 import org.apache.poi.hssf.record.formula.eval.NumberEval;
 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.udf.UDFFinder;
 import org.apache.poi.hssf.usermodel.HSSFCell;
 import org.apache.poi.hssf.usermodel.HSSFEvaluationWorkbook;
 import org.apache.poi.hssf.usermodel.HSSFWorkbook;
@@ -47,9 +48,9 @@ public final class ForkedEvaluator {
 	private WorkbookEvaluator _evaluator;
 	private ForkedEvaluationWorkbook _sewb;
 
-	private ForkedEvaluator(EvaluationWorkbook masterWorkbook, IStabilityClassifier stabilityClassifier) {
+	private ForkedEvaluator(EvaluationWorkbook masterWorkbook, IStabilityClassifier stabilityClassifier, UDFFinder udfFinder) {
 		_sewb = new ForkedEvaluationWorkbook(masterWorkbook);
-		_evaluator = new WorkbookEvaluator(_sewb, stabilityClassifier);
+		_evaluator = new WorkbookEvaluator(_sewb, stabilityClassifier, udfFinder);
 	}
 	private static EvaluationWorkbook createEvaluationWorkbook(Workbook wb) {
 		if (wb instanceof HSSFWorkbook) {
@@ -61,8 +62,17 @@ public final class ForkedEvaluator {
 //		}
 		throw new IllegalArgumentException("Unexpected workbook type (" + wb.getClass().getName() + ")");
 	}
+	/**
+	 * @deprecated (Sep 2009) (reduce overloading) use {@link #create(Workbook, IStabilityClassifier, UDFFinder)}
+	 */
 	public static ForkedEvaluator create(Workbook wb, IStabilityClassifier stabilityClassifier) {
-		return new ForkedEvaluator(createEvaluationWorkbook(wb), stabilityClassifier);
+		return create(wb, stabilityClassifier, null);
+	}
+	/**
+	 * @param udfFinder pass <code>null</code> for default (AnalysisToolPak only)
+	 */
+	public static ForkedEvaluator create(Workbook wb, IStabilityClassifier stabilityClassifier, UDFFinder udfFinder) {
+		return new ForkedEvaluator(createEvaluationWorkbook(wb), stabilityClassifier, udfFinder);
 	}
 
 	/**
diff --git a/src/java/org/apache/poi/ss/usermodel/Name.java b/src/java/org/apache/poi/ss/usermodel/Name.java
index 0cc9d98e9e..a07154e5fe 100644
--- a/src/java/org/apache/poi/ss/usermodel/Name.java
+++ b/src/java/org/apache/poi/ss/usermodel/Name.java
@@ -49,8 +49,6 @@ package org.apache.poi.ss.usermodel;
  *  name.setRefersToFormula("IF(Loan_Amount*Interest_Rate>0,1,0)");
  *
  * </blockquote></pre>
- *  
- * Modified 8/31/09 by Petr Udalau - added method setFunction(boolean)
  */
 public interface Name {
 
@@ -61,14 +59,14 @@ public interface Name {
      */
     String getSheetName();
 
-    /** 
+    /**
      * Gets the name of the named range
      *
      * @return named range name
      */
     String getNameName();
 
-    /** 
+    /**
      * Sets the name of the named range
      *
      * <p>The following is a list of syntax rules that you need to be aware of when you create and edit names.</p>
@@ -118,7 +116,7 @@ public interface Name {
     void setNameName(String name);
 
     /**
-     * Returns the formula that the name is defined to refer to. 
+     * Returns the formula that the name is defined to refer to.
      *
      * @return the reference for this name, <code>null</code> if it has not been set yet. Never empty string
      * @see #setRefersToFormula(String)
diff --git a/src/java/org/apache/poi/ss/usermodel/Workbook.java b/src/java/org/apache/poi/ss/usermodel/Workbook.java
index cbbc2a4268..99f4ddba89 100644
--- a/src/java/org/apache/poi/ss/usermodel/Workbook.java
+++ b/src/java/org/apache/poi/ss/usermodel/Workbook.java
@@ -21,15 +21,12 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.util.List;
 
-import org.apache.poi.hssf.record.formula.functions.FreeRefFunction;
 import org.apache.poi.ss.usermodel.Row.MissingCellPolicy;
 
 /**
  * High level representation of a Excel workbook.  This is the first object most users
  * will construct whether they are reading or writing a workbook.  It is also the
  * top level object for creating new sheets/etc.
- * 
- * Modified 09/07/09 by Petr Udalau - added methods for work with UDFs of this Workbook. 
  */
 public interface Workbook {
 
@@ -189,7 +186,7 @@ public interface Workbook {
      * @param index of the sheet to remove (0-based)
      */
     void removeSheetAt(int index);
-    
+
     /**
      * Sets the repeating rows and columns for a sheet (as found in
      * File->PageSetup->Sheet).  This is function is included in the workbook
@@ -374,7 +371,7 @@ public interface Workbook {
 	 * Sets the policy on what to do when
 	 *  getting missing or blank cells from a row.
      *
-	 * This will then apply to all calls to 
+	 * This will then apply to all calls to
 	 *  {@link Row#getCell(int)} }. See
 	 *  {@link MissingCellPolicy}
 	 */
@@ -467,29 +464,4 @@ public interface Workbook {
      * @param hidden 0 for not hidden, 1 for hidden, 2 for very hidden
      */
     void setSheetHidden(int sheetIx, int hidden);
-    
-    /**
-	 * Find and return user defined function (UDF) with specified name.
-	 * 
-	 * @param functionName
-	 *            UDF name
-	 * @return instance of FreeRefFunction or null if no UDF with the specified
-	 *         name exists.
-	 */
-	FreeRefFunction getUserDefinedFunction(String functionName);
-	
-	/**
-	 * Add user defined function (UDF) to workbook
-	 * 
-	 * @param name
-	 * @param function
-	 */
-	void registerUserDefinedFunction(String name, FreeRefFunction function);
-
-	/**
-	 * Returns user defined functions (UDF) names
-	 * 
-	 * @return list of UDF names
-	 */
-	List<String> getUserDefinedFunctionNames();
 }
diff --git a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFEvaluationWorkbook.java b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFEvaluationWorkbook.java
index 5e6fd93904..5264281f00 100644
--- a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFEvaluationWorkbook.java
+++ b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFEvaluationWorkbook.java
@@ -20,7 +20,6 @@ package org.apache.poi.xssf.usermodel;
 import org.apache.poi.hssf.record.formula.NamePtg;
 import org.apache.poi.hssf.record.formula.NameXPtg;
 import org.apache.poi.hssf.record.formula.Ptg;
-import org.apache.poi.hssf.record.formula.functions.FreeRefFunction;
 import org.apache.poi.ss.formula.*;
 import org.apache.poi.ss.SpreadsheetVersion;
 import org.openxmlformats.schemas.spreadsheetml.x2006.main.CTDefinedName;
@@ -29,8 +28,6 @@ import org.openxmlformats.schemas.spreadsheetml.x2006.main.CTDefinedName;
  * Internal POI use only
  *
  * @author Josh Micich
- * 
- * Modified 09/07/09 by Petr Udalau - added methods for searching for UDFs of this Workbook. 
  */
 public final class XSSFEvaluationWorkbook implements FormulaRenderingWorkbook, EvaluationWorkbook, FormulaParsingWorkbook {
 
@@ -180,8 +177,4 @@ public final class XSSFEvaluationWorkbook implements FormulaRenderingWorkbook, E
 	public SpreadsheetVersion getSpreadsheetVersion(){
 		return SpreadsheetVersion.EXCEL2007;
 	}
-
-    public FreeRefFunction findUserDefinedFunction(String functionName) {
-        return _uBook.getUserDefinedFunction(functionName);
-    }
 }
diff --git a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFFormulaEvaluator.java b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFFormulaEvaluator.java
index 8780ae23f3..0130eca232 100644
--- a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFFormulaEvaluator.java
+++ b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFFormulaEvaluator.java
@@ -24,6 +24,8 @@ import org.apache.poi.hssf.record.formula.eval.ErrorEval;
 import org.apache.poi.hssf.record.formula.eval.NumberEval;
 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.udf.UDFFinder;
+import org.apache.poi.hssf.usermodel.HSSFWorkbook;
 import org.apache.poi.ss.formula.IStabilityClassifier;
 import org.apache.poi.ss.formula.WorkbookEvaluator;
 import org.apache.poi.ss.usermodel.Cell;
@@ -47,16 +49,31 @@ public class XSSFFormulaEvaluator implements FormulaEvaluator {
 	private WorkbookEvaluator _bookEvaluator;
 
 	public XSSFFormulaEvaluator(XSSFWorkbook workbook) {
-		this(workbook, null);
+		this(workbook, null, null);
 	}
 	/**
 	 * @param stabilityClassifier used to optimise caching performance. Pass <code>null</code>
-	 * for the (conservative) assumption that any cell may have its definition changed after 
+	 * for the (conservative) assumption that any cell may have its definition changed after
 	 * evaluation begins.
+	 * @deprecated (Sep 2009) (reduce overloading) use {@link #create(HSSFWorkbook, IStabilityClassifier, UDFFinder)}
 	 */
 	public XSSFFormulaEvaluator(XSSFWorkbook workbook, IStabilityClassifier stabilityClassifier) {
-		_bookEvaluator = new WorkbookEvaluator(XSSFEvaluationWorkbook.create(workbook), stabilityClassifier);
+		_bookEvaluator = new WorkbookEvaluator(XSSFEvaluationWorkbook.create(workbook), stabilityClassifier, null);
 	}
+	private XSSFFormulaEvaluator(XSSFWorkbook workbook, IStabilityClassifier stabilityClassifier, UDFFinder udfFinder) {
+		_bookEvaluator = new WorkbookEvaluator(XSSFEvaluationWorkbook.create(workbook), stabilityClassifier, udfFinder);
+	}
+
+	/**
+	 * @param stabilityClassifier used to optimise caching performance. Pass <code>null</code>
+	 * for the (conservative) assumption that any cell may have its definition changed after
+	 * evaluation begins.
+	 * @param udfFinder pass <code>null</code> for default (AnalysisToolPak only)
+	 */
+	public static XSSFFormulaEvaluator create(XSSFWorkbook workbook, IStabilityClassifier stabilityClassifier, UDFFinder udfFinder) {
+		return new XSSFFormulaEvaluator(workbook, stabilityClassifier, udfFinder);
+	}
+
 
 	/**
 	 * Should be called whenever there are major changes (e.g. moving sheets) to input cells
diff --git a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFWorkbook.java b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFWorkbook.java
index ffd1736119..67d4f69bf0 100644
--- a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFWorkbook.java
+++ b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFWorkbook.java
@@ -32,7 +32,6 @@ import org.apache.poi.POIXMLDocumentPart;
 import org.apache.poi.POIXMLException;
 import org.apache.poi.POIXMLProperties;
 import org.apache.poi.hssf.record.formula.SheetNameFormatter;
-import org.apache.poi.hssf.record.formula.functions.FreeRefFunction;
 import org.apache.poi.openxml4j.exceptions.OpenXML4JException;
 import org.apache.poi.openxml4j.opc.OPCPackage;
 import org.apache.poi.openxml4j.opc.PackagePart;
@@ -41,7 +40,6 @@ import org.apache.poi.openxml4j.opc.PackageRelationship;
 import org.apache.poi.openxml4j.opc.PackageRelationshipTypes;
 import org.apache.poi.openxml4j.opc.PackagingURIHelper;
 import org.apache.poi.openxml4j.opc.TargetMode;
-import org.apache.poi.ss.usermodel.Name;
 import org.apache.poi.ss.usermodel.Row;
 import org.apache.poi.ss.usermodel.Sheet;
 import org.apache.poi.ss.usermodel.Workbook;
@@ -65,8 +63,6 @@ import org.openxmlformats.schemas.spreadsheetml.x2006.main.*;
  * High level representation of a SpreadsheetML workbook.  This is the first object most users
  * will construct whether they are reading or writing a workbook.  It is also the
  * top level object for creating new sheets/etc.
- * 
- * Modified 09/07/09 by Petr Udalau - added methods for work with UDFs of this Workbook. 
  */
 public class XSSFWorkbook extends POIXMLDocument implements Workbook, Iterable<XSSFSheet> {
     private static final Pattern COMMA_PATTERN = Pattern.compile(",");
@@ -133,9 +129,6 @@ public class XSSFWorkbook extends POIXMLDocument implements Workbook, Iterable<X
     private List<XSSFPictureData> pictures;
 
     private static POILogger logger = POILogFactory.getLogger(XSSFWorkbook.class);
-    
-    /** Map of user defined functions, key - function name, value - instance of FreeRefFunctions */
-	private Map<String, FreeRefFunction> udfFunctions = new HashMap<String, FreeRefFunction>();
 
     /**
      * Create a new SpreadsheetML workbook.
@@ -1352,23 +1345,4 @@ public class XSSFWorkbook extends POIXMLDocument implements Workbook, Iterable<X
     public MapInfo getMapInfo(){
     	return mapInfo;
     }
-
-    public FreeRefFunction getUserDefinedFunction(String functionName) {
-    	return udfFunctions.get(functionName);
-    }
-    
-    public void registerUserDefinedFunction(String functionName, FreeRefFunction freeRefFunction) {
-    	Name udfDeclaration = getName(functionName);
-        if (udfDeclaration == null) {
-            udfDeclaration = createName();
-        }
-        udfDeclaration.setNameName(functionName);
-        udfDeclaration.setFunction(true);
-        udfFunctions.put(functionName, freeRefFunction);
-    }
-    
-	public List<String> getUserDefinedFunctionNames() {
-		return new ArrayList<String>(udfFunctions.keySet());
-	}
-
 }
diff --git a/src/testcases/org/apache/poi/hssf/record/formula/eval/TestExternalFunction.java b/src/testcases/org/apache/poi/hssf/record/formula/eval/TestExternalFunction.java
index b2937b0fcb..2cfbbfec41 100644
--- a/src/testcases/org/apache/poi/hssf/record/formula/eval/TestExternalFunction.java
+++ b/src/testcases/org/apache/poi/hssf/record/formula/eval/TestExternalFunction.java
@@ -17,97 +17,79 @@
 
 package org.apache.poi.hssf.record.formula.eval;
 
-import java.io.IOException;
-
 import junit.framework.TestCase;
 
 import org.apache.poi.hssf.HSSFTestDataSamples;
 import org.apache.poi.hssf.record.formula.functions.FreeRefFunction;
-import org.apache.poi.hssf.record.formula.toolpack.DefaultToolPack;
-import org.apache.poi.hssf.record.formula.toolpack.MainToolPacksHandler;
-import org.apache.poi.hssf.record.formula.toolpack.ToolPack;
+import org.apache.poi.hssf.record.formula.udf.DefaultUDFFinder;
+import org.apache.poi.hssf.record.formula.udf.AggregatingUDFFinder;
+import org.apache.poi.hssf.record.formula.udf.UDFFinder;
 import org.apache.poi.hssf.usermodel.HSSFCell;
 import org.apache.poi.hssf.usermodel.HSSFFormulaEvaluator;
 import org.apache.poi.hssf.usermodel.HSSFRow;
 import org.apache.poi.hssf.usermodel.HSSFSheet;
 import org.apache.poi.hssf.usermodel.HSSFWorkbook;
 import org.apache.poi.ss.formula.OperationEvaluationContext;
-import org.apache.poi.ss.usermodel.Workbook;
 
 /**
- * 
  * @author Josh Micich
- * 
- * Modified 09/14/09 by Petr Udalau - Test of registering UDFs in workbook and
- * using ToolPacks.
+ * @author Petr Udalau - registering UDFs in workbook and using ToolPacks.
  */
 public final class TestExternalFunction extends TestCase {
 
-    private static class MyFunc implements FreeRefFunction {
-        public ValueEval evaluate(ValueEval[] args, OperationEvaluationContext ec) {
-            if (args.length != 1 || !(args[0] instanceof StringEval)) {
-                return ErrorEval.VALUE_INVALID;
-            } else {
-                StringEval input = (StringEval) args[0];
-                return new StringEval(input.getStringValue() + "abc");
-            }
-        }
-    }
-
-    private static class MyFunc2 implements FreeRefFunction {
-        public ValueEval evaluate(ValueEval[] args, OperationEvaluationContext ec) {
-            if (args.length != 1 || !(args[0] instanceof StringEval)) {
-                return ErrorEval.VALUE_INVALID;
-            } else {
-                StringEval input = (StringEval) args[0];
-                return new StringEval(input.getStringValue() + "abc2");
-            }
-        }
-    }
-
-    /**
-     * Creates and registers user-defined function "MyFunc()" directly with POI.
-     * This is VB function defined in "testNames.xls". In future there must be
-     * some parser of VBA scripts which will register UDFs.
-     */
-    private void registerMyFunc(Workbook workbook) {
-        workbook.registerUserDefinedFunction("myFunc", new MyFunc());
-    }
-
-    /**
-     * Creates example ToolPack which contains function "MyFunc2()".
-     */
-    private void createExampleToolPack() {
-        ToolPack exampleToolPack = new DefaultToolPack();
-        exampleToolPack.addFunction("myFunc2", new MyFunc2());
-        MainToolPacksHandler.instance().addToolPack(exampleToolPack);
-    }
-
-    /**
-     * Checks that an external function can get invoked from the formula
-     * evaluator.
-     * 
-     * @throws IOException
-     * 
-     */
-    public void testInvoke() {
-        HSSFWorkbook wb = HSSFTestDataSamples.openSampleWorkbook("testNames.xls");
-        HSSFSheet sheet = wb.getSheetAt(0);
-
-        registerMyFunc(wb);
-        createExampleToolPack();
-
-        HSSFRow row = sheet.getRow(0);
-        HSSFCell myFuncCell = row.getCell(1); //=myFunc("_")
-
-        HSSFCell myFunc2Cell = row.getCell(2); //=myFunc2("_")
-
-        HSSFFormulaEvaluator fe = new HSSFFormulaEvaluator(wb);
-        try {
-            assertEquals("_abc", fe.evaluate(myFuncCell).getStringValue());
-            assertEquals("_abc2", fe.evaluate(myFunc2Cell).getStringValue());
-        } catch (Exception e) {
-            assertFalse(true);
-        }
-    }
+	private static class MyFunc implements FreeRefFunction {
+		public MyFunc() {
+			//
+		}
+
+		public ValueEval evaluate(ValueEval[] args, OperationEvaluationContext ec) {
+			if (args.length != 1 || !(args[0] instanceof StringEval)) {
+				return ErrorEval.VALUE_INVALID;
+			}
+			StringEval input = (StringEval) args[0];
+			return new StringEval(input.getStringValue() + "abc");
+		}
+	}
+
+	private static class MyFunc2 implements FreeRefFunction {
+		public MyFunc2() {
+			//
+		}
+
+		public ValueEval evaluate(ValueEval[] args, OperationEvaluationContext ec) {
+			if (args.length != 1 || !(args[0] instanceof StringEval)) {
+				return ErrorEval.VALUE_INVALID;
+			}
+			StringEval input = (StringEval) args[0];
+			return new StringEval(input.getStringValue() + "abc2");
+		}
+	}
+
+	/**
+	 * Checks that an external function can get invoked from the formula
+	 * evaluator.
+	 */
+	public void testInvoke() {
+		HSSFWorkbook wb = HSSFTestDataSamples.openSampleWorkbook("testNames.xls");
+		HSSFSheet sheet = wb.getSheetAt(0);
+
+		/**
+		 * register the two test UDFs in a UDF finder, to be passed to the evaluator
+		 */
+		UDFFinder udff1 = new DefaultUDFFinder(new String[] { "myFunc", },
+				new FreeRefFunction[] { new MyFunc(), });
+		UDFFinder udff2 = new DefaultUDFFinder(new String[] { "myFunc2", },
+				new FreeRefFunction[] { new MyFunc2(), });
+		UDFFinder udff = new AggregatingUDFFinder(udff1, udff2);
+
+
+		HSSFRow row = sheet.getRow(0);
+		HSSFCell myFuncCell = row.getCell(1); // =myFunc("_")
+
+		HSSFCell myFunc2Cell = row.getCell(2); // =myFunc2("_")
+
+		HSSFFormulaEvaluator fe = HSSFFormulaEvaluator.create(wb, null, udff);
+		assertEquals("_abc", fe.evaluate(myFuncCell).getStringValue());
+		assertEquals("_abc2", fe.evaluate(myFunc2Cell).getStringValue());
+	}
 }
diff --git a/src/testcases/org/apache/poi/ss/formula/TestWorkbookEvaluator.java b/src/testcases/org/apache/poi/ss/formula/TestWorkbookEvaluator.java
index 9035ecbedb..41aa0ab57b 100644
--- a/src/testcases/org/apache/poi/ss/formula/TestWorkbookEvaluator.java
+++ b/src/testcases/org/apache/poi/ss/formula/TestWorkbookEvaluator.java
@@ -44,7 +44,7 @@ public class TestWorkbookEvaluator extends TestCase {
 
 	private static ValueEval evaluateFormula(Ptg[] ptgs) {
 		OperationEvaluationContext ec = new OperationEvaluationContext(null, null, 0, 0, 0, null);
-		return new WorkbookEvaluator(null, null).evaluateFormula(ec, ptgs);
+		return new WorkbookEvaluator(null, null, null).evaluateFormula(ec, ptgs);
 	}
 
 	/**
diff --git a/src/testcases/org/apache/poi/ss/formula/WorkbookEvaluatorTestHelper.java b/src/testcases/org/apache/poi/ss/formula/WorkbookEvaluatorTestHelper.java
index b8b5de991e..673cb9500c 100644
--- a/src/testcases/org/apache/poi/ss/formula/WorkbookEvaluatorTestHelper.java
+++ b/src/testcases/org/apache/poi/ss/formula/WorkbookEvaluatorTestHelper.java
@@ -22,7 +22,7 @@ import org.apache.poi.hssf.usermodel.HSSFWorkbook;
 
 /**
  * Allows tests to execute {@link WorkbookEvaluator}s and track the internal workings.
- *  
+ *
  * @author Josh Micich
  */
 public final class WorkbookEvaluatorTestHelper {
@@ -30,8 +30,8 @@ public final class WorkbookEvaluatorTestHelper {
 	private WorkbookEvaluatorTestHelper() {
 		// no instances of this class
 	}
-	
+
 	public static WorkbookEvaluator createEvaluator(HSSFWorkbook wb, EvaluationListener listener) {
-		return new WorkbookEvaluator(HSSFEvaluationWorkbook.create(wb), listener, null);
+		return new WorkbookEvaluator(HSSFEvaluationWorkbook.create(wb), listener, null, null);
 	}
 }