encapsulated hasUnlimitedVarags() logic into FunctionMetadata

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@775575 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/poi/hssf/record/formula/function/FunctionMetadata.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,
@@ -16,12 +16,24 @@
 ==================================================================== */
 
 package org.apache.poi.hssf.record.formula.function;
+
+import org.apache.poi.ss.SpreadsheetVersion;
+
 /**
  * Holds information about Excel built-in functions.
  *
  * @author Josh Micich
  */
 public final class FunctionMetadata {
+	/**
+	 * maxParams=30 in functionMetadata.txt means the maximum number arguments supported
+	 * by the given version of Excel. Validation routines should take the actual limit (Excel 97 or 2007)
+	 * from the SpreadsheetVersion enum.
+	 * Perhaps a value like 'M' should be used instead of '30' in functionMetadata.txt
+	 * to make that file more version neutral.
+	 * @see org.apache.poi.ss.formula.FormulaParser#validateNumArgs(int, FunctionMetadata)
+	 */
+	private static final short FUNCTION_MAX_PARAMS = 30;
 
 	private final int _index;
 	private final String _name;
@@ -58,7 +70,17 @@ public final class FunctionMetadata {
 		return _returnClassCode;
 	}
 	public byte[] getParameterClassCodes() {
-		return (byte[]) _parameterClassCodes.clone();
+		return _parameterClassCodes.clone();
+	}
+	/**
+	 * Some varags functions (like VLOOKUP) have a specific limit to the number of arguments that 
+	 * can be passed.  Other functions (like SUM) don't have such a limit.  For those functions,
+	 * the spreadsheet version determines the maximum number of arguments that can be passed.
+	 * @return <code>true</code> if this function can the maximum number of arguments allowable by
+	 * the {@link SpreadsheetVersion}
+	 */
+	public boolean hasUnlimitedVarags() {
+		return FUNCTION_MAX_PARAMS == _maxParams;
 	}
 	public String toString() {
 		StringBuffer sb = new StringBuffer(64);

src/java/org/apache/poi/hssf/record/formula/function/FunctionMetadataRegistry.java

@@ -20,7 +20,7 @@ package org.apache.poi.hssf.record.formula.function;
 import java.util.Map;
 import java.util.Set;
 /**
- * Allows clients to get <tt>FunctionMetadata</tt> instances for any built-in function of Excel.
+ * Allows clients to get {@link FunctionMetadata} instances for any built-in function of Excel.
  *
  * @author Josh Micich
  */
@@ -30,14 +30,6 @@ public final class FunctionMetadataRegistry {
 	 */
 	public static final String FUNCTION_NAME_IF = "IF";
 
-    /**
-     * maxParams=30 in functionMetadata.txt means the maximum number arguments supported
-     * by the given version of Excel. Validation routines should take the actual limit (Excel 97 or 2007)
-     * from the SpreadsheetVersion enum.
-     * @see org.apache.poi.ss.formula.FormulaParser#validateNumArgs(int, FunctionMetadata)
-     */
-    public static final short FUNCTION_MAX_PARAMS = 30;
-
     public static final short FUNCTION_INDEX_SUM = 4;
 	public static final short FUNCTION_INDEX_EXTERNAL = 255;
 	private static FunctionMetadataRegistry _instance;

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

@@ -31,7 +31,6 @@ import org.apache.poi.hssf.usermodel.HSSFErrorConstants;
 import org.apache.poi.ss.util.AreaReference;
 import org.apache.poi.ss.util.CellReference;
 import org.apache.poi.ss.util.CellReference.NameType;
-import org.apache.poi.ss.SpreadsheetVersion;
 
 /**
  * This class parses a formula string into a List of tokens in RPN order.
@@ -984,14 +983,20 @@ public final class FormulaParser {
 			msg += " but got " + numArgs + ".";
 			throw new FormulaParseException(msg);
 		}
-        //the maximum number of arguments depends on the Excel version
+		//the maximum number of arguments depends on the Excel version
-        int maxArgs = fm.getMaxParams();
+		int maxArgs;
-        if( maxArgs == FunctionMetadataRegistry.FUNCTION_MAX_PARAMS) {
+		if (fm.hasUnlimitedVarags()) {
-            //_book can be omitted by test cases
+			if(_book != null) {
-            if(_book != null) maxArgs = _book.getSpreadsheetVersion().getMaxFunctionArgs();
+				maxArgs = _book.getSpreadsheetVersion().getMaxFunctionArgs();
-        }
+			} else {
+				//_book can be omitted by test cases
+				maxArgs = fm.getMaxParams(); // just use BIFF8 
+			}
+		} else {
+			maxArgs = fm.getMaxParams();
+		}
 
-        if(numArgs > maxArgs) {
+		if(numArgs > maxArgs) {
 			String msg = "Too many arguments to function '" + fm.getName() + "'. ";
 			if(fm.hasFixedArgsLength()) {
 				msg += "Expected " + maxArgs;