Fix for bug 45354 - Proper distinguishing of cell references and named ranges within formulas

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@674953 13f79535-47bb-0310-9956-ffa450edef68

src/documentation/content/xdocs/changes.xml

@@ -37,6 +37,7 @@
 
 		<!-- Don't forget to update status.xml too! -->
         <release version="3.1.1-alpha1" date="2008-??-??">
+           <action dev="POI-DEVELOPERS" type="fix">45354 - Fixed recognition of named ranges within formulas</action>
            <action dev="POI-DEVELOPERS" type="fix">45338 - Fix HSSFWorkbook to give you the same HSSFFont every time, and then fix it to find newly added fonts</action>
            <action dev="POI-DEVELOPERS" type="fix">45336 - Fix HSSFColor.getTripletHash()</action>
            <action dev="POI-DEVELOPERS" type="fix">45334 - Fixed formula parser to handle dots in identifiers</action>

src/documentation/content/xdocs/status.xml

@@ -34,6 +34,7 @@
 	<!-- Don't forget to update changes.xml too! -->
     <changes>
         <release version="3.1.1-alpha1" date="2008-??-??">
+           <action dev="POI-DEVELOPERS" type="fix">45354 - Fixed recognition of named ranges within formulas</action>
            <action dev="POI-DEVELOPERS" type="fix">45338 - Fix HSSFWorkbook to give you the same HSSFFont every time, and then fix it to find newly added fonts</action>
            <action dev="POI-DEVELOPERS" type="fix">45336 - Fix HSSFColor.getTripletHash()</action>
            <action dev="POI-DEVELOPERS" type="fix">45334 - Fixed formula parser to handle dots in identifiers</action>

src/java/org/apache/poi/hssf/model/FormulaParser.java

@@ -29,6 +29,7 @@ import org.apache.poi.hssf.record.formula.function.FunctionMetadataRegistry;
 import org.apache.poi.hssf.usermodel.HSSFWorkbook;
 import org.apache.poi.hssf.util.AreaReference;
 import org.apache.poi.hssf.util.CellReference;
+import org.apache.poi.hssf.util.CellReference.NameType;
 
 /**
  * This class parses a formula string into a List of tokens in RPN order.
@@ -293,9 +294,14 @@ public final class FormulaParser {
 
         // This can be either a cell ref or a named range
         // Try to spot which it is
-        if (isValidCellReference(name)) {
+        int nameType = CellReference.classifyCellReference(name);
+        if (nameType == NameType.CELL) {
             return new RefPtg(name);
         }
+        if (nameType != NameType.NAMED_RANGE) {
+            new FormulaParseException("Name '" + name
+                + "' does not look like a cell reference or named range");
+        }
 
         for(int i = 0; i < book.getNumberOfNames(); i++) {
             // named range name matching is case insensitive
@@ -303,11 +309,12 @@ public final class FormulaParser {
                 return new NamePtg(name, book);
             }
         }
-        throw new FormulaParseException("Found reference to named range \""
+        throw new FormulaParseException("Specified named range '"
-                    + name + "\", but that named range wasn't defined!");
+                    + name + "' does not exist in the current workbook.");
     }
 
     /**
+     * @param name an 'identifier' like string (i.e. contains alphanums, and dots)
      * @return <code>null</code> if name cannot be split at a dot
      */
     private AreaReference parseArea(String name) {
@@ -323,6 +330,8 @@ public final class FormulaParser {
                 return null;
             }
         }
+        // This expression is only valid as an area ref, if the LHS and RHS of the dot(s) are both
+        // cell refs.  Otherwise, this expression must be a named range name
         String partA = name.substring(0, dotPos);
         if (!isValidCellReference(partA)) {
             return null;
@@ -336,12 +345,14 @@ public final class FormulaParser {
         return new AreaReference(topLeft, bottomRight);
     }
 
+    /**
+     * @return <code>true</code> if the specified name is a valid cell reference
+     */
     private static boolean isValidCellReference(String str) {
-        // TODO - exact rules for recognising cell references may be too complicated for regex 
+        return CellReference.classifyCellReference(str) == NameType.CELL;
-        return CELL_REFERENCE_PATTERN.matcher(str).matches();
     }
-    
+
-    
+
     /**
      * Note - Excel function names are 'case aware but not case sensitive'.  This method may end
      * up creating a defined name record in the workbook if the specified name is not an internal

src/java/org/apache/poi/hssf/record/formula/SheetNameFormatter.java

@@ -14,13 +14,14 @@
    See the License for the specific language governing permissions and
    limitations under the License.
 ==================================================================== */
-        
 
 package org.apache.poi.hssf.record.formula;
 
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import org.apache.poi.hssf.util.CellReference;
+
 /**
  * Formats sheet names for use in formula expressions.
  * 
@@ -28,14 +29,12 @@ import java.util.regex.Pattern;
  */
 public final class SheetNameFormatter {
 	
-	private static final String BIFF8_LAST_COLUMN = "IV";
-	private static final int BIFF8_LAST_COLUMN_TEXT_LEN = BIFF8_LAST_COLUMN.length();
-	private static final String BIFF8_LAST_ROW = String.valueOf(0x10000);
-	private static final int BIFF8_LAST_ROW_TEXT_LEN = BIFF8_LAST_ROW.length();
-
 	private static final char DELIMITER = '\'';
 	
-	private static final Pattern CELL_REF_PATTERN = Pattern.compile("([A-Za-z])+[0-9]+");
+	/**
+	 * Matches a single cell ref with no absolute ('$') markers
+	 */
+	private static final Pattern CELL_REF_PATTERN = Pattern.compile("([A-Za-z]+)([0-9]+)");
 
 	private SheetNameFormatter() {
 		// no instances of this class
@@ -105,27 +104,27 @@ public final class SheetNameFormatter {
 		return false;
 	}
 	
-    /**
+	/**
-     * @return <code>true</code> if the presence of the specified character in a sheet name would 
+	 * @return <code>true</code> if the presence of the specified character in a sheet name would 
-     * require the sheet name to be delimited in formulas.  This includes every non-alphanumeric 
+	 * require the sheet name to be delimited in formulas.  This includes every non-alphanumeric 
-     * character besides underscore '_'.
+	 * character besides underscore '_'.
-     */
+	 */
-    /* package */ static boolean isSpecialChar(char ch) {
+	/* package */ static boolean isSpecialChar(char ch) {
-        // note - Character.isJavaIdentifierPart() would allow dollars '$'
+		// note - Character.isJavaIdentifierPart() would allow dollars '$'
-        if(Character.isLetterOrDigit(ch)) {
+		if(Character.isLetterOrDigit(ch)) {
-            return false;
+			return false;
-        }
+		}
-        switch(ch) {
+		switch(ch) {
-            case '_': // underscore is ok
+			case '_': // underscore is ok
-                return false;
+				return false;
-            case '\n':
+			case '\n':
-            case '\r':
+			case '\r':
-            case '\t':
+			case '\t':
-                throw new RuntimeException("Illegal character (0x" 
+				throw new RuntimeException("Illegal character (0x" 
-                        + Integer.toHexString(ch) + ") found in sheet name");
+						+ Integer.toHexString(ch) + ") found in sheet name");
-        }
+		}
-        return true;
+		return true;
-    }
+	}
 	
 
 	/**
@@ -149,64 +148,11 @@ public final class SheetNameFormatter {
 	 * <p/>
 	 * For better or worse this implementation attempts to replicate Excel's formula renderer.
 	 * Excel uses range checking on the apparent 'row' and 'column' components.  Note however that
-	 * the maximum sheet size varies across versions:
+	 * the maximum sheet size varies across versions.
-	 * <p/>
+	 * @see org.apache.poi.hssf.util.CellReference
-	 * <blockquote><table border="0" cellpadding="1" cellspacing="0" 
-	 *                 summary="Notable cases.">
-	 *   <tr><th>Version&nbsp;&nbsp;</th><th>File Format&nbsp;&nbsp;</th>
-	 *   	<th>Last Column&nbsp;&nbsp;</th><th>Last Row</th></tr>
-	 *   <tr><td>97-2003</td><td>BIFF8</td><td>"IV" (2^8)</td><td>65536 (2^14)</td></tr>
-	 *   <tr><td>2007</td><td>BIFF12</td><td>"XFD" (2^14)</td><td>1048576 (2^20)</td></tr>
-	 * </table></blockquote>
-	 * POI currently targets BIFF8 (Excel 97-2003), so the following behaviour can be observed for
-	 * this method:
-	 * <blockquote><table border="0" cellpadding="1" cellspacing="0" 
-	 *                 summary="Notable cases.">
-	 *   <tr><th>Input&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</th>
-	 *   	<th>Result&nbsp;</th></tr>
-	 *   <tr><td>"A1", 1</td><td>true</td></tr>
-	 *   <tr><td>"a111", 1</td><td>true</td></tr>
-	 *   <tr><td>"A65536", 1</td><td>true</td></tr>
-	 *   <tr><td>"A65537", 1</td><td>false</td></tr>
-	 *   <tr><td>"iv1", 2</td><td>true</td></tr>
-	 *   <tr><td>"IW1", 2</td><td>false</td></tr>
-	 *   <tr><td>"AAA1", 3</td><td>false</td></tr>
-	 *   <tr><td>"a111", 1</td><td>true</td></tr>
-	 *   <tr><td>"Sheet1", 6</td><td>false</td></tr>
-	 * </table></blockquote>
 	 */
-	/* package */ static boolean cellReferenceIsWithinRange(String rawSheetName, int numberOfLetters) {
+	/* package */ static boolean cellReferenceIsWithinRange(String lettersPrefix, String numbersSuffix) {
-		
+		return CellReference.cellReferenceIsWithinRange(lettersPrefix, numbersSuffix);
-		if(numberOfLetters > BIFF8_LAST_COLUMN_TEXT_LEN) {
-			// "Sheet1" case etc
-			return false; // that was easy
-		}
-		int nDigits = rawSheetName.length() - numberOfLetters;
-		if(nDigits > BIFF8_LAST_ROW_TEXT_LEN) {
-			return false; 
-		}
-		if(numberOfLetters == BIFF8_LAST_COLUMN_TEXT_LEN) {
-			String colStr = rawSheetName.substring(0, BIFF8_LAST_COLUMN_TEXT_LEN).toUpperCase();
-			if(colStr.compareTo(BIFF8_LAST_COLUMN) > 0) {
-				return false;
-			}
-		} else {
-			// apparent column name has less chars than max
-			// no need to check range
-		}
-		
-		if(nDigits == BIFF8_LAST_ROW_TEXT_LEN) {
-			String colStr = rawSheetName.substring(numberOfLetters);
-			// ASCII comparison is valid if digit count is same
-			if(colStr.compareTo(BIFF8_LAST_ROW) > 0) {
-				return false;
-			}
-		} else {
-			// apparent row has less chars than max
-			// no need to check range
-		}
-		
-		return true;
 	}
 
 	/**
@@ -239,7 +185,7 @@ public final class SheetNameFormatter {
 		
 		// rawSheetName == "Sheet1" gets this far.
 		String lettersPrefix = matcher.group(1);
-		return cellReferenceIsWithinRange(rawSheetName, lettersPrefix.length());
+		String numbersSuffix = matcher.group(2);
+		return cellReferenceIsWithinRange(lettersPrefix, numbersSuffix);
 	}
-
 }

src/java/org/apache/poi/hssf/util/CellReference.java

@@ -17,6 +17,9 @@
 
 package org.apache.poi.hssf.util;
 
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
 import org.apache.poi.hssf.record.formula.SheetNameFormatter;
 
 /**
@@ -25,6 +28,14 @@ import org.apache.poi.hssf.record.formula.SheetNameFormatter;
  * @author  Dennis Doubleday (patch to seperateRowColumns())
  */
 public final class CellReference {
+	/**
+	 * Used to classify identifiers found in formulas as cell references or not.
+	 */
+	public static final class NameType {
+		public static final int CELL = 1;
+		public static final int NAMED_RANGE = 2;
+		public static final int BAD_CELL_OR_NAMED_RANGE = -1;
+	}
     /** The character ($) that signifies a row or column value is absolute instead of relative */ 
     private static final char ABSOLUTE_REFERENCE_MARKER = '$';
     /** The character (!) that separates sheet names from cell references */ 
@@ -32,6 +43,20 @@ public final class CellReference {
     /** The character (') used to quote sheet names when they contain special characters */
     private static final char SPECIAL_NAME_DELIMITER = '\'';
     
+    /**
+     * Matches a run of letters followed by a run of digits.  The run of letters is group 1 and the
+     * run of digits is group 2.  Each group may optionally be prefixed with a single '$'.
+     */
+	private static final Pattern CELL_REF_PATTERN = Pattern.compile("\\$?([A-Za-z]+)\\$?([0-9]+)");
+	/**
+	 * Named range names must start with a letter or underscore.  Subsequent characters may include
+	 * digits or dot.  (They can even end in dot).
+	 */
+	private static final Pattern NAMED_RANGE_NAME_PATTERN = Pattern.compile("[_A-Za-z][_.A-Za-z0-9]*");
+	private static final String BIFF8_LAST_COLUMN = "IV";
+	private static final int BIFF8_LAST_COLUMN_TEXT_LEN = BIFF8_LAST_COLUMN.length();
+	private static final String BIFF8_LAST_ROW = String.valueOf(0x10000);
+	private static final int BIFF8_LAST_ROW_TEXT_LEN = BIFF8_LAST_ROW.length();
 
     private final int _rowIndex;
     private final int _colIndex;
@@ -119,8 +144,131 @@ public final class CellReference {
         return retval-1;
     }
 
-
     /**
+     * Classifies an identifier as either a simple (2D) cell reference or a named range name
+     * @return one of the values from <tt>NameType</tt> 
+     */
+    public static int classifyCellReference(String str) {
+    	int len = str.length();
+    	if (len < 1) {
+    		throw new IllegalArgumentException("Empty string not allowed");
+    	}
+    	char firstChar = str.charAt(0);
+    	switch (firstChar) {
+        	case ABSOLUTE_REFERENCE_MARKER:
+        	case '.':
+        	case '_':
+        		break;
+        	default:
+        		if (!Character.isLetter(firstChar)) {
+            		throw new IllegalArgumentException("Invalid first char (" + firstChar 
+            				+ ") of cell reference or named range.  Letter expected");
+            	}
+    	}
+    	if (!Character.isDigit(str.charAt(len-1))) {
+    		// no digits at end of str
+    		return validateNamedRangeName(str);
+    	}
+    	Matcher cellRefPatternMatcher = CELL_REF_PATTERN.matcher(str);
+    	if (!cellRefPatternMatcher.matches()) {
+    		return validateNamedRangeName(str);
+    	}
+    	String lettersGroup = cellRefPatternMatcher.group(1);
+    	String digitsGroup = cellRefPatternMatcher.group(2);
+    	if (cellReferenceIsWithinRange(lettersGroup, digitsGroup)) {
+    		// valid cell reference
+    		return NameType.CELL;
+    	}
+    	// If str looks like a cell reference, but is out of (row/col) range, it is a valid
+    	// named range name
+    	// This behaviour is a little weird.  For example, "IW123" is a valid named range name
+    	// because the column "IW" is beyond the maximum "IV".  Note - this behaviour is version
+    	// dependent.  In Excel 2007, "IW123" is not a valid named range name.
+    	if (str.indexOf(ABSOLUTE_REFERENCE_MARKER) >= 0) {
+    		// Of course, named range names cannot have '$'
+    		return NameType.BAD_CELL_OR_NAMED_RANGE;
+    	}
+    	return NameType.NAMED_RANGE;
+    }
+
+    private static int validateNamedRangeName(String str) {
+		if (!NAMED_RANGE_NAME_PATTERN.matcher(str).matches()) {
+			return NameType.BAD_CELL_OR_NAMED_RANGE;
+		}
+		return NameType.NAMED_RANGE;
+		
+	}
+    
+    
+	/**
+	 * Used to decide whether a name of the form "[A-Z]*[0-9]*" that appears in a formula can be 
+	 * interpreted as a cell reference.  Names of that form can be also used for sheets and/or
+	 * named ranges, and in those circumstances, the question of whether the potential cell 
+	 * reference is valid (in range) becomes important.
+	 * <p/>
+	 * Note - that the maximum sheet size varies across Excel versions:
+	 * <p/>
+	 * <blockquote><table border="0" cellpadding="1" cellspacing="0" 
+	 *                 summary="Notable cases.">
+	 *   <tr><th>Version&nbsp;&nbsp;</th><th>File Format&nbsp;&nbsp;</th>
+	 *   	<th>Last Column&nbsp;&nbsp;</th><th>Last Row</th></tr>
+	 *   <tr><td>97-2003</td><td>BIFF8</td><td>"IV" (2^8)</td><td>65536 (2^14)</td></tr>
+	 *   <tr><td>2007</td><td>BIFF12</td><td>"XFD" (2^14)</td><td>1048576 (2^20)</td></tr>
+	 * </table></blockquote>
+	 * POI currently targets BIFF8 (Excel 97-2003), so the following behaviour can be observed for
+	 * this method:
+	 * <blockquote><table border="0" cellpadding="1" cellspacing="0" 
+	 *                 summary="Notable cases.">
+	 *   <tr><th>Input&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</th>
+	 *   	<th>Result&nbsp;</th></tr>
+	 *   <tr><td>"A", "1"</td><td>true</td></tr>
+	 *   <tr><td>"a", "111"</td><td>true</td></tr>
+	 *   <tr><td>"A", "65536"</td><td>true</td></tr>
+	 *   <tr><td>"A", "65537"</td><td>false</td></tr>
+	 *   <tr><td>"iv", "1"</td><td>true</td></tr>
+	 *   <tr><td>"IW", "1"</td><td>false</td></tr>
+	 *   <tr><td>"AAA", "1"</td><td>false</td></tr>
+	 *   <tr><td>"a", "111"</td><td>true</td></tr>
+	 *   <tr><td>"Sheet", "1"</td><td>false</td></tr>
+	 * </table></blockquote>
+	 * 
+	 * @param colStr a string of only letter characters
+	 * @param rowStr a string of only digit characters
+	 * @return <code>true</code> if the row and col parameters are within range of a BIFF8 spreadsheet.
+	 */
+	public static boolean cellReferenceIsWithinRange(String colStr, String rowStr) {
+		int numberOfLetters = colStr.length();
+		if(numberOfLetters > BIFF8_LAST_COLUMN_TEXT_LEN) {
+			// "Sheet1" case etc
+			return false; // that was easy
+		}
+		int nDigits = rowStr.length();
+		if(nDigits > BIFF8_LAST_ROW_TEXT_LEN) {
+			return false; 
+		}
+		if(numberOfLetters == BIFF8_LAST_COLUMN_TEXT_LEN) {
+			if(colStr.toUpperCase().compareTo(BIFF8_LAST_COLUMN) > 0) {
+				return false;
+			}
+		} else {
+			// apparent column name has less chars than max
+			// no need to check range
+		}
+		
+		if(nDigits == BIFF8_LAST_ROW_TEXT_LEN) {
+			// ASCII comparison is valid if digit count is same
+			if(rowStr.compareTo(BIFF8_LAST_ROW) > 0) {
+				return false;
+			}
+		} else {
+			// apparent row has less chars than max
+			// no need to check range
+		}
+		
+		return true;
+	}
+
+	/**
      * Separates the row from the columns and returns an array of three Strings.  The first element
      * is the sheet name. Only the first element may be null.  The second element in is the column 
      * name still in ALPHA-26 number format.  The third element is the row.

src/testcases/org/apache/poi/hssf/model/TestFormulaParser.java

@@ -46,6 +46,7 @@ import org.apache.poi.hssf.record.formula.SubtractPtg;
 import org.apache.poi.hssf.record.formula.UnaryMinusPtg;
 import org.apache.poi.hssf.record.formula.UnaryPlusPtg;
 import org.apache.poi.hssf.usermodel.HSSFCell;
+import org.apache.poi.hssf.usermodel.HSSFName;
 import org.apache.poi.hssf.usermodel.HSSFRow;
 import org.apache.poi.hssf.usermodel.HSSFSheet;
 import org.apache.poi.hssf.usermodel.HSSFWorkbook;
@@ -791,4 +792,37 @@ public final class TestFormulaParser extends TestCase {
 		assertEquals("ERROR.TYPE", funcPtg.getName());
 	}
 	
+	public void testNamedRangeThatLooksLikeCell() {
+		HSSFWorkbook wb = new HSSFWorkbook();
+		HSSFSheet sheet = wb.createSheet("Sheet1");
+		HSSFName name = wb.createName();
+		name.setReference("Sheet1!B1");
+		name.setNameName("pfy1");
+
+		Ptg[] ptgs;
+		try {
+			ptgs = FormulaParser.parse("count(pfy1)", wb);
+		} catch (IllegalArgumentException e) {
+			if (e.getMessage().equals("Specified colIx (1012) is out of range")) {
+				throw new AssertionFailedError("Identified bug 45354");
+			}
+			throw e;
+		}
+		assertEquals(2, ptgs.length);
+		assertEquals(NamePtg.class, ptgs[0].getClass());
+
+		HSSFCell cell = sheet.createRow(0).createCell((short)0);
+		cell.setCellFormula("count(pfy1)");
+		assertEquals("COUNT(pfy1)", cell.getCellFormula());
+		try {
+			cell.setCellFormula("count(pf1)");
+			throw new AssertionFailedError("Expected formula parse execption");
+		} catch (FormulaParseException e) {
+			if (!e.getMessage().equals("Specified named range 'pf1' does not exist in the current workbook.")) {
+				throw e;
+			}
+		}
+		cell.setCellFormula("count(fp1)"); // plain cell ref, col is in range
+		
+	}
 }

src/testcases/org/apache/poi/hssf/record/formula/TestSheetNameFormatter.java

@@ -14,7 +14,6 @@
    See the License for the specific language governing permissions and
    limitations under the License.
 ==================================================================== */
-        
 
 package org.apache.poi.hssf.record.formula;
 
@@ -76,7 +75,9 @@ public final class TestSheetNameFormatter extends TestCase {
 	}
 	
 	private static void confirmCellRange(String text, int numberOfPrefixLetters, boolean expected) {
-		assertEquals(expected, SheetNameFormatter.cellReferenceIsWithinRange(text, numberOfPrefixLetters));
+		String prefix = text.substring(0, numberOfPrefixLetters);
+		String suffix = text.substring(numberOfPrefixLetters);
+		assertEquals(expected, SheetNameFormatter.cellReferenceIsWithinRange(prefix, suffix));
 	}
 	
 	/**
@@ -93,7 +94,7 @@ public final class TestSheetNameFormatter extends TestCase {
 		confirmCellRange("AAA1", 3, false);
 		confirmCellRange("a111", 1, true);
 		confirmCellRange("Sheet1", 6, false);
-        confirmCellRange("iV65536", 2, true);  // max cell in Excel 97-2003
+		confirmCellRange("iV65536", 2, true);  // max cell in Excel 97-2003
-        confirmCellRange("IW65537", 2, false);
+		confirmCellRange("IW65537", 2, false);
 	}
 }

src/testcases/org/apache/poi/hssf/util/TestCellReference.java

@@ -20,6 +20,8 @@ package org.apache.poi.hssf.util;
 
 import junit.framework.TestCase;
 
+import org.apache.poi.hssf.util.CellReference.NameType;
+
 
 public final class TestCellReference extends TestCase {
     
@@ -75,7 +77,6 @@ public final class TestCellReference extends TestCase {
         confirmCell(cf, "Amazing!", 0, 0, false, false, "'Amazing!'!A1");
     }
 
-    
     /* package */ static void confirmCell(CellReference cf, String expSheetName, int expRow, 
             int expCol, boolean expIsRowAbs, boolean expIsColAbs, String expText) {
         
@@ -87,8 +88,22 @@ public final class TestCellReference extends TestCase {
         assertEquals("text is wrong", expText, cf.formatAsString());
     }
 
-    public static void main(String [] args) {
+    public void testClassifyCellReference() {
-        System.out.println("Testing org.apache.poi.hssf.util.TestCellReference");
+        confirmNameType("a1", NameType.CELL);
-        junit.textui.TestRunner.run(TestCellReference.class);
+        confirmNameType("pfy1", NameType.NAMED_RANGE);
+        confirmNameType("pf1", NameType.NAMED_RANGE); // (col) out of cell range
+        confirmNameType("fp1", NameType.CELL);
+        confirmNameType("pf$1", NameType.BAD_CELL_OR_NAMED_RANGE);
+        confirmNameType("_A1", NameType.NAMED_RANGE);
+        confirmNameType("A_1", NameType.NAMED_RANGE);
+        confirmNameType("A1_", NameType.NAMED_RANGE);
+        confirmNameType(".A1", NameType.BAD_CELL_OR_NAMED_RANGE);
+        confirmNameType("A.1", NameType.NAMED_RANGE);
+        confirmNameType("A1.", NameType.NAMED_RANGE);
+    }
+    
+    private void confirmNameType(String ref, int expectedResult) {
+        int actualResult = CellReference.classifyCellReference(ref);
+        assertEquals(expectedResult, actualResult);
     }
 }