Some minor code cleanup.

Author: appel1

src/ExcelDataReader/Core/BinaryFormat/XlsBiffBlankCell.cs

@@ -36,22 +36,10 @@ internal XlsBiffBlankCell(byte[] bytes)
         /// Gets a value indicating whether the cell's record identifier is BIFF2-specific. 
         /// The shared binary layout of BIFF2 cells are different from BIFF3+.
         /// </summary>
-        public bool IsBiff2Cell
+        public bool IsBiff2Cell => Id switch
         {
-            get
-            {
-                switch (Id)
-                {
-                    case BIFFRECORDTYPE.NUMBER_OLD:
-                    case BIFFRECORDTYPE.INTEGER_OLD:
-                    case BIFFRECORDTYPE.LABEL_OLD:
-                    case BIFFRECORDTYPE.BLANK_OLD:
-                    case BIFFRECORDTYPE.BOOLERR_OLD:
-                        return true;
-                    default:
-                        return false;
-                }
-            }
-        }
+            BIFFRECORDTYPE.NUMBER_OLD or BIFFRECORDTYPE.INTEGER_OLD or BIFFRECORDTYPE.LABEL_OLD or BIFFRECORDTYPE.BLANK_OLD or BIFFRECORDTYPE.BOOLERR_OLD => true,
+            _ => false,
+        };
     }
 }

src/ExcelDataReader/Core/BinaryFormat/XlsBiffFormatString.cs

@@ -34,19 +34,11 @@ internal XlsBiffFormatString(byte[] bytes, int biffVersion)
             }
         }
 
-        public ushort Index
+        public ushort Index => Id switch
         {
-            get
-            {
-                switch (Id)
-                {
-                    case BIFFRECORDTYPE.FORMAT_V23:
-                        throw new NotSupportedException("Index is not available for BIFF2 and BIFF3 FORMAT records.");
-                    default:
-                        return ReadUInt16(0);
-                }
-            }
-        }
+            BIFFRECORDTYPE.FORMAT_V23 => throw new NotSupportedException("Index is not available for BIFF2 and BIFF3 FORMAT records."),
+            _ => ReadUInt16(0),
+        };
 
         /// <summary>
         /// Gets the string value.

src/ExcelDataReader/Core/BinaryFormat/XlsBiffMergeCells.cs

@@ -13,15 +13,15 @@ public XlsBiffMergeCells(byte[] bytes)
         {
             var count = ReadUInt16(0);
 
-            MergeCells = new List<CellRange>();
+            MergeCells = new();
             for (int i = 0; i < count; i++)
             {
                 var fromRow = ReadInt16(2 + i * 8 + 0);
                 var toRow = ReadInt16(2 + i * 8 + 2);
                 var fromCol = ReadInt16(2 + i * 8 + 4);
                 var toCol = ReadInt16(2 + i * 8 + 6);
 
-                CellRange mergeCell = new CellRange(fromCol, fromRow, toCol, toRow);
+                CellRange mergeCell = new(fromCol, fromRow, toCol, toRow);
                 MergeCells.Add(mergeCell);
             }
         }

src/ExcelDataReader/Core/BinaryFormat/XlsBiffSST.cs

@@ -9,13 +9,12 @@ namespace ExcelDataReader.Core.BinaryFormat
     /// </summary>
     internal sealed class XlsBiffSST : XlsBiffRecord
     {
-        private readonly List<IXlsString> _strings;
-        private readonly XlsSSTReader _reader = new XlsSSTReader();
+        private readonly List<IXlsString> _strings = new();
+        private readonly XlsSSTReader _reader = new();
 
         internal XlsBiffSST(byte[] bytes)
             : base(bytes)
         {
-            _strings = new List<IXlsString>();
             ReadSstStrings();
         }
 

src/ExcelDataReader/Core/BinaryFormat/XlsWorkbook.cs

@@ -17,29 +17,27 @@ internal XlsWorkbook(Stream stream, string password, Encoding fallbackEncoding)
         {
             Stream = stream;
 
-            using (var biffStream = new XlsBiffStream(stream, password: password))
-            {
-                if (biffStream.BiffVersion == 0)
-                    throw new ExcelReaderException(Errors.ErrorWorkbookGlobalsInvalidData);
+            using var biffStream = new XlsBiffStream(stream, password: password);
+            if (biffStream.BiffVersion == 0)
+                throw new ExcelReaderException(Errors.ErrorWorkbookGlobalsInvalidData);
 
-                BiffVersion = biffStream.BiffVersion;
-                SecretKey = biffStream.SecretKey;
-                Encryption = biffStream.Encryption;
-                Encoding = biffStream.BiffVersion == 8 ? Encoding.Unicode : fallbackEncoding;
+            BiffVersion = biffStream.BiffVersion;
+            SecretKey = biffStream.SecretKey;
+            Encryption = biffStream.Encryption;
+            Encoding = biffStream.BiffVersion == 8 ? Encoding.Unicode : fallbackEncoding;
 
-                if (biffStream.BiffType == BIFFTYPE.WorkbookGlobals)
-                {
-                    ReadWorkbookGlobals(biffStream);
-                }
-                else if (biffStream.BiffType == BIFFTYPE.Worksheet)
-                {
-                    // set up 'virtual' bound sheet pointing at this
-                    Sheets.Add(new XlsBiffBoundSheet(0, XlsBiffBoundSheet.SheetType.Worksheet, XlsBiffBoundSheet.SheetVisibility.Visible, "Sheet"));
-                }
-                else
-                {
-                    throw new ExcelReaderException(Errors.ErrorWorkbookGlobalsInvalidData);
-                }
+            if (biffStream.BiffType == BIFFTYPE.WorkbookGlobals)
+            {
+                ReadWorkbookGlobals(biffStream);
+            }
+            else if (biffStream.BiffType == BIFFTYPE.Worksheet)
+            {
+                // set up 'virtual' bound sheet pointing at this
+                Sheets.Add(new XlsBiffBoundSheet(0, XlsBiffBoundSheet.SheetType.Worksheet, XlsBiffBoundSheet.SheetVisibility.Visible, "Sheet"));
+            }
+            else
+            {
+                throw new ExcelReaderException(Errors.ErrorWorkbookGlobalsInvalidData);
             }
         }
 
@@ -156,7 +154,7 @@ private void ReadWorkbookGlobals(XlsBiffStream biffStream)
             var formats = new Dictionary<int, XlsBiffFormatString>();
 
             XlsBiffRecord rec;
-            while ((rec = biffStream.Read()) != null && !(rec is XlsBiffEof))
+            while ((rec = biffStream.Read()) != null && rec is not XlsBiffEof)
             {
                 switch (rec)
                 {
@@ -196,11 +194,7 @@ private void ReadWorkbookGlobals(XlsBiffStream biffStream)
                         SST = sst;
                         break;
                     case XlsBiffContinue sstContinue:
-                        if (SST != null)
-                        {
-                            SST.ReadContinueStrings(sstContinue);
-                        }
-
+                        SST?.ReadContinueStrings(sstContinue);
                         break;
                     case XlsBiffRecord _ when rec.Id == BIFFRECORDTYPE.MMS:
                         Mms = rec;
@@ -222,10 +216,7 @@ private void ReadWorkbookGlobals(XlsBiffStream biffStream)
                 }
             }
 
-            if (SST != null)
-            {
-                SST.Flush();
-            }
+            SST?.Flush();
 
             foreach (var format in formats)
             {