Natural compared case order

chrisg32 · Jan 3, 2019 · 73c7731 · 73c7731
1 parent 84dbd17
commit 73c7731
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Showing 4 changed files with 34 additions and 7 deletions.
diff --git a/Commons.Test/Util/NaturalComparerTests.cs b/Commons.Test/Util/NaturalComparerTests.cs
@@ -21,7 +21,8 @@ public enum ComparerEquality
         [InlineData("a", "b", ComparerEquality.LessThan)]
         [InlineData("b", "a", ComparerEquality.GreaterThan)]
         [InlineData("a", "a", ComparerEquality.Equal)]
-        [InlineData("a", "A", ComparerEquality.GreaterThan)]
+        [InlineData("a", "A", ComparerEquality.GreaterThan, NaturalComparerOptions.LowercaseFirst)]
+        [InlineData("A", "a", ComparerEquality.GreaterThan)]
         //single number & character
         [InlineData("4", "a", ComparerEquality.LessThan)]
         [InlineData("a", "4", ComparerEquality.GreaterThan)]
@@ -72,6 +73,8 @@ public enum ComparerEquality
         [InlineData("aa", " aa", ComparerEquality.Equal, NaturalComparerOptions.IgnoreWhiteSpace)]
         [InlineData("aa ", " aa", ComparerEquality.Equal, NaturalComparerOptions.IgnoreWhiteSpace)]
         [InlineData("aa", " a\ta", ComparerEquality.Equal, NaturalComparerOptions.IgnoreWhiteSpace)]
+        //capitalization order
+        [InlineData("added4", "Added11", ComparerEquality.LessThan)]
         public void TestCompare(string left, string right, ComparerEquality expectedResult, NaturalComparerOptions options = NaturalComparerOptions.None)
         {
             var comparer = new NaturalComparer(options);

diff --git a/Commons/Commons.csproj b/Commons/Commons.csproj
@@ -6,7 +6,7 @@
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
     <Description>A collection of useful C# utilities, extensions, and data structures.</Description>
     <Authors>Chris Gonzales</Authors>
-    <Version>1.0.2</Version>
+    <Version>1.0.3</Version>
     <PackageTags>Commons C# DataStructures Dictionary Extensions</PackageTags>
     <Copyright>Copyright 2019 Chris Gonzales</Copyright>
     <PackageIconUrl>https://chrisg32.github.io/assets/cg_logo.png</PackageIconUrl>

diff --git a/Commons/Util/NaturalComparer.cs b/Commons/Util/NaturalComparer.cs
@@ -1,7 +1,6 @@
 using System.Collections.Generic;
 using System.Text;
 using System.Text.RegularExpressions;
-using CG.Commons.Extensions;
 
 namespace CG.Commons.Util
 {
@@ -10,12 +9,14 @@ public class NaturalComparer : IComparer<string>
         private readonly bool _ignoreCase;
         private readonly bool _ignoreWhitespace;
         private readonly bool _checkTrailingDecimalLength;
+        private readonly bool _lowercaseFirst;
 
         public NaturalComparer(NaturalComparerOptions options = NaturalComparerOptions.None)
         {
             _ignoreCase = options.HasFlag(NaturalComparerOptions.IgnoreCase);
             _ignoreWhitespace = options.HasFlag(NaturalComparerOptions.IgnoreWhiteSpace);
             _checkTrailingDecimalLength = options.HasFlag(NaturalComparerOptions.CheckTrailingDecimalLength);
+            _lowercaseFirst = options.HasFlag(NaturalComparerOptions.LowercaseFirst);
         }
 
         //less than zero = x is less than y
@@ -27,7 +28,7 @@ public NaturalComparer(NaturalComparerOptions options = NaturalComparerOptions.N
         /// </summary>
         /// <param name="left">The left string to compare.</param>
         /// <param name="right">The right string to compare.</param>
-        /// <returns>If the right string is less than the left the return value will be less than zero.
+        /// <returns>If the left string is less than the right the return value will be less than zero.
         ///  If the left string is greater than the right than a value greater than zero is returned.
         ///  If the left string is equal to the right string zero is returned.</returns>
         public int Compare(string left, string right)
@@ -95,13 +96,35 @@ public int Compare(string left, string right)
                 if (yIsNum) return 1;
 
                 //both characters are not numeric so we simply compare
-                var cresult = xchar.CompareTo(ychar);
+                var cresult = CapitalOrderComparison(xchar, ychar);
                 if (cresult != 0) return cresult;
             }
 
         }
 
-        private string GetNumericString(IReadOnlyList<char> source, ref int index)
+        private int CapitalOrderComparison(char x, char y)
+        {
+            var result = x.CompareTo(y);
+            if (result == 0) return result;
+            if (char.IsLetter(x) && char.IsLetter(y))
+            {
+                result = char.ToLowerInvariant(x).CompareTo(char.ToLowerInvariant(y));
+                if (result != 0) return result;
+                if (_lowercaseFirst)
+                {
+                    if (!char.IsLower(x) && char.IsLower(y)) return -1;
+                    if (char.IsLower(x) && !char.IsLower(y)) return 1;
+                }
+                else
+                {
+                    if (!char.IsLower(x) && char.IsLower(y)) return 1;
+                    if (char.IsLower(x) && !char.IsLower(y)) return -1;
+                }
+            }
+            return result;
+        }
+
+        private static string GetNumericString(IReadOnlyList<char> source, ref int index)
         {
             var sb = new StringBuilder();
             while (index < source.Count && (char.IsDigit(source[index]) || source[index] == '.'))

diff --git a/Commons/Util/NaturalComparerOptions.cs b/Commons/Util/NaturalComparerOptions.cs
@@ -8,6 +8,7 @@ public enum NaturalComparerOptions
         None,
         IgnoreCase,
         IgnoreWhiteSpace,
-        CheckTrailingDecimalLength
+        CheckTrailingDecimalLength,
+        LowercaseFirst
     }
 }