100% readonly fields and ReadOnlySpan

.editorconfig

@@ -0,0 +1,26 @@
+# top-most EditorConfig file
+root = true
+
+[*.cs]
+end_of_line = lf
+indent_style = space
+indent_size = 4
+
+# IDE0049: Use framework type
+dotnet_style_predefined_type_for_locals_parameters_members = true
+dotnet_style_predefined_type_for_member_access = true
+
+# IDE0008: Use explicit type
+csharp_style_var_when_type_is_apparent = true
+csharp_style_var_for_built_in_types = true
+csharp_style_var_elsewhere = true
+
+# IDE0009: Member access should be qualified.
+dotnet_style_qualification_for_method = false
+dotnet_style_qualification_for_event = false
+dotnet_style_qualification_for_field = false
+dotnet_style_qualification_for_property = false
+
+# IDE0058: Expression value is never used
+csharp_style_unused_value_expression_statement_preference = discard_variable:none
+dotnet_diagnostic.IDE0058.severity = none

Hashids.net.sln

@@ -5,46 +5,33 @@ VisualStudioVersion = 16.0.29324.140
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{A6015393-39EA-44E3-BF0A-37D2BC5CC874}"
 	ProjectSection(SolutionItems) = preProject
+		.editorconfig = .editorconfig
 		LICENSE.txt = LICENSE.txt
 		README.md = README.md
 	EndProjectSection
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Hashids.net", "src\Hashids.net\Hashids.net.csproj", "{4802CAD5-1B10-4C3F-9333-B80664A9A4FC}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Hashids.net", "src\Hashids.net\Hashids.net.csproj", "{4802CAD5-1B10-4C3F-9333-B80664A9A4FC}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Hashids.net.test", "test\Hashids.net.test\Hashids.net.test.csproj", "{3BB2139F-2788-4B8C-9A2E-9F35BFCD3EBB}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Hashids.net.test", "test\Hashids.net.test\Hashids.net.test.csproj", "{3BB2139F-2788-4B8C-9A2E-9F35BFCD3EBB}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Hashids.net.benchmark", "test\Hashids.net.benchmark\Hashids.net.benchmark.csproj", "{5A9F0EB0-FFE0-41BF-8A8D-11CD23B283B7}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Hashids.net.benchmark", "test\Hashids.net.benchmark\Hashids.net.benchmark.csproj", "{5A9F0EB0-FFE0-41BF-8A8D-11CD23B283B7}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
-		NET40|Any CPU = NET40|Any CPU
-		NET45|Any CPU = NET45|Any CPU
 		Release|Any CPU = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
 		{4802CAD5-1B10-4C3F-9333-B80664A9A4FC}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{4802CAD5-1B10-4C3F-9333-B80664A9A4FC}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{4802CAD5-1B10-4C3F-9333-B80664A9A4FC}.NET40|Any CPU.ActiveCfg = Debug|Any CPU
-		{4802CAD5-1B10-4C3F-9333-B80664A9A4FC}.NET40|Any CPU.Build.0 = Debug|Any CPU
-		{4802CAD5-1B10-4C3F-9333-B80664A9A4FC}.NET45|Any CPU.ActiveCfg = Debug|Any CPU
-		{4802CAD5-1B10-4C3F-9333-B80664A9A4FC}.NET45|Any CPU.Build.0 = Debug|Any CPU
 		{4802CAD5-1B10-4C3F-9333-B80664A9A4FC}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{4802CAD5-1B10-4C3F-9333-B80664A9A4FC}.Release|Any CPU.Build.0 = Release|Any CPU
 		{3BB2139F-2788-4B8C-9A2E-9F35BFCD3EBB}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{3BB2139F-2788-4B8C-9A2E-9F35BFCD3EBB}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{3BB2139F-2788-4B8C-9A2E-9F35BFCD3EBB}.NET40|Any CPU.ActiveCfg = Debug|Any CPU
-		{3BB2139F-2788-4B8C-9A2E-9F35BFCD3EBB}.NET40|Any CPU.Build.0 = Debug|Any CPU
-		{3BB2139F-2788-4B8C-9A2E-9F35BFCD3EBB}.NET45|Any CPU.ActiveCfg = Debug|Any CPU
-		{3BB2139F-2788-4B8C-9A2E-9F35BFCD3EBB}.NET45|Any CPU.Build.0 = Debug|Any CPU
 		{3BB2139F-2788-4B8C-9A2E-9F35BFCD3EBB}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{3BB2139F-2788-4B8C-9A2E-9F35BFCD3EBB}.Release|Any CPU.Build.0 = Release|Any CPU
 		{5A9F0EB0-FFE0-41BF-8A8D-11CD23B283B7}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{5A9F0EB0-FFE0-41BF-8A8D-11CD23B283B7}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5A9F0EB0-FFE0-41BF-8A8D-11CD23B283B7}.NET40|Any CPU.ActiveCfg = Debug|Any CPU
-		{5A9F0EB0-FFE0-41BF-8A8D-11CD23B283B7}.NET40|Any CPU.Build.0 = Debug|Any CPU
-		{5A9F0EB0-FFE0-41BF-8A8D-11CD23B283B7}.NET45|Any CPU.ActiveCfg = Debug|Any CPU
-		{5A9F0EB0-FFE0-41BF-8A8D-11CD23B283B7}.NET45|Any CPU.Build.0 = Debug|Any CPU
 		{5A9F0EB0-FFE0-41BF-8A8D-11CD23B283B7}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{5A9F0EB0-FFE0-41BF-8A8D-11CD23B283B7}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection

src/Hashids.net/ArrayExtensions.cs

@@ -1,5 +1,7 @@
-using System;
+using System;
 using System.Buffers;
+using System.Collections.Generic;
+using System.Text.RegularExpressions;
 
 namespace HashidsNet
 {
@@ -12,14 +14,22 @@ public static T[] SubArray<T>(this T[] array, int index)
 
         public static T[] SubArray<T>(this T[] array, int index, int length)
         {
+            if (index == 0 && length == array.Length) return array;
+            if (length == 0) return Array.Empty<T>();
+
             var subarray = new T[length];
             Array.Copy(array, index, subarray, 0, length);
             return subarray;
         }
 
         public static T[] Append<T>(this T[] array, T[] appendArray, int index, int length)
         {
-            var newArray = new T[array.Length + length - index];
+            if (length == 0) return array;
+
+            int newLength = array.Length + length - index;
+            if (newLength == 0) return Array.Empty<T>();
+
+            var newArray = new T[newLength];
             Array.Copy(array, 0, newArray, 0, array.Length);
             Array.Copy(appendArray, index, newArray, array.Length, length - index);
             return newArray;
@@ -44,5 +54,18 @@ public static void ReturnToPool<T>(this T[] array)
 
             ArrayPool<T>.Shared.Return(array);
         }
+
+#if NETCOREAPP3_1_OR_GREATER
+        /// <remarks>This method exists because <see cref="ReadOnlySpan{T}"/> does not implement <see cref="IEnumerable{T}"/> and using <c>.AsEnumerable()</c> will cause boxing.</remarks>
+        public static bool Any<T>(this ReadOnlySpan<T> span, Func<T,bool> predicate)
+        {
+            for(int i = 0; i < span.Length; i++)
+            {
+                if(predicate(span[i])) return true;
+            }
+
+            return false;
+        }
+#endif
     }
 }

src/Hashids.net/Hashids.Obsolete.cs

@@ -1,16 +1,15 @@
 using System;
+using System.ComponentModel;
 
 namespace HashidsNet
 {
-    /// <summary>
-    /// Generate YouTube-like hashes from one or many numbers. Use hashids when you do not want to expose your database ids to the user.
-    /// </summary>
     public partial class Hashids : IHashids
     {
         /// <summary>
         /// Encodes the provided numbers into a hash.
         /// </summary>
         [Obsolete("Use 'Encode' instead. The method was renamed to better explain what it actually does.")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
         public virtual string Encrypt(params int[] numbers)
         {
             return Encode(numbers);
@@ -20,6 +19,7 @@ public virtual string Encrypt(params int[] numbers)
         /// Encrypts the provided hex-string to a hash.
         /// </summary>
         [Obsolete("Use 'EncodeHex' instead. The method was renamed to better explain what it actually does.")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
         public virtual string EncryptHex(string hex)
         {
             return EncodeHex(hex);
@@ -29,6 +29,7 @@ public virtual string EncryptHex(string hex)
         /// Decodes the provided hash into an array of numbers.
         /// </summary>
         [Obsolete("Use 'Decode' instead. Method was renamed to better explain what it actually does.")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
         public virtual int[] Decrypt(string hash)
         {
             return Decode(hash);
@@ -38,6 +39,7 @@ public virtual int[] Decrypt(string hash)
         /// Decodes the provided hash to a hex-string.
         /// </summary>
         [Obsolete("Use 'DecodeHex' instead. The method was renamed to better explain what it actually does.")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
         public virtual string DecryptHex(string hash)
         {
             return DecodeHex(hash);