1.3.0

DynamicEnums/DynamicEnum.cs

@@ -4,6 +4,7 @@ using System.Globalization;
 using System.Linq;
 using System.Numerics;
 using System.Reflection;
+using System.Text;
 
 #if NET6_0_OR_GREATER
 using System.Diagnostics.CodeAnalysis;
@@ -29,13 +30,22 @@ namespace DynamicEnums {
     /// </remarks>
     public abstract class DynamicEnum {
 
+        private const BindingFlags ConstructorFlags = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic;
+        private static readonly Type[] ConstructorTypes = {typeof(string), typeof(BigInteger), typeof(bool)};
         private static readonly Dictionary<Type, Storage> Storages = new Dictionary<Type, Storage>();
-        private readonly BigInteger value;
 
         private Dictionary<DynamicEnum, bool> allFlagsCache;
         private Dictionary<DynamicEnum, bool> anyFlagsCache;
+        private BigInteger value;
         private string name;
 
+        /// <summary>
+        /// Creates a new dynamic enum instance.
+        /// This constructor is protected as it is only invoked via reflection.
+        /// This constructor is only called if the class doesn't have the <see cref="DynamicEnum(string,BigInteger,bool)"/> constructor.
+        /// </summary>
+        protected DynamicEnum() {}
+
         /// <summary>
         /// Creates a new dynamic enum instance.
         /// This constructor is protected as it is only invoked via reflection.
@@ -44,8 +54,8 @@ namespace DynamicEnums {
         /// <param name="value">The value</param>
         /// <param name="defined">Whether this enum value <see cref="IsDefined(DynamicEnum)"/>, and thus, not a combined flag.</param>
         protected DynamicEnum(string name, BigInteger value, bool defined) {
-            this.value = value;
             this.name = name;
+            this.value = value;
         }
 
         /// <summary>
@@ -84,17 +94,32 @@ namespace DynamicEnums {
         /// <summary>Returns a string that represents the current object.</summary>
         /// <returns>A string that represents the current object.</returns>
         public override string ToString() {
-            if (this.name == null) {
+            if (this.name != null)
-                var included = new List<DynamicEnum>();
-                if (DynamicEnum.GetValue(this) != 0) {
-                    foreach (var v in DynamicEnum.GetValues(this.GetType())) {
-                        if (this.HasAllFlags(v) && DynamicEnum.GetValue(v) != 0)
-                            included.Add(v);
-                    }
-                }
-                this.name = included.Count > 0 ? string.Join(" | ", included) : DynamicEnum.GetValue(this).ToString();
-            }
                 return this.name;
+
+            var storage = DynamicEnum.GetStorage(this.GetType());
+            if (!storage.CombinedNameCache.TryGetValue(this, out var combinedName)) {
+                // Enum ToString remarks: https://learn.microsoft.com/en-us/dotnet/api/system.enum.tostring
+                // If the FlagsAttribute is not applied to this enumerated type and there is a named constant equal to the value of this instance, then the return value is a string containing the name of the constant.
+                // If the FlagsAttribute is applied and there is a combination of one or more named constants equal to the value of this instance, then the return value is a string containing a delimiter-separated list of the names of the constants.
+                // Otherwise, the return value is the string representation of the numeric value of this instance.
+                var included = new StringBuilder();
+                var remain = DynamicEnum.GetValue(this);
+                foreach (var other in storage.Values.Values) {
+                    if (this.HasAllFlags(other)) {
+                        var otherValue = DynamicEnum.GetValue(other);
+                        if (otherValue != 0) {
+                            if (included.Length > 0)
+                                included.Append(" | ");
+                            included.Append(other);
+                            remain &= ~otherValue;
+                        }
+                    }
+                }
+                combinedName = included.Length > 0 && remain == 0 ? included.ToString() : DynamicEnum.GetValue(this).ToString();
+                storage.CombinedNameCache.Add(this, combinedName);
+            }
+            return combinedName;
         }
 
         /// <summary>
@@ -433,7 +458,17 @@ namespace DynamicEnums {
             [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors | DynamicallyAccessedMemberTypes.NonPublicConstructors)]
 #endif
             Type type, string name, BigInteger value, bool defined) {
-            return (DynamicEnum) Activator.CreateInstance(type, BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic, null, new object[] {name, value, defined}, CultureInfo.InvariantCulture);
+            // try to call the constructor with parameters first
+            var parameterConstructor = type.GetConstructor(DynamicEnum.ConstructorFlags, null, DynamicEnum.ConstructorTypes, null);
+            if (parameterConstructor != null)
+                return (DynamicEnum) parameterConstructor.Invoke(DynamicEnum.ConstructorFlags, null, new object[] {name, value, defined}, CultureInfo.InvariantCulture);
+
+            // default to the empty constructor and set the values manually
+            var emptyConstructor = type.GetConstructor(DynamicEnum.ConstructorFlags, null, Type.EmptyTypes, null);
+            var ret = (DynamicEnum) emptyConstructor.Invoke(DynamicEnum.ConstructorFlags, null, null, CultureInfo.InvariantCulture);
+            ret.name = name;
+            ret.value = value;
+            return ret;
         }
 
         private class Storage {
@@ -445,6 +480,7 @@ namespace DynamicEnums {
             public readonly Dictionary<(DynamicEnum, DynamicEnum), DynamicEnum> AndCache = new Dictionary<(DynamicEnum, DynamicEnum), DynamicEnum>();
             public readonly Dictionary<(DynamicEnum, DynamicEnum), DynamicEnum> XorCache = new Dictionary<(DynamicEnum, DynamicEnum), DynamicEnum>();
             public readonly Dictionary<DynamicEnum, DynamicEnum> NegCache = new Dictionary<DynamicEnum, DynamicEnum>();
+            public readonly Dictionary<DynamicEnum, string> CombinedNameCache = new Dictionary<DynamicEnum, string>();
 
             public void ClearCaches() {
                 this.FlagCache.Clear();
@@ -453,6 +489,7 @@ namespace DynamicEnums {
                 this.AndCache.Clear();
                 this.XorCache.Clear();
                 this.NegCache.Clear();
+                this.CombinedNameCache.Clear();
             }
 
         }

DynamicEnums/DynamicEnums.csproj

@@ -13,7 +13,7 @@
         <RepositoryUrl>https://github.com/Ellpeck/DynamicEnums</RepositoryUrl>
         <PackageLicenseExpression>MIT</PackageLicenseExpression>
         <PackageReadmeFile>README.md</PackageReadmeFile>
-        <VersionPrefix>1.2.0</VersionPrefix>
+        <VersionPrefix>1.3.0</VersionPrefix>
     </PropertyGroup>
 
     <ItemGroup>

README.md

@@ -19,9 +19,6 @@ public class MyEnum : DynamicEnum {
     public static readonly MyEnum FlagTwo = DynamicEnum.AddFlag<MyEnum>("FlagTwo");
     public static readonly MyEnum FlagThree = DynamicEnum.AddFlag<MyEnum>("FlagThree");
  
-    // this constructor is called internally using reflection
-    public MyEnum(string name, BigInteger value) : base(name, value) {}
-
     // you can optionally create operator overloads for easier operations
     public static implicit operator BigInteger(MyEnum value) => DynamicEnum.GetValue(value);
     public static implicit operator MyEnum(BigInteger value) => DynamicEnum.GetEnumValue<MyEnum>(value);

Tests/EnumTests.cs

@@ -32,8 +32,12 @@ public class EnumTests {
         var flags = new TestDynamicEnum[100];
         for (var i = 0; i < flags.Length; i++)
             flags[i] = DynamicEnum.AddFlag<TestDynamicEnum>("Flag" + i);
+        var zero = DynamicEnum.Add<TestDynamicEnum>("Zero", 0);
         var combined = DynamicEnum.Add<TestDynamicEnum>("Combined", DynamicEnum.GetValue(DynamicEnum.Or(flags[7], flags[13])));
 
+        DynamicEnum.Add<TestEnumWithConstructor>("Test", 10);
+        Assert.AreEqual(DynamicEnum.GetEnumValue<TestEnumWithConstructor>(10).ToString(), "TestModified");
+
         Assert.AreEqual(DynamicEnum.GetValue(flags[7]), BigInteger.One << 7);
         Assert.AreEqual(DynamicEnum.GetEnumValue<TestDynamicEnum>(BigInteger.One << 75), flags[75]);
 
@@ -53,8 +57,13 @@ public class EnumTests {
 
         Assert.AreEqual(DynamicEnum.Parse<TestDynamicEnum>("Flag24"), flags[24]);
         Assert.AreEqual(DynamicEnum.Parse<TestDynamicEnum>("Flag24 | Flag43"), DynamicEnum.Or(flags[24], flags[43]));
+
         Assert.AreEqual(flags[24].ToString(), "Flag24");
+        Assert.AreEqual(zero.ToString(), "Zero");
+        Assert.AreEqual(DynamicEnum.GetEnumValue<TestDynamicEnum>(0).ToString(), "Zero");
         Assert.AreEqual(DynamicEnum.Or(flags[24], flags[43]).ToString(), "Flag24 | Flag43");
+        Assert.AreEqual(DynamicEnum.Or(flags[24], DynamicEnum.GetEnumValue<TestDynamicEnum>(new BigInteger(1) << 99)).ToString(), "Flag24 | Flag99");
+        Assert.AreEqual(DynamicEnum.Or(flags[24], DynamicEnum.GetEnumValue<TestDynamicEnum>(new BigInteger(1) << 101)).ToString(), (DynamicEnum.GetValue(flags[24]) | new BigInteger(1) << 101).ToString());
 
         Assert.True(DynamicEnum.IsDefined(flags[27]));
         Assert.True(DynamicEnum.IsDefined(combined));
@@ -63,7 +72,7 @@ public class EnumTests {
 
         Assert.AreEqual(
             new[] {flags[0], flags[7], flags[13], combined},
-            DynamicEnum.GetFlags(DynamicEnum.Or(DynamicEnum.Or(flags[0], flags[13]), flags[7])));
+            DynamicEnum.GetFlags(DynamicEnum.Or(DynamicEnum.Or(flags[0], flags[13]), flags[7]), false));
 
         Assert.AreEqual(
             new[] {flags[0], flags[7], flags[13]},
@@ -84,9 +93,11 @@ public class EnumTests {
 
     }
 
-    private class TestDynamicEnum : DynamicEnum {
+    private class TestDynamicEnum : DynamicEnum;
 
-        public TestDynamicEnum(string name, BigInteger value, bool defined) : base(name, value, defined) {}
+    private class TestEnumWithConstructor : DynamicEnum {
+
+        public TestEnumWithConstructor(string name, BigInteger value, bool defined) : base($"{name}Modified", value, defined) {}
 
     }