Improved performance.

src/LightResults/Common/StringHelper.cs

@@ -0,0 +1,117 @@
+using System.Collections.Immutable;
+
+namespace LightResults.Common;
+
+internal static class StringHelper
+{
+    public static string GetResultString(string typeName, string successString, string informationString)
+    {
+        const string preResultStr = " { IsSuccess = ";
+        const string postResultStr = " }";
+#if NET6_0_OR_GREATER
+        var stringLength = typeName.Length + preResultStr.Length + successString.Length + informationString.Length + postResultStr.Length;
+
+        var str = string.Create(stringLength, (typeName, successString, informationString), (span, state) => { span.TryWrite($"{state.typeName}{preResultStr}{state.successString}{state.informationString}{postResultStr}", out _); });
+
+        return str;
+#else
+        return $"{typeName}{preResultStr}{successString}{informationString}{postResultStr}";
+#endif
+    }
+
+    public static string GetResultValueString<T>(T value)
+    {
+        var valueString = value?.ToString() ?? "";
+
+        const string preValueStr = ", Value = ";
+        const string charStr = "'";
+        const string stringStr = "\"";
+
+        if (value is bool || value is sbyte || value is byte || value is short || value is ushort || value is int || value is uint || value is long || value is ulong ||
+#if NET7_0_OR_GREATER
+            value is Int128 || value is UInt128 ||
+#endif
+            value is decimal || value is float || value is double)
+        {
+#if NET6_0_OR_GREATER
+            var stringLength = preValueStr.Length + valueString.Length;
+
+            var str = string.Create(stringLength, valueString, (span, state) => { span.TryWrite($"{preValueStr}{state}", out _); });
+
+            return str;
+#else
+            return $"{preValueStr}{valueString}";
+#endif
+        }
+
+        if (value is char)
+        {
+#if NET6_0_OR_GREATER
+            var stringLength = preValueStr.Length + charStr.Length + valueString.Length + charStr.Length;
+
+            var str = string.Create(stringLength, valueString, (span, state) => { span.TryWrite($"{preValueStr}{charStr}{state}{charStr}", out _); });
+
+            return str;
+#else
+            return $"{preValueStr}{charStr}{valueString}{charStr}";
+#endif
+        }
+
+        if (value is string)
+        {
+#if NET6_0_OR_GREATER
+            var stringLength = preValueStr.Length + stringStr.Length + valueString.Length + stringStr.Length;
+
+            var str = string.Create(stringLength, valueString, (span, state) => { span.TryWrite($"{preValueStr}{stringStr}{state}{stringStr}", out _); });
+
+            return str;
+#else
+            return $"{preValueStr}{stringStr}{valueString}{stringStr}";
+#endif
+        }
+
+        return "";
+    }
+
+    public static string GetResultErrorString(ImmutableArray<IError> errors)
+    {
+        if (errors[0].Message.Length <= 0)
+            return "";
+
+        var errorMessage = errors[0].Message;
+
+        const string preErrorStr = ", Error = \"";
+        const string postErrorStr = "\"";
+#if NET6_0_OR_GREATER
+        var stringLength = preErrorStr.Length + errorMessage.Length + postErrorStr.Length;
+
+        var str = string.Create(stringLength, errorMessage, (span, state) => { span.TryWrite($"{preErrorStr}{state}{postErrorStr}", out _); });
+
+        return str;
+#else
+        return $"{preErrorStr}{errorMessage}{postErrorStr}";
+#endif
+    }
+
+    public static string GetErrorString(IError error)
+    {
+        var errorType = error.GetType().Name;
+
+        if (error.Message.Length <= 0)
+            return errorType;
+
+        var errorMessage = error.Message;
+
+        const string preErrorStr = " { Message = \"";
+        const string postErrorStr = "\" }";
+#if NET6_0_OR_GREATER
+        var stringLength = errorType.Length + preErrorStr.Length + errorMessage.Length + postErrorStr.Length;
+
+        var str = string.Create(stringLength, (errorType, errorMessage), (span, state) => { span.TryWrite($"{state.errorType}{preErrorStr}{state.errorMessage}{postErrorStr}", out _); });
+
+        return str;
+#else
+        return $"{errorType}{preErrorStr}{errorMessage}{postErrorStr}";
+#endif
+    }
+}

src/LightResults/Compiler/CompilerServices.cs

@@ -0,0 +1,36 @@
+using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
+
+// ReSharper disable CheckNamespace
+
+namespace System.Runtime.CompilerServices
+{
+    [ExcludeFromCodeCoverage]
+    [DebuggerNonUserCode]
+    internal static class IsExternalInit;
+
+    [ExcludeFromCodeCoverage]
+    [DebuggerNonUserCode]
+    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Field | AttributeTargets.Property, Inherited = false)]
+    internal sealed class RequiredMemberAttribute : Attribute;
+
+    [ExcludeFromCodeCoverage]
+    [DebuggerNonUserCode]
+    [AttributeUsage(AttributeTargets.All, AllowMultiple = true, Inherited = false)]
+    internal sealed class CompilerFeatureRequiredAttribute(string featureName) : Attribute
+    {
+        public const string RefStructs = nameof(RefStructs);
+        public const string RequiredMembers = nameof(RequiredMembers);
+        public string FeatureName { get; } = featureName;
+
+        public bool IsOptional { get; init; }
+    }
+}
+
+namespace System.Diagnostics.CodeAnalysis
+{
+    [ExcludeFromCodeCoverage]
+    [DebuggerNonUserCode]
+    [AttributeUsage(AttributeTargets.Constructor)]
+    internal sealed class SetsRequiredMembersAttribute : Attribute;
+}

src/LightResults/Error.cs

@@ -3,8 +3,9 @@
 
 #else
 using System.Collections.Immutable;
-
 #endif
+using LightResults.Common;
+
 namespace LightResults;
 
 /// <summary>Represents an error with a message and associated metadata.</summary>
@@ -86,9 +87,6 @@ public Error(string message, IDictionary<string, object> metadata)
     /// <inheritdoc />
     public override string ToString()
     {
-        if (Message.Length > 0)
-            return Message;
-
-        return base.ToString() ?? "";
+        return StringHelper.GetErrorString(this);
     }
-}
+}

src/LightResults/IResult.cs

@@ -13,7 +13,12 @@ public interface IResult
 
     /// <summary>Gets a collection of errors associated with the result.</summary>
     /// <returns>An <see cref="IReadOnlyCollection{T}" /> of <see cref="IError" /> representing the errors.</returns>
-    IReadOnlyList<IError> Errors { get; }
+    IReadOnlyCollection<IError> Errors { get; }
+
+    /// <summary>Gets the error of the result, throwing an exception if the result is successful.</summary>
+    /// <returns>The error of the result.</returns>
+    /// <exception cref="InvalidOperationException">Thrown when attempting to get or set the value of a failed result.</exception>
+    IError Error { get; }
 
     /// <summary>Checks if the result contains an error of the specific type.</summary>
     /// <typeparam name="TError">The type of error to check for.</typeparam>
@@ -25,6 +30,7 @@ public interface IResult
 public interface IResult<out TValue> : IResult
 {
     /// <summary>Gets the value of the result, throwing an exception if the result is failed.</summary>
+    /// <returns>The value of the result.</returns>
     /// <exception cref="InvalidOperationException">Thrown when attempting to get or set the value of a failed result.</exception>
     public TValue Value { get; }
-}
+}