fixes and adjustments

Railway/Result.cs

@@ -45,6 +45,9 @@ public readonly partial struct Result : IEquatable<Result>
     [Pure, MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static Result Failure(string error) => Error.New(error ?? throw new ArgumentNullException(nameof(error)));
 
+    [Pure, MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static Result Failure(string type, string error) => Error.New(type, error ?? throw new ArgumentNullException(nameof(error)));
+
     [Pure, MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static Result Failure(Error error) => new(error ?? throw new ArgumentNullException(nameof(error)));
 
@@ -54,6 +57,9 @@ public readonly partial struct Result : IEquatable<Result>
     [Pure, MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static Result<T> Failure<T>(string error) => Error.New(error ?? throw new ArgumentNullException(nameof(error)));
 
+    [Pure, MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static Result<T> Failure<T>(string type, string error) => Error.New(type, error ?? throw new ArgumentNullException(nameof(error)));
+
     [Pure, MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static Result<T> Failure<T>(Error error) => new(error ?? throw new ArgumentNullException(nameof(error)));
 
@@ -76,7 +82,10 @@ public readonly partial struct Result : IEquatable<Result>
     public static explicit operator Result(SuccessUnit _) => new(null);
 
     [Pure] public bool IsSuccess => State == ResultState.Success;
-    [Pure] public bool IsFailure => State == ResultState.Error;
+
+    [Pure]
+    [MemberNotNullWhen(true, nameof(Error))]
+    public bool IsFailure => State == ResultState.Error;
 
     [Pure] public bool TryGetValue([MaybeNullWhen(false)]out SuccessUnit? u, [MaybeNullWhen(true), NotNullWhen(false)]out Error? error)
     {
@@ -97,17 +106,18 @@ public readonly partial struct Result : IEquatable<Result>
     }
     [Pure] public bool TryGetError([MaybeNullWhen(false)]out Error error)
     {
-        if (IsSuccess)
+        switch (State)
         {
-            error = default;
-            return false;
+            case ResultState.Success:
+                error = default;
+                return false;
+
+            case ResultState.Error:
+                error = Error!;
+                return true;
+
+            default: throw new ResultNotInitializedException();
         }
-        if (IsFailure)
-        {
-            error = Error!;
-            return true;
-        }
-        throw new ResultNotInitializedException();
     }
 
     [Pure] public override string ToString() => State switch
@@ -127,9 +137,12 @@ public readonly partial struct Result : IEquatable<Result>
     [Pure] public override bool Equals(object? obj) => obj is Result other && Equals(other);
     [Pure] public bool Equals(Result other)
     {
-        if (State == ResultState.Bottom || other.State == ResultState.Bottom)
+        if (State == ResultState.Bottom)
             throw new ResultNotInitializedException();
 
+        if (other.State == ResultState.Bottom)
+            throw new ResultNotInitializedException(nameof(other));
+
         return Error == other.Error;
     }
     [Pure] public static bool operator ==(Result left, Result right) => left.Equals(right);