Class Result<TValue, TError>

Namespace: REslava.Result

Assembly: REslava.Result.dll

Represents the result of an operation with a typed value and a strongly-typed error. The error type is constrained to IError, enabling exhaustive error matching when combined with ErrorsOf<T1, T2> error unions.

public sealed class Result<TValue, TError> where TError : IError

Type Parameters

TValue: The type of the success value.
TError: The concrete error type. Must implement IError.

Inheritance: object

Result<TValue, TError>

Inherited Members: object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

Extension Methods: ResultTErrorBindExtensions.Bind<TIn, TOut, T1, T2>(Result<TIn, T1>, Func<TIn, Result<TOut, T2>>)

ResultTErrorEnsureExtensions.EnsureAsync<TValue, T1, T2>(Result<TValue, T1>, Func<TValue, Task<bool>>, T2)

ResultTErrorEnsureExtensions.Ensure<TValue, T1, T2>(Result<TValue, T1>, Func<TValue, bool>, T2)

ResultTErrorMapErrorExtensions.MapError<TValue, TErrorIn, TErrorOut>(Result<TValue, TErrorIn>, Func<TErrorIn, TErrorOut>)

ResultTErrorMapExtensions.Map<TIn, TOut, TError>(Result<TIn, TError>, Func<TIn, TOut>)

ResultTErrorTapExtensions.TapOnFailure<TValue, TError>(Result<TValue, TError>, Action<TError>)

ResultTErrorTapExtensions.Tap<TValue, TError>(Result<TValue, TError>, Action<TValue>)

ValidationExtensions.EnsureNotNull<TCollection>(TCollection?, string, string?)

Remarks

Unlike Result<TValue> which accumulates errors in a list, this type carries exactly one concrete error. Use with Bind to grow the error union one slot at a time, enabling compile-time exhaustive matching at the call site:

Result<Order, ValidationError> Validate(CheckoutRequest req) => ...
Result<Order, InventoryError>  ReserveInventory(Order order) => ...

// Pipeline — union grows automatically
Result<Order, ErrorsOf<ValidationError, InventoryError>>
Process(CheckoutRequest req) =>
    Validate(req).Bind(ReserveInventory);

Properties

Context

Ambient context carried through this pipeline — entity type, runtime identity, correlation, operation name, and tenant. Seeded automatically by Ok/Fail and propagated by all pipeline operators (parent-wins).

public ResultContext? Context { get; }

Property Value

ResultContext

Error

Gets the error value.

public TError Error { get; }

Property Value

TError

Exceptions

InvalidOperationException: Thrown when the result is a success. Check IsFailure first.

IsFailure

Gets a value indicating whether the operation failed.

public bool IsFailure { get; }

Property Value

bool

IsSuccess

Gets a value indicating whether the operation succeeded.

public bool IsSuccess { get; }

Property Value

bool

Value

Gets the success value.

public TValue Value { get; }

Property Value

TValue

Exceptions

InvalidOperationException: Thrown when the result is a failure. Check IsSuccess first.

Methods

Fail(TError)

Creates a failed result with the given error.

public static Result<TValue, TError> Fail(TError error)

Parameters

error TError

Returns

Result<TValue, TError>

Ok(TValue)

Creates a successful result with the given value.

public static Result<TValue, TError> Ok(TValue value)

Parameters

value TValue

Returns

Result<TValue, TError>

ToString()

Returns a string that represents the current object.

public override string ToString()

Returns

string: A string that represents the current object.

WithContext(string?, string?, string?, string?)

Returns a copy of this result with additional context values merged in. Only non-null arguments overwrite existing context fields.

public Result<TValue, TError> WithContext(string? entityId = null, string? correlationId = null, string? operationName = null, string? tenantId = null)

Parameters

entityId string
correlationId string
operationName string
tenantId string

Returns

Result<TValue, TError>