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@@ -26,160 +26,6 @@
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import Foundation
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-#if swift(>=4.3)
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-/// Result type already built-in
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-#else
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-/// A value that represents either a success or failure, capturing associated
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-/// values in both cases.
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-public enum Result<Success, Failure> {
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- /// A success, storing a `Value`.
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- case success(Success)
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-
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- /// A failure, storing an `Error`.
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- case failure(Failure)
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-
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- /// Evaluates the given transform closure when this `Result` instance is
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- /// `.success`, passing the value as a parameter.
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- ///
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- /// Use the `map` method with a closure that returns a non-`Result` value.
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- ///
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- /// - Parameter transform: A closure that takes the successful value of the
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- /// instance.
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- /// - Returns: A new `Result` instance with the result of the transform, if
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- /// it was applied.
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- public func map<NewSuccess>(
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- _ transform: (Success) -> NewSuccess
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- ) -> Result<NewSuccess, Failure> {
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- switch self {
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- case let .success(success):
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- return .success(transform(success))
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- case let .failure(failure):
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- return .failure(failure)
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- }
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- }
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-
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- /// Evaluates the given transform closure when this `Result` instance is
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- /// `.failure`, passing the error as a parameter.
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- ///
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- /// Use the `mapError` method with a closure that returns a non-`Result`
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- /// value.
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- ///
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- /// - Parameter transform: A closure that takes the failure value of the
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- /// instance.
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- /// - Returns: A new `Result` instance with the result of the transform, if
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- /// it was applied.
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- public func mapError<NewFailure>(
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- _ transform: (Failure) -> NewFailure
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- ) -> Result<Success, NewFailure> {
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- switch self {
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- case let .success(success):
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- return .success(success)
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- case let .failure(failure):
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- return .failure(transform(failure))
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- }
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- }
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-
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- /// Evaluates the given transform closure when this `Result` instance is
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- /// `.success`, passing the value as a parameter and flattening the result.
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- ///
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- /// - Parameter transform: A closure that takes the successful value of the
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- /// instance.
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- /// - Returns: A new `Result` instance, either from the transform or from
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- /// the previous error value.
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- public func flatMap<NewSuccess>(
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- _ transform: (Success) -> Result<NewSuccess, Failure>
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- ) -> Result<NewSuccess, Failure> {
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- switch self {
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- case let .success(success):
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- return transform(success)
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- case let .failure(failure):
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- return .failure(failure)
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- }
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- }
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-
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- /// Evaluates the given transform closure when this `Result` instance is
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- /// `.failure`, passing the error as a parameter and flattening the result.
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- ///
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- /// - Parameter transform: A closure that takes the error value of the
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- /// instance.
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- /// - Returns: A new `Result` instance, either from the transform or from
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- /// the previous success value.
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- public func flatMapError<NewFailure>(
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- _ transform: (Failure) -> Result<Success, NewFailure>
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- ) -> Result<Success, NewFailure> {
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- switch self {
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- case let .success(success):
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- return .success(success)
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- case let .failure(failure):
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- return transform(failure)
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- }
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- }
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-}
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-
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-extension Result where Failure: Error {
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- /// Returns the success value as a throwing expression.
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- ///
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- /// Use this method to retrieve the value of this result if it represents a
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- /// success, or to catch the value if it represents a failure.
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- ///
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- /// let integerResult: Result<Int, Error> = .success(5)
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- /// do {
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- /// let value = try integerResult.get()
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- /// print("The value is \(value).")
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- /// } catch error {
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- /// print("Error retrieving the value: \(error)")
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- /// }
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- /// // Prints "The value is 5."
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- ///
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- /// - Returns: The success value, if the instance represents a success.
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- /// - Throws: The failure value, if the instance represents a failure.
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- public func get() throws -> Success {
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- switch self {
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- case let .success(success):
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- return success
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- case let .failure(failure):
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- throw failure
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- }
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- }
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-}
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-
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-extension Result where Failure == Swift.Error {
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- /// Creates a new result by evaluating a throwing closure, capturing the
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- /// returned value as a success, or any thrown error as a failure.
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- ///
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- /// - Parameter body: A throwing closure to evaluate.
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- @_transparent
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- public init(catching body: () throws -> Success) {
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- do {
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- self = .success(try body())
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- } catch {
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- self = .failure(error)
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- }
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- }
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-}
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-
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-extension Result : Equatable where Success : Equatable, Failure: Equatable { }
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-
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-extension Result : Hashable where Success : Hashable, Failure : Hashable { }
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-
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-extension Result : CustomDebugStringConvertible {
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- public var debugDescription: String {
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- var output = "Result."
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- switch self {
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- case let .success(value):
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- output += "success("
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- debugPrint(value, terminator: "", to: &output)
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- case let .failure(error):
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- output += "failure("
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- debugPrint(error, terminator: "", to: &output)
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- }
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- output += ")"
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-
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- return output
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- }
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-}
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-#endif
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-
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// These helper methods are not public since we do not want them to be exposed or cause any conflicting.
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// However, they are just wrapper of `ResultUtil` static methods.
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extension Result where Failure: Error {
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