Class Try<TryResult>

A Try is a container for a value or an error. It is used to handle exceptions in a functional way. A Try can be successful or a failure. A successful Try contains a value, while a failed Try contains an error. A Try can be mapped to a new Try, or the value can be extracted from the Try. If the Try is a failure, the error can be extracted or mapped to a new error. The Try can also be used to perform actions on the value, or to provide a default value if the Try is a failure. The Try can be used to chain operations together.

Example

const result = Try.of(someFunctionThatMightThrow)
 .map(value => value + 1)
 .andThen(console.log)
 .getOrElse(() => 5);

Type Parameters

  • TryResult

Constructors

constructor

Properties

error? isSuccessful value?

Methods

andThen flatMap get getCause getOrElse getOrElseThrow isFailure isSuccess map mapAsync mapFailure onFailure recoverWith failure of success

Constructors

Private constructor

Properties

Private Optional Readonly error

error?: Error

Private Readonly isSuccessful

isSuccessful: boolean

Private Optional Readonly value

value?: TryResult

Methods

andThen

  • andThen(transformer): Try<TryResult>

  • Perform an action on the embedded value, but continue with the same Try. Does not throw if the Try is a failure. If the transformer throws, the result will be a failed Try.

    Parameters

    • transformer: Transformer<TryResult, unknown>

      A function that takes the Try's value and returns nothing.

    Returns Try<TryResult>

    The original Try if it was a failure or the transformer succeeded, otherwise a new Try with the failure of the transformer.

flatMap

  • flatMap<NextTryResult>(transformer?): Try<NextTryResult>

  • Map the Try to a new Try, but flatten the result. If the Try is a failure, the new Try will be a failure.

    Type Parameters

    • NextTryResult

    Parameters

    Returns Try<NextTryResult>

    A new Try with the result of the transformer, a new Try with the error if one occured in the transformer, or the original Try if it is a failure.

get

getCause

  • getCause(): Error

  • Return the error embedded in the Try, or throw an error if the Try is a success.

    Returns Error

    The error embedded in the Try.

getOrElse

getOrElseThrow

  • getOrElseThrow(failureMapper?): TryResult

  • Return the value embedded in the Try, or throw the result of the executor if the Try is a failure.

    Parameters

    • failureMapper: ((error) => Error) = ...

      A function that takes the Try's error and returns an error.

        • (error): Error

        • Parameters

          • error: Error

          Returns Error

    Returns TryResult

    The value embedded in the Try.

isFailure

  • isFailure(): boolean

  • Check if the Try is a failure.

    Returns boolean

    true if the Try is a failure, false otherwise.

isSuccess

  • isSuccess(): boolean

  • Check if the Try is successful.

    Returns boolean

    true if the Try is successful, false otherwise.

map

mapAsync

  • mapAsync<NextTryResult>(transformer): AsyncTry<NextTryResult>

  • Map the Try to a new AsyncTry with the result of the Async Transformer. If the Try is a failure, the new AsyncTry will be a failure.

    Type Parameters

    • NextTryResult

    Parameters

    • transformer: Transformer<TryResult, Promise<NextTryResult>>

      An async function that takes the Try's value and returns a new value as a Promise.

    Returns AsyncTry<NextTryResult>

    A new AsyncTry with the result of the transformer, a new AsyncTry with the error if one occured in the transformer, or a new AsyncTry with the original failure if this is a failure.

mapFailure

  • mapFailure(failureMapper): Try<TryResult>

  • Map the embedded failure. Does nothing if the Try is a success.

    Parameters

    • failureMapper: ((error) => Error)

      A function that takes the Try's error and maps it to a new error.

        • (error): Error

        • Parameters

          • error: Error

          Returns Error

    Returns Try<TryResult>

    The original Try if it is a success, or a new Try with the mapped error.

onFailure

  • onFailure(transformer): Try<TryResult>

  • Perform an action on the Error that caused this Try to be a failure. Does nothing if the Try is a success.

    Parameters

    • transformer: Transformer<Error, unknown>

      A function that takes the Try's error and returns nothing.

    Returns Try<TryResult>

    The original Try if it was a success or the transformer succeeded, otherwise a new Try with the failure of the transformer.

recoverWith

  • recoverWith(failureMapper): Try<TryResult>

  • Map the embedded failure to a new successful Try. Does nothing if the Try is a success. If the failureMapper throws, the result will be a failed Try.

    Parameters

    • failureMapper: ((error) => TryResult)

      A function that takes the Try's error and maps it to a new successful Try.

    Returns Try<TryResult>

    The original Try if it is a success, or a new Try with the original failure mapped to a success.

Static failure

  • failure(error): Try<never>

  • Create a new failed Try with an error.

    Parameters

    • error: Error

      The error to embed in the Try.

    Returns Try<never>

    A new Try with the error.

Static of

  • of<TryResult>(executor): Try<TryResult>

  • Create a new Try by trying to execute the executor. If the executor throws an error, the Try will be a failure. If the executor returns a value, the Try will be successful and contain the return value of the executor.

    Type Parameters

    • TryResult

    Parameters

    • executor: Executor<TryResult>

      A function that might return a value or throw an error.

    Returns Try<TryResult>

    A new Try with the result of the executor, or a new Try with the error if one occured in the executor.

Static success

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