getOrReraise

AsyncResult.getOrReraise

Namespace: FsToolkit.ErrorHandling

Unwraps the Ok value from an async result. If the result is Error, the contained exception is re-raised, preserving the original stack trace (on .NET; on Fable it is raised directly).

This function is only applicable when the error type is exn.

Function Signature:

Async<Result<'ok, exn>> -> Async<'ok>

Examples

Example 1

Unwrapping a successful result:

let result : Async<int> =
  AsyncResult.ok 42
  |> AsyncResult.getOrReraise
// evaluates to 42

Example 2

Re-raising an exception from a failing async computation:

let value : Async<string> =
  AsyncResult.ofTask (System.Threading.Tasks.Task.FromException<string>(System.Exception("oops")))
  |> AsyncResult.getOrReraise
// raises System.Exception "oops"

Example 3

Using catch together with getOrReraise to control which exceptions become errors:

let run () : Async<int> =
  riskyOperation ()
  |> AsyncResult.catch id
  |> AsyncResult.getOrReraise