foldResult

AsyncResult.foldResult

Namespace: FsToolkit.ErrorHandling

Function Signature:

('a -> 'b) -> ('c -> 'b) -> Async<Result<'a, 'c>> -> Async<'b>

This is just a shortcut for Async.map Result.fold. See Result.fold for more.

Examples

Example 1

type HttpResponse<'a, 'b> =
  | Ok of 'a
  | InternalError of 'b

// CreatePostRequest -> Async<Result<PostId, exn>>
let createPost (req : CreatePostRequest) = async {
  // ...
}

// Async<HttpResponse>
let handler (httpReq : HttpRequest) = 
  // ... 
  
  // Async<Result<PostId, exn>>
  let createPostAR = createPost httpReq

  createPostAR
  |> AsyncResult.fold Ok InternalError