map2

AsyncResultOption.map2
Namespace: FsToolkit.ErrorHandling
Function Signature:
('a -> 'b -> 'c)
  -> Async<Result<'a option, 'd>>
  -> Async<Result<'b option, 'd>>
  -> Async<Result<'c option, 'd>>
Examples
Note: Many use-cases requiring map operations can also be solved using the asyncResultOption computation expression.
Example 1
Given the following functions:
getPostById : PostId -> Async<Result<Post option, exn>>
getUserById : UserId -> Async<Result<User option, exn>>
userTweet : Post -> User -> UserTweet
Then given a PostId and a UserId, we can call userTweet like this:
// Async<Result<UserTweet option, Exception>>
AsyncResultOption.map2 userTweet (getPostById postId) (getUserById userId)

map

map3

Last modified 1yr ago