Prelude.fs

[<AutoOpen>]
module Prelude

type AsyncResult<'T, 'TError> =
    Async<Result<'T, 'TError>>

module AsyncResult =
    let map (mapping : 'T -> 'U) (result : AsyncResult<'T, 'TError>) : AsyncResult<'U, 'TError> =
        async {
            match! result with
            | Ok value -> return Ok (mapping value)
            | Error err -> return Error err
        }

    let bind (mapping : 'T -> AsyncResult<'U, 'TError>) (result : AsyncResult<'T, 'TError>) : AsyncResult<'U, 'TError> =
        async {
            match! result with
            | Ok value -> return! mapping value
            | Error err -> return Error err
        }