Choice Combining Result CE

ResultChoiceCE.fs

type ResultBuilder () =

  member inline _.Return (x) = Ok x

  member inline _.Bind(x,f) =
    match x with
    | Ok x -> f x
    | Error e -> Error <| e


  member inline _.Bind(x: Result<_,_>,f: 'a -> Result<_,_>) =
    match x with
    | Ok x ->
      match f x with
      | Ok x -> Ok x
      | Error (Choice1Of7 e) -> Choice1Of7 e  |> Error
      | Error (Choice2Of7 e) -> Choice2Of7 e  |> Error
      | Error (Choice3Of7 e) -> Choice3Of7 e  |> Error
      | Error (Choice4Of7 e) -> Choice4Of7 e  |> Error
      | Error (Choice5Of7 e) -> Choice5Of7 e  |> Error
      | Error (Choice6Of7 e) -> Choice6Of7 e  |> Error
      | Error (Choice7Of7 e) -> Choice7Of7 e  |> Error
    | Error (e) -> Error <| Choice7Of7 e
  member inline _.Bind(x: Result<_,_>,f: 'a -> Result<_,_>) =
    match x with
    | Ok x ->
      match f x with
      | Ok x -> Ok x
      | Error (Choice1Of7 e) -> Choice1Of7 e  |> Error
      | Error (Choice2Of7 e) -> Choice2Of7 e  |> Error
      | Error (Choice3Of7 e) -> Choice3Of7 e  |> Error
      | Error (Choice4Of7 e) -> Choice4Of7 e  |> Error
      | Error (Choice5Of7 e) -> Choice5Of7 e  |> Error
      | Error (Choice6Of7 e) -> Choice6Of7 e  |> Error
      | Error (Choice7Of7 e) -> Choice7Of7 e  |> Error
    | Error (e) -> Error <| Choice6Of7 e
  member inline _.Bind(x: Result<_,_>,f: 'a -> Result<_,_>) =
    match x with
    | Ok x ->
      match f x with
      | Ok x -> Ok x
      | Error (Choice1Of7 e) -> Choice1Of7 e  |> Error
      | Error (Choice2Of7 e) -> Choice2Of7 e  |> Error
      | Error (Choice3Of7 e) -> Choice3Of7 e  |> Error
      | Error (Choice4Of7 e) -> Choice4Of7 e  |> Error
      | Error (Choice5Of7 e) -> Choice5Of7 e  |> Error
      | Error (Choice6Of7 e) -> Choice6Of7 e  |> Error
      | Error (Choice7Of7 e) -> Choice7Of7 e  |> Error
    | Error (e) -> Error <| Choice5Of7 e
  member inline _.Bind(x: Result<_,_>,f: 'a -> Result<_,_>) =
    match x with
    | Ok x ->
      match f x with
      | Ok x -> Ok x
      | Error (Choice1Of7 e) -> Choice1Of7 e  |> Error
      | Error (Choice2Of7 e) -> Choice2Of7 e  |> Error
      | Error (Choice3Of7 e) -> Choice3Of7 e  |> Error
      | Error (Choice4Of7 e) -> Choice4Of7 e  |> Error
      | Error (Choice5Of7 e) -> Choice5Of7 e  |> Error
      | Error (Choice6Of7 e) -> Choice6Of7 e  |> Error
      | Error (Choice7Of7 e) -> Choice7Of7 e  |> Error
    | Error (e) -> Error <| Choice4Of7 e
  member inline _.Bind(x: Result<_,_>,f: 'a -> Result<_,_>) =
    match x with
    | Ok x ->
      match f x with
      | Ok x -> Ok x
      | Error (Choice1Of7 e) -> Choice1Of7 e  |> Error
      | Error (Choice2Of7 e) -> Choice2Of7 e  |> Error
      | Error (Choice3Of7 e) -> Choice3Of7 e  |> Error
      | Error (Choice4Of7 e) -> Choice4Of7 e  |> Error
      | Error (Choice5Of7 e) -> Choice5Of7 e  |> Error
      | Error (Choice6Of7 e) -> Choice6Of7 e  |> Error
      | Error (Choice7Of7 e) -> Choice7Of7 e  |> Error
    | Error (e) -> Error <| Choice3Of7 e
  member inline _.Bind(x: Result<_,_>,f: 'a -> Result<_,_>) =
    match x with
    | Ok x ->
      match f x with
      | Ok x -> Ok x
      | Error (Choice1Of7 e) -> Choice1Of7 e  |> Error
      | Error (Choice2Of7 e) -> Choice2Of7 e  |> Error
      | Error (Choice3Of7 e) -> Choice3Of7 e  |> Error
      | Error (Choice4Of7 e) -> Choice4Of7 e  |> Error
      | Error (Choice5Of7 e) -> Choice5Of7 e  |> Error
      | Error (Choice6Of7 e) -> Choice6Of7 e  |> Error
      | Error (Choice7Of7 e) -> Choice7Of7 e  |> Error
    | Error (e) -> Error <| Choice2Of7 e
  member inline _.Bind(x: Result<_,_>,f: 'a -> Result<_,_>) =
    match x with
    | Ok x ->
      match f x with
      | Ok x -> Ok x
      | Error (Choice1Of7 e) -> Choice1Of7 e  |> Error
      | Error (Choice2Of7 e) -> Choice2Of7 e  |> Error
      | Error (Choice3Of7 e) -> Choice3Of7 e  |> Error
      | Error (Choice4Of7 e) -> Choice4Of7 e  |> Error
      | Error (Choice5Of7 e) -> Choice5Of7 e  |> Error
      | Error (Choice6Of7 e) -> Choice6Of7 e  |> Error
      | Error (Choice7Of7 e) -> Choice7Of7 e  |> Error
    | Error (e) -> Error <| Choice1Of7 e


    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of6 e) -> Error <| Choice1Of6 e
        | Error (Choice2Of6 e) -> Error <| Choice2Of6 e
        | Error (Choice3Of6 e) -> Error <| Choice3Of6 e
        | Error (Choice4Of6 e) -> Error <| Choice4Of6 e
        | Error (Choice5Of6 e) -> Error <| Choice5Of6 e
        | Error (Choice6Of6 e) -> Error <| Choice6Of6 e
      | Error (e) -> Error <| Choice6Of6 e
    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of6 e) -> Error <| Choice1Of6 e
        | Error (Choice2Of6 e) -> Error <| Choice2Of6 e
        | Error (Choice3Of6 e) -> Error <| Choice3Of6 e
        | Error (Choice4Of6 e) -> Error <| Choice4Of6 e
        | Error (Choice5Of6 e) -> Error <| Choice5Of6 e
        | Error (Choice6Of6 e) -> Error <| Choice6Of6 e
      | Error (e) -> Error <| Choice5Of6 e
    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of6 e) -> Error <| Choice1Of6 e
        | Error (Choice2Of6 e) -> Error <| Choice2Of6 e
        | Error (Choice3Of6 e) -> Error <| Choice3Of6 e
        | Error (Choice4Of6 e) -> Error <| Choice4Of6 e
        | Error (Choice5Of6 e) -> Error <| Choice5Of6 e
        | Error (Choice6Of6 e) -> Error <| Choice6Of6 e
      | Error (e) -> Error <| Choice4Of6 e
    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of6 e) -> Error <| Choice1Of6 e
        | Error (Choice2Of6 e) -> Error <| Choice2Of6 e
        | Error (Choice3Of6 e) -> Error <| Choice3Of6 e
        | Error (Choice4Of6 e) -> Error <| Choice4Of6 e
        | Error (Choice5Of6 e) -> Error <| Choice5Of6 e
        | Error (Choice6Of6 e) -> Error <| Choice6Of6 e
      | Error (e) -> Error <| Choice3Of6 e
    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of6 e) -> Error <| Choice1Of6 e
        | Error (Choice2Of6 e) -> Error <| Choice2Of6 e
        | Error (Choice3Of6 e) -> Error <| Choice3Of6 e
        | Error (Choice4Of6 e) -> Error <| Choice4Of6 e
        | Error (Choice5Of6 e) -> Error <| Choice5Of6 e
        | Error (Choice6Of6 e) -> Error <| Choice6Of6 e
      | Error (e) -> Error <| Choice2Of6 e
    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of6 e) -> Error <| Choice1Of6 e
        | Error (Choice2Of6 e) -> Error <| Choice2Of6 e
        | Error (Choice3Of6 e) -> Error <| Choice3Of6 e
        | Error (Choice4Of6 e) -> Error <| Choice4Of6 e
        | Error (Choice5Of6 e) -> Error <| Choice5Of6 e
        | Error (Choice6Of6 e) -> Error <| Choice6Of6 e
      | Error (e) -> Error <| Choice1Of6 e


    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of5 e) -> Error <| Choice1Of5 e
        | Error (Choice2Of5 e) -> Error <| Choice2Of5 e
        | Error (Choice3Of5 e) -> Error <| Choice3Of5 e
        | Error (Choice4Of5 e) -> Error <| Choice4Of5 e
        | Error (Choice5Of5 e) -> Error <| Choice5Of5 e
      | Error (e) -> Error <| Choice5Of5 e
    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of5 e) -> Error <| Choice1Of5 e
        | Error (Choice2Of5 e) -> Error <| Choice2Of5 e
        | Error (Choice3Of5 e) -> Error <| Choice3Of5 e
        | Error (Choice4Of5 e) -> Error <| Choice4Of5 e
        | Error (Choice5Of5 e) -> Error <| Choice5Of5 e
      | Error (e) -> Error <| Choice4Of5 e
    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of5 e) -> Error <| Choice1Of5 e
        | Error (Choice2Of5 e) -> Error <| Choice2Of5 e
        | Error (Choice3Of5 e) -> Error <| Choice3Of5 e
        | Error (Choice4Of5 e) -> Error <| Choice4Of5 e
        | Error (Choice5Of5 e) -> Error <| Choice5Of5 e
      | Error (e) -> Error <| Choice3Of5 e
    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of5 e) -> Error <| Choice1Of5 e
        | Error (Choice2Of5 e) -> Error <| Choice2Of5 e
        | Error (Choice3Of5 e) -> Error <| Choice3Of5 e
        | Error (Choice4Of5 e) -> Error <| Choice4Of5 e
        | Error (Choice5Of5 e) -> Error <| Choice5Of5 e
      | Error (e) -> Error <| Choice2Of5 e

    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of5 e) -> Error <| Choice1Of5 e
        | Error (Choice2Of5 e) -> Error <| Choice2Of5 e
        | Error (Choice3Of5 e) -> Error <| Choice3Of5 e
        | Error (Choice4Of5 e) -> Error <| Choice4Of5 e
        | Error (Choice5Of5 e) -> Error <| Choice5Of5 e
      | Error (e) -> Error <| Choice1Of5 e




    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of4 e) -> Error <| Choice1Of4 e
        | Error (Choice2Of4 e) -> Error <| Choice2Of4 e
        | Error (Choice3Of4 e) -> Error <| Choice3Of4 e
        | Error (Choice4Of4 e) -> Error <| Choice4Of4 e
      | Error (e) -> Error <| Choice4Of4 e
    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of4 e) -> Error <| Choice1Of4 e
        | Error (Choice2Of4 e) -> Error <| Choice2Of4 e
        | Error (Choice3Of4 e) -> Error <| Choice3Of4 e
        | Error (Choice4Of4 e) -> Error <| Choice4Of4 e
      | Error (e) -> Error <| Choice3Of4 e
    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of4 e) -> Error <| Choice1Of4 e
        | Error (Choice2Of4 e) -> Error <| Choice2Of4 e
        | Error (Choice3Of4 e) -> Error <| Choice3Of4 e
        | Error (Choice4Of4 e) -> Error <| Choice4Of4 e
      | Error (e) -> Error <| Choice2Of4 e

    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of4 e) -> Error <| Choice1Of4 e
        | Error (Choice2Of4 e) -> Error <| Choice2Of4 e
        | Error (Choice3Of4 e) -> Error <| Choice3Of4 e
        | Error (Choice4Of4 e) -> Error <| Choice4Of4 e
      | Error (e) -> Error <| Choice1Of4 e


    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of3 e) -> Error <| Choice1Of3 e
        | Error (Choice2Of3 e) -> Error <| Choice2Of3 e
        | Error (Choice3Of3 e) -> Error <| Choice3Of3 e
      | Error (e) -> Error <| Choice1Of3 e


    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of3 e) -> Error <| Choice1Of3 e
        | Error (Choice2Of3 e) -> Error <| Choice2Of3 e
        | Error (Choice3Of3 e) -> Error <| Choice3Of3 e
      | Error (e) -> Error <| Choice2Of3 e


    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of3 e) -> Error <| Choice1Of3 e
        | Error (Choice2Of3 e) -> Error <| Choice2Of3 e
        | Error (Choice3Of3 e) -> Error <| Choice3Of3 e
      | Error (e) -> Error <| Choice3Of3 e


  member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
    match x with
    | Ok x ->
      match f x with
      | Ok x -> Ok x
      | Error (Choice1Of2 e) -> Error <| Choice1Of2 e
      | Error (Choice2Of2 e) -> Error <| Choice2Of2 e
    | Error (e) -> Error <| Choice1Of2 e


  member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
    match x with
    | Ok x ->
      match f x with
      | Ok x -> Ok x
      | Error (Choice1Of2 e) -> Error <| Choice1Of2 e
      | Error (Choice2Of2 e) -> Error <| Choice2Of2 e
    | Error (e) -> Error <| Choice2Of2 e


  member _.BindReturn(x, f) =
    match x with
    | Ok x -> Ok (f x)
    | Error e -> Error e
let result = ResultBuilder()

[<AutoOpen>]
module ResultBuilderExtensions =
  type ResultBuilder with

    member inline _.Bind(x: Result<'a,'b>,f: 'a -> Result<'d,'e>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error e -> Error <| Choice2Of2 e
      | Error (e) -> Error <| Choice1Of2 e


[<AutoOpen>]
module ResultBuilderExtensions2 =
  type ResultBuilder with

    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of2 e) -> Error <| Choice2Of3 e
        | Error (Choice2Of2 e) -> Error <| Choice3Of3 e
      | Error (e) -> Error <| Choice1Of3 e


    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of3 e) -> Error <| Choice2Of4 e
        | Error (Choice2Of3 e) -> Error <| Choice3Of4 e
        | Error (Choice3Of3 e) -> Error <| Choice4Of4 e
      | Error (e) -> Error <| Choice1Of4 e


    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of4 e) -> Error <| Choice2Of5 e
        | Error (Choice2Of4 e) -> Error <| Choice3Of5 e
        | Error (Choice3Of4 e) -> Error <| Choice4Of5 e
        | Error (Choice4Of4 e) -> Error <| Choice5Of5 e
      | Error (e) -> Error <| Choice1Of5 e


    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of5 e) -> Error <| Choice2Of6 e
        | Error (Choice2Of5 e) -> Error <| Choice3Of6 e
        | Error (Choice3Of5 e) -> Error <| Choice4Of6 e
        | Error (Choice4Of5 e) -> Error <| Choice5Of6 e
        | Error (Choice5Of5 e) -> Error <| Choice6Of6 e
      | Error (e) -> Error <| Choice1Of6 e

    member inline _.Bind(x: Result<'a,_>,f: 'a -> Result<'d,_>) =
      match x with
      | Ok x ->
        match f x with
        | Ok x -> Ok x
        | Error (Choice1Of6 e) -> Error <| Choice2Of7 e
        | Error (Choice2Of6 e) -> Error <| Choice3Of7 e
        | Error (Choice3Of6 e) -> Error <| Choice4Of7 e
        | Error (Choice4Of6 e) -> Error <| Choice5Of7 e
        | Error (Choice5Of6 e) -> Error <| Choice6Of7 e
        | Error (Choice6Of6 e) -> Error <| Choice7Of7 e
      | Error (e) -> Error <| Choice1Of7 e

type FoodErrors =
| BadFood
| SpilledMilk


let getFood () = result {
  let! _ = Error BadFood
  return 42
}

type CatErrors =
| CatHungry
| CatHappy

let petCat () = result {
  let! _ = Error CatHappy

  return 0
}


type WalkAroundErrors =
| SteppedOnLego
| DirtyFloor

let walkAround () = result {
  let! _ = Error SteppedOnLego

  return 1701
}

type CoffeeErrors =
| HasSugar
| HasCream

let coffee () = result {
  let! _ = Error HasSugar

  return 1
}

type Error1 =
| ErrorA
| ErrorB

type Error2 =
| ErrorC
| ErrorD
type Error3 =
| ErrorE
| ErrorF
type Error4 =
| ErrorG
| ErrorH


let kitchenActivity () = result {
  let! x = getFood ()
  printfn "Side effect!"
  let! y = petCat ()
  let! z = walkAround ()
  let! a = coffee ()
  let! _ = Error ErrorA
  let! _ = Error ErrorB
  let! _ = Error ErrorC
  let! _ = Error ErrorD
  let! _ = Error ErrorE
  let! _ = Error ErrorG
  let! _ = Error ErrorG

  return x + y + z + a
}