Reports

The launchMissilesAt example would in F# be something like:

type Country = BigEnemy | MediumEnemy | PunyEnemy | TradePartner | Ally | BestAlly

let launchMissilesAt country =
    printfn "bombed %A" country

(*
GFunc
type GFunc<'R> =
    abstract Invoke : 'T -> 'R
*)

// inspired by GFunc 
type ElementPicker =
    abstract Pick : 'T list -> 'T

let g =
    {new ElementPicker with
        member this.Pick(xs) = xs |> List.head }    // or something alike

//let g =
//    {new ElementPicker with
//        member this.Pick(_) = BestAlly }
//This expression was expected to have type
//    ''a'    
//but here has type
//    'Country'    

let f = launchMissilesAt <| g.Pick [BigEnemy; MediumEnemy; PunyEnemy]

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