[<ImmutableObject true>]
type Status(value : bool) =
    let Value = value

    member this.Positive
        with get() = if value then true else false

    member this.Negative
        with get() = if value then false else true

[<ImmutableObject true>]
type WhenResult<'TIn>(value: 'TIn, status: bool)  =
    member this.Status : Status = new Status(status)
    member this.Value = value



[<Extension>]
type SelectivelyExecuteExtension =

    [<Extension>]
    static member inline When<'TIn>(self: 'TIn, action: Func<'TIn,bool>) =
       new WhenResult<'TIn>(self, action.Invoke self)

    [<Extension>]
    static member inline Do<'TIn>(result: WhenResult<'TIn>, action: Action<'TIn>) =
        if result.Status.Positive
        then action.Invoke(result.Value)
        result

    [<Extension>]
    static member inline Else<'TIn>(result: WhenResult<'TIn>, action: Func<'TIn,'TIn>) =
        if result.Status.Negative
        then action.Invoke(result.Value)
        else result.Value