React.E.Option

# Module React.E.Option

    module Option: sig .. end

Events with option occurences.

    val some : 'a React.event -> 'a option React.event

`some e` is `map (fun v -> Some v) e`.

    val value : ?default:'a React.signal -> 'a option React.event -> 'a React.event

`value default e` either silences `None` occurences if `default` is unspecified or replaces them by the value of `default` at the occurence time.

- [`value ~default e`]t`= v` if [`e`]t `= Some (Some v)`.
- [`value ?default:None e`]t`= None` if [`e`]t = `None`.
- [`value ?default:(Some s) e`]t`= v` if [`e`]t = `None` and [`s`]t `= v`.