jobjo

(* Functors and modular implicits
 * opam switch 4.02.0+modular-implicits
 * eval `opam config env`
 *)
module type FUNCTOR = sig
  type 'a t
  val map : ('a -> 'b) -> 'a t -> 'b t
end
let map {F : FUNCTOR} = F.map

jobjo

(* General functor signature. *)
module type FUNCTOR = sig
  type 'a t
  val map : ('a -> 'b) -> 'a t -> 'b t
end

(* General def of catamorphism module, parameterized by a functor *)
module Cata (F : FUNCTOR) = struct

  type 'a t = 'a F.t

jobjo

// Functor interface.
type Functor<'F> = { map : ('T -> 'U) -> 'F<'T> -> 'F<'U> }
 
// Monad interface.
type Monad<'M> = {
    return : 'T -> 'M<'T>
    join : 'M<'M<'T>> -> 'M<'T>
}
 
// Monad "library" (operations over monads).

jobjo

open System
open System.Collections.Generic

// The problem I'm addressing is aggregating elements from a tree.
// In my particular scenario I'm interested in collecting all leaf nodes
// into an array. The fundamental problem is captured by the different versions
// of aggregate, listed below. The functions are merely simulating the branching
// and aggregation steps. I'm not concerned about the order of the elements.
// In the comments are the total times in milliseconds 
// running the functions with n = 1e6. That is generating an array of roughly 

jobjo

        Formlet.Do {
            let! n = Controls.Button "Add Tabs"
            return!
                List.init n (fun ix -> 
                    ("Tab " + string ix, Controls.Input "")
                )
                |> Controls.TabsChoose
        }

jobjo

var createCounter = function() {
    var x = 0;
    return (
        function () {
            x = x + 1;
            return x;
        }
    );
}

jobjo

type MyControl() =
    inherit IntelliFactory.WebSharper.Web.Control ()

    [<JavaScript>]
    override this.Body =

        let inpCtrl str =
            Controls.Input str
            |> Enhance.WithSubmitButton
            |> Enhance.WithFormContainer

jobjo

    [<JavaScript>]
    let InputDate () =
        let inputId = NewId ()
        Controls.InputDatepicker None
        |> Formlet.MapElement (fun el -> Div [Attr.Id inputId] -< [el])
        |>! OnAfterRender (fun el ->
            JQuery.JQuery.Of("#" + inputId).Find("input").Val("").Ignore
        )

jobjo

open M
Foo ()

jobjo

Formlet.Do {
    let! x = Controls.RadioButtonGroup None [("item1","item1");("item2","item2");("item3","item3")]
    return x
}
|> Formlet.Map Some
|> Formlet.InitWith None
|> Enhance.WithSubmitAndResetButtons
|> Enhance.WithFormContainer