votelist.elm

import Html as H exposing (Html)
import Html.Attributes as A
import Html.Events as Events
import Signal exposing (Signal, Address)
import StartApp.Simple as App

import List

options : List String
options =
  [ "Forte"
  , "Suave"
  , "Lento"
  , "Rápido"
  ]

type alias Model = 
  { votes : List (String, Int) }
  
type Action =
  Vote String
  
findAndApply : (a -> a) -> b -> List (b, a) -> List (b, a)
findAndApply f x l =
  case l of
    ((a,b) :: t) ->
      if a == x then (a,(f b)) :: t 
      else (a,b) :: (findAndApply f x t)
    
    [] -> []
    
voteList : Address Action -> List (String, Int) -> Html
voteList address l =
  let list = 
    List.map (\(str, n) ->
                H.li []
                [ H.text (str ++ " : " ++ (toString n)) 
                , H.button 
                  [ Events.onClick address (Vote str) ]
                  [ H.text "Votar" ]
                ]
             ) l
  in H.ul [] list

initialModel : Model
initialModel = 
  { votes = List.map (\x -> (x,0)) options  }
  
update : Action -> Model -> Model
update (Vote str) model =
  { model | votes = findAndApply (\x -> x+1) str model.votes }

view : Address Action -> Model -> Html
view address model =
  H.div []
  [ H.div []
    [ voteList address model.votes ]
  ]

main : Signal Html
main = 
  App.start 
    { model = initialModel
    , view = view
    , update = update
    }