Small elm app for civilian / in-army people tracking

Army.elm

import Html exposing (..)
import Html.App as Html
import Html.Attributes exposing (..)
import Html.Events exposing (..)
import String as String

main = 
 Html.beginnerProgram 
  { model = model 
  , update = update
  , view = view
  }
  
type PersonStatus = Civilian | Army

type alias Person = 
 { status : PersonStatus
 , name : String
 , id : Int
 }
 
newPerson {personName, personId} =  
  Person Civilian personName personId

model = 
 { personName = ""
 , personId = 0
 , people = [] 
 }

type Action 
  = NewName String
  | AddNewCivilian
  | CivilianToArmy Int
  --| ArmyToCivilian
  --| RemoveDead

update action model =
  case action of
   NewName name -> 
    { model | personName = name}
   AddNewCivilian -> 
    { model 
     | personId = model.personId + 1
     , people = (newPerson model)::model.people}
   CivilianToArmy id ->
    let updatePerson id person =
     if id == person.id then 
      { person | status = Army }
     else 
      person
    in
     { model | people = List.map (updatePerson id) model.people}


view model =
  div []
   [ h2 [] [ text "People" ]
   , div [] (List.map viewPerson model.people)
   , input [ placeholder "Name", onInput NewName] []
   , button [ 
      onClick AddNewCivilian, 
      disabled (String.length model.personName == 0) ] 
      [ text "add civilian" ]
   ]

viewPerson {status, name, id} =
  div [] 
   [ text ((toString status) ++ " #" ++ (toString id) ++ " " ++ name)
   , viewPersonControls status id
   ]
   
viewPersonControls status id =
  case status of
   Civilian ->
    button [ onClick (CivilianToArmy id) ] 
     [ text "to army" ]
   Army ->
    span [] []