Example of the way the dialog is currently implemented. See full files here: https://github.com/mark-chimes/trading-post

DialogAppend.elm

# types

type alias Model =
    { viewState : ViewState
    , gameState : GameState
    }

type alias GameState =
    { gold : Int
    , goldOfferGetVal : Int
    , offerOrGet : OfferGet
	...
    , currentCustomer : Customer
    , dialog : List String
    , currentTrade : Trade
    }

type alias Trade =
    { goldOffered : Int
    }


type Msg
    = Noop
	...
    | Speak String
    | ChangeMoney Int
    | ConfirmTradeMsg
	
# State

speakAndRespond : GameState -> String -> GameState
speakAndRespond gameState playerSpeech =
    { gameState
        | dialog =
            gameState.dialog
                |> appendDialog "You" playerSpeech
                |> appendDialog gameState.currentCustomer.name (npcDialog gameState)
        , currentTrade = updateTradeGold gameState.offerOrGet gameState.goldOfferGetVal gameState.currentTrade
    }


npcDialog : GameState -> String
npcDialog gameState =
    case gameState.actionRadioState of
        MoneyDiscussion ->
            case gameState.offerOrGet of
                Offer ->
                    "Sure, I'd love " ++ toString gameState.goldOfferGetVal ++ " gold!"

                Get ->
                    "Well, if I'm going to add " ++ toString gameState.goldOfferGetVal ++ " gold, you'd better make it worth my while!"

        _ ->
            "Nah, not interested, thanks."


updateTradeGold : OfferGet -> Int -> Trade -> Trade
updateTradeGold offerGet gold trade =
    { trade | goldOffered = calculateChangeInGoldTrade offerGet trade.goldOffered gold }


calculateChangeInGoldTrade : OfferGet -> Int -> Int -> Int
calculateChangeInGoldTrade offerGet oldGold alteredGold =
    case offerGet of
        Offer ->
            oldGold + alteredGold

        Get ->
            oldGold - alteredGold


appendDialog : String -> String -> List String -> List String
appendDialog personName string dialog =
    (personName ++ ": " ++ string) :: dialog