Customization about quicktype HOT 2 CLOSED

module Options where

-- 'Options' is some opaque foreign type that holds a heterogeneous collection of `Option a`
foreign import data Options :: Type

foreign import optionsEmpty :: Options
foreign import optionsAdd :: forall a. Options -> Option a -> Options
foreign import optionsGet :: forall a. Options -> String -> Maybe (Option a)

data OptionKind
    = Boolean
    | String
    | Choice (Array String)

type Option a =
    { kind :: OptionKind
    , value :: Json -- this is foreign data that should be an `a` but we don't assume it is
    , default :: a
    , label :: String
    }

-- We use this from JavaScript to put values into options
-- Storing an invalid value will cause the Option to revert to its default value
setValueFromJS :: forall a. Option a -> Json -> Option a
setValueFromJS opt v = opt { value = v }

booleanOption :: String -> Boolean -> Option Boolean
booleanOption label default =
    { kind: Boolean
    , value: fromBoolean default
    , default
    , label
    }

-- An example option
renderProperties :: Option Boolean
renderProperties = booleanOption "Render Properties" true

class OptionValue a where
  getValue :: Option a -> Maybe a
  setValue :: Option a -> a -> Option a

instance optionValueBoolean :: OptionValue Boolean where
  getValue { value } = toBoolean value
  setValue opt b = opt { value = fromBoolean b }

-- Helpers for reading Options
getValueOrDefault :: forall a. Option a -> a
getValueOrDefault opt@{ default } = fromMaybe default $ getValue opt

getOption :: forall a. Options -> Option a -> Maybe (Option a)
getOption opts { label } = optionsGet opts label

getOptionOrDefault :: forall a. Options -> Option a -> a
getOptionOrDefault opts opt@{ default } = fromMaybe default $ getOption opts opt

-- Nice, but definitely not necessary
infixr 5 getOptionOrDefault as ~>

-- Later when we have an `options :: Options` coming from the CLI or web app:
let shouldRender = options ~> renderProperties