halogen-websocket-ipc-playzone/src/App/PermissionLevel.purs

module App.PermissionLevel where

import Data.Codec.Argonaut as CA
import Data.Maybe (Maybe(..))

data PermissionLevel
  = None
  | Read
  | Edit
  | Admin

-- | Codec for just encoding a single value of type `PermissionLevel`
codec :: CA.JsonCodec PermissionLevel
codec =
  CA.prismaticCodec "PermissionLevel" from to CA.string
  where
    from :: String -> Maybe PermissionLevel
    from = case _ of
      "none"  -> Just None
      "read"  -> Just Read
      "edit"  -> Just Edit
      "admin" -> Just Admin
      _ -> Nothing

    to :: PermissionLevel -> String
    to = case _ of
      None  -> "none"
      Read  -> "read"
      Edit  -> "edit"
      Admin -> "admin"