Driver.hs

-- | Per-query settings
data RunFlag =
  ReadMode ReadModeOpt |
  NoReply |
  Durability Durability |
  Profile |
  ArrayLimit Int

data Durability = Hard | Soft

renderOption :: RunFlag -> (Text, Datum)
renderOption (ReadMode Majority) = "read_mode" .= ("majority" :: String)
renderOption (ReadMode Single) = "read_mode" .= ("single" :: String)
renderOption (ReadMode Outdated) = "read_mode" .= ("outdated" :: String)
renderOption NoReply = "noreply" .= True
renderOption (Durability Soft) = "durability" .= ("soft" :: String)
renderOption (Durability Hard) = "durability" .= ("hard" :: String)
renderOption Profile = "profile" .= True
renderOption (ArrayLimit n) = "array_limit" .= n

ReQL.hs

data ReadModeOpt = Majority | Single | Outdated

-- | State used to build a Term
data QuerySettings = QuerySettings {
  queryToken :: Int64,
  queryDefaultDatabase :: Database,
  queryVarIndex :: Int,
  -- queryUseOutdated :: Maybe Bool <- was this
  queryReadMode :: Maybe ReadModeOpt
  }
  
instance Expr Table where
  expr (Table mdb name _) = withQuerySettings $ \QuerySettings {..} ->
    op' TABLE (fromMaybe queryDefaultDatabase mdb, name) $ catMaybes [
      -- fmap ("use_outdated" :=) queryUseOutdated ] <- was
      fmap ("read_mode" :=) queryReadMode ]