f.hs

{-# LANGUAGE ApplicativeDo #-}
{-# LANGUAGE RecordWildCards #-}
instance FromJSON MyFlag where
  parseJSON (Object v) = do
    code <- v .: "code"
    name <- v .: "name"
    full_name <- v .: "full_name"
    relative_height <- v .: "relative_height"
    relative_width <- v .: "relative_width"
    pure MyFlag{..}