-- | Output a list of strings, ignoring empty ones and separating the
--   rest with the given separator.
sepBy :: String   -- ^ separator
      -> [String] -- ^ fields to output
      -> String
sepBy sep = concat . intersperse sep . filter (not . null)
sepBy :: String   -- ^ separator
      -> [String] -- ^ fields to output
      -> String
sepBy sep = concat . intersperse sep . filter (not . null)
sepBy sep = concat . intersperse sep . filter (not . null)