parseOpts :: O.Parser Options
parseOpts = Options 
  <$> O.strOption (O.metavar "DELIM" <> O.value "," <> O.short 'a' <> O.help "Concatentated array elem delimiter. Defaults to comma.")
  <*> O.argument O.str (O.metavar "FIELDS" <> O.help "JSON keypath expressions")
  <*> O.argument O.str (O.metavar "OUTFILE" <> O.help "Output file to write to. Use '-' to emit binary xlsx data to STDOUT.") 
  <*> O.switch (O.long "debug" <> O.help "Debug keypaths")
  <*> maxStrLen
parseOpts :: O.Parser Options
parseOpts = Options 
  <$> O.strOption (O.metavar "DELIM" <> O.value "," <> O.short 'a' <> O.help "Concatentated array elem delimiter. Defaults to comma.")
  <*> O.argument O.str (O.metavar "FIELDS" <> O.help "JSON keypath expressions")
  <*> O.argument O.str (O.metavar "OUTFILE" <> O.help "Output file to write to. Use '-' to emit binary xlsx data to STDOUT.") 
  <*> O.switch (O.long "debug" <> O.help "Debug keypaths")
  <*> maxStrLen
parseOpts = Options 
  <$> O.strOption (O.metavar "DELIM" <> O.value "," <> O.short 'a' <> O.help "Concatentated array elem delimiter. Defaults to comma.")
  <*> O.argument O.str (O.metavar "FIELDS" <> O.help "JSON keypath expressions")
  <*> O.argument O.str (O.metavar "OUTFILE" <> O.help "Output file to write to. Use '-' to emit binary xlsx data to STDOUT.") 
  <*> O.switch (O.long "debug" <> O.help "Debug keypaths")
  <*> maxStrLen