I think this withRecovery function could give us a lot of what we want, even without a multiple-error feature. But let's wait a bit and see how #222 goes.

https://markkarpov.com/tutorial/megaparsec.html#reporting-multiple-parse-errors

“One prerequisite for having a multi-error parser is that it should be possible to skip over a problematic part of input and resume parsing from a position that is known to be good.”

Right now, we have no support for multiple errors, so if the user wants to see multiple withRecovery errors then the user must do something like return all the errors in the parsers’s return type.

Another option is that the user could use runParserT with a runStateT monad transformer to save an Array ParseError.

flip runStateT [] $ runParserT "bad bad bad" do
many do
  skipSpaces
  withRecovery 
    (\err -> do
      lift $ modify (\errors -> snoc errors err)
      takeWhile (not <<< isSpace)
    )
    string "good"