I wonder if the lazy nature of Haskell's Attoparsec parsing library would have prevented the issue by default (without needing to set-up a limit in the parser).

I wonder if the lazy nature of Haskell's Attoparsec parsing library would have prevented the issue by default (without needing to set-up a limit in the parser). I think it depends on how the resulting lazy structure is used, but it might be true that the person writing the parser may not need to worry in the least about it, since evaluation and resulting memory allocation would be up to the person that uses the result from the parser because of the language's lazy-by-default nature.