Hi Bryan,
If parser combinators aren't great for "relatively standard" things such as CSV, then what *are* they good for?
there is no such thing as a "parser combinator library". There are many different libraries for writing parsers, and these libraries each have vastly different design goals. Attoparsec, for example, is specifically designed to be fast, and I don't see any reason why it shouldn't be possible to implement a high-performance CSV parsing library on top of that package. In fact, I believe Cassava does exactly that. Parsec and the newer Megaparsec, on the other hand, put more emphasis on good error messages than an performance. Now, good error messages matter when you're parsing a sophisticated input language with many different non-trivial constructs, but for a CSV parser there's really not much to be done in terms of "good error messages" because the syntax is so simple. Therefore, Parsec might not be the best choice for that particular use-case. Anyway, I don't think that it makes much sense to talk about all those libraries as if they were all the same and had all the same properties, because they don't. Best regards, Peter