I'm new to Haskell and Parsec. After reading Chapter 16 Using Parsec of Real World Haskell, a question appeared in my mind: Why and when is Parsec better than other parser generators like Yacc/Bison/Antlr?
My understanding is that Parsec creates a nice DSL of writing parsers and Haskell makes it very easy and expressive. But parsing is such a standard/popular technology that deserves its own language, which outputs to multiple target languages. So when shall we use Parsec instead of, say, generating Haskell code from Bison/Antlr?
This question might go a little beyond technology, and into the realm of industry practice. When writing a parser from scratch, what's the benefit of picking up Haskell/Parsec compared to Bison/Antlr or something similar?
BTW: my question is quite similar to this one but wasn't answered satisfactorily there.
You might want to see this question as well as the linked one in your question.
Which Haskell parsing technology is most pleasant to use, and why?
In Haskell the competition is between Parsec (and other parser combinators) and the parser generator Happy. I'd pick Happy if I already had an LR grammar to work from - parser combinators take grammars in LL form and the translation from LR to LL takes some effort and a combinator parser will usually be significantly slower. If I don't have a grammar I'll use Parsec, it is more flexible (powerful) than Happy and its more fun to work "in Haskell" than generate code with Happy and Alex. If you use Happy for parsing you almost always need to use Alex for lexing.
For industry practice, it would be odd to decide to use Haskell just to get Parsec. For parsing, most of the current crop of languages will have at least a parser generator and probably something more flexible like a port of Parsec or a PEG system.
Ira Baxter's answer to the linked question was spot-on about a parser getting you merely to the foothold of the Himalayas for writing a translator, but being part of a translator is only one of the uses for a parser, so there are still many domains where fairly minimalist systems like ANTLR, Happy and Parsec are satisfactory.