Hi, I'm adding HUnit tests to a parser that uses Parsec, and I wanted to see test coverage of my parser. I've successfully used hpc to get a coverage report, but it has a significant deficiency: An expression in my parser will show as covered if the expression is ever evaluated, but I'd really like to see branch coverage of the parser monads. For example, if I have a single test that parses the string "*" with the following parser: plusOrStar = do result <- (string "+" <|> string "*") _ <- (many $ string " ") return result then hpc will report that all the code is covered, but I'd like to be able to see the fact that (string "+") only ever failed, and that (string "*") only ever succeeded. Are there any existing tools for getting that sort of coverage report for parsers or monads? Is there an approach other than hpc that I should be considering to get confidence in my test suite? If not, I understand that hpc works by doing source-code transformation--does it seem like a reasonable endeavor to try to customize it to do what I am interested in? Thanks, --Aaron V.