Hello, > From: David Leimbach <leim...@gmail.com> > > Hi everyone, > > Yet at the same time, I'm quite enamored with the beauty of "interact" and > functions of that sort. I realize mixing the effects of the lazy IO and > pure code may not be the clearest way to write code for everyone, but there > is something about being able to get linewise data as > > interact (unlines . fmap someLineWiseFunction . lines) > > that is just kind of cool.
I think so too. I really like the "interact" style of code; I find it supremely elegant. However I also find it insufficient for many interesting cases. One general problem is the difficulty of embedding monadic code into interact functions. Usually "interact" requires a pure function. Although in many cases I think it would be possible to have interactM :: (String -> IO String) -> IO () in practice these functions don't usually exist, perhaps because they can have some surprising behavior. In my opinion IO is a weakness of Haskell, and many Haskell users either subconciously or actively seek out alternative approaches. I offer as evidence the frequency with which beginners ask the cafe about "handle closed before data could be read" errors, and also the proliferation of IO libraries. I know which I approach I think represents the best way forward, but I would be surprised if there was a community consensus at this point. In any case, I'm glad there are a multitude of options and each probably has a place and purpose. Cheers, John Lato _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
