Felipe Lessa <felipe.le...@gmail.com> wrote: > On Sat, Jul 3, 2010 at 9:25 AM, Ertugrul Soeylemez <e...@ertes.de> wrote: > > Haskell provides a lot of low level glue like laziness, currying and > > other very helpful language features. But what is different in > > Haskell is that it doesn't seem to provide any high level glue like > > other languages do, especially when it comes to the IO world. There > > is a somewhat powerful module system, but nothing to bring modules > > and the objects they define together in a consistent way. > > When I first read this paragraph, I thought: "STM to the rescue!". > STM is one of the best concurrent world glues, IMHO.
I found that I get along with the basic concurrency constructs. STM may be handy in a few applications, but in none that I write. > If you want, you may use Haskell just as you as PHP or C: just put > everything in IO. Your code will get uglier and the type system won't > catch many bugs, but that's what we get when doing C or PHP, right? Not really. Even when programming in such a style, Haskell is much safer than PHP with its braindead type system, and still somewhat safer than C. > > The problem with that approach is: This makes my code harder to > > understand for beginners. Usually they can tell /what/ my code is > > doing, because it's written in natural language as much as possible, > > but they couldn't reproduce it. And when they try to learn it, they > > give up fast, because you need quite some background for that. Also > > sometimes when I write Haskell, my friend sits beside me and > > watches. When he asks (as a PHP programmer with some C background), > > say, about my types, I can't give a brief explanation like I could > > in other languages. > > I agree that it gets harder to reason about the code. In fact, > sometimes I stack monad transformers in the wrong order. However, as > Ivan says, if the feature is useful for you, don't be afraid of using > it. Beginners may have a hard time grasping the concepts for the > first time, but that's only until they "get it". I find monad transformers easy to reason about, and in most cases the stacking order doesn't make a difference at all. Just remember to change the running function, too. The problem with them is that beginners learn them very late. > > Yesterday I was writing a toy texture handler for OpenGL (for > > loading and selecting textures). He asked about my TextureT > > type. I couldn't explain it, because you couldn't even express such > > a thing in PHP or C. > > > > type TextureT = StateT Config > > > > -- Note that this is MonadLib. > > -- BaseM m IO corresponds to MonadIO m. > > selectTexture :: BaseM m IO => B.ByteString -> TextureT m () > > "It is the type of functions that may access and modify a state of > type Config." Then you need to explain "type of functions" and this explicitly implicit "state" and why you have to do it that way in Haskell. Greets, Ertugrul -- nightmare = unsafePerformIO (getWrongWife >>= sex) http://ertes.de/ _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe