Re: [Haskell-beginners] IO / State / Do Syntax

27 Aug 2012

      Hi

you don't need the State monad for your problem. Standard functional
composition is enough:

---8<---
initResources =
   let
      images = ["someimage.png", "someimage2.png"]
      keywords = ["pic1keyword", "pic2keyword"]
   in do
       pics <- mapM loadImage images
       let rt = foldr go emptyResourceTracker $ zip pics keywords
       -- use rt
   where
      go (pic, kw) rt = storeImage rt kw pic
--->8---

Anyways, if you are interested in Monad transformers in general, go
check out http://book.realworldhaskell.org/read/monad-transformers.html

HTH

Alex

Re: [Haskell-beginners] IO / State / Do Syntax

Alexander Bernauer