On Mon, 2 Mar 2009, John Lato wrote:
Hello,
I am not a super-geek (at least, not compared to others on this list), but I'll take a try at this anyway. The benefits of iteratees mostly depend on differences between lazy and strict IO (see ch. 7 of Real World Haskell for more on this).
Maybe a good text for http://www.haskell.org/haskellwiki/Enumerator_and_iteratee ? While I think that the Iteratee pattern has benefits, I suspect that it can't be combined with regular lazy functions, e.g. of type [a] -> [a]. Say I have a chain of functions: read a file, parse it into a tag soup, parse that into an XML tree, transform that tree, format that into a string, write that to a file, and all of these functions are written in a lazy way, which is currently considered good style, I can't use them in conjunction with iteratees. This means, almost all Haskell libraries have to be rewritten or extended from lazy style to iteratee style. The question for me is then: Why having laziness in Haskell at all? Or at least, why having laziness by default, why not having laziness annotation instead of strictness annotation.