On Wed, 21 Dec 2005, Creighton Hogg wrote:
On Wed, 21 Dec 2005, Henning Thielemann wrote:
The drawback is that I saw many Haskell programs implemented with IO read/write functions which could be easily implemented without IO, using laziness.
Can you think of any examples of things like that? Given that I'm still learning how to take advantage of laziness it'd be pretty interesting.
Some example for writing a text the IO oriented way: do putStrLn "bla" replicateM 5 (putStrLn "blub") putStrLn "end" whereas the lazy way is putStr (unlines (["bla"] ++ replicate 5 "blub" ++ ["end"])) You see that the construction of the text is separated from the output, but the effect is rather the same in both variants: The text is constructed simultaneously with output. You could also make the separation explicit: text :: String text = unlines (["bla"] ++ replicate 5 "blub" ++ ["end"]) main = putStr text