For me there is just no such thing as spare time any more - it’s basically time when I should be doing something else. So when this popped up I thought it would be an ideal time to learn a bit of Haskell. I had a quick play at the time and had the “Oh! Haskell doesn’t have mutable variables!” revelation (although I didn’t know they were called mutable back then) had a bit more of a play with recursion, etc and then got busy with other stuff for, well, almost a year(!) until I ‘found’ time again:
-- Selection Sort in Haskell -- -- Cheating by using IORef for mutable variables since I don't know what I'm doing -- with Haskell, although do have an inkling that the benefit of Haskell is that -- all of below can be done in about three lines. -- -- Assumes integer input only. import Data.IORef import Data.List.Split -- cabal install split -- http://hackage.haskell.org/packages/archive/split/0.1.2.3/doc/html/Data-List-Split.html#v%3asplitOn -- I'm not even going to think about doing this myself. -- Used to get a comma delimted string as a list main = do -- Set up 'variables' putStr "Enter List to Sort:" stringinput <- getLine let listinput = splitOn "," stringinput -- Convert comma delimited string to list let intinput = [ read x :: Int | x <- listinput] --Convert list of strings to list of Integers --Need to specify type http://learnyouahaskell.com/types-and-typeclasses unsortlistIO <- newIORef intinput elementIO <- newIORef  sortlistIO <- newIORef  sort unsortlistIO elementIO sortlistIO sort unsortlistIO' elementIO' sortlistIO' = do unsortlist <- (readIORef unsortlistIO') sortlist <- (readIORef sortlistIO') -- initialise, for all intents and purposes --print unsortlist --debug if ((length unsortlist) > 0) then do -- Note to self: Must remember to ident these after if! -- find smallest element(s) unsortlist <- (readIORef unsortlistIO') writeIORef elementIO' (filter (==(minimum unsortlist)) unsortlist) element <- readIORef elementIO' -- Add to sorted list sortlist <- readIORef sortlistIO' writeIORef sortlistIO' (sortlist++element) -- remove from original list writeIORef unsortlistIO' (filter (not.(==(minimum unsortlist))) unsortlist) readIORef sortlistIO' --print sortlist --debug sort unsortlistIO' elementIO' sortlistIO' -- loop. Ha! else return sortlist -- Note to self: must be careful about returning the right type of thing
I gather the benefit of Haskell is that this can actually be written in a couple of lines. Maybe in another eleven months time I’ll have figured that out.