On Sat, Jan 30, 2010 at 9:38 PM, Daniel Fischer
Also, is there a more direct way of printing an array?
Sure,
printing immutable arrays:
print arr ~> array (lo,hi) [(lo,arr!lo), ... , (hi,arr!hi)] print (assocs arr) ~> [(lo,arr!lo), ... , (hi,arr!hi)] print (elems arr) ~> [(arr!lo), ... , (arr!hi)]
Those are all fine.
printing IO[U]Arrays:
do immArr <- freeze arr print (immArr :: [U]Array ix el)
do ass <- getAssocs arr print ass
(getAssocs arr >>= print)
do els <- getElems arr print els
On the other hand, all those suggestions have a severe efficiency problem due to the IO Monad strictness, for instance (getAssocs arr
= print) will start by creating the whole list of associations before printing any of it.
More efficient and still better than the initial code would be : mapM_ (readArray arr >=> print) [1..9] -- Jedaï