Fernan Bolando wrote:
what is the simplest way to implement the following code in haskell? it's just printing the contents of 2D array.
for(i = 0; i < imax; i++){ for(n = 0; n < nmax; n++){ printf("%i:%i = %f\n", array[i][n]); } } *%* ghci
* / _ \ /\ /\/ __(_) / /_\// /_/ / / | | GHC Interactive, version 6.6, for Haskell 98. / /_\\/ __ / /___| | http://www.haskell.org/ghc/ \____/\/ /_/\____/|_| Type :? for help. Loading package base ... linking ... done. Prelude>* :m + Data.Array *Prelude Data.Array>* let a = listArray ((0,0),(2,2)) [1..9] This is how it looks by default: *Prelude Data.Array>* a array ((0,0),(2,2)) [((0,0),1),((0,1),2),((0,2),3),((1,0),4),((1,1),5),((1,2),6),((2,0),7),((2,1),8),((2,2),9)] 'assocs' builds the corresponding assoc list: *Prelude Data.Array> *assocs a [((0,0),1),((0,1),2),((0,2),3),((1,0),4),((1,1),5),((1,2),6),((2,0),7),((2,1),8),((2,2),9)] 'map show' converts it into a list of strings: *Prelude Data.Array>* map show $ assocs a ["((0,0),1)","((0,1),2)","((0,2),3)","((1,0),4)","((1,1),5)","((1,2),6)","((2,0),7)","((2,1),8)","((2,2),9)"] 'unlines' to convert to a single string where each list element is one line, and 'putStrLn' to print it: *Prelude Data.Array> *putStrLn $ unlines $ map show $ assocs a **((0,0),1) ((0,1),2) ((0,2),3) ((1,0),4) ((1,1),5) ((1,2),6) ((2,0),7) ((2,1),8) ((2,2),9) * *To get the exact same output, replace 'show' with a custom-built function. * Prelude Data.Array>* putStrLn $ unlines $ map (\((i,j),v)-> show i++":"++show j++"="++show v) $ assocs a 0:0=1 0:1=2 0:2=3 1:0=4 1:1=5 1:2=6 2:0=7 2:1=8 2:2=9