Dynamic.hs

-- This example demonstrates using of `DynamicIOArray`,
-- i.e. arrays whose bounds can be changed dynamically,
-- including automatic growth as `writeArray` requires.
--
-- Other types of dynamic arrays - DynamicIOUArray, DynamicSTArray,
-- DynamicSTUArray and manually constructed dynamic array types
-- can be used in the same fashion.
import Data.ArrayBZ.Dynamic

main = do
          -- This array will grow at least two times each time when index is out of bounds,
          -- because it is created using `newDynamicArray growTwoTimes`
          arr <- newDynamicArray growTwoTimes (0,-1) 99 :: IO (DynamicIOArray Int Int)
          -- At this moment the array is empty
          printArray arr

          -- During this cycle the array extended 3 times
          for [0..5] $ \i ->
             writeArray arr i i
          printArray arr

          -- During this cycle the array extended one more time
          for [-5 .. -1] $ \i ->
             writeArray arr i i
          printArray arr

          -- Operation that explicitly resizes the array
          resizeDynamicArray arr (3,15)
          printArray arr

          -- This array will not grow automatically because it is created using `newArray`,
          -- but it can be resized explicitly using `resizeDynamicArray`
          arr <- newArray (0,-1) 99 :: IO (DynamicIOArray Int Int)
          resizeDynamicArray arr (0,0)
          printArray arr
          writeArray arr 1 1  -- this operation raises error


-- Print dynamic array bounds and contents
printArray arr = do
          bounds   <- getBounds arr
          contents <- getElems  arr
          putStrLn (show bounds++" : "++show contents)

for list action = mapM_ action list