[Haskell-cafe] Allocating enormous amounts of memory and wondering why

[Bulat Ziganshin]

Hello Jefferson,

Monday, July 9, 2007, 1:26:18 AM, you wrote:

> I'm using the Data.AltBinary package to read in a list of 4.8 million
> floats and 1.6 million ints.

>   coordinates <- get pointsH :: IO [Float]
>   galaxies <- get pointsH :: IO [Int]

thank you for discovering bug in the library! next version will
include thought-reading module which will be able to find how
much values to actually want to read. as a temporary workaround, you
can use the following code

>   coordinates <- getList pointsH (48*10^5) :: IO [Float]
>   galaxies <- getList pointsH (16*10^5) :: IO [Int]

> Doing so caused the memory footprint to blow up to more than 2gb,

it was because 'get' reads number of items in the list from input
stream itself ;)

-- 
Best regards,
 Bulat                            mailto:Bulat.Ziganshin at gmail.com