Wolfgang Jeltsch wrote: | > 1. Today I spend a few hours trying to track down a memory leak. It | > turns out I just didn't realize how much space a string takes up. | > On my machine "replicate 5000000 'a'" will use 90MB of space! | | You have to take into account that Chars (in GHC) take 4 | bytes of memory because they denote Unicode codepoints. | 5,000,000 times 4 bytes is already 20 MB. (The rest is | only a constant factor. ;-))
You have to realize that the space usage does not (necessarily) come from duplicating the character 'a'. In a lazy implementation, the representation of that character will be shared by all elements in the list. So, what is happening that there is 1 cell in the heap containing the representation of 'a', and then a linked list of length 5000000, where each element points to that cell. Just my 2 öre. /Koen _______________________________________________ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
