[Haskell-cafe] Re: Lock-Free Data Structures using STMs in Haskell

9 Apr 2008


      Bryan O'Sullivan  writes:
...
Pete Kazmier wrote:
...
data ArrayBlockingQueueSTM e = ArrayBlockingQueueSTM {
    [...]
    sa :: Array Int (TVar e)
  }
It's unclear to me why the Array's elements must be wrapped in TVars.
To allow them to be modified.  You can't otherwise modify the elements
of an array without going into the ST monad.
Thanks!  I forgot about the whole immutable thing :-)  Haven't used
arrays yet while learning Haskell!