DDC compiler and effects; better than Haskell? (was Re: [Haskell-cafe] unsafeDestructiveAssign?)

[Richard O'Keefe]

On Aug 15, 2009, at 2:55 PM, John A. De Goes wrote:
>> If you don't like the file system, consider mutable memory. An  
>> effect system will tell me I can safely update two pieces of non- 
>> overlapping, contiguous memory concurrently, even in different  
>> threads if the complexity so justifies it. The IO monad is a poor  
>> man's solution to the problem of effects.

In the presence of out-of-order memory writes, write buffers,
caches, &c, I'm not going to contradict you, but it certainly
isn't as _obvious_ as it used to be.

I've come across an experimental microprocessor where I _think_
it isn't safe if you have

	--------+---------
          data 1 | data 2
         ----+--------+----
               cache
	      line

whether that's so on any other processor is beyond my expertise.