xml in fptools?

[Simon Marlow]

Bulat Ziganshin wrote:
> Hello Simon,
> 
> Friday, May 26, 2006, 2:52:34 PM, you wrote:
> 
> 
>>>Assuming we do have imprecise exceptions what is wrong with lazy IO?
> 
> 
>>I'm not even certain that lazy I/O doesn't upset referential 
>>transparency.  It seems hard to construct a concrete counter example 
>>though.  My intuition is something like this: if evaluating a thunk can
>>cause IO to take place, then the act of evaluating that thunk might 
>>affect the value of another lazy I/O computation, and hence it should be
>>possible to get different results by evaluating the thunks in a 
>>different order.  I'm concerned that in the presence of dependencies 
>>between lazy I/O computations, the order of evaluation might be visible.
> 
> 
> of course it can if, or example, we evaluate two hGetContents on the
> same Handle; or read the file that is written by other computation

Both of those are illegal in Haskell.  It might be possible to construct 
an example using pipes, though.

Cheers,
	Simon