On Mon, 29 Nov 2004, Simon Peyton-Jones wrote:
This unfortunate observabilty of an ordering (or hash value) that is
needed only for efficient finite maps, is very annoying. I wish I knew
a way round it. As it is we can pick
a) expose Ord/Hash, but have unpredictable results
b) not
At 13:43 29/11/04 -0800, John Meacham wrote:
On Mon, Nov 29, 2004 at 03:09:53PM -, Simon Peyton-Jones wrote:
> | > In fact GHC at least *already* generates a unique integer for each
> | > TypeRep. A good idea, since it means comparisons can be done in unit
> | > time. Thus indexing can be done
On Mon, Nov 29, 2004 at 03:09:53PM -, Simon Peyton-Jones wrote:
> | > In fact GHC at least *already* generates a unique integer for each
> | > TypeRep. A good idea, since it means comparisons can be done in unit
> | > time. Thus indexing can be done trivially using this integer as a
> | > hash
| > In fact GHC at least *already* generates a unique integer for each
| > TypeRep. A good idea, since it means comparisons can be done in unit
| > time. Thus indexing can be done trivially using this integer as a
| > hash function.
|
| Yes, I have seen this in the code, too. The Ord and Typeable
