[r6rs-discuss] Unicode issues

From: Thomas Lord <lord>
Date: Wed, 29 Aug 2007 20:00:41 -0700

Aubrey Jaffer wrote:
> Not so! If you use records to specify the new type, then EQV? won't
> work on these new characters. States r5.97rs-lib section 6.1
> Mutability and equivalence of records:
>
> * If obj1 and obj2 are both records of the same record type, and
> are the results of two separate calls to record constructors, then
> eqv? returns #f.
>

Oh my goodness. That's very, very bad. That reifies an execution
model in a particularly unforgivable way.

I was just thinking, earlier today, that R6 blows it by introducing
intentional types when the only real demand was for user-defined
disjoint types. I was thinking of libraries but the same design
pattern issue relates to records.

New rule: shun opaque types! Extensional types only!

Sigh.

-t
Received on Wed Aug 29 2007 - 23:00:41 UTC