[r6rs-discuss] [Formal] eliminate library export immutability loophole

From: AndrevanTonder <andre>
Date: Mon Mar 12 18:36:34 2007

On Mon, 12 Mar 2007, R. Kent Dybvig wrote:

> Andre van Tonder wrote:
>
>> I get the following, which I think is also consistent with the current
>> specification:
>>
>> (0 0)
>> (3 3)
>
> Perhaps, though the wording of the library semantics section implies that
> the export variable locations are created and initialized after the RHS
> and body expressions are evaluated.

But I think the statement "The effect of returning twice to the continuation of
the last body expression is unspecified", allows an implementation to output
the above, to output

   (0 0)
   ("wizard" "Oz")

or to fail, all without violating the spec :-)

Andre
Received on Mon Mar 12 2007 - 18:36:01 UTC