On Fri, 9 Mar 2007, R. Kent Dybvig wrote:
The present description of libraries leaves open the possibility that a continuation grabbed within a variable definition's right-hand-side expression and subsequently invoked might cause the reinitialization, with different values, of some or all of the local counterparts of the exported variables, effecting implicit assignments to variables that are supposed to immutable.....
Proposal: Add new wording to the effect that the continuation of the right-hand-side expression of a library variable definition should not be returned to more than once and that implementations either "should" or "must" raise an exception if this occurs.
Do you intend this to apply to all variable definitions or just to those that are exported? It only seems natural for the latter case. If one is going to apply this also to unexported definitions, the question arises as to why one wouldn't apply it also to internal definitions in lambda bodies. I have not been able to think of a good reason to treat the latter differently.
Regards Andre _______________________________________________ r6rs-discuss mailing list [email protected] http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
