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next order of business

It seems like issues relating to the treatment of constants in compiled
code, which have been discussed on the common-lisp mailing list for the
past few weeks, should probably be the next thing we try to address.  I
believe that the main thing that has to be done here is to explicitly
state that it is an error to destructively modify structured constants
(since the current wording in CLtL allows the compiler to collapse EQUAL
structures), and to clarify exactly what kinds of destructive operations
would be forbidden.  For example, I do not believe we would want to
prohibit alteration of the "fields" of a quoted symbol such as the
property list.  There are other, more radical approaches we could
take -- such as forbidding implementations to collapse constants or put
them in read-only storage -- but I don't know if any of these would get
much support.  Comments, anyone?  I could try to sketch out a proposal
on this over the weekend and bring it to Cambridge for discussion.