Generative record types

[Gerald Jay Sussman <gjs@martigny.ai.mit.edu>]

     I am in favor of opaque types, and object to the make-record-type
     proposal on the grounds that it builds into the language support for
     breaking abstractions.  If we had a mechanism for specifying
     programming environment support, abstraction breaking mechanisms would
     be worth considering, but not as part of the language.

I would like to weigh in against opacity.  I particularly like the
fact that the language has explicit support for breaking abstractions.
This is one of the best parts of Lisp-derived languages, as it removes
the distinction between systems programming, environmental support,
and other programming tasks.

I know that I am in a minority of programmers on this issue, but I
feel pretty strongly about it.  Probably the main reason why the
language has not progressed recently is that there is internal
division on this particular issue.