Re: Making I/O streams entities

[MOON@MIT-MC]

RG's original idea of entities was that they be closures that accept
the :WHICH-OPERATIONS operation.  I/O streams already are such; in fact,
I suspect all other things that claim to be entities are not.  So
it would be OK to make them DTP-ENTITY instead of DTP-CLOSURE if that's
still what DTP-ENTITY means.

On the other hand, I do not at all think it is appropriate to change the
system to use classes and message-passing for I/O streams.  There isn't
much to be gained by this, I/O streams already do what we want them to do,
and I don't consider the message-passing and class stuff to be mature enough
yet to be reasonable to put into low-level stuff that doesn't need it
and to be worth putting into the cold load.