readtable hacking

[DAVE.TOURETZKY at CMU-10A]

I've had two requests from users for readtable hacks.  Can you tell
me how to do the following?

1) Make ] be both a letter and a break character.  Example: the
character sequence AB]CD should produce three atoms: AB, ], and CD.

2) Implement an Interlisp-style "super paren", e.g. make ] or escape
insert enough right parens to close out the current s-expression.
Alternatively, it could insert some constant number of right parens,
providing we can make the constant big enough.

Thanks,  -- Dave Touretzky