Readable Hash-Tables

[ELIOT@cs.umass.edu]

   From: Barry Margolin <barmar@think.COM>

       Better still for DESCRIBE, at least,
       would be a portable public domain implementation.

   Until we define CL functions for examining defstruct structures (e.g. a
   function that takes a structure name and returns a list of slot accessor
   functions) it will not be possible to write a portable DESCRIBE that can
   tell you the contents of a structure.  Also, there are no accessors
   at all for some other types, such as RANDOM-STATE and HASH-TABLE (and
   this is the one that prompted this discussion).

   One of the reasons that DESCRIBE is part of the standard is because it
   is impossible to write a useful version of it using the existing
   accessors.

                                                barmar

I was aware of this, and it is the principal reason why DESCRIBE *should*
be defined in terms of a portable standard.  I think Common Lisp
should be commited to providing user-level support for its concepts.
I consider this as part of the criteria for being complete.  By
stipulating that DESCRIBE can be written in portable CL and then
extending the language to make this true we will have satisfied one
of the requirements for making CL complete.  More generally I believe
that Common Lisp should be powerful enough to implement a portable
programming environment.  

Chris Eliot