Table class hierarchy

[Mark S. Miller <mark>]

Date: Thu, 9 Nov 89 16:21:22 PST
   From: heh (Hugh Hoover)

	   The suggestions you made in your note (Nov 9, 10:33:40 1989) suggests
   the following detailed hierarchy (including implementation classes)

		-----------ScruTable --------------
	      /                   \                \
	 MuTable ----            ImmuTable      TableView
	  /          \                             /|\
   HashTable       IntegerTable                  ...  ...
		       |
		    Vector
		       |
		   WordVector

Is there a user-visible class called TableView?  Or is "table view"
simply a verbal description of ScruTables which are constructed to be
views of some other Table?  I think this is related to the issue of
whether to declare UnaryFn obsolete.

As discussed, if Vector & WordVector are MuTables, then they should be
Array and WordArray.  I don't think a formal type distinction has yet
been given to justify Array & WordArray as user-visible types.  Here
it is:

An Array is a MuTable whose domain is a contiguous sequence of
integers starting at zero and counting up.  A WordArray is an Array
whose range elements are each a PackOBits, all of the same word size. 

Should we revive Vector & WordVector, their definition is similar,
except they are ImmuTables.