Indirect arrays

[MOON at SCRC-TENEX]

There are other uses for indirect arrays besides those in Guy's message.  For
what they are worth:

(4) Making a subsequence of an array manipulable as an array (a first-class
object rather than a triplet of array,start,end), while retaining sharing
of side-effects on the elements, when not implementing FORTRAN nor PL/I.

(5) Making an array of n-bit bytes look like an array of m-bit bytes.

For the n-dimension/1-dimension case, rather than making specific kludges
for the particular cases that happened to be thought of first (MAPARRAY and
RAVEL), I would prefer to put in a general AREF-like function for accessing
n-dimensional arrays as if they were 1-dimensional, and its corresponding
SETF-er.  These already exist in the Lisp machine, but I won't tell you their
names, since the names are gross.