xrotate.icn: Procedure to rotate values in list or record

link xrotate
April 30, 1993; Ralph E. Griswold
This file is in the public domain.

xrotate(X, i) rotates the values in X right by one position.  It works
for lists and records.

This procedure is mainly interesting as a recursive version of

     x1 :=: x2 :=: x3 :=: ... xn

since a better method for lists is

     push(L, pull(L))