Compound Variable Names

name may be "compound" in that it may be composed of several parts (separated by periods) some of which may have variable values. The parts are then substituted independently, to generate a fully resolved name. In general,

s0.s1.s2.---.sn	is substituted to form
d0.v1.v2.---.vn	where d0 is uppercase of s0, and
	v1-vn are values of s1-sn

This facility may be used for traditional arrays, content-addressable arrays, and other indirect addressing modes. As an example, the sequence:

J = 5; a.j = "fred";

would assign fred to the variable A.5.

The stem of name (i.e. that part up to and including the first ".") may be specified on the DROP and PROCEDURE EXPOSE instructions and affect all variables starting with that stem. An assignment to a stem assigns the new value to all possible variables with that stem.