SIMSCRIPT II.5 Programming Language

SIMSCRIPT II.5 Programming Language
every MAN and WOMAN owns a FAMILY and has a
BANK.ACCOUNT
the statement:
create each MAN and WOMAN
reserves arrays for the attributes of MAN and WOMAN and the compound entity MAN, WOMAN. The
create statement is in fact interpreted as several reserve statements:
reserve JOB(*) and SALARY(*) as N.MAN
reserve F.INVESTMENTS(*),L.INVESTMENTS(*) and
N.INVESTMENTS(*) as N.WOMAN
reserve F.FAMILY(*,*),L.FAMILY(*,*), N.FAMILY(*,*) and
BANK.ACCOUNT(*,*) as N.MAN by N.WOMAN
Attributes of permanent compound entities can be released in the normal way with a destroy
each statement such as:
destroy each MAN and WOMAN
4.12 Implied Subscripts
Preceding sections described how attributes are defined and illustrated their use. Examples showed
that attributes resemble subscripted variables when they appear in programs. Every attribute reference
is of the form:
attribute name(entity identification)
For attributes of individual entities, the entity identification is either an index or a pointer value. For
attributes of compound entities, the entity identification is a list of index or pointer values.
The automatic definition of global variables with the same names as declared entities was also mentioned.
It was seen that in the context of create, destroy, and for each, where no variable
was explicitly named, the name of the appropriate global variable was understood.
Because all attributes of permanent or temporary entities are declared in the program preamble, either
explicitly, or implicitly by declaring set membership or ownership, it is possible to assume a
default or implied subscript if one is omitted from an attribute or set reference. The implied subscript
used is the variable having the same name as the entity associated with the attribute or setreferenced.
In the case of compound entities, subscripts are implied in the order they appear in the
defining every statement. For obvious reasons, common attributes, shared by more than one entity,
cannot have implied subscripts. Some examples of entity definitions and implied subscripts follow.
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