SIMSCRIPT II.5 Programming Language

SIMSCRIPT II.5 Programming Language
4.9 Entity Control Phrases
Two forms of the for statement make it possible to step through collections of entities, just as the
for v = E1 to E2 by E3 statement makes it possible to step through successive elements of arrays.
One form deals exclusively with permanent entities and the other deals with sets.
Permanent entities, having their attributes stored as arrays, are indexed sequentially. The first entity
of the permanent entity class AUTO has index 1, the second 2, ..., and the n th N.AUTO. To step
through a sequence of index numbers from 1 to N.entity for a particular permanent entity class,
use the control phrases:
or
for each entity
for each entity called variable
The first form is equivalent to the statement for entity = 1 to N.entity, where entity is
the global variable with the same name as the entity class. Thus, the statement for each AUTO
is interpreted as for AUTO = 1 to N.AUTO. The words every and all may be used in place
of each, if desired.
The second form above is interpreted as for variable = 1 to N.entity, where the variable
named in the called phrase, instead of the global variable with the same name as the entity, takes
on the sequential index values. This variable can be global or local, and cannot be subscripted.
These control phrases may be combined as desired with other for, with, unless, while, and
until control phrases.
The following statements illustrate a typical permanent entity for phrase application.
Program preamble:
permanent entities
every MALE has an AGE and a SALARY
Main program:
read N.MALE
create every MALE
for every MALE, read AGE(MALE), SALARY(MALE)
:
for every MALE with AGE(MALE) ge 21
do
add SALARY(MALE) to SUM
add 1 to N
loop
:
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