SIMSCRIPT II.5 Programming Language

SIMSCRIPT II.5 Programming Language
the for statement are bypassed. The control variable can be either local or global, and cannot be
subscripted. Form 2a does the same task as form 1, except that it starts with the set member
identified by the indicated expression. Form 2b is similar to 2a, but starts with the set member that
follows the identified member. If the identified member is not in the set (denoted by a 0 in its
membership attribute), the program terminates with an error message. In both 1 and 2, the words
every and all can be used instead of each, and the words in, on, and at used as synonyms for
of.
To step backward through a set, the phrase:
in reverse order
is placed after the set name. Set control can range from simple statements such as:
for every JOB in QUEUE
to complicated statements such as:
for all FISH after MINNOW(I) in POND in reverse order
Many variations of for statements are possible. In the following illustrations, we assume that
permanent entities with identification numbers 1, 2, 3, 4, 5, and 6 are filed in a set in the order
of 1, 3, 2, 4, 6, 5. They may have arrived in this order and been stored as FIFO, or they may
have been ranked on some attribute value. The method of ranking is not important in this example.
Table 4-1 shows different control statements and indicates the sequence of entities that are passed
on to the controlled statements by each. The entities are filed in a set named FILE. The local variable
J is used within the control loop for the selected entity index numbers.
Table 4-2 lists the set attributes that are required for the different set operations described.
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