SIMSCRIPT II.5 Programming Language

Advanced Topics
The generation of specific set routines can also be suppressed to conserve memory space when their
associated operations are not used in a program. To do so, a list of the set operation codes, shown
in table 6-5, is attached to a define set statement in the following form:
,without set operation code list routines
The comma is optional. A typical program might contain the statement:
define QUEUE as a FIFO set without P and N
attributes and without FB, FA and RS routines
Table 6-5. Set Operation-Set Attribute Relationships
Set Operation
Mneumonic
Set Name Prefix
Required Set
Attribute
FF T. F,S
FL U. F,L,S
FB V. F,S,P
FA W. F,S
RF X. F,S
RL Y. F,L,S,P
RS Z. F,S,P
In unusual cases, where the programmer wants to use set-type statements but wants to provide his
own set operation routines, all seven routines can be deleted. The codes F and R delete the four file
and three remove routines, respectively. A complete range of set specifications is thus possible.
Mere mention of a set name in every statements calls for all three set attributes for the owner and
member entities and all seven set routines. Additional definition in a define set statement can
selectively delete set attributes and set routines. The extreme statement:
define set as a set without F,L,P,S,M and N
attributes without F and R routines
removes all mechanisms that make set operations possible.
6.10 Left-Handed Functions
Functions are normally used in a "right-handed" manner. That is, they are referenced as on the
right-hand side of an assignment operator, where they return a single value computed from a
number of given arguments. An example of a right-handed SIMSCRIPT II.5 function is the use of
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