SIMSCRIPT II.5 Programming Language

Modelling Concepts
1. Declaration:
Use:
permanent entities
every PERSON has an AGE
let AGE = 1
is interpreted as:
let AGE(PERSON) = 1
Whenever the attribute AGE appears without an entity reference, the variable PERSON is used as the
index value. There is always a global variable associated with each entity class, PERSON in this
case. It is possible, within a routine, to define a of the same name, in which case the current value
of this local variable is used as the implicit subscript. That is, any unsubscripted use is interpreted
as shown above. If a local variable exists, then, consistently, it takes precedence over the global
name. The practice of declaring such local variables allows implicit subscripting to be used while
minimizing the danger of side effects.
2. Declaration:
Use:
temporary entities
every SHIP owns some CARGO
every CONSIGNMENT belongs to a CARGO
create a SHIP
.
.
create a CONSIGNMENT
file CONSIGNMENT in CARGO
.
.
which is interpreted as:
create a CONSIGNMENT called CONSIGNMENT
file CONSIGNMENT in CARGO(SHIP)
3. Declaration:
Use:
permanent entities
every CITY,STATE has a POPULATION
let POPULATION = 400000
interpreted as:
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