Expressions
Expressions are a combination of variables, operations, and method invocations that evaluate to some value. Expressions can be used in arguments of component instantiations, in guards of transitions, and as part of statements in actions of automata.
Given the following types
public class Person {
public int age;
public String name;
public Role role;
public String getFullName();
}
public class Role {
public int id;
}
and imports of these types
import montiarc.types.Person;
import montiarc.types.Role;
the following are valid expressions
Object creation
Person p = Person.Person();
Person p declares a variable of type Person
and Person.Person() creates the corresponding object.
Field access
p.age = 35;
accesses the field age of variable p and sets its value to 35.
p.name = "Max";
accesses the field name of variable p and sets its value to "Max"
p.role = Role.Role();
access the field role of variable p and creates a Object of type Role
p.role.id = 5;
access the field id of field role of variable p and sets it to 5
int age2 = p.age;
accesses field age of variable p and stores it in a new variable age2
Method invocation
p.getFullName()
invokes method getFullName() on the object behind variable p
Arithmetic Operators
Arithmetic operators perform mathematical operations and return a number.
| Operator | Name | Example |
|---|---|---|
| + | Addition | a + b |
| - | Subtraction | a - b |
| * | Multiplication | a * b |
| / | Division | a / b |
| % | Modulo | a % b |
Assignment Operators
Assignment operators assign a value to a variable or send a message via a port.
| Operator | Example | Abbreviation for |
|---|---|---|
| = | a = b | |
| += | a += b | a = a + b |
| -= | a -= b | a = a - b |
| *= | a *= b | a = a * b |
| /= | a /= b | a = a / b |
| %= | a %= b | a = a % b |
Comparison Operators
Comparison operators compare two values and return a boolean.
| Operator | Name | Example |
|---|---|---|
| == | Equal to | a == b |
| != | Not equal to | a != b |
| > | Greater than | a > b |
| < | Less than | a < b |
| >= | Greater than or equal | a >= b |
| <= | Less than or equal | a <= b |
Logical Operators
Logical operators operate on boolean values and return a boolean.
| Operator | Name | Example |
|---|---|---|
| && | Logical and | a && b |
| || | Logical or | a || b |
| ! | Logical not | !a |