Expressions

Intervals

Intervals are specific to the ARL rule language.

Intervals can be used in swicth expressions, and with the in and !in operators.

Intervals can be finite or infinite, using -oo for minus infinity and +oo for plus infinity. Interval bounds can be included in intervals.

For example:

2 in [1,3]
x !in ]-oo,0]

switch

The switch keyword can be used in expressions. It is quite similar to the switch expression introduced in Java 14.

String label =switch (experience) {
      case1, 2:"Junior";
      case3, 4:"Senior";
      case5:"Expert";
      default:thrownewIllegalArgumentException("unexpected experience");
    };

For more information about the types that can be used with switch, see the Statements section.

Instance creation

Like in Java, the new keyword can be used to create an instance, with or without passing parameter values.

List mylist = newArrayList();
Point myPoint = newPoint(1,2);

Method invocation

Like in Java, static methods and instance methods can be invoked in the ARL rule language.

The following example shows a static method call:

BigInteger bi = ...
if (BigInteger.valueOf(12).equals(bi))
  // code to be executed

The following example shows an instance method call:

String s = ...
if (s.contains("A"))
  // code block

Some methods can take a variable number of arguments. This is also known as Variable Arguments, or Varargs.

The following example shows a method with a variable number of arguments:

public static int sum(int... args) {
  int sum = 0;
  for(int x: args){
    sum += x;
  }
  return sum;

It can be used as follows:

int result = sum(2,5,6);