Recipe 0.7. Creating a conditional expression

You want to create a conditional expression from other conditions.

Here is an example of code to define conditional expression:

// an engine handles expression building
ConditionInterpreter<Double> engine =
	ConditionInterpreter.newInstance();
	
// the engine has an internal symbol table that map a symbol name with
// a condition

// creation and registering of the condition "c1"
engine.addCondition("c1", new ConditionImpl.Builder<Double,
	Double>(0.).operator(OperatorGreaterThan.newInstance()).build());
 
// creation and registering of the condition "c2"
engine.addCondition("c2", new ConditionImpl.Builder<Double,
	Double>(10.).operator(OperatorLowerThan.newInstance()).build());

// creation of a complex condition over "c1" and "c2"  
Condition<Double> condition = engine.compile("c1 & c2");

// test the new conditional expression
Assert.assertTrue(condition.isTrue(4.));
Assert.assertFalse(condition.isTrue(14.));

See also this link to conditions.