Operator overloading in Xbase

Domainmodel-2.xtext

OpOr:
    '||' | 'OR';
OpAnd:
    '&&' | 'AND';

Domainmodel.xtext

grammar org.eclipse.xtext.example.domainmodel.Domainmodel with org.eclipse.xtext.xbase.Xbase
 
...
 
Operation:
    'op' name=ValidID '(' (params+=FullJvmFormalParameter (',' params+=FullJvmFormalParameter)*)? ')' (':' type=JvmTypeReference)?
        body=XBlockExpression;

DomainmodelRuntimeModule.java

public class DomainmodelRuntimeModule extends AbstractDomainmodelRuntimeModule {
    [...]
    public Class bindOperatorMapping() {
        return OperatorMappingCustom.class;
    }
}

OperatorMappingCustom-2.java

@Singleton
public class OperatorMappingCustom extends OperatorMapping {
    public static final QualifiedName AND_2 = create("AND");
    public static final QualifiedName OR_2 = create("OR");
 
    @Override
    public QualifiedName getMethodName(QualifiedName operator) {
        if (AND_2.equals(operator)) {
            return getMethodName(AND);
        }
        if (OR_2.equals(operator)) {
            return getMethodName(OR);
        }
        return super.getMethodName(operator);
    }
}

OperatorMappingCustom.java

@Singleton
public class OperatorMappingCustom extends OperatorMapping {
    public static final QualifiedName AND_2 = create("AND");
    public static final QualifiedName OR_2 = create("OR");
}

ParserTest-2.xtend

return s!= null && s.length > 0 AND s.startsWith("bar")

ParserTest.xtend

@Test
def void testOverriddenKeyword() {
    val model = '''
        package example {
          entity MyEntity {
            property : String
            op foo(String s) {
                return s!= null && s.length > 0 AND s.startsWith("bar")
            }
          }
        }
    '''.parse
    val pack = model.elements.head as PackageDeclaration
    val entity = pack.elements.head as Entity
    val op = entity.features.last as Operation
    val method = op.jvmElements.head as JvmOperation
    model.eResource.assertNoErrors
    Assert::assertEquals("boolean", method.returnType.simpleName)
}

Xbase.xtext

OpOr:
    '||';
OpAnd:
    '&&';