Design by Contract in Xtend

[Serbest Hammade]

Hello,

I'am writing my master thesis about implementing Design by Contract elements in Xtend.
So far i implemented pre- and postcondition for methods and simple ranged invariants for member variable.
An Example:

    def int getSeconds(int hour)
    pre hour range 0 .. 23
    post result range 0 .. 1380
    {
        return hour * 60;
    }  

would be generating following Java code:

    public int getSeconds(final int hour) {
        assert hour >= 0;
        assert hour <= 23;
        int result = getSecondsCall(hour);
        assert result >= 0;
        assert result <= 1380;
        return result;    
    }
 
    public int getSecondsCall(final int hour) {
        return (hour * 60);
    }

And for class member variable with a numerical type:

    int second range 0 .. 59

to

    private int second;
    private void invSecond() {
        assert second >= 0;
        assert second <= 59;    
    }

(invSecond is called from the getters and setters)

For that features, I have edited the following files from org.eclipse.xtend.core

• src/org/eclipse/xtend/core/Xtend.xtext
• src/org/eclipse/xtend/core/jvmmodel/XtendJvmModelInferrer.java
• src/org/eclipse/xtend/core/validation/XtendValidator.java
• model/Xtend.ecore

and added my own rule system to XtendMember. In that way XtendClass, XtendInterface, XtendFunction and XtendField could have rules. (You can find my changes in https://github.com/SHammade/xtext-xtend-dbc/)

So far, so good... Now i want to add inheritance in that way you can add pre- and postconditions on method declaration in interfaces and the classes, which implement these have to implement the pre- and postconditions as well.
But I found no way from Validator or QuickfixProvider to get the declared XtendInterface, only variables from type JvmTypeReference.
Is there a way to get the declared XtendInterface from the JvmTypeReference?

thx,
Serbest