Marks

course.js is an application to calculate the marks of a student taking different courses

Program

The program to evaluate is shown in the following

//--- Base behavior definition
Person = Trait({
  name: "",
  role: function() {
    console.log("base person method");
  }
});

//--- Adaptations definition
function makeStudentTrait(marks) {
   return Trait({
     role: function() {
       console.log("Student method");
     },
     setMarks: function(newMarks) {
       marks = newMarks;
     },
     marks: function() {
       return marks;
     },
     printMarks: function() {
       console.log("Marks for the student " + this.name);
       for(var i=0; i<marks.length; i++) {
         console.log(marks[i].course + ": " + marks[i].mark);
       }
     }
  });
}

ProfessorOps = Trait({
  role: function() {
    console.log("Professor method");
  },
  giveMark: function(mark, student) {
    var newMarks = student.marks();
    newMarks[newMarks.length] = {
      "course": rop.isActive() ? "ROP" : "SE",
      "mark": mark
    };
    console.log(newMarks);
    student.setMarks(newMarks);
  }
});

//context instances
rop = new cop.Context({
    name: "rop"
});
se = new cop.Context({
    name : "se"
})


//--- Object instances definition
var nicolas = Object.create(Object.prototype, Person);
nicolas.name = "Nicolas";
var thomas = Object.create(Object.prototype, Person);
thomas.name = "Thomas";
var ly = Object.create(Object.prototype, Person);
ly.name = "Ly";
var martin = Object.create(Object.prototype, Person);
martin.name = "Martin";
var markus = Object.create(Object.prototype, Person);
markus.name = "Markus";

//--- Context-object-behaviora adaptations association

rop.adapt(nicolas, makeStudentTrait([]));
rop.adapt(thomas, ProfessorOps);
rop.adapt(ly, makeStudentTrait([]));
rop.adapt(martin, makeStudentTrait([]));
rop.adapt(markus, makeStudentTrait([]));

se.adapt(nicolas, ProfessorOps);
se.adapt(thomas, makeStudentTrait([]));

//--- Main
rop.activate();
thomas.giveMark(1, nicolas);
thomas.giveMark(1, ly);
thomas.giveMark(1, markus);
thomas.role();

var marks = markus.printMarks();

Precision and Recall

We begin the analysis with calculating the points-to set for the marks variable. The baseline cannot detect the implementation of the marks method, and therefore has and Unknonw result. While our implementation we point to an array of marks, which we call i4.

This array, should have only one instance (of the marks), while we detect three different instances pts(i4[0]) = {Object (instance 1), Object (instance 2), Object (instance 3)}. This may be explained by the 3 calls to the function giveMarks (one per student).

Analysis	Instances	True Positives	False Positives	False Negatives	Precision	Recall
Baseline	2	0	1	1	0	0
Whole Program	2	0	1	1	0	0
Our	2	1	2	0	0.33	1

Performance

All times are shown in ms.

Analysis	No. of Nodes	No. of Edges	Processing time	Analysis time
Baseline	150	149	688 ± 13.6	436 ± 26.7
Whole Program	248	253	969 ± 53.8	602 ± 27
Our	159	158	857 ± 35.8	383 ± 12.6