var createGrader = require("cs558-grader");

//The only argument it takes is the path to the top of the directory tree 
//of the unpacked assignment submissions.
var grader = createGrader(pathToSrcTree);

//grader has a single member function, grade(). grader.grade() is passed 
//the student name, the assignment number, the attempt number, and a 
// callback, the callback is passed an error string if there is an error, 
// otherwise the callback itself is passed as the callback to the grading 
// function, where if there is no error passed, the second argument will 
// be the score received for the submission.
grader.grade("name", assignmentNumber, attemptNumber, function(err, val){
  if(err){
    //error either in the submission grading or building the grading function
  }else{
    //val will be the score received for the particular submission
  }
});