How to use

flatten

function

in

CollectionChain

Promise.all(semesters.map(function (semester) {
      return self.__getSemesterCourses__(semester);
    }
  )).then(function (coursesArray) {
    return _.chain(coursesArray).flatten().uniq(function (course) {
      return course.id;
    }).value();
  }, function (err) {
    return self.__getAllCoursesOffline__();
  })

_.chain(os.networkInterfaces())
  .values()
  .flatten()
  .filter(function(val) {
   return (val.family == 'IPv4' && val.internal == false)
  })
  .map('address')
  .first()
  .value()

_.chain(prefix)
  .map(function (p) {
   var prefix = p[0]
   var starts = p[1]
   var dissolve = p[2]
   var result = []
   if (word.indexOf(prefix) == 0) {
    result = starts.map(function (start) {
     var sub = word.substring(prefix.length)
     sub = (dissolve) ? start+sub : sub
     if ((sub.indexOf(start) == 0) || (start == '*'))
      return sub
     else
      return ''
    })
   }
   return result
  })
  .flatten()
  .filter(function (c) { return c !== '' })
  .filter(function (c) { return Word.prototype.isBasicWord(c) })
  .value()

Promise.all(semesters.map(function (semester) {
      return self.__getSemesterExams__(semester);
    }
  )).then(function (examsArray) {
    return _.chain(examsArray).flatten().uniq(function (exam) {
      return exam.course.id;
    }).value();
  }, function (err) {
    return self.__getAllExamsOffline__();
  })

_.chain(confix)
  .map(function (p) {
   var confix = p[0]
   var starts = p[1]
   var dissolve = p[2]
   var end = p[3]
   var result = []
   if (word.indexOf(confix) == 0) {
    result = starts.map(function (start) {
     var sub = word.substring(confix.length)
     sub = (dissolve) ? start+sub : sub
     if ((sub.indexOf(start) == 0) || (start == '*')) {
      var limit = sub.length-end.length
      if (sub.lastIndexOf(end) == limit)
       sub = sub.substring(0, limit)
      return sub
     }
     else
      return ''
    })
   }
   return result
  })
  .flatten()
  .filter(function (c) { return c !== '' })
  .filter(function (c) { return Word.prototype.isBasicWord(c) })
  .value()