added lesson 6

src/Lesson6/Primes.sc

@@ -0,0 +1,29 @@
+def time(f: => Unit => Any): Long = {
+  val start = System.currentTimeMillis()
+  f()
+  val end = System.currentTimeMillis()
+  end - start
+}
+
+def timeVerbose(s: String)(f: => Unit => Any): Unit = {
+  println(s"[$s] Measuring time...")
+  val duration = time(f)
+  println(s"[$s] It took ${duration}ms")
+}
+
+def isPrime(i: Int): Boolean =
+  i match {
+    case i if i <= 1 => false
+    case 2 => true
+    case _ => !(2 until i).exists(x => i%x == 0)
+  }
+
+def primeSum(max: Int)(isPrimeFunc: Int => Boolean): List[(Int, Int)] = {
+  for (i <- (1 to max).toList;
+       j <- (1 to max).toList;
+       if isPrimeFunc(i + j)) yield (i, j)
+}
+
+timeVerbose("Normal Prime"){
+  primeSum(1000)(isPrime)
+}