added lesson 2

src/Lesson2/Curryfication.sc

@@ -0,0 +1,6 @@
+def mul(x: Int, y: Int): Int = x * y
+
+def mulCurry(x: Int) = (y :Int) => x * y
+
+def mulCurryScala(x: Int)(y: Int): Int = x * y
+

src/Lesson2/SumInts.sc

@@ -0,0 +1,20 @@
+def sumInts(a: Int, b: Int): Double =
+  if (a > b) 0 else a + sumInts(a + 1, b)
+
+def sumCubes(a: Int, b: Int): Double =
+  if (a > b) 0 else a * a * a + sumCubes(a + 1, b)
+
+def sumRec(a: Int, b: Int): Double =
+  if (a > b) 0 else 1.0 / a + sumRec(a + 1, b)
+
+def mapReduce(f: Int => Double, a: Int, b: Int): Double =
+  if (a > b) 0 else f(a) + mapReduce(f, a + 1, b)
+
+sumInts(3, 5)
+sumCubes(1, 3)
+sumRec(1, 3)
+
+mapReduce(i => i, 3, 5)
+mapReduce(i => i*i*i, 1, 3)
+mapReduce(i => 1.0/i, 1, 3)
+