# HG changeset patch
# User Christian Urban <urbanc@in.tum.de>
# Date 1520856710 0
# Node ID 3141278cfc526712b7b1d3658544b158232ca486
# Parent  e380f5cf27f1133b939b2f86fb007ac698321d80
updated

diff -r e380f5cf27f1 -r 3141278cfc52 progs/lecture2.scala
--- a/progs/lecture2.scala	Thu Mar 08 12:33:09 2018 +0000
+++ b/progs/lecture2.scala	Mon Mar 12 12:11:50 2018 +0000
@@ -178,6 +178,20 @@
 // ... how are we supposed to know that this returns -1
 
 
+//other example for options...NaN
+val squareRoot: PartialFunction[Double, Double] = { 
+    case d: Double if d > 0 => Math.sqrt(d) 
+}
+
+val list: List[Double] = List(4, 16, 25, -9)
+
+val result = list.map(Math.sqrt)
+// => result: List[Double] = List(2.0, 4.0, 5.0, NaN)
+
+val result = list.collect(squareRoot)
+// => result: List[Double] = List(2.0, 4.0, 5.0)
+
+
 // Higher-Order Functions
 //========================