Merge pull request #58 from andreas-roehler/master

solution2.1.7.3_AR simplified

chapter02/worksheets/solution2.1.7.3_AR.scala

@@ -1,12 +1,12 @@
-/** author: Andreas Röhler */
-
 /** Exercise 2.1.7.3
 Given two sequences p: Seq[String] and q: Seq[Boolean] of equal length, compute a
 Seq[String] with those elements of p for which the corresponding element of q is true.
 Hint: use zip, map, filter. */ 
 
-val result = Seq("Joe", "Bob", "Mary").zip(Seq(true, false, true)).map { case (x, y) => if (y == true) x else () }.filter(_ != (())).map{ case x => x.toString }
-assert(result == List("Joe", "Mary"))
+val result = Seq("Joe", "Bob", "Mary").zip(Seq(true, false, true))
+  // .map { case (x, y) => if (y == true) x else () }.filter(_ != (())).map{ case x => x.toString }
+  .filter { case (x, y) => y }.map { case ( x, y) => x }
+  assert(result == List("Joe", "Mary"))
 
 // scala> :load solution2.1.7.3_AR.scala
 // Loading solution2.1.7.3_AR.scala...