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Task/Text-processing-2/Scala/text-processing-2.scala

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+object DataMunging2 {
+  import scala.io.Source
+  import scala.collection.immutable.{TreeMap => Map}
+
+  val pattern = """^(\d+-\d+-\d+)""" + """\s+(\d+\.\d+)\s+(-?\d+)""" * 24 + "$" r;
+
+  def main(args: Array[String]) {
+    val files = args map (new java.io.File(_)) filter (file => file.isFile && file.canRead)
+    val (numFormatErrors, numValidRecords, dateMap) =
+      files.iterator.flatMap(file => Source fromFile file getLines ()).
+        foldLeft((0, 0, new Map[String, Int] withDefaultValue 0)) {
+        case ((nFE, nVR, dM), line) => pattern findFirstMatchIn line map (_.subgroups) match {
+          case Some(List(date, rawData @ _*)) =>
+            val allValid = (rawData map (_ toDouble) iterator) grouped 2 forall (_.last > 0)
+            (nFE, nVR + (if (allValid) 1 else 0), dM(date) += 1)
+          case None => (nFE + 1, nVR, dM)
+        }
+      }
+
+    dateMap foreach {
+      case (date, repetitions) if repetitions > 1 => println(date+": "+repetitions+" repetitions")
+      case _ =>
+    }
+
+    println("""|
+               |Valid records: %d
+               |Duplicated dates: %d
+               |Duplicated records: %d
+               |Data format errors: %d
+               |Invalid data records: %d
+               |Total records: %d""".stripMargin format (
+              numValidRecords,
+              dateMap filter { case (_, repetitions) => repetitions > 1 } size,
+              dateMap.valuesIterable filter (_ > 1) map (_ - 1) sum,
+              numFormatErrors,
+              dateMap.valuesIterable.sum - numValidRecords,
+              dateMap.valuesIterable.sum))
+  }
+}