homework_4 - Горбунов Матвей

homeworks/homework_4/src/main/scala/Cell.scala

@@ -0,0 +1,28 @@
+trait Cell
+
+class EmptyCell extends Cell {
+  override def toString: String = "empty"
+}
+
+class NumberCell(number: Int) extends Cell {
+  override def toString: String = number.toString
+}
+
+class StringCell(value: String) extends Cell{
+  override def toString: String = value
+}
+
+class ReferenceCell(ix:Int, iy:Int, table: Table) extends Cell {
+  private def getCell  = table.getCell(ix, iy)
+  private val visited : Set[Cell] = Set(this)
+  private def getValue(cell: Option[Cell], visited: Set[Cell]): String = cell match {
+    case None => "outOfRange"
+    case Some(cell) => cell match {
+      case c: ReferenceCell if visited.contains(c) => "cyclic"
+      case c: ReferenceCell => c.getValue(c.getCell, visited + c)
+      case _ => cell.toString
+    }
+  }
+
+  override def toString: String = getValue(getCell, visited)
+}

homeworks/homework_4/src/main/scala/Table.scala

@@ -0,0 +1,21 @@
+import scala.collection.mutable
+
+class Table(x: Int, y:Int) {
+  private val inner =  mutable.Map[Int, Cell]().withDefault(_ => new EmptyCell)
+
+  def getCell(ix: Int, iy: Int): Option[Cell] = {
+    val index = ix + iy * x
+    if (isInBorders(ix, iy))
+      Option(inner(index))
+    else None
+  }
+
+  def setCell(ix: Int, iy: Int, cell: Cell): Unit = {
+    val index = ix + iy * x
+    inner(index) = cell
+  }
+
+  private def isInBorders(ix:Int, iy:Int) : Boolean = {
+    ix >= 0 && ix < x && iy >= 0 && iy < y
+  }
+}

homeworks/homework_4/src/test/scala/Test.scala

@@ -5,7 +5,7 @@ object Test extends TestSuite {
         'test_createTable - {
             val table = new Table(3, 3)
             for (i <- 0 until 9) {
-                assert(table.getCell(i / 3, i % 3).toString == Some("empty"))
+                assert(table.getCell(i / 3, i % 3).map(_.toString)  == Some("empty"))
             }
             assert(table.getCell(0, -1).map(_.toString) == None)
             assert(table.getCell(-1, 0).map(_.toString) == None)