From ddfe2e74ecf827a0659696c3a21756f3038d585a Mon Sep 17 00:00:00 2001 From: Martin Odersky Date: Tue, 16 May 2006 11:27:18 +0000 Subject: Fixed bug 592 --- test/files/pos/bug592.scala | 71 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 test/files/pos/bug592.scala (limited to 'test/files/pos') diff --git a/test/files/pos/bug592.scala b/test/files/pos/bug592.scala new file mode 100644 index 0000000000..4d41f112ee --- /dev/null +++ b/test/files/pos/bug592.scala @@ -0,0 +1,71 @@ +trait Graph { + type Edge; + type Node <: NodeIntf; + + trait NodeIntf { + def connectWith(node: Node): Edge; + } + + def nodes: List[Node]; + def edges: List[Edge]; + def addNode: Node; + + protected var ids = 0; +} + +abstract class DirectedGraph extends Graph { + type Edge <: EdgeImpl; + + class EdgeImpl(origin: Node, dest: Node) { + def from = origin; + def to = dest; + override def toString = ""+origin+" --> "+dest + } + + class NodeImpl requires Node extends NodeIntf { + val id = ids + ids = ids + 1 + def connectWith(node: Node): Edge = { + val edge = newEdge(this, node); + edges = edge :: edges; + edge; + } + override def toString = "Node "+id + } + + protected def newNode: Node; + protected def newEdge(from: Node, to: Node): Edge; + var nodes: List[Node] = Nil; + var edges: List[Edge] = Nil; + + def addNode: Node = { + val node = newNode; + nodes = node :: nodes; + node; + } +} + +class ConcreteDirectedGraph extends DirectedGraph { + type Edge = EdgeImpl; + type Node = NodeImpl; + + protected def newNode: Node = { + new NodeImpl; + } + + protected def newEdge(f: Node, t: Node): Edge = { + new EdgeImpl(f, t); + } +} + +object ExplicitThis { + def main(args: Array[String]): Unit = { + val g: Graph = new ConcreteDirectedGraph; + val n1 = g.addNode; + val n2 = g.addNode; + val n3 = g.addNode; + Console.println(n1.connectWith(n2)) + Console.println(n2.connectWith(n3)) + Console.println(n1.connectWith(n3)) + } +} -- cgit v1.2.3