Scala example source code file (test5refine.scala)

This example Scala source code file (test5refine.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

f, g, g, i, if, if, ig, ig, m, p, q, q, x, y

The Scala test5refine.scala source code

import scala._;

object test {

  abstract trait F { type If; }

  def f[Jf](h: Jf):F { type If = Jf } = f[Jf](h);

  abstract trait G { type Ig; }

  def g[Jg](h: Jg):G { type Ig = Jg } = g[Jg](h);

  abstract class M() {
      type P;
      abstract class I() {
	  type X;

	  // Methods to check the type X and P as seen from instances of I
	  def chk_ix(x: X): Unit = {}
	  def chk_ip(p: P): Unit = {}

	  // Value with type X as seen from instances of I
	  def val_ix: X = val_ix;
      }

      val i: I { type X = G { type Ig = P } } = null;

      // Values with types P and i.X as seen from instances of M
      def val_mp: P = val_mp;
      def val_mix: G { type Ig = P } = g[P](val_mp);
  }

  abstract class N() extends M() {
      type Q;
      type P = F { type If = Q };
      val j:J { type Y = G { type Ig = Q } } = null;

      abstract class J() extends I() {
	  type Y;
	  type X = G { type Ig = Y; };
	  // Values with types Y and X as seen from instances of J
	  def val_jy: Y = val_jy;
	  def val_jx: G { type Ig = Y; } = g[Y](val_jy);

	  // Check type P
	  chk_ip(val_mp);
	  chk_ip(val_np);
      }

      // Values with types Q, X.P, i.X, j.Y and j.X as seen from instances of N
      def val_nq: Q = val_nq;
      def val_np: F { type If = Q } = f[Q](val_nq);
      def val_nix: G { type Ig = F { type If = Q } } = g[F { type If = Q }](val_np);
      def val_njy: G { type Ig = Q; } = g[Q](val_nq);
      def val_njx: G { type Ig = G { type Ig = Q }} = g[G { type Ig = Q; }](val_njy);

      // Check type i.P
      i.chk_ip(val_mp);
      i.chk_ip(val_np);

      // Check type j.P
      j.chk_ip(val_mp);
      j.chk_ip(val_np); 

      // Check type i.X
      i.chk_ix(i.val_ix);
      i.chk_ix(val_mix);
      i.chk_ix(val_nix);

      // Check j.X
      j.chk_ix(j.val_ix);
      j.chk_ix(j.val_jx);
      j.chk_ix(val_njx); 
  }
}