source: branches/PushGP/HeuristicLab.Algorithms.PushGP/HeuristicLab.Algorithms.PushGP/Expressions/RandExpressions.cs @ 14513

namespace HeuristicLab.Algorithms.PushGP.Expressions
{
  using HeuristicLab.Algorithms.PushGP.Generators;
  using HeuristicLab.Algorithms.PushGP.Interpreter;

  /// <summary>
  ///     Pushes a random NAME.
  /// </summary>
  public class NameRandExpression : StatelessExpression
  {
    protected override string InitStringRepresentation()
    {
      return "NAME.RAND";
    }

    public override void Eval(IPushGpInterpreter interpreter)
    {
      var name = NameGenerator.RandomName();

      interpreter.NameStack.Push(name);
    }
  }

  /// <summary>
  ///     Pushes a random integer.
  /// </summary>
  public class IntegerRandExpression : StatelessExpression
  {
    protected override string InitStringRepresentation()
    {
      return "INTEGER.RAND";
    }

    public override void Eval(IPushGpInterpreter interpreter)
    {
      var value = IntegerGenerator.RandomInteger(
        interpreter.Configuration.MinRandomInteger,
        interpreter.Configuration.MaxRandomInteger);

      interpreter.IntegerStack.Push(value);
    }
  }

  /// <summary>
  ///     Pushes a random float.
  /// </summary>
  public class FloatRandExpression : StatelessExpression
  {
    protected override string InitStringRepresentation()
    {
      return "FLOAT.RAND";
    }

    public override void Eval(IPushGpInterpreter interpreter)
    {
      var value = FloatGenerator.RandomFloat(
        interpreter.Configuration.MinRandomFloat,
        interpreter.Configuration.MaxRandomFloat);

      interpreter.FloatStack.Push(value);
    }
  }

  /// <summary>
  ///     Pushes a random boolean.
  /// </summary>
  public class BooleanRandExpression : StatelessExpression
  {
    protected override string InitStringRepresentation()
    {
      return "BOOLEAN.RAND";
    }

    public override void Eval(IPushGpInterpreter interpreter)
    {
      var value = BooleanGenerator.RandomBoolean();

      interpreter.BooleanStack.Push(value);
    }
  }

  /// <summary>
  ///     Pushes random expressions onto the code stack.
  /// </summary>
  public class CodeRandExpression : StatelessExpression
  {
    protected override string InitStringRepresentation()
    {
      return "CODE.RAND";
    }

    public override void Eval(IPushGpInterpreter interpreter)
    {
      if ((interpreter.IntegerStack.Count == 0) || (interpreter.IntegerStack.Top < 1)) return;

      var size = (int)(interpreter.IntegerStack.Pop() % interpreter.Configuration.MaxPointsInRandomExpression);

      var expression = CodeGenerator.RandomProgram(size, interpreter.CustomExpressions);

      interpreter.CodeStack.Push(expression);
    }
  }
}