//// <summary>
/// Returns an int value encapsulated in an object item that indicates a promotion level.
/// </summary>
/// <param name="firstOperand">An array to promote.</param>
/// <returns>Returns a promotion value.</returns>
public override object Exec(ArrayType firstOperand, object arg)
{
// * Array and bounded type variable
ArrayType array = TypeExpression.As <ArrayType>(this.secondOperand);
if (array != null)
{
TypeExpression firstOperandArrayTypeExpression = firstOperand.ArrayTypeExpression;
TypeExpression secondOperandArrayTypeExpression = array.ArrayTypeExpression;
if (firstOperandArrayTypeExpression is TypeVariable && ((TypeVariable)firstOperandArrayTypeExpression).Substitution != null)
{
firstOperandArrayTypeExpression = ((TypeVariable)firstOperandArrayTypeExpression).Substitution;
}
if (secondOperandArrayTypeExpression is TypeVariable && ((TypeVariable)secondOperandArrayTypeExpression).Substitution != null)
{
secondOperandArrayTypeExpression = ((TypeVariable)secondOperandArrayTypeExpression).Substitution;
}
return(firstOperandArrayTypeExpression.Equals(secondOperandArrayTypeExpression) ? 0 : -1);
}
// * A free variable is a complete promotion
TypeVariable typeVariable = this.secondOperand as TypeVariable;
if (typeVariable != null && typeVariable.Substitution == null)
{
return(0);
}
// * Union type and bounded type variable
UnionType unionType = TypeExpression.As <UnionType>(this.secondOperand);
if (unionType != null)
{
return(unionType.SuperType(firstOperand));
}
// * Field type and bounded type variable
FieldType fieldType = TypeExpression.As <FieldType>(this.secondOperand);
if (fieldType != null)
{
return(firstOperand.AcceptOperation(new PromotionLevelOperation(fieldType.FieldTypeExpression), arg));
}
// * Use the BCL object oriented approach
return(firstOperand.AsClassType().AcceptOperation(this, arg));
}
public override object Exec(TypeExpression te, object arg)
{
return(te.Equals(this.typeExpression));
}