/// <summary>
/// Adds a new inherited type
/// </summary>
/// <param name="inheritedClass">Information about inherited type.</param>
/// <param name="fileName">File name.</param>
/// <param name="line">Line number.</param>
/// <param name="column">Column number.</param>
public override void AddBaseClass(ClassType inheritedClass, Location location)
{
System.Diagnostics.Debug.Assert(false, "A base class cannot be added to an interface.");
}
// Loop Detection
// Helper Methods
#region methodCall()
/// <summary>
/// This method does the type inference in a method call including unification.
/// It requires that a) the method to be invoked has been previously analyzed with this visitor
/// b) The formalMethod parameter is the result of the overload resolution
/// </summary>
/// <param name="actualImplicitObject">The actual implicit object</param>
/// <param name="formalMethod">The formal method to be called</param>
/// <param name="args">The ordered types of the actual parameters</param>
/// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
/// <param name="activeSortOfUnification">The active sort of unification used (Equivalent is the default
/// one and Incremental is used in the SSA bodies of the while, for and do statements)</param>
/// <param name="fileName">File name.</param>
/// <param name="line">Line number.</param>
/// <param name="column">Column number.</param>
/// <returns>The type expression of the returned value</returns>
public static TypeExpression methodCall(TypeExpression actualImplicitObject, MethodType formalMethod, TypeExpression[] args,
MethodType methodAnalyzed, SortOfUnification activeSortOfUnification, Location location)
{
UserType userType = formalMethod.MemberInfo.Class;
MethodType actualMethod = null;
// * We must create a new type with type variables for the object's attributes (the formal implicit object)
IDictionary <TypeVariable, TypeVariable> typeVariableMappings = new Dictionary <TypeVariable, TypeVariable>();
// * If the method is an instance one and the actual object is not this, we create a new implicit object to unify
if (!formalMethod.MemberInfo.hasModifier(Modifier.Static) && actualImplicitObject != null && actualImplicitObject != methodAnalyzed.memberInfo.Class)
{
// * Unifies the implicit objects (actual and formal)
UserType formalImplicitObject = (UserType)userType.CloneType(typeVariableMappings);
if (!actualImplicitObject.Unify(formalImplicitObject, SortOfUnification.Equivalent, new List <Pair <TypeExpression, TypeExpression> >()))
{
// * If the formal implicit object already has substitution (fields declararion with assignments), we override it with a union type
formalImplicitObject.Unify(actualImplicitObject, SortOfUnification.Override, new List <Pair <TypeExpression, TypeExpression> >());
}
actualImplicitObject.ValidTypeExpression = false;
}
// * If "this" is the actual implicit object, the return type is the original return type of the method
TypeExpression originalReturnType = formalMethod.Return;
if (formalMethod.HasTypeVariables() || formalMethod.Constraints.Count > 0)
{
// * We must also generate a method with fresh variables (formal method)
// when it has parameters with type variables or constraints
formalMethod = formalMethod.CloneMethodType(typeVariableMappings);
}
// * If the method has type variables...
if (formalMethod.HasTypeVariables())
{
// * We create the actual method:
// 1.- The actual return type
TypeVariable actualReturnType = TypeVariable.NewTypeVariable;
// 2.- The actual method
actualMethod = new MethodType(actualReturnType);
// 3.- The actual parameters
foreach (TypeExpression arg in args)
{
actualMethod.AddParameter(arg);
}
// * Unifies both methods
if (!actualMethod.Unify(formalMethod, SortOfUnification.Equivalent, new List <Pair <TypeExpression, TypeExpression> >()))
{
ErrorManager.Instance.NotifyError(new UnificationError(actualMethod.FullName, location));
return(null);
}
}
// * Otherwise, arguments promotion must be checked
else
{
if (args.Length != formalMethod.ParameterListCount)
{
ErrorManager.Instance.NotifyError(new ArgumentNumberError(formalMethod.FullName, args.Length, location));
return(null);
}
for (int i = 0; i < args.Length; i++)
{
if (args[i].AcceptOperation(PromotionOperation.Create(formalMethod.paramList[i], methodAnalyzed, location), null) == null)
{
return(null);
}
}
}
// * Method constraints satisfaction
if (formalMethod.Constraints.Count > 0)
{
formalMethod.Constraints.Check(methodAnalyzed, actualImplicitObject, true, activeSortOfUnification, location);
}
// * The returned type is the the actual method if there has been a unification and
// in case the method is a instance method, a concrete object has been used (not this) or
// a different implicit object (the this reference is changed in the SSA algorithm)
if (actualMethod != null && (formalMethod.MemberInfo.hasModifier(Modifier.Static) ||
ClassType.IsConcreteType(actualImplicitObject) != null ||
actualImplicitObject != formalMethod.MemberInfo.Class))
{
TypeVariable returnType = (TypeVariable)actualMethod.Return;
if (returnType.Substitution != null)
{
return(returnType.EquivalenceClass.Substitution);
}
return(returnType);
}
// * The original returned type if there has been no unification or the implicit object is "this"
return(originalReturnType);
}
