// WriteType Unification
#region Unify
/// <summary>
/// This method unifies two type expressions (this and te)
/// </summary>
/// <param name="te">The expression to be unfied with this</param>
/// <param name="unification">Indicates if the kind of unification (equivalent, incremental or override).</param>
/// <param name="previouslyUnified">To detect infinite loops. The previously unified pairs of type expressions.</param>
/// <returns>If the unification was successful</returns>
public override bool Unify(TypeExpression te, SortOfUnification unification, IList <Pair <TypeExpression, TypeExpression> > previouslyUnified)
{
if (te == null)
{
return(false);
}
bool success = this.addToMyEquivalenceClass(te, unification, previouslyUnified);
// * Clears the type expression cache
this.ValidTypeExpression = te.ValidTypeExpression = false;
return(success);
}
/// <summary>
/// Tries to unify the constraints of a method call
/// </summary>
/// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
/// <param name="actualImplicitObject">Only suitable in an assignment constraint. It represents the actual object used to pass the message.</param>
/// <param name="showInvocationMessage">To show the invocation line and column in case an error exists</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="location">The location where method is called</param>
public override TypeExpression Check(MethodType methodAnalyzed, TypeExpression actualImplicitObject, bool showInvocationMessage,
SortOfUnification activeSortOfUnification, Location location)
{
TypeExpression result = (TypeExpression)this.FirstOperand.AcceptOperation(new CastOperation(this.CastType, methodAnalyzed, this.Location), null);
if (result == null && showInvocationMessage)
{
ErrorManager.Instance.NotifyError(new ConstraintError(location));
return(null);
}
// * If no error exists, we return the casttype
return(this.CastType);
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="alpha">The type expression to be modified</param>
/// <param name="beta">The type to be added</param>
/// <param name="sortOfUnification">The kind of unification used in the assignment</param>
public FieldTypeAssignmentConstraint(FieldType alpha, TypeExpression beta, SortOfUnification sortOfUnification)
{
this.alpha = alpha;
this.beta = beta;
if (sortOfUnification == SortOfUnification.Equivalent)
{
// * Equivalence is translated into override when fields are assigned
this.sortOfUnification = SortOfUnification.Override;
}
else
{
this.sortOfUnification = sortOfUnification;
}
}
/// <summary>
/// Tries to unify the constraints of a method call
/// </summary>
/// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
/// <param name="actualImplicitObject">Only suitable in an assignment constraint. It represents the actual object used to pass the message.</param>
/// <param name="showInvocationMessage">To show the invocation line and column in case an error exists</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="location">The location of the method call.</param>
/// <returns>If the unification has been satisfied</returns>
public override TypeExpression Check(MethodType methodAnalyzed, TypeExpression actualImplicitObject, bool showInvocationMessage,
SortOfUnification activeSortOfUnification, Location location)
{
TypeExpression result = (TypeExpression)this.FirstOperand.Exec(new BracketOperation(this.SecondOperand, methodAnalyzed, true, this.Location));
if (result == null && showInvocationMessage)
{
ErrorManager.Instance.NotifyError(new ConstraintError(location));
return(null);
}
// * If no error exists, we unify the return type variable with the actual result
this.ReturnType.Unify(result, SortOfUnification.Equivalent, new List <Pair <TypeExpression, TypeExpression> >());
this.ReturnType.ValidTypeExpression = this.ValidTypeExpression = false;
return(this.ReturnType);
}
// WriteType Promotion
#region PromotionLevel() ANULADA
///// <summary>
///// Returns a value that indicates a promotion level.
///// </summary>
///// <param name="type">WriteType to promotion.</param>
///// <returns>Returns a promotion value.</returns>
//public override int PromotionLevel(TypeExpression type) {
// // * Bool type and type variable
// if (TypeExpression.As<BoolType>(type)!=null)
// return 0;
// // * WriteType variable
// TypeVariable typeVariable = type as TypeVariable;
// if (typeVariable != null && typeVariable.Substitution==null)
// // * A free variable is complete promotion
// return 0;
// // * Union type
// UnionType unionType = TypeExpression.As<UnionType>(type);
// if (unionType != null)
// return unionType.SuperType(this);
// // * Field type and bounded type variable
// FieldType fieldType = TypeExpression.As<FieldType>(type);
// if (fieldType != null)
// return this.PromotionLevel(fieldType.FieldTypeExpression);
// // * Use the BCL object oriented approach
// return this.BCLType.PromotionLevel(type);
//}
#endregion
// WriteType Unification
#region Unify
/// <summary>
/// This method unifies two type expressions (this and te)
/// </summary>
/// <param name="te">The expression to be unfied with this</param>
/// <param name="unification">Indicates if the kind of unification (equivalent, incremental or override).</param>
/// <param name="previouslyUnified">To detect infinite loops. The previously unified pairs of type expressions.</param>
/// <returns>If the unification was successful</returns>
public override bool Unify(TypeExpression te, SortOfUnification unification, IList <Pair <TypeExpression, TypeExpression> > previouslyUnified)
{
BoolType bt = te as BoolType;
if (bt != null)
{
return(true);
}
if (te is TypeVariable && unification != SortOfUnification.Incremental)
{
// * No incremental unification is commutative
return(te.Unify(this, unification, previouslyUnified));
}
return(false);
}
/// <summary>
/// Adds a type variable to the object's equivalence class
/// </summary>
/// <param name="typeExpression">The type variable to add</param>
/// <param name="unification">Indicates if the kind of unification (equivalent, incremental or override).</param>
/// <param name="previouslyUnified">To detect infinite loops. The previously unified pairs of type expressions.</param>
/// <returns>If the type variable has been actually added</returns>
/// EN esta clase se le ha cambiado su visibilidad
internal bool addToMyEquivalenceClass(TypeExpression typeExpression, SortOfUnification unification, IList <Pair <TypeExpression, TypeExpression> > previouslyUnified)
{
// * It the type variable does not have a equivalence class, we create it
if (this.equivalenceClass == null)
{
this.equivalenceClass = new EquivalenceClass(this);
}
bool added = this.equivalenceClass.add(typeExpression, unification, previouslyUnified);
this.ValidTypeExpression = false;
if (typeExpression is TypeVariable)
{
typeExpression.ValidTypeExpression = false;
}
return(added);
}
// WriteType Unification
#region Unify
/// <summary>
/// This method unifies two type expressions (this and te)
/// </summary>
/// <param name="te">The expression to be unfied with this</param>
/// <param name="unification">Indicates if the kind of unification (equivalent, incremental or override).</param>
/// <param name="previouslyUnified">To detect infinite loops. The previously unified pairs of type expressions.</param>
/// <returns>If the unification was successful</returns>
public override bool Unify(TypeExpression te, SortOfUnification unification, IList <Pair <TypeExpression, TypeExpression> > previouslyUnified)
{
// * Infinite recursion detection
Pair <TypeExpression, TypeExpression> pair = new Pair <TypeExpression, TypeExpression>(this, te);
if (previouslyUnified.Contains(pair))
{
return(true);
}
previouslyUnified.Add(pair);
bool success = false;
ArrayType at = te as ArrayType;
if (at != null)
{
success = this.arrayType.Unify(at.arrayType, unification, previouslyUnified);
}
else if (te is TypeVariable)
{
TypeVariable typeVariable = (TypeVariable)te;
if (unification != SortOfUnification.Incremental)
{
// * Incremental is commutative
success = typeVariable.Unify(this, unification, previouslyUnified);
}
else // * Array(var) should unify to Var=Array(int)
{
if (typeVariable.Substitution != null)
{
success = this.Unify(typeVariable.Substitution, unification, previouslyUnified);
}
else
{
success = false;
}
}
}
else if (te is UnionType)
{
success = te.Unify(this, unification, previouslyUnified);
}
// * Clears the type expression cache
this.ValidTypeExpression = false;
te.ValidTypeExpression = false;
return(success);
}
/// <summary>
/// Assigns all the attributes in two this references, generating the appropriate constraints.
/// </summary>
/// <param name="classType">The type of this</param>
/// <param name="typeOfThis1">The first value of this' type</param>
/// <param name="typeOfThis2">The second value of this' type</param>
/// <param name="methodAnalyzed">Method being analyzed</param>
/// <param name="unification">WriteType of unification</param>
/// <param name="actualImplicitObject">The actual implicit object</param>
/// <summary>
public static void AssignAttributes(UserType classType, TypeExpression typeOfThis1, TypeExpression typeOfThis2,
MethodType methodAnalyzed, SortOfUnification unification, TypeExpression actualImplicitObject,
Location location)
{
if (methodAnalyzed == null)
{
return;
}
foreach (KeyValuePair <string, AccessModifier> pair in classType.Fields)
{
TypeExpression fieldType = pair.Value.Type,
fieldType1 = getFieldType(typeOfThis1, pair.Key),
fieldType2 = getFieldType(typeOfThis2, pair.Key);
TypeExpression unionType = UnionType.collect(fieldType1, fieldType2);
fieldType.AcceptOperation(new AssignmentOperation(unionType, AssignmentOperator.Assign, methodAnalyzed, unification, actualImplicitObject, location), null);
}
}
/// <summary>
/// Check if the type can make a method operation.
/// </summary>
/// <param name="actualImplicitObject">The actual implicit object employed to pass the message</param>
/// <param name="arguments">Arguments of the method.</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>WriteType obtained with the operation.</returns>
//public override TypeExpression Parenthesis(TypeExpression actualImplicitObject, TypeExpression[] arguments, MethodType methodAnalyzed,
// SortOfUnification activeSortOfUnification, Location loc) {
// TypeExpression method = overloadResolution(arguments, loc);
// if (method == null)
// return null;
// return method.Parenthesis(actualImplicitObject, arguments, methodAnalyzed, activeSortOfUnification, loc);
//}
#endregion
// WriteType Unification
#region Unify
/// <summary>
/// This method unifies two type expressions (this and te)
/// </summary>
/// <param name="te">The expression to be unfied with this</param>
/// <param name="unification">Indicates if the kind of unification (equivalent, incremental or override).</param>
/// <param name="previouslyUnified">To detect infinite loops. The previously unified pairs of type expressions.</param>
/// <returns>If the unification was successful</returns>
public override bool Unify(TypeExpression te, SortOfUnification unification, IList <Pair <TypeExpression, TypeExpression> > previouslyUnified)
{
// * Infinite recursion detection
Pair <TypeExpression, TypeExpression> pair = new Pair <TypeExpression, TypeExpression>(this, te);
if (previouslyUnified.Contains(pair))
{
return(true);
}
previouslyUnified.Add(pair);
// * Clears the type expression cache
this.ValidTypeExpression = false;
te.ValidTypeExpression = false;
// TODO
return(false);
}
/// <summary>
/// This method unifies two type expressions (this and te)
/// </summary>
/// <param name="te">The expression to be unfied with this</param>
/// <param name="unification">Indicates if the kind of unification (equivalent, incremental or override).</param>
/// <param name="previouslyUnified">To detect infinite loops. The previously unified pairs of type expressions.</param>
/// <returns>If the unification was successful</returns>
public override bool Unify(TypeExpression te, SortOfUnification unification, IList <Pair <TypeExpression, TypeExpression> > previouslyUnified)
{
InterfaceType it = TypeExpression.As <InterfaceType>(te);
if (it != null)
{
bool success = (bool)this.AcceptOperation(new EquivalentOperation(it), null);
// * Clears the type expression cache
this.ValidTypeExpression = false;
te.ValidTypeExpression = false;
return(success);
}
if (te is TypeVariable && unification != SortOfUnification.Incremental)
{
// * No incremental unification is commutative
return(te.Unify(this, unification, previouslyUnified));
}
return(false);
}
// WriteType Unification
#region Unify
/// <summary>
/// This method unifies two type expressions (this and te)
/// </summary>
/// <param name="te">The expression to be unfied with this</param>
/// <param name="unification">Indicates if the kind of unification (equivalent, incremental or override).</param>
/// <param name="previouslyUnified">To detect infinite loops. The previously unified pairs of type expressions.</param>
/// <returns>If the unification was successful</returns>
public override bool Unify(TypeExpression te, SortOfUnification unification, IList <Pair <TypeExpression, TypeExpression> > previouslyUnified)
{
DoubleType dt = te as DoubleType;
if (dt != null)
{
return(true);
}
if (te is TypeVariable && unification != SortOfUnification.Incremental)
{
// * No incremental unification is commutative
return(te.Unify(this, unification, previouslyUnified));
}
if (te is FieldType && unification == SortOfUnification.Equivalent)
{
return(((FieldType)te).FieldTypeExpression.Unify(this, unification, previouslyUnified));
}
return(false);
}
/// Assigns all the attributes in many this references, generating the appropriate constraints.
/// </summary>
/// <param name="classType">The type of this</param>
/// <param name="typesOfThisAfterCases">The types of this after each case</param>
/// <param name="methodAnalyzed">Method being analyzed</param>
/// <param name="unification">WriteType of unification</param>
/// <param name="actualImplicitObject">The actual implicit object</param>
public static void AssignAttributes(UserType classType, IList <TypeExpression> typesOfThisAfterCases,
MethodType methodAnalyzed, SortOfUnification unification, TypeExpression actualImplicitObject,
Location location)
{
if (methodAnalyzed == null)
{
return;
}
foreach (KeyValuePair <string, AccessModifier> pair in classType.Fields)
{
TypeExpression fieldType = pair.Value.Type;
TypeExpression unionType = null;
foreach (TypeExpression typeOfThis in typesOfThisAfterCases)
{
TypeExpression eachFieldType = getFieldType(typeOfThis, pair.Key);
unionType = UnionType.collect(unionType, eachFieldType);
}
fieldType.AcceptOperation(new AssignmentOperation(unionType, AssignmentOperator.Assign, methodAnalyzed, unification, actualImplicitObject, location), null);
}
}
/// <summary>
/// Checks the constraints of a attribute assigment in a method call
/// </summary>
/// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
/// <param name="actualImplicitObject">Only suitable in an assignment constraint. It represents the actual object used to pass the message.</param>
/// <param name="showInvocationMessage">To show the invocation line and column in case an error exists</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="location">Location of the method call</param>
/// <returns>The return type expression</returns>
public override TypeExpression Check(MethodType methodAnalyzed, TypeExpression actualImplicitObject, bool showInvocationMessage,
SortOfUnification activeSortOfUnification, Location location)
{
if (this.alpha.Substitution == null)
{
this.alpha.AcceptOperation(new AssignmentOperation(this.beta, AssignmentOperator.Assign, methodAnalyzed, this.sortOfUnification, actualImplicitObject, location), null);
return(this.alpha);
}
FieldType fieldType = this.alpha.Substitution as FieldType;
if (fieldType == null)
{
ErrorManager.Instance.NotifyError(new UnknownMemberError(this.memberName, location));
return(null);
}
SortOfUnification unification = activeSortOfUnification == SortOfUnification.Incremental ? SortOfUnification.Incremental: this.sortOfUnification;
fieldType.AcceptOperation(new AssignmentOperation(this.beta, AssignmentOperator.Assign, methodAnalyzed, unification, actualImplicitObject, location), null);
return(fieldType);
}
/// <summary>
/// Tries to unify the constraints of a method call
/// </summary>
/// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
/// <param name="actualImplicitObject">Only suitable in an assignment constraint. It represents the actual object used to pass the message.</param>
/// <param name="showInvocationMessage">To show the invocation line and column in case an error exists</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="location">Location of the method call</param>
/// <returns>If the unification has been satisfied</returns>
public override TypeExpression Check(MethodType methodAnalyzed, TypeExpression actualImplicitObject, bool showInvocationMessage,
SortOfUnification activeSortOfUnification, Location location)
{
TypeExpression result;
if (this.op != null)
{
//result = this.FirstOperand.Promotion(this.SecondOperand, (Enum)this.Operator, methodAnalyzed, this.Location);
result = (TypeExpression)this.FirstOperand.AcceptOperation(PromotionOperation.Create(this.SecondOperand, (Enum)this.Operator, methodAnalyzed, this.Location), null);
}
else
{
result = (TypeExpression)this.FirstOperand.AcceptOperation(PromotionOperation.Create(this.SecondOperand, methodAnalyzed, this.Location), null);
}
if (result == null && showInvocationMessage)
{
ErrorManager.Instance.NotifyError(new ConstraintError(location));
return(null);
}
// * If no error exists, we return the supertype
return(this.SecondOperand);
}
/// <summary>
/// Tries to unify the constraints of a method call
/// </summary>
/// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
/// <param name="actualImplicitObject">Only suitable in an assignment constraint. It represents the actual object used to pass the message.</param>
/// <param name="showInvocationMessage">To show the invocation line and column in case an error exists</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="location">The location where the location is called</param>
/// <returns>If the unification has been satisfied</returns>
public override TypeExpression Check(MethodType methodAnalyzed, TypeExpression actualImplicitObject, bool showInvocationMessage,
SortOfUnification activeSortOfUnification, Location location)
{
// * If the actual implicit object is a field, we take its field's type
FieldType implicitObjectAsField = TypeExpression.As <FieldType>(this.actualImplicitObject);
ClassType implicitObjectAsClass;
TypeExpression implicitObject = this.ActualImplicitObject;
if (implicitObjectAsField != null)
{
implicitObject = implicitObjectAsField.FieldTypeExpression;
implicitObjectAsClass = TypeExpression.As <ClassType>(implicitObjectAsField.FieldTypeExpression);
}
else
{
implicitObjectAsClass = TypeExpression.As <ClassType>(this.actualImplicitObject);
}
// * If the actual implicit object is concrete, so it is the saved implicit object
if (ClassType.IsConcreteType(actualImplicitObject) != null && implicitObjectAsClass != null)
{
implicitObjectAsClass.ConcreteType = true;
}
// * If the unification in the method call is incremental, this is the one to be used
SortOfUnification unification = activeSortOfUnification == SortOfUnification.Incremental ? SortOfUnification.Incremental : this.sortOfUnification;
// * Checks the parenthesis operation
TypeExpression result = (TypeExpression)this.FirstOperand.AcceptOperation(new ParenthesisOperation(implicitObject, this.Parameters, methodAnalyzed, unification, this.Location), null);
if (result == null && showInvocationMessage)
{
ErrorManager.Instance.NotifyError(new ConstraintError(location));
return(null);
}
// * If no error exists, we unify the return type variable with the actual result
this.ReturnType.Unify(result, SortOfUnification.Equivalent, new List <Pair <TypeExpression, TypeExpression> >());
this.ReturnType.ValidTypeExpression = this.ValidTypeExpression = false;
return(this.ReturnType);
}
///// <summary>
///// Check if the type can make an operation of field access.
///// Generates an error if the attribute does not exist.
///// Generates a constraint in case it is applied to a free variable.
///// </summary>
///// <param name="field">Field to access.</param>
///// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
///// <param name="previousDot">To detect infinite loops. The types that have been previously passed the dot message. Used for union types.</param>
///// <param name="fileName">File name.</param>
///// <param name="line">Line number.</param>
///// <param name="column">Column number.</param>
///// <returns>WriteType obtained with the operation.</returns>
//public override TypeExpression Dot(string field, MethodType methodAnalyzed, IList<TypeExpression> previousDot, Location loc) {
// if (this.fieldType != null) {
// // * If the field type is a dynamic union type, so it is the union
// UnionType unionType = As<UnionType>(this.fieldType);
// if (unionType != null)
// DynVarOptions.Instance.AssignDynamism(this.fieldType, this.IsDynamic);
// return this.fieldType.Dot(field, methodAnalyzed, previousDot, loc);
// }
// return null;
//}
///// <summary>
///// Tries to find a attribute.
///// No error is generated if the attribute does not exist.
///// It does not generate a constraint in case it is applied to a free variable.
///// </summary>
///// <param name="memberName">Member to access.</param>
///// <param name="previousDot">To detect infinite loops. The types that have been previously passed the dot message. Used for union types.</param>
///// <returns>WriteType obtained with the operation.</returns>
//public override TypeExpression Dot(string memberName, IList<TypeExpression> previousDot) {
// if (this.fieldType != null)
// return this.fieldType.Dot(memberName, previousDot);
// return null;
//}
#endregion
//#region Bracket() anulada
///// <summary>
///// Check if the type can make an array operation.
///// </summary>
///// <param name="index">TypeExpression of the index.</param>
///// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
///// <param name="showErrorMessage">Indicates if an error message should be shown (used for dynamic types)</param>
///// <param name="fileName">File name.</param>
///// <param name="line">Line number.</param>
///// <param name="column">Column number.</param>
///// <returns>WriteType obtained with the operation.</returns>
//public override TypeExpression Bracket(TypeExpression index, MethodType methodAnalyzed, bool showErrorMessage, Location loc) {
// if (this.fieldType != null)
// return this.fieldType.Bracket(index, methodAnalyzed, showErrorMessage, loc);
// return null;
//}
//#endregion
#region Assignment() ANULADA
/// <summary>
/// Check if the type can make an assignment operation.
/// </summary>
/// <param name="operand">WriteType expression of the operand of binary expression.</param>
/// <param name="op">Operator.</param>
/// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
/// <param name="unification">Indicates if the kind of unification (equivalent, incremental or override).</param>
/// <param name="actualImplicitObject">Only suitable when the assignment is executed as a constraint of a method call. In that case,
/// this parameter represents the actual object used to pass the message; null otherwise.</param>
/// <param name="location"> Location of the element</param>
/// <returns>WriteType obtained with the operation.</returns>
//public override TypeExpression Assignment(TypeExpression operand, AssignmentOperator op, MethodType methodAnalyzed, SortOfUnification unification,
// TypeExpression actualImplicitObject, Location location) {
// // * We check if a constraint must be generated. Is it an assignment of the implicit object's field?
// bool found = false;
// // * In case it has free variables and the reference used is this, we add a constraint to the method
// if (this.HasTypeVariables() && methodAnalyzed != null && ClassType.IsConcreteType(actualImplicitObject) == null) {
// // * They should be the same exact (sub)classes. This represent the same instance, not another instance of the same class.
// ClassType methodSuperClass = (ClassType)methodAnalyzed.MemberInfo.Class;
// while (!(found = (this.MemberInfo.Class == methodSuperClass)) && methodSuperClass != null)
// methodSuperClass = methodSuperClass.BaseClass;
// if (found) {
// // * An assignment constraint is added, postponing the type inference
// // * If an actual implicit object is used, we take its field's type
// FieldType fieldType = this;
// ClassType thisType = TypeExpression.As<ClassType>(actualImplicitObject);
// if (thisType == null) {
// FieldType field = TypeExpression.As<FieldType>(actualImplicitObject);
// if (field != null)
// thisType = TypeExpression.As<ClassType>(field.FieldTypeExpression);
// }
// if (thisType != null)
// fieldType = (FieldType)thisType.Fields[this.MemberInfo.MemberIdentifier].WriteType;
// methodAnalyzed.AddConstraint(new FieldTypeAssignmentConstraint(fieldType, operand, unification));
// methodAnalyzed.ValidTypeExpression = false;
// return this.fieldType;
// }
// }
// if (!found && this.fieldType != null)
// return this.fieldType.Assignment(operand, op, null, unification, actualImplicitObject, location);
// return null;
//}
#endregion
#region Arithmetic() >NUL>C>
/*
* /// <summary>
* /// Check if the type can make an arithmetic operation.
* /// </summary>
* /// <param name="operand">WriteType expression of the operand of binary expression.</param>
* /// <param name="op">Operator.</param>
* /// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
* /// <param name="showErrorMessage">Indicates if an error message should be shown (used for dynamic types)</param>
* /// <param name="fileName">File name.</param>
* /// <param name="line">Line number.</param>
* /// <param name="column">Column number.</param>
* /// <returns>WriteType obtained with the operation.</returns>
* public override TypeExpression Arithmetic(TypeExpression operand, Enum op, MethodType methodAnalyzed, bool showErrorMessage, Location loc) {
* if (this.fieldType != null)
* return this.fieldType.Arithmetic(operand, op, methodAnalyzed, showErrorMessage, loc);
* return null;
* }
*
* /// <summary>
* /// Check if the type can make an arithmetic operation.
* /// </summary>
* /// <param name="op">Operator.</param>
* /// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
* /// <param name="showErrorMessage">Indicates if an error message should be shown (used for dynamic types)</param>
* /// <param name="fileName">File name.</param>
* /// <param name="line">Line number.</param>
* /// <param name="column">Column number.</param>
* /// <returns>WriteType obtained with the operation.</returns>
* public override TypeExpression Arithmetic(UnaryOperator op, MethodType methodAnalyzed, bool showErrorMessage, Location loc) {
* return this.fieldType.Arithmetic(op, methodAnalyzed, showErrorMessage, loc);
* }
*/
#endregion
#region Relational()ANULADA
/* /// <summary>
* /// Check if the type can make an relational operation.
* /// </summary>
* /// <param name="operand">WriteType expression of the operand of binary expression.</param>
* /// <param name="op">Operator.</param>
* /// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
* /// <param name="showErrorMessage">Indicates if an error message should be shown (used for dynamic types)</param>
* /// <param name="fileName">File name.</param>
* /// <param name="line">Line number.</param>
* /// <param name="column">Column number.</param>
* /// <returns>WriteType obtained with the operation.</returns>
* public override TypeExpression Relational(TypeExpression operand, RelationalOperator op, MethodType methodAnalyzed, bool showErrorMessage, Location loc) {
* if (this.fieldType != null)
* return this.fieldType.Relational(operand, op, methodAnalyzed, showErrorMessage, loc);
* return null;
* }
*
*/
#endregion
#region PromotionLevl()--># /// <summary>
/// Returns a value that indicates a promotion level.
/// </summary>
/// <param name="type">WriteType to promotion.</param>
/// <returns>Returns a promotion value.</returns>
//public override int PromotionLevel(TypeExpression type) {
// if (this.fieldType != null)
// return this.fieldType.PromotionLevel(type);
// return -1;
//}
/// <summary>
#endregion
#region Promotion ANULADA
/// Requires the implicit object to be a subtype of the type parameter
/// </summary>
/// <param name="type">WriteType to promotion.</param>
/// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
/// <param name="op">An optional operator to report error messages.</param>
/// <param name="fileName">File name.</param>
/// <param name="line">Line number.</param>
/// <param name="column">Column number.</param>
///// <returns>The supertype; null if there has been some error.</returns>
//public override TypeExpression Promotion(TypeExpression type, Enum op, MethodType methodAnalyzed, Location loc) {
// if (this.fieldType != null)
// return this.fieldType.Promotion(type, op, methodAnalyzed, loc);
// return null;
//}
#endregion
#region Cast() ANULADA
/// <summary>
/// Tells if the type can be cast to the casttype
/// </summary>
/// <param name="castType">The expected type</param>
/// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
/// <param name="fileName">File name.</param>
/// <param name="line">Line number.</param>
/// <param name="column">Column number.</param>
///// <returns>The returned type expression</returns>
//public override TypeExpression Cast(TypeExpression castType, MethodType methodAnalyzed, Location loc) {
// if (this.fieldType != null)
// return this.fieldType.Cast(castType, methodAnalyzed, loc);
// return null;
//}
#endregion
// WriteType Unification
#region Unify
/// <summary>
/// This method unifies two type expressions (this and te)
/// </summary>
/// <param name="te">The expression to be unfied with this</param>
/// <param name="unification">Indicates if the kind of unification (equivalent, incremental or override).</param>
/// <param name="previouslyUnified">To detect infinite loops. The previously unified pairs of type expressions.</param>
/// <returns>If the unification was successful</returns>
public override bool Unify(TypeExpression te, SortOfUnification unification, IList <Pair <TypeExpression, TypeExpression> > previouslyUnified)
{
FieldType ft = te as FieldType;
if (ft != null)
{
bool success = this.fieldType.Unify(ft.fieldType, unification, previouslyUnified);
if (success) // * Dynamic type
{
DynVarOptions.Instance.AssignDynamism(this, ft.isDynamic);
}
// * Clears the type expression cache
this.ValidTypeExpression = false;
te.ValidTypeExpression = false;
return(success);
}
if (te is TypeVariable && unification != SortOfUnification.Incremental)
{
// * No incremental unification is commutative
return(te.Unify(this, unification, previouslyUnified));
}
return(false);
}
// WriteType Unification
#region Unify
/// <summary>
/// This method unifies two type expressions (this and te)
/// </summary>
/// <param name="te">The expression to be unfied with this</param>
/// <param name="unification">Indicates if the kind of unification (equivalent, incremental or override).</param>
/// <param name="previouslyUnified">To detect infinite loops. The previously unified pairs of type expressions.</param>
/// <returns>If the unification was successful</returns>
public override bool Unify(TypeExpression te, SortOfUnification unification, IList <Pair <TypeExpression, TypeExpression> > previouslyUnified)
{
// * Infinite recursion detection
Pair <TypeExpression, TypeExpression> pair = new Pair <TypeExpression, TypeExpression>(this, te);
if (previouslyUnified.Contains(pair))
{
return(true);
}
previouslyUnified.Add(pair);
// * First checks that all the expression are equivalent. Otherwise substitutions could be
// partially applied to type variables that should finally not be unified
bool equivalent = true;
foreach (TypeExpression type in this.typeSet)
{
if (!(equivalent = (bool)type.AcceptOperation(new EquivalentOperation(te), null)))
{
break;
}
}
if (!equivalent)
{
return(false);
}
// * Lets unify, incrementing type variables with union types
foreach (TypeExpression type in this.typeSet)
{
// * Unification of union types is incremental
te.Unify(type, SortOfUnification.Incremental, previouslyUnified);
}
// * Clears the type expression cache
this.ValidTypeExpression = false;
te.ValidTypeExpression = false;
return(true);
}
// WriteType Promotion
#region PromotionLevel() ANULADA
//public virtual int PromotionLevel(TypeExpression type) {
// return -1;
//}
#endregion
#region Promotion() ANULADA
/// <summary>
/// Requires the implicit object to be a subtype of the type parameter
/// </summary>
/// <param name="type">WriteType to promotion.</param>
/// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
/// <param name="op">An optional operator to report error messages.</param>
/// <param name="fileName">File name.</param>
/// <param name="line">Line number.</param>
/// <param name="column">Column number.</param>
/// <returns>The supertype; null if there has been some error.</returns>
//public virtual TypeExpression Promotion(TypeExpression type, MethodType methodAnalyzed, Location location) {
// if ((int) this.AcceptOperation(new PromotionLevelOperation(type)) == -1) {
// ErrorManager.Instance.NotifyError(new TypePromotionError(this.FullName, type.FullName, location));
// return null;
// }
// return type;
//}
//public virtual TypeExpression Promotion(TypeExpression type, Enum op, MethodType methodAnalyzed, Location location) {
// if ((int)this.AcceptOperation( new PromotionLevelOperation(type)) == -1) {
// ErrorManager.Instance.NotifyError(new TypePromotionError(this.FullName, type.FullName, op.ToString(), location));
// return null;
// }
// return type;
//}
#endregion
#region Cast() ANULADA
/// <summary>
/// Tells if the type can be cast to the casttype
/// </summary>
/// <param name="castType">The expected type</param>
/// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
/// <param name="fileName">File name.</param>
/// <param name="line">Line number.</param>
/// <param name="column">Column number.</param>
/// <returns>The returned type expression</returns>
//public virtual TypeExpression Cast(TypeExpression castType, MethodType methodAnalyzed, Location loc) {
// if (castType == null)
// return null;
// if (((int)castType.AcceptOperation(new PromotionLevelOperation(this)) != -1) || ((int)this.AcceptOperation(new PromotionLevelOperation(castType)) != -1))
// return castType;
// ErrorManager.Instance.NotifyError(new TypeCastError(this.FullName, castType.FullName, loc));
// return null;
//}
#endregion
#region EqualsForOverload() ANULADA
/// <summary>
/// Used to not repeat methods in overload
/// </summary>
/// <param name="typeExpression">The other type expression</param>
/// <returns>If both represent the same type</returns>
//public virtual bool EqualsForOverload(object typeExpression) {
// // * By default, we use the equals comparison
// return this.Equals(typeExpression);
//}
#endregion
// WriteType Unification
#region Unify()
/// <summary>
/// Tries to unify the type expression of this and the parameter
/// </summary>
/// <param name="te">The type expression to be unified together with this</param>
/// <param name="unification">Indicates if the kind of unification (equivalent, incremental or override).</param>
/// <param name="previouslyUnified">To detect infinite loops. The previously unified pairs of type expressions.</param>
/// <returns>If both type expressionas could be unfied</returns>
public abstract bool Unify(TypeExpression te, SortOfUnification unification, IList <Pair <TypeExpression, TypeExpression> > previouslyUnified);
// WriteType Unification
#region Unify
/// <summary>
/// This method unifies two type expressions (this and te)
/// </summary>
/// <param name="te">The expression to be unfied with this</param>
/// <param name="unification">Indicates if the kind of unification (equivalent, incremental or override).</param>
/// <param name="previouslyUnified">To detect infinite loops. The previously unified pairs of type expressions.</param>
/// <returns>If the unification was successful</returns>
public override bool Unify(TypeExpression te, SortOfUnification unification, IList <Pair <TypeExpression, TypeExpression> > previouslyUnified)
{
return(this.RealType.Unify(te, unification, previouslyUnified));
}
/// <summary>
/// Costructor of the assignment operation.
/// </summary>
/// <param name="rightOperand">TypeExpression to be assigned to the stored firstOperand operand.</param>
/// <param name="op">Kind o</param>
/// <param name="methodAnalyzed">The Actual Method Being Analysed</param>
/// <param name="unification">Kind of unification to use: Equivalent, Incremental and Override.</param>
/// <param name="actualImplicitObject">The actual "this" objet we are visiting.</param>
/// <param name="location">The location (file, line, column) of text being analyzed.</param>
public AssignmentOperation(TypeExpression rightOperand, AssignmentOperator op, MethodType methodAnalyzed, SortOfUnification unification, TypeExpression actualImplicitObject, Location location)
{
this.rightOperand = rightOperand;
this.op = op;
this.methodAnalyzed = methodAnalyzed;
this.unification = unification;
this.actualImplicitObject = actualImplicitObject;
this.location = location;
}
/// <summary>
/// Tries to unify the constraints of a method call
/// </summary>
/// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
/// <param name="actualImplicitObject">Only suitable in an assignment constraint. It represents the actual object used to pass the message.</param>
/// <param name="showInvocationMessage">To show the invocation line and column in case an error exists</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="location">The location of the method call</param>
/// <returns>If the unification has been satisfied</returns>
public override TypeExpression Check(MethodType methodAnalyzed, TypeExpression actualImplicitObject, bool showInvocationMessage, SortOfUnification activeSortOfUnification, Location location)
{
foreach (ConstraintList constraint in this.ConstraintLists)
{
TypeExpression result = constraint.Check(methodAnalyzed, actualImplicitObject, false, activeSortOfUnification, location);
if (result != null)
{
return(result);
}
}
if (showInvocationMessage)
{
ErrorManager.Instance.NotifyError(new ConstraintError(location));
}
return(null);
}
// 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);
}
/// <summary>
/// This method unifies two type expressions (this and te)
/// </summary>
/// <param name="te">The expression to be unfied with this</param>
/// <param name="unification">Indicates if the kind of unification (equivalent, incremental or override).</param>
/// <param name="previouslyUnified">To detect infinite loops. The previously unified pairs of type expressions.</param>
/// <returns>If the unification was successful</returns>
public override bool Unify(TypeExpression te, SortOfUnification unification, IList <Pair <TypeExpression, TypeExpression> > previouslyUnified)
{
return(false);
}
/// <summary>
/// To add a new type to the class equivalence.
/// </summary>
/// <param name="te">The type to be added</param>
/// <param name="unification">Indicates if the kind of unification (equivalent, incremental or override).</param>
/// <param name="previouslyUnified">To detect infinite loops. The previously unified pairs of type expressions.</param>
/// <returns>If the substitution has been correctly applied</returns>
public bool add(TypeExpression te, SortOfUnification unification, IList <Pair <TypeExpression, TypeExpression> > previouslyUnified)
{
TypeVariable tv = te as TypeVariable;
if (tv != null) // * Another type variable
// * Tries to add its substitution
{
if (tv.Substitution != null) // * If it has a substitution
{
if (!this.add(tv.EquivalenceClass.Substitution, unification, previouslyUnified)) // * We try to add it to ourselves
{
return(false); // * Both susbstitutions are not the same
}
}
// * If no error, we add it to the equivalence class
this.typeVariables[tv.Variable] = tv;
if (tv.EquivalenceClass != null) // * The parameter already has a equivalence class
{
foreach (KeyValuePair <int, TypeVariable> pair in tv.EquivalenceClass.TypeVariables)
{
if (!this.typeVariables.ContainsKey(pair.Key))
{
// * We recursively add all the element of the equivalence class
this.typeVariables[pair.Key] = pair.Value;
this.add(pair.Value, unification, previouslyUnified);
}
}
}
// * Finally, we update the equivalence class of tv
tv.EquivalenceClass = this;
return(true);
}
// * te is not a type variable
if (this.substitution != null)
{
// * A substitution already exists
if (unification == SortOfUnification.Equivalent)
{
// * They must be equivalent
if (!(bool)this.substitution.AcceptOperation(new EquivalentOperation(te), null))
{
return(false);
}
if (te.HasTypeVariables())
{
// var1=Array(int) must be unified to Array(var1)
return(te.Unify(this.substitution, unification, previouslyUnified));
}
return(true);
}
if (unification == SortOfUnification.Incremental)
{
// * The incremental behaviour implies a union of all the types
this.substitution = UnionType.collect(this.substitution, te);
return(true);
}
// * Override unification (the susbstitution is overridden)
this.substitution = te;
return(true);
}
// * We set the type as a susbstitution
substitution = te;
return(true);
}
/// <summary>
///// Check if the type can make an assignment operation.
///// </summary>
///// <param name="operand">WriteType expression of the operand of binary expression.</param>
///// <param name="op">Operator.</param>
///// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
///// <param name="unification">Indicates if the kind of unification (equivalent, incremental or override).</param>
///// <param name="actualImplicitObject">Only suitable when the assignment is executed as a constraint of a method call. In that case,
///// this parameter represents the actual object used to pass the message; null otherwise.</param>
///// <param name="fileName">File name.</param>
///// <param name="line">Line number.</param>
///// <param name="column">Column number.</param>
///// <returns>WriteType obtained with the operation.</returns>
//public override TypeExpression Assignment(TypeExpression operand, AssignmentOperator op, MethodType methodAnalyzed, SortOfUnification unification,
// TypeExpression actualImplicitObject, Location location) {
// if (op == AssignmentOperator.Assign)
// return operand;
// else
// ErrorManager.Instance.NotifyError(new AssignmentError(operand.FullName, this.FullName, location));
// return null;
//}
#endregion
#region Arithmetic() ANULADA
/*
* /// <summary>
* /// Check if the type can make an arithmetic operation.
* /// </summary>
* /// <param name="operand">WriteType expression of the operand of binary expression.</param>
* /// <param name="op">Operator.</param>
* /// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
* /// <param name="showErrorMessage">Indicates if an error message should be shown (used for dynamic types)</param>
* /// <param name="fileName">File name.</param>
* /// <param name="line">Line number.</param>
* /// <param name="column">Column number.</param>
* /// <returns>WriteType obtained with the operation.</returns>
* public override TypeExpression Arithmetic(TypeExpression operand, Enum op, MethodType methodAnalyzed, bool showErrorMessage, Location loc) {
* if (op.Equals(ArithmeticOperator.Plus) && operand.Equivalent(StringType.Instance))
* return StringType.Instance;
* if (showErrorMessage)
* ErrorManager.Instance.NotifyError(new TypePromotionError(operand.FullName, this.FullName, op.ToString(), loc));
* return null;
* } */
#endregion
// WriteType Promotion
#region PromotionLevel() ANULADA
/// <summary>
/// Returns a value that indicates a promotion level.
/// </summary>
/// <param name="type">WriteType to promotion.</param>
/// <returns>Returns a promotion value.</returns>
//public override int PromotionLevel(TypeExpression type) {
// // * Built-in types: no promotion, except string
// if (type is BoolType || type is CharType || type is DoubleType || type is IntType || type is VoidType)
// return -1;
// // * BCL Value Types (structs): No promotion
// BCLClassType bclClass = TypeExpression.As<BCLClassType>(type);
// if (bclClass != null) {
// if (bclClass.TypeInfo.IsValueType)
// return -1;
// // * Correct promotion to classes that are not value types
// return 0;
// }
// // * WriteType variable
// TypeVariable typeVariable = type as TypeVariable;
// if (typeVariable != null) {
// if (typeVariable.Substitution != null)
// // * If the variable is bounded, the promotion is the one of its substitution
// return this.PromotionLevel(typeVariable.EquivalenceClass.Substitution);
// // * A free variable is complete promotion
// return 0;
// }
// // * Union type
// UnionType unionType = TypeExpression.As<UnionType>(type);
// if (unionType != null)
// return unionType.SuperType(this);
// // * Field type and bounded type variable
// FieldType fieldType = TypeExpression.As<FieldType>(type);
// if (fieldType != null)
// return this.PromotionLevel(fieldType.FieldTypeExpression);
// // * Correct Promotion
// return 0;
//}
#endregion
// WriteType Unification
#region Unify
/// <summary>
/// This method unifies two type expressions (this and te)
/// </summary>
/// <param name="unification">Indicates if the kind of unification (equivalent, incremental or override).</param>
/// <param name="te">The expression to be unfied with this</param>
/// <param name="previouslyUnified">To detect infinite loops. The previously unified pairs of type expressions.</param>
/// <returns>If the unification was successful</returns>
public override bool Unify(TypeExpression te, SortOfUnification unification, IList <Pair <TypeExpression, TypeExpression> > previouslyUnified)
{
throw new NotImplementedException("NullType.Unify() Not implemented");
}
/// <summary>
/// Checks the satisfaction of a constraint in a method call
/// </summary>
/// <param name="methodAnalyzed">The method that is being analyzed when the operation is performed.</param>
/// <param name="actualImplicitObject">Only suitable in an assignment constraint. It represents the actual object used to pass the message.</param>
/// <param name="showInvocationMessage">To show the invocation line and column in case an error exists</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="location">The location where the method is called</param>
/// <returns>The return type expression</returns>
public abstract TypeExpression Check(MethodType methodAnalyzed, TypeExpression actualImplicitObject, bool showInvocationMessage,
SortOfUnification activeSortOfUnification, Location location);
// WriteType Promotion
#region PromotionLevel()
/// <summary>
/// Returns a value thdat indicates a promotion level.
/// </summary>
/// <param name="type">WriteType to promotion.</param>
/// <returns>Returns a promotion value.</returns>
//public override int PromotionLevel(TypeExpression type) {
// int aux, less = -1;
// // * The same type
// if (this == type)
// return 0;
// // * Equivalent types
// if ((bool)this.AcceptOperation(new EquivalentOperation(type)))
// return 0;
// // * Field type and bounded type variable
// FieldType fieldType = TypeExpression.As<FieldType>(type);
// if (fieldType != null)
// return this.PromotionLevel(fieldType.FieldTypeExpression);
// // * WriteType variable
// TypeVariable typeVariable = type as TypeVariable;
// if (typeVariable != null) {
// if (typeVariable.Substitution != null)
// // * If the variable is bounded, the promotion is the one of its substitution
// return this.PromotionLevel(typeVariable.EquivalenceClass.Substitution);
// // * A free variable is complete promotion
// return 0;
// }
// // * Inheritance
// if (this.BaseClass == null)
// // * Object only promotes to object
// return -1;
// if ((bool)this.baseClass.AcceptOperation(new EquivalentOperation(type)))
// return 1;
// else {
// aux = this.baseClass.PromotionLevel(type);
// if (aux != -1)
// return aux + 1;
// }
// // * Interfaces
// if (this.interfaceList.Count != 0) {
// for (int i = 0; i < this.interfaceList.Count; i++) {
// if ((bool)this.interfaceList[i].AcceptOperation( new EquivalentOperation(type))) {
// if ((less > 1) || (less == -1))
// less = 1;
// }
// else {
// aux = this.interfaceList[i].PromotionLevel(type);
// if (aux != -1) {
// if ((less > (aux + 1)) || (less == -1))
// less = aux + 1;
// }
// }
// }
// }
// if (less != -1)
// return less;
// // * Union type
// UnionType unionType = TypeExpression.As<UnionType>(type);
// if (unionType != null)
// return unionType.SuperType(this);
// // * No promotion
// return -1;
//}
#endregion
// WriteType Unification
#region Unify
/// <summary>
/// This method unifies two type expressions (this and te)
/// </summary>
/// <param name="te">The expression to be unfied with this</param>
/// <param name="unification">Indicates if the kind of unification (equivalent, incremental or override).</param>
/// <param name="previouslyUnified">To detect infinite loops. The previously unified pairs of type expressions.</param>
/// <returns>If the unification was successful</returns>
public override bool Unify(TypeExpression te, SortOfUnification unification, IList <Pair <TypeExpression, TypeExpression> > previouslyUnified)
{
// * Infinite recursion detection
Pair <TypeExpression, TypeExpression> pair = new Pair <TypeExpression, TypeExpression>(this, te);
if (previouslyUnified.Contains(pair))
{
return(true);
}
previouslyUnified.Add(pair);
ClassType ct = te as ClassType;
bool success = true;
// * Class WriteType
if (ct != null)
{
// * Inheritance is taken into account
if ((int)ct.AcceptOperation(new PromotionLevelOperation(this), null) == -1)
{
return(false);
}
// * Walk upward in the tree till find the correct class
while (!(bool)ct.AcceptOperation(new EquivalentOperation(this), null))
{
ct = ct.baseClass;
}
// * Now we unify the fields
foreach (string key in this.Fields.Keys)
{
FieldType thisField = (FieldType)this.Fields[key].Type,
teField = (FieldType)ct.Fields[key].Type;
if (thisField.FieldTypeExpression is ClassTypeProxy || teField.FieldTypeExpression is ClassTypeProxy)
{
success = thisField.FieldTypeExpression.FullName.Equals(teField.FieldTypeExpression.FullName);
}
else if (!(thisField.Unify(teField, unification, previouslyUnified)))
{
success = false;
}
if (!success)
{
break;
}
}
if (success && this.baseClass != null)
{
// * The same with the base class
this.baseClass.Unify(ct.baseClass, unification, previouslyUnified);
}
// * If one of the classes is a concrete type, so it is the other
if (success)
{
this.ConcreteType = ct.ConcreteType = this.ConcreteType || ct.ConcreteType;
}
}
// * WriteType variable
else if (te is TypeVariable)
{
TypeVariable typeVariable = (TypeVariable)te;
if (unification != SortOfUnification.Incremental)
{
// * Incremental is commutative
success = typeVariable.Unify(this, unification, previouslyUnified);
}
// * Incremental unification (not commutative)
else if (typeVariable.Substitution != null)
{
// * Class(var) should unify to Var=Class(int)
success = this.Unify(typeVariable.Substitution, unification, previouslyUnified);
}
else
{
success = false;
}
}
// * Union WriteType
else if (te is UnionType)
{
success = te.Unify(this, unification, previouslyUnified);
}
// * Class WriteType Proxy
else if (te is ClassTypeProxy)
{
success = this.Unify(((ClassTypeProxy)te).RealType, unification, previouslyUnified);
}
else if (te is FieldType)
{
success = this.Unify(((FieldType)te).FieldTypeExpression, unification, previouslyUnified);
}
else
{
success = false;
}
// * Clears the type expression cache
this.ValidTypeExpression = false;
te.ValidTypeExpression = false;
return(success);
}
/// <summary>
/// Constructor for method call constraints
/// </summary>
/// <param name="firstOperand">WriteType of the first operand</param>
/// <param name="actualImplicitObject">The actual implicit object used to pass the message</param>
/// <param name="parameters">The set of actual parameters</param>
/// <param name="sortOfUnification">The kind of unification used in the method call</param>
/// <param name="location">The original location where the constraint has been generated</param>
public ParenthesisConstraint(TypeExpression firstOperand, TypeExpression actualImplicitObject, TypeExpression[] parameters, SortOfUnification sortOfUnification, Location location)
: base(firstOperand, location)
{
this.actualImplicitObject = actualImplicitObject;
this.parameters = parameters;
this.sortOfUnification = sortOfUnification;
}
public ParenthesisOperation(TypeExpression actualImplicitObject, TypeExpression[] arguments, MethodType methodAnalyzed, SortOfUnification activeSortOfUnification, Location location)
{
this.actualImplicitObject = actualImplicitObject;
this.arguments = arguments;
this.methodAnalyzed = methodAnalyzed;
this.activeSortOfUnification = activeSortOfUnification;
this.location = location;
}