IsError() public static method

public static IsError ( Expression node ) : bool
node Boo.Lang.Compiler.Ast.Expression
return bool
Exemplo n.º 1
0
        /// <summary>
        /// Checks if a specified type argument violates the constraints
        /// declared on a specified type paramter.
        /// </summary>
        public bool ViolatesParameterConstraints(IGenericParameter parameter, TypeReference argumentNode)
        {
            IType argument = TypeSystemServices.GetEntity(argumentNode) as IType;

            // Ensure argument is a valid type
            if (argument == null || TypeSystemServices.IsError(argument))
            {
                return(false);
            }

            bool valid = true;

            // Check type semantics constraints
            if (parameter.IsClass && !argument.IsClass)
            {
                Errors.Add(CompilerErrorFactory.GenericArgumentMustBeReferenceType(ConstructionNode, parameter, argument));
                valid = false;
            }

            if (parameter.IsValueType && !argument.IsValueType)
            {
                Errors.Add(CompilerErrorFactory.GenericArgumentMustBeValueType(argumentNode, parameter, argument));
                valid = false;
            }

            // Check for default constructor
            if (parameter.MustHaveDefaultConstructor && !HasDefaultConstructor(argument))
            {
                Errors.Add(CompilerErrorFactory.GenericArgumentMustHaveDefaultConstructor(argumentNode, parameter, argument));
                valid = false;
            }

            // Check base type constraints
            IType[] baseTypes = parameter.GetTypeConstraints();
            if (baseTypes != null)
            {
                foreach (IType baseType in baseTypes)
                {
                    // Don't check for System.ValueType supertype constraint
                    // if parameter also has explicit value type constraint
                    if (baseType == _tss.ValueTypeType && parameter.IsValueType)
                    {
                        continue;
                    }

                    if (!baseType.IsAssignableFrom(argument))
                    {
                        Errors.Add(CompilerErrorFactory.GenericArgumentMustHaveBaseType(argumentNode, parameter, argument, baseType));
                        valid = false;
                    }
                }
            }

            return(!valid);
        }
Exemplo n.º 2
0
        public void ResolveArrayTypeReference(ArrayTypeReference node)
        {
            if (node.Entity != null)
            {
                return;
            }

            ResolveTypeReference(node.ElementType);

            IType elementType = TypeSystemServices.GetType(node.ElementType);

            if (TypeSystemServices.IsError(elementType))
            {
                node.Entity = TypeSystemServices.ErrorEntity;
            }
            else
            {
                int rank = null == node.Rank ? 1 : (int)node.Rank.Value;
                node.Entity = _context.TypeSystemServices.GetArrayType(elementType, rank);
            }
        }
Exemplo n.º 3
0
        /// <summary>
        /// Constructs an entity from a generic definition and arguments, after ensuring the construction is valid.
        /// </summary>
        /// <param name="definition">The generic definition entity.</param>
        /// <param name="node">The node in which construction occurs.</param>
        /// <param name="argumentNodes">The nodes of the arguments supplied for generic construction.</param>
        /// <returns>The constructed entity.</returns>
        public IEntity ConstructEntity(IEntity definition, Node constructionNode, TypeReferenceCollection argumentNodes)
        {
            // Ensure definition is a valid entity
            if (definition == null || TypeSystemServices.IsError(definition))
            {
                return(TypeSystemServices.ErrorEntity);
            }

            // Ambiguous generic constructions are handled separately
            if (definition.EntityType == EntityType.Ambiguous)
            {
                return(ConstructAmbiguousEntity((Ambiguous)definition, constructionNode, argumentNodes));
            }

            // Check that the construction is valid
            if (!CheckGenericConstruction(definition, constructionNode, argumentNodes, Errors))
            {
                return(TypeSystemServices.ErrorEntity);
            }

            // Construct a type or a method according to the definition
            IType[] arguments = Array.ConvertAll <TypeReference, IType>(
                argumentNodes.ToArray(),
                delegate(TypeReference tr) { return((IType)tr.Entity); });

            if (IsGenericType(definition))
            {
                return(((IType)definition).GenericInfo.ConstructType(arguments));
            }
            if (IsGenericMethod(definition))
            {
                return(((IMethod)definition).GenericInfo.ConstructMethod(arguments));
            }

            // Should never be reached - if definition is neither a generic type nor a generic method,
            // CheckGenericConstruction would've indicated this
            return(TypeSystemServices.ErrorEntity);
        }