Boo.Lang.Compiler.Steps.BindAndApplyAttributes.OnAttribute C# (CSharp) Метод

        public override void OnAttribute(Boo.Lang.Compiler.Ast.Attribute attribute)
        {
            if (null != attribute.Entity)
            {
                return;
            }

            _elements.Clear();

            if (!NameResolutionService.ResolveQualifiedName(_elements, BuildAttributeName(attribute.Name, true)))
            {
                if (!NameResolutionService.ResolveQualifiedName(_elements, BuildAttributeName(attribute.Name, false)))
                {
                    NameResolutionService.ResolveQualifiedName(_elements, attribute.Name);
                }
            }

            if (_elements.Count == 0)
            {
                string suggestion = NameResolutionService.GetMostSimilarTypeName(BuildAttributeName(attribute.Name, true));
                if (null == suggestion)
                    suggestion = NameResolutionService.GetMostSimilarTypeName(BuildAttributeName(attribute.Name, false));

                Error(attribute, CompilerErrorFactory.UnknownAttribute(attribute, attribute.Name, suggestion));
                return;
            }

            if (_elements.Count > 1)
            {
                Error(attribute, CompilerErrorFactory.AmbiguousReference(
                                attribute,
                                attribute.Name,
                                _elements));
                return;
            }

            // if _elements.Count == 1
            IEntity tag = (IEntity)_elements[0];
            if (EntityType.Type != tag.EntityType)
            {
                Error(attribute, CompilerErrorFactory.NameNotType(attribute, attribute.Name, null));
                return;
            }

            IType attributeType = ((ITypedEntity)tag).Type;
            if (IsAstAttribute(attributeType))
            {
                ExternalType externalType = attributeType as ExternalType;
                if (null == externalType)
                {
                    Error(attribute, CompilerErrorFactory.AstAttributeMustBeExternal(attribute, attributeType.FullName));
                }
                else
                {
                    ScheduleAttributeApplication(attribute, externalType.ActualType);

                    RemoveCurrentNode();
                }
            }
            else
            {
                if (!IsSystemAttribute(attributeType))
                {
                    Error(attribute, CompilerErrorFactory.TypeNotAttribute(attribute, attributeType.FullName));
                }
                else
                {
                    // remember the attribute's type
                    attribute.Name = attributeType.FullName;
                    attribute.Entity = attributeType;
                    CheckAttributeParameters(attribute);
                }
            }
        }