System.Xml.Xsl.XsltOld.Processor.GetGlobalParameter C# (CSharp) Method

        internal object GetGlobalParameter(XmlQualifiedName qname) {
            object parameter = args.GetParam(qname.Name, qname.Namespace);
            if (parameter == null) {
                return null;
            }
            if (
                parameter is XPathNodeIterator ||
                parameter is XPathNavigator ||
                parameter is Boolean ||
                parameter is Double ||
                parameter is String
            ) {
                // doing nothing
            } else if (
                parameter is Int16 || parameter is UInt16 ||
                parameter is Int32 || parameter is UInt32 ||
                parameter is Int64 || parameter is UInt64 ||
                parameter is Single || parameter is Decimal
            ) {
                parameter = XmlConvert.ToXPathDouble(parameter);
            } else {
                parameter = parameter.ToString();
            }
            return parameter;
        }

        internal override void Execute(Processor processor, ActionFrame frame)
        {
            Debug.Assert(processor != null && frame != null && frame.State != ValueCalculated);
            object value = null;

            switch (frame.State)
            {
                case Initialized:
                    if (IsGlobal)
                    {
                        if (frame.GetVariable(_varKey) != null)
                        { // This var was calculated already
                            frame.Finished();
                            break;
                        }
                        // Mark that the variable is being computed to check for circular references
                        frame.SetVariable(_varKey, BeingComputedMark);
                    }
                    // If this is a parameter, check whether the caller has passed the value
                    if (this.varType == VariableType.GlobalParameter)
                    {
                        value = processor.GetGlobalParameter(this.name);
                    }
                    else if (this.varType == VariableType.LocalParameter)
                    {
                        value = processor.GetParameter(this.name);
                    }
                    if (value != null)
                    {
                        goto case ValueCalculated;
                    }

                    // If value was not passed, check the 'select' attribute
                    if (this.selectKey != Compiler.InvalidQueryKey)
                    {
                        value = processor.RunQuery(frame, this.selectKey);
                        goto case ValueCalculated;
                    }

                    // If there is no 'select' attribute and the content is empty, use the empty string
                    if (this.containedActions == null)
                    {
                        value = string.Empty;
                        goto case ValueCalculated;
                    }

                    // RTF case
                    NavigatorOutput output = new NavigatorOutput(this.baseUri);
                    processor.PushOutput(output);
                    processor.PushActionFrame(frame);
                    frame.State = ProcessingChildren;
                    break;

                case ProcessingChildren:
                    RecordOutput recOutput = processor.PopOutput();
                    Debug.Assert(recOutput is NavigatorOutput);
                    value = ((NavigatorOutput)recOutput).Navigator;
                    goto case ValueCalculated;

                case ValueCalculated:
                    Debug.Assert(value != null);
                    frame.SetVariable(_varKey, value);
                    frame.Finished();
                    break;

                default:
                    Debug.Fail("Invalid execution state inside VariableAction.Execute");
                    break;
            }
        }