BFSchema.AstConvert.GetBFSTree C# (CSharp) Method

        public BinaryFileSchema GetBFSTree(PegNode rootnode)
        {
            //First pass below root. Expecting datablocks and byteOrder fields.
            PegNode node = rootnode.child_;
            do
            {
                PegNode field = node;
                EBinaryFileSchemaParser field_id = GetNodeId(field);
                bool isformat = false;
                BfsSourceRange formatrange = GetSourceRange(field);
                BfsSourceRange blocktyperange;

                //BYTEORDER
                if (GetNodeId(field) == EBinaryFileSchemaParser.byteorder)
                {
                    BfsByteOrder byteorder = new BfsByteOrder();
                    StoreSourceRange(field, byteorder);
                    if ( GetNodeId(field.child_) == EBinaryFileSchemaParser.littleendian)
                        byteorder.ByteOrder = BfsByteOrderEnum.LittleEndian;
                    else if (GetNodeId(field.child_) == EBinaryFileSchemaParser.bigendian)
                        byteorder.ByteOrder = BfsByteOrderEnum.BigEndian;
                    else
                        byteorder.ByteOrder = BfsByteOrderEnum.LanguageDefault;
                    schema.ByteOrder = byteorder;
                }
                else
                {
                    PegNode block_content = field.child_;

                    //If the first node is a 'format' flag, go to next sibling
                    if (GetNodeId(block_content) == EBinaryFileSchemaParser.formatspecifier)
                    {
                        isformat = true;
                        formatrange = GetSourceRange(block_content);
                        block_content = block_content.next_;
                    }

                    blocktyperange = GetSourceRange(block_content);
                    block_content = block_content.next_;

                    IBfsDataBlock block;
                    switch (field_id)
                    {
                        //STRUCT
                        case EBinaryFileSchemaParser.p_struct:
                            block = new BfsStruct();
                            StoreSourceRange(node, block);
                            block.IsFormat = isformat;
                            ConvertStructType(block_content, block as IBfsStructType);
                            schema.DatablockList.Add(block);
                            break;

                        //ABS_OFFSET
                        case EBinaryFileSchemaParser.abs_offset:
                            block = new BfsAbsOffset();
                            StoreSourceRange(node, block);
                            block.IsFormat = isformat;
                            ConvertStructType(block_content, block as IBfsStructType);
                            schema.DatablockList.Add(block);
                            break;

                        //REL_OFFSET
                        case EBinaryFileSchemaParser.rel_offset:
                            block = new BfsRelOffset();
                            StoreSourceRange(node, block);
                            block.IsFormat = isformat;
                            ConvertStructType(block_content, block as IBfsStructType);
                            schema.DatablockList.Add(block);
                            break;

                        //ENUM
                        case EBinaryFileSchemaParser.p_enum:
                            block = new BfsEnum();
                            StoreSourceRange(node, block);
                            block.IsFormat = isformat;
                            ConvertEnumType(block_content, block as BfsEnum);
                            schema.DatablockList.Add(block);
                            break;

                        //BITFIELD
                        case EBinaryFileSchemaParser.bitfield:
                            block = new BfsBitfield();
                            StoreSourceRange(node, block);
                            block.BlockTypeSourceRange = GetSourceRange(field);
                            block.IsFormat = isformat;
                            ConvertBitfieldType(block_content, block as BfsBitfield);
                            schema.DatablockList.Add(block);
                            break;

                        default:
                            throw new AstConvertException("Not a data-block: " + GetNodeId(block_content));
                    }

                    block.BlockTypeSourceRange = blocktyperange;
                    if (isformat)
                        block.FormatSourceRange = formatrange;
                }

            }
            while ((node = node.next_) != null);

            return schema;
        }

        public static BinaryFileSchema ParseBfs(BinaryFileSchema schema, string source, IBfsErrorHandler errorHandler)
        {
            gotError = false;
            handler = errorHandler;
            BinaryFileSchemaParser.BinaryFileSchemaParser parser = new BinaryFileSchemaParser.BinaryFileSchemaParser();
            parser.Construct(source, new StreamErrorHandler(errorHandler) );
            bool matches = false;
            try
            {
                matches = parser.bfschema();
            }
            catch (PegException ex)
            {
                errorHandler.HandleMessage(ex.Message);
            }

            if (!matches)
            {
                ReportMessage("Schema didn't parse.");
                return null;
            }

            AstConvert converter = new AstConvert(schema,source);
            schema = converter.GetBFSTree(parser.GetRoot());
            schema = CheckBfs(schema,errorHandler);

            return schema;
        }