added explicit sheet position

marshaller.go

@@ -6,6 +6,7 @@ import (
 	"github.com/viant/xunsafe"
 	"github.com/xuri/excelize/v2"
 	"reflect"
+	"sort"
 	"unsafe"
 )
 
@@ -77,7 +78,17 @@ func (m *Marshaller) buildSheets(v any, structType reflect.Type, parent *session
 	xStruct := xunsafe.NewStruct(structType)
 	ptr := xunsafe.AsPointer(v)
 	var aSheet *workSheet
-	for i := range xStruct.Fields {
+
+	var fields = xStruct.Fields
+	sort.Slice(fields, func(i, j int) bool {
+		posI := sheetPos(&xStruct.Fields[i])
+		posJ := sheetPos(&xStruct.Fields[j])
+		if posI == posJ {
+			return xStruct.Fields[i].Index < xStruct.Fields[j].Index
+		}
+		return posI < posJ
+	})
+	for i := range fields {
 		field := &xStruct.Fields[i]
 		fieldType := field.Type
 		if fieldType.Kind() == reflect.Ptr {
@@ -116,6 +127,13 @@ func (m *Marshaller) buildSheets(v any, structType reflect.Type, parent *session
 	return aSheet, nil
 }
 
+func sheetPos(field *xunsafe.Field) int {
+	if tag, _ := parseTag(field.Tag); tag != nil {
+		return tag.SheetPos
+	}
+	return int(field.Index)
+}
+
 func (m *Marshaller) buildSheet(v any, tableType reflect.Type, aSession *session) (*workSheet, error) {
 	aTable, err := NewTable(tableType, aSession.tag, aSession, nil)
 	if err != nil {

tag.go

@@ -24,6 +24,7 @@ type (
 		HeaderStyle  *StyleTag
 		CellStyle    *StyleTag
 		ColumnStyle  *StyleTag
+		SheetPos     int
 		Blank        bool
 		Position     *int
 		Inverted     *bool //inverted orientation
@@ -142,13 +143,21 @@ func (t *Tag) update(key, value string, styles *[]*StyleTag) error {
 		if err := convertAndSetInt(&t.RowOffset, "rowOffset", value); err != nil {
 			return err
 		}
+	case "sheetpos":
+		var pos int
+		if err := convertAndSetInt(&pos, "sheetPos", value); err != nil {
+			return err
+		}
+		t.SheetPos = pos
+
 	case "pos":
 		var pos int
 		if err := convertAndSetInt(&pos, "pos", value); err != nil {
 			return err
 		}
 		t.Position = &pos
 	default:
+
 		if strings.HasSuffix(attr, "style") {
 			var style = &StyleTag{Style: value}
 			if index := strings.Index(attr, "."); index != -1 {