groot/{rarrow,rdict,rtree}: add [N] or [X] to generated struct tags in types generated from StreamerInfos

Author: sbinet

groot/rarrow/rarrow.go

@@ -8,6 +8,7 @@ package rarrow // import "go-hep.org/x/hep/groot/rarrow"
 import (
 	"fmt"
 	"reflect"
+	"strings"
 
 	"github.com/apache/arrow/go/arrow"
 	"github.com/apache/arrow/go/arrow/array"
@@ -164,6 +165,9 @@ func dataTypeFromGo(typ reflect.Type) arrow.DataType {
 			if v, ok := f.Tag.Lookup("groot"); ok {
 				name = v
 			}
+			if idx := strings.Index(name, "["); idx > 0 {
+				name = name[:idx]
+			}
 			fields[i] = arrow.Field{
 				Name: name,
 				Type: dataTypeFromGo(f.Type),

groot/rdict/object.go

@@ -133,10 +133,14 @@ func genTypeFromSI(sictx rbytes.StreamerInfoContext, si rbytes.StreamerInfo) ref
 	var fields = make([]reflect.StructField, 0, len(si.Elements()))
 	for _, se := range si.Elements() {
 		rt := genTypeFromSE(sictx, se)
+		et := se.Title()
+		if rt.Kind() == reflect.Array {
+			et = fmt.Sprintf("[%d]", rt.Len())
+		}
 		ft := reflect.StructField{
 			Name: "ROOT_" + cxxNameSanitizer.Replace(se.Name()),
 			Type: rt,
-			Tag:  reflect.StructTag(fmt.Sprintf("groot:%q", se.Name())),
+			Tag:  reflect.StructTag(fmt.Sprintf("groot:%q", se.Name()+et)),
 		}
 		fields = append(fields, ft)
 	}

groot/rtree/read_streamers.go

@@ -48,6 +48,9 @@ func fieldOf(rt reflect.Type, field string) int {
 		if name == "" {
 			name = f.Name
 		}
+		if idx := strings.Index(name, "["); idx > 0 {
+			name = name[:idx]
+		}
 		if name == field {
 			return i
 		}