tape/dynamic.go

@@ -114,7 +114,7 @@ func DecodeAnyInto(decoder *Decoder, destination any, tag Tag) (n int, err error
 // destination from the tag and data. The head of the decoder must be at the
 // start of the payload.
 func DecodeAny(decoder *Decoder, tag Tag) (value any, n int, err error) {
-	destination, err := skeletonValue(decoder, tag)
+	destination, err := skeletonPointer(decoder, tag)
 	if err != nil { return nil, n, err }
 	nn, err := DecodeAnyInto(decoder, destination, tag)
 	n += nn; if err != nil { return nil, n, err }
@@ -192,12 +192,12 @@ func decodeAnyOrError(decoder *Decoder, destination reflect.Value, tag Tag) (n i
 		setString(destination, string(buffer))
 	case OTA:
 		// OTA: <length: UN> <elementTag: tape.Tag> <values>*
+		oldDestination := destination
 		if isTypeAny(destination.Type()) {
 			// need a skeleton value if we are assigning to any.
 			value, err := skeletonValue(decoder, tag)
 			if err != nil { return n, err }
-			destination.Set(value)
-			destination = value.Elem()
+			destination = value
 		}
 		length, nn, err := decoder.ReadUintN(tag.CN() + 1)
 		n += nn; if err != nil { return n, err }
@@ -232,6 +232,7 @@ func decodeAnyOrError(decoder *Decoder, destination reflect.Value, tag Tag) (n i
 				return n, err
 			}
 		}
+		oldDestination.Set(destination)
 	case KTV:
 		// KTV: <length: UN> (<key: U16> <tag: Tag> <value>)*
 		length, nn, err := decoder.ReadUintN(tag.CN() + 1)
@@ -245,7 +246,7 @@ func decodeAnyOrError(decoder *Decoder, destination reflect.Value, tag Tag) (n i
 			n += nn; if err != nil { return n, err }
 			itemTag, nn, err := decoder.ReadTag()
 			n += nn; if err != nil { return n, err }
-			value, err := skeletonValue(decoder, itemTag)
+			value, err := skeletonPointer(decoder, itemTag)
 			if err != nil { return n, err }
 			nn, err = decodeAny(decoder, value.Elem(), itemTag)
 			n += nn; if err != nil { return n, err }
@@ -473,10 +474,18 @@ func decodeAndSetFloat(decoder *Decoder, destination reflect.Value, bytes int) (
 	return n, errCantAssignf("unsupported bit width float%d", bytes * 8)
 }
 
-// skeletonValue returns a pointer value. In order for it to be set, it must be
-// dereferenced using Elem(). The head of the decoder must be at the start of
-// the payload.
+// skeletonValue returns an addressable value. It can be set directly. The head
+// of the decoder must be at the start of the payload when calling.
 func skeletonValue(decoder *Decoder, tag Tag) (reflect.Value, error) {
+	ptr, err := skeletonPointer(decoder, tag)
+	if err != nil { return reflect.Value { }, err }
+	return ptr.Elem(), nil
+}
+
+// skeletonPointer returns a pointer value. In order for it to be set, it must
+// be dereferenced using Elem(). The head of the decoder must be at the start of
+// the payload when calling.
+func skeletonPointer(decoder *Decoder, tag Tag) (reflect.Value, error) {
 	typ, err := typeOf(decoder, tag)
 	if err != nil { return reflect.Value { }, err }
 	return reflect.New(typ), nil
@@ -484,7 +493,7 @@ func skeletonValue(decoder *Decoder, tag Tag) (reflect.Value, error) {
 
 // typeOf returns the type of the current tag being decoded. It does not use up
 // the decoder, it only peeks. The head of the decoder must be at the start of
-// the payload.
+// the payload when calling.
 func typeOf(decoder *Decoder, tag Tag) (reflect.Type, error) {
 	switch tag.WithoutCN() {
 	case SI: