replace some Interface() check when encode private embed struct

encode.go

@@ -64,6 +64,12 @@ var dblQuotedReplacer = strings.NewReplacer(
 	"\x7f", `\u007f`,
 )
 
+var (
+	marshalToml = reflect.TypeOf((*Marshaler)(nil)).Elem()
+	marshalText = reflect.TypeOf((*encoding.TextMarshaler)(nil)).Elem()
+	timeType    = reflect.TypeOf((*time.Time)(nil)).Elem()
+)
+
 // Marshaler is the interface implemented by types that can marshal themselves
 // into valid TOML.
 type Marshaler interface {
@@ -154,12 +160,12 @@ func (enc *Encoder) encode(key Key, rv reflect.Value) {
 	// If we can marshal the type to text, then we use that. This prevents the
 	// encoder for handling these types as generic structs (or whatever the
 	// underlying type of a TextMarshaler is).
-	switch t := rv.Interface().(type) {
-	case encoding.TextMarshaler, Marshaler:
+	switch {
+	case isMarshaler(rv):
 		enc.writeKeyValue(key, rv, false)
 		return
-	case Primitive: // TODO: #76 would make this superfluous after implemented.
-		enc.encode(key, reflect.ValueOf(t.undecoded))
+	case rv.Type() == primitiveType: // TODO: #76 would make this superfluous after implemented.
+		enc.encode(key, reflect.ValueOf(rv.Interface().(Primitive).undecoded))
 		return
 	}
 
@@ -429,11 +435,19 @@ func (enc *Encoder) eStruct(key Key, rv reflect.Value, inline bool) {
 		rt                      = rv.Type()
 		fieldsDirect, fieldsSub [][]int
 		addFields               func(rt reflect.Type, rv reflect.Value, start []int)
+		ptrto                   func(t reflect.Type) reflect.Type
 	)
+	ptrto = func(t reflect.Type) reflect.Type {
+		if t.Kind() == reflect.Ptr {
+			return ptrto(t.Elem())
+		}
+		return t
+	}
 	addFields = func(rt reflect.Type, rv reflect.Value, start []int) {
 		for i := 0; i < rt.NumField(); i++ {
 			f := rt.Field(i)
-			if f.PkgPath != "" && !f.Anonymous { /// Skip unexported fields.
+			isEmbed := f.Anonymous && ptrto(f.Type).Kind() == reflect.Struct
+			if f.PkgPath != "" && !isEmbed { /// Skip unexported fields.
 				continue
 			}
 			opts := getOptions(f.Tag)
@@ -447,7 +461,7 @@ func (enc *Encoder) eStruct(key Key, rv reflect.Value, inline bool) {
 			// not anonymous, like encoding/json does.
 			//
 			// Non-struct anonymous fields use the normal encoding logic.
-			if f.Anonymous {
+			if isEmbed {
 				if getOptions(f.Tag).name == "" && frv.Kind() == reflect.Struct {
 					addFields(frv.Type(), frv, append(start, f.Index...))
 					continue
@@ -531,7 +545,7 @@ func tomlTypeOfGo(rv reflect.Value) tomlType {
 	}
 
 	if rv.Kind() == reflect.Struct {
-		if _, ok := rv.Interface().(time.Time); ok {
+		if rv.Type() == timeType {
 			return tomlDatetime
 		}
 		if isMarshaler(rv) {
@@ -572,13 +586,8 @@ func tomlTypeOfGo(rv reflect.Value) tomlType {
 }
 
 func isMarshaler(rv reflect.Value) bool {
-	switch rv.Interface().(type) {
-	case encoding.TextMarshaler:
-		return true
-	case Marshaler:
-		return true
-	}
-	return false
+	return rv.Type().Implements(marshalText) ||
+		rv.Type().Implements(marshalToml)
 }
 
 // isTableArray reports if all entries in the array or slice are a table.