forgejo-federation/vendor/github.com/blevesearch/bleve/mapping/reflect.go
2017-01-25 10:43:02 +08:00

89 lines
2.1 KiB
Go

// Copyright (c) 2014 Couchbase, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package mapping
import (
"reflect"
"strings"
)
func lookupPropertyPath(data interface{}, path string) interface{} {
pathParts := decodePath(path)
current := data
for _, part := range pathParts {
current = lookupPropertyPathPart(current, part)
if current == nil {
break
}
}
return current
}
func lookupPropertyPathPart(data interface{}, part string) interface{} {
val := reflect.ValueOf(data)
typ := val.Type()
switch typ.Kind() {
case reflect.Map:
// FIXME can add support for other map keys in the future
if typ.Key().Kind() == reflect.String {
key := reflect.ValueOf(part)
entry := val.MapIndex(key)
if entry.IsValid() {
return entry.Interface()
}
}
case reflect.Struct:
field := val.FieldByName(part)
if field.IsValid() && field.CanInterface() {
return field.Interface()
}
case reflect.Ptr:
ptrElem := val.Elem()
if ptrElem.IsValid() && ptrElem.CanInterface() {
return lookupPropertyPathPart(ptrElem.Interface(), part)
}
}
return nil
}
const pathSeparator = "."
func decodePath(path string) []string {
return strings.Split(path, pathSeparator)
}
func encodePath(pathElements []string) string {
return strings.Join(pathElements, pathSeparator)
}
func mustString(data interface{}) (string, bool) {
if data != nil {
str, ok := data.(string)
if ok {
return str, true
}
}
return "", false
}
// parseTagName extracts the field name from a struct tag
func parseTagName(tag string) string {
if idx := strings.Index(tag, ","); idx != -1 {
return tag[:idx]
}
return tag
}