campaigner/vendor/github.com/trivago/tgo/treflect/clone.go

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// Copyright 2015-2018 trivago N.V.
//
// 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 treflect
import (
"reflect"
)
// Clone does a deep copy of the given value.
// Please note that field have to be public in order to be copied.
// Private fields will be ignored.
func Clone(v interface{}) interface{} {
value := reflect.ValueOf(v)
copy := clone(value)
return copy.Interface()
}
func clone(v reflect.Value) reflect.Value {
switch v.Kind() {
case reflect.Struct:
copy := reflect.New(v.Type())
for i := 0; i < v.Type().NumField(); i++ {
field := v.Field(i)
targetField := copy.Elem().Field(i)
if !targetField.CanSet() {
continue // ignore private fields
}
fieldCopy := clone(field)
targetField.Set(fieldCopy)
}
return copy.Elem()
case reflect.Chan:
copy := reflect.MakeChan(v.Type(), v.Len())
return copy
case reflect.Map:
copy := reflect.MakeMap(v.Type())
keys := v.MapKeys()
for _, k := range keys {
fieldCopy := clone(v.MapIndex(k))
copy.SetMapIndex(k, fieldCopy)
}
return copy
case reflect.Slice:
copy := reflect.MakeSlice(v.Type(), v.Len(), v.Len())
for i := 0; i < v.Len(); i++ {
elementCopy := clone(v.Index(i))
copy.Index(i).Set(elementCopy)
}
return copy
case reflect.Array:
copy := reflect.New(v.Type()).Elem()
for i := 0; i < v.Len(); i++ {
elementCopy := clone(v.Index(i))
copy.Index(i).Set(elementCopy)
}
return copy
default:
copy := reflect.New(v.Type())
copy.Elem().Set(v)
return copy.Elem()
}
}