92 lines
2.4 KiB
Go
92 lines
2.4 KiB
Go
/*
|
|
Copyright 2015 The Kubernetes Authors.
|
|
|
|
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 field
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
"strconv"
|
|
)
|
|
|
|
// Path represents the path from some root to a particular field.
|
|
type Path struct {
|
|
name string // the name of this field or "" if this is an index
|
|
index string // if name == "", this is a subscript (index or map key) of the previous element
|
|
parent *Path // nil if this is the root element
|
|
}
|
|
|
|
// NewPath creates a root Path object.
|
|
func NewPath(name string, moreNames ...string) *Path {
|
|
r := &Path{name: name, parent: nil}
|
|
for _, anotherName := range moreNames {
|
|
r = &Path{name: anotherName, parent: r}
|
|
}
|
|
return r
|
|
}
|
|
|
|
// Root returns the root element of this Path.
|
|
func (p *Path) Root() *Path {
|
|
for ; p.parent != nil; p = p.parent {
|
|
// Do nothing.
|
|
}
|
|
return p
|
|
}
|
|
|
|
// Child creates a new Path that is a child of the method receiver.
|
|
func (p *Path) Child(name string, moreNames ...string) *Path {
|
|
r := NewPath(name, moreNames...)
|
|
r.Root().parent = p
|
|
return r
|
|
}
|
|
|
|
// Index indicates that the previous Path is to be subscripted by an int.
|
|
// This sets the same underlying value as Key.
|
|
func (p *Path) Index(index int) *Path {
|
|
return &Path{index: strconv.Itoa(index), parent: p}
|
|
}
|
|
|
|
// Key indicates that the previous Path is to be subscripted by a string.
|
|
// This sets the same underlying value as Index.
|
|
func (p *Path) Key(key string) *Path {
|
|
return &Path{index: key, parent: p}
|
|
}
|
|
|
|
// String produces a string representation of the Path.
|
|
func (p *Path) String() string {
|
|
// make a slice to iterate
|
|
elems := []*Path{}
|
|
for ; p != nil; p = p.parent {
|
|
elems = append(elems, p)
|
|
}
|
|
|
|
// iterate, but it has to be backwards
|
|
buf := bytes.NewBuffer(nil)
|
|
for i := range elems {
|
|
p := elems[len(elems)-1-i]
|
|
if p.parent != nil && len(p.name) > 0 {
|
|
// This is either the root or it is a subscript.
|
|
buf.WriteString(".")
|
|
}
|
|
if len(p.name) > 0 {
|
|
buf.WriteString(p.name)
|
|
} else {
|
|
fmt.Fprintf(buf, "[%s]", p.index)
|
|
}
|
|
}
|
|
return buf.String()
|
|
}
|