1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
|
// Copyright 2019 Red Hat, 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 path
import (
"fmt"
"strings"
)
type ContextPath struct {
Path []interface{}
Tag string
}
// New returns a new ContextPath with the given tag and path. It's a helper since go's
// literal syntax is quite verbose, especially with []interface{}{...}.
func New(tag string, path ...interface{}) ContextPath {
return ContextPath{
Tag: tag,
Path: path,
}
}
func (c ContextPath) String() string {
strs := []string{"$"}
for _, e := range c.Path {
strs = append(strs, fmt.Sprintf("%v", e))
}
return strings.Join(strs, ".")
}
// Append returns a new ContextPath with the specified elements appended.
// The underlying array is sometimes reused, so if the original path might
// be used in future Append operations, the returned ContextPath should not
// be stored into a long-lived data structure. (Store a copy instead.)
func (c ContextPath) Append(e ...interface{}) ContextPath {
return ContextPath{
Path: append(c.Path, e...),
Tag: c.Tag,
}
}
// Copy returns an identical ContextPath that shares no state with the
// original. When storing a ContextPath into a data structure, usually a
// copy should be stored instead of the original (for example, Report does
// this), since Append sometimes modifies the path's underlying array in
// place.
func (c ContextPath) Copy() ContextPath {
// make sure to preserve reflect.DeepEqual() equality
var path []interface{}
if c.Path != nil {
path = append(path, c.Path...)
}
return ContextPath{
Path: path,
Tag: c.Tag,
}
}
// Head returns the first element in the path, panics if empty.
func (c ContextPath) Head() interface{} {
return c.Path[0]
}
func (c ContextPath) Tail() ContextPath {
if len(c.Path) == 0 {
return ContextPath{}
}
return ContextPath{
Path: c.Path[1:],
Tag: c.Tag,
}
}
func (c ContextPath) Pop() ContextPath {
if len(c.Path) == 0 {
return ContextPath{}
}
return ContextPath{
Path: c.Path[:c.Len()-1],
Tag: c.Tag,
}
}
func (c ContextPath) Len() int {
return len(c.Path)
}
|
