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
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
# YAML support for the Go language
Introduction
------------
The yaml package enables Go programs to comfortably encode and decode YAML
values. It was developed within [Canonical](https://www.canonical.com) as
part of the [juju](https://juju.ubuntu.com) project, and is based on a
pure Go port of the well-known [libyaml](http://pyyaml.org/wiki/LibYAML)
C library to parse and generate YAML data quickly and reliably.
Compatibility
-------------
The yaml package supports most of YAML 1.2, but preserves some behavior
from 1.1 for backwards compatibility.
Specifically, as of v3 of the yaml package:
- YAML 1.1 bools (_yes/no, on/off_) are supported as long as they are being
decoded into a typed bool value. Otherwise they behave as a string. Booleans
in YAML 1.2 are _true/false_ only.
- Octals encode and decode as _0777_ per YAML 1.1, rather than _0o777_
as specified in YAML 1.2, because most parsers still use the old format.
Octals in the _0o777_ format are supported though, so new files work.
- Does not support base-60 floats. These are gone from YAML 1.2, and were
actually never supported by this package as it's clearly a poor choice.
and offers backwards
compatibility with YAML 1.1 in some cases.
1.2, including support for
anchors, tags, map merging, etc. Multi-document unmarshalling is not yet
implemented, and base-60 floats from YAML 1.1 are purposefully not
supported since they're a poor design and are gone in YAML 1.2.
Installation and usage
----------------------
The import path for the package is *gopkg.in/yaml.v3*.
To install it, run:
go get gopkg.in/yaml.v3
API documentation
-----------------
If opened in a browser, the import path itself leads to the API documentation:
- [https://gopkg.in/yaml.v3](https://gopkg.in/yaml.v3)
API stability
-------------
The package API for yaml v3 will remain stable as described in [gopkg.in](https://gopkg.in).
License
-------
The yaml package is licensed under the MIT and Apache License 2.0 licenses.
Please see the LICENSE file for details.
Example
-------
```Go
package main
import (
"fmt"
"log"
"gopkg.in/yaml.v3"
)
var data = `
a: Easy!
b:
c: 2
d: [3, 4]
`
// Note: struct fields must be public in order for unmarshal to
// correctly populate the data.
type T struct {
A string
B struct {
RenamedC int `yaml:"c"`
D []int `yaml:",flow"`
}
}
func main() {
t := T{}
err := yaml.Unmarshal([]byte(data), &t)
if err != nil {
log.Fatalf("error: %v", err)
}
fmt.Printf("--- t:\n%v\n\n", t)
d, err := yaml.Marshal(&t)
if err != nil {
log.Fatalf("error: %v", err)
}
fmt.Printf("--- t dump:\n%s\n\n", string(d))
m := make(map[interface{}]interface{})
err = yaml.Unmarshal([]byte(data), &m)
if err != nil {
log.Fatalf("error: %v", err)
}
fmt.Printf("--- m:\n%v\n\n", m)
d, err = yaml.Marshal(&m)
if err != nil {
log.Fatalf("error: %v", err)
}
fmt.Printf("--- m dump:\n%s\n\n", string(d))
}
```
This example will generate the following output:
```
--- t:
{Easy! {2 [3 4]}}
--- t dump:
a: Easy!
b:
c: 2
d: [3, 4]
--- m:
map[a:Easy! b:map[c:2 d:[3 4]]]
--- m dump:
a: Easy!
b:
c: 2
d:
- 3
- 4
```
|
