|
|
# 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 1.1 and 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.v2*.
To install it, run:
go get gopkg.in/yaml.v2
API documentation -----------------
If opened in a browser, the import path itself leads to the API documentation:
* [https://gopkg.in/yaml.v2](https://gopkg.in/yaml.v2)
API stability -------------
The package API for yaml v2 will remain stable as described in [gopkg.in](https://gopkg.in).
License -------
The yaml package is licensed under the Apache License 2.0. Please see the LICENSE file for details.
Example -------
```Go package main
import ( "fmt" "log"
"gopkg.in/yaml.v2" )
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 ```
|