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 as part of the juju project, and is based on a pure Go port of the well-known libyaml C library to parse and generate YAML data quickly and reliably.

Compatibility

The yaml package is almost compatible with YAML 1.1, including support for anchors, tags, etc. There are still a few missing bits, such as document merging, base-60 floats (huh?), and multi-document unmarshalling. These features are not hard to add, and will be introduced as necessary.

Installation and usage

The import path for the package is gopkg.in/v1/yaml.

To install it, run:

go get gopkg.in/v1/yaml

API documentation

If opened in a browser, the import path itself leads to the API documentation:

• https://gopkg.in/v1/yaml

API stability

The package API for yaml v1 will remain stable as described in gopkg.in.

License

The yaml package is licensed under the LGPL with an exception that allows it to be linked statically. Please see the LICENSE file for details.

Example

package main

import (
        "fmt"
        "log"

        "gopkg.in/v1/yaml"
)

var data = `
a: Easy!
b:
  c: 2
  d: [3, 4]
`

type T struct {
        A string
        B struct{C int; D []int ",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