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go-yaml/yaml · source

Snapshot 0 · 2026-11-04T12:47:23Z · Go ·

GitHub description at capture

YAML support for the Go language.

README at capture

# THIS PROJECT IS UNMAINTAINED

This was one of my first Go projects, bootstapped over the christmas break of 2010 and well maintained for over a decade, often with help from contributors. Sadly, in the last few years my own free time, both personal and professional, became less common, and none of the contributions turned into more extensive long term engagements. I was hoping to address the situation by moving it into a dedicated professional team at a more resourceful home such as Canonical, Google, etc, but that hasn't materialized in time either.  So I'm now taking the more explicit action of clearly labeling the project as unmaintained, to inform the community of what should already be obvious by now.

There's still a chance I may come back and bring this project to where I wish it should go, but something else will have to change for this to be viable.  Unfortunately, despite my own lack of time for the project, I cannot just "hand off" maintenance to an individual or to a small group either, due to the likelyhood of the project going back into an unmaintained, unstable, or even abused state.

Sorry about that.

_-- Gustavo Niemeyer_

# ORIGINAL README

## 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
```