Revert v2 line length change as discussed in #670

It was clearly a mistake to accept the default formatting change in v2,
and now there's no ideal choice. Either we revert the change and break
some projects twice, or we keep the change and break some projects once.
Given the report comes from Kubernetes, which has a relevant community
and code size, we'll revert it. At the same time, to simplify the life
of those that already started migrating towards the v3 behavior, a new
FutureLineWrap function is being introduced to trivially preserve the
new behavior where desired.

The v3 branch is not affected by this, and will retain the default
non-wrapping behavior. It will also be changed soon to support per
arbitrary line-wrapping for individual encoding operations.

Thanks to everyone who offered code and ideas, and apologies for
the trouble.
4 files changed
tree: 32e8d4cd33ca7feab3e2b4081202299f7556af4e
  1. .travis.yml
  2. apic.go
  3. decode.go
  4. decode_test.go
  5. emitterc.go
  6. encode.go
  7. encode_test.go
  8. example_embedded_test.go
  9. go.mod
  10. LICENSE
  11. LICENSE.libyaml
  12. limit_test.go
  13. NOTICE
  14. parserc.go
  15. readerc.go
  16. README.md
  17. resolve.go
  18. scannerc.go
  19. sorter.go
  20. suite_test.go
  21. writerc.go
  22. yaml.go
  23. yamlh.go
  24. yamlprivateh.go
README.md

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 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:

API stability

The package API for yaml v2 will remain stable as described in gopkg.in.

License

The yaml package is licensed under the Apache License 2.0. Please see the LICENSE file for details.

Example

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