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fuchsia / third_party / github.com / go-yaml / yaml / 389beb8b70826bc617f5e8d713fe89e5af05f4cc
commit389beb8b70826bc617f5e8d713fe89e5af05f4cc[log] [tgz]
authorGustavo Niemeyer <[email protected]>Fri Apr 05 15:46:35 2019 +0100
committerGustavo Niemeyer <[email protected]>Fri Apr 05 15:46:35 2019 +0100
tree7063ef2374ee5af20b154e693f26212996108481
parent7c00162d41f567cd4a5d9ff829afff062bc82e9c [diff]
Preserve data in existing fields that are not decoded.

This behavior change means it's now possible to pre-initialize
values and then provide them to decoding, with the result being
a sum of the previous data and the successfuly decoded fields.

Particular care needs to be taken in loops that decode into the same
value repeatedly. If the variable decoded into is declared in a scope
out of the loop block, following iterations will observe data decoded in
previous iterations. To fix that just move the variable declaration
inside the loop.

Discussed in #395.
2 files changed
tree: 7063ef2374ee5af20b154e693f26212996108481
  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. node_test.go
  12. NOTICE
  13. parserc.go
  14. readerc.go
  15. README.md
  16. resolve.go
  17. scannerc.go
  18. sorter.go
  19. suite_test.go
  20. writerc.go
  21. yaml.go
  22. yamlh.go
  23. 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 1.2, 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:

API stability

The package API for yaml v3 will remain stable as described in 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

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
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