TOML stands for Tom's Obvious, Minimal Language. This Go package provides a
reflection interface similar to Go's standard library json
and xml
packages.
Compatible with TOML version v1.0.0.
Documentation: https://pkg.go.dev/github.com/BurntSushi/toml
See the releases page for a
changelog; this information is also in the git tag annotations (e.g. git show v0.4.0
).
This library requires Go 1.18 or newer; add it to your go.mod with:
% go get github.com/BurntSushi/toml@latest
It also comes with a TOML validator CLI tool:
% go install github.com/BurntSushi/toml/cmd/tomlv@latest
% tomlv some-toml-file.toml
For the simplest example, consider some TOML file as just a list of keys and values:
Age = 25
Cats = [ "Cauchy", "Plato" ]
Pi = 3.14
Perfection = [ 6, 28, 496, 8128 ]
DOB = 1987-07-05T05:45:00Z
Which can be decoded with:
type Config struct {
Age int
Cats []string
Pi float64
Perfection []int
DOB time.Time
}
var conf Config
_, err := toml.Decode(tomlData, &conf)
You can also use struct tags if your struct field name doesn't map to a TOML key value directly:
some_key_NAME = "wat"
type TOML struct {
ObscureKey string `toml:"some_key_NAME"`
}
Beware that like other decoders only exported fields are considered when encoding and decoding; private fields are silently ignored.
Here's an example that automatically parses values in a mail.Address
:
contacts = [
"Donald Duck <donald@duckburg.com>",
"Scrooge McDuck <scrooge@duckburg.com>",
]
Can be decoded with:
// Create address type which satisfies the encoding.TextUnmarshaler interface.
type address struct {
*mail.Address
}
func (a *address) UnmarshalText(text []byte) error {
var err error
a.Address, err = mail.ParseAddress(string(text))
return err
}
// Decode it.
func decode() {
blob := `
contacts = [
"Donald Duck <donald@duckburg.com>",
"Scrooge McDuck <scrooge@duckburg.com>",
]
`
var contacts struct {
Contacts []address
}
_, err := toml.Decode(blob, &contacts)
if err != nil {
log.Fatal(err)
}
for _, c := range contacts.Contacts {
fmt.Printf("%#v\n", c.Address)
}
// Output:
// &mail.Address{Name:"Donald Duck", Address:"donald@duckburg.com"}
// &mail.Address{Name:"Scrooge McDuck", Address:"scrooge@duckburg.com"}
}
To target TOML specifically you can implement UnmarshalTOML
TOML interface in
a similar way.
See the _example/
directory for a more complex example.