Golang yaml generation double entries - parsing

Question

I want to generate the following in yaml:
- bar: hello
- bar: another
pint: guiness
- bar: second
pint: ""
in Golang, however making the following example, I get the output below:
- bar:
- bar: hello
- bar: another
pint: guiness
- bar:
- bar: second
pint: ""
It seems the YAML Golang parser puts the names of the structs in the YAML it generates like - bar: and then the member array under it. I don't want that, as it will break other things.
package main
import (
"fmt"
"gopkg.in/yaml.v2"
"log"
)
type bar struct {
Bar string
}
type foo struct {
Bars []bar `yaml:"bar"`
Pint string `yaml:"pint"`
}
func main() {
f := make([]foo, 2)
f[0].Bars = make([]bar, 2)
f[0].Bars[0].Bar = "hello"
f[0].Bars[1].Bar = "another"
f[0].Pint = "guiness"
f[1].Bars = make([]bar, 1)
f[1].Bars[0].Bar = "second"
y, err := yaml.Marshal(f)
if err != nil {
log.Fatalf("Marshal: %v", err)
}
fmt.Println(string(y))
}
I wondered if there is a way to get it to generate it like the first example?
Even if it means I have to use another YAML library.

Answer 1

Take a look at this example:
package main
import (
"fmt"
"log"
yaml "gopkg.in/yaml.v2"
)
type T struct {
Bar string `yaml:"bar,omitempty"`
Pint string `yaml:"pint,omitempty"`
}
func main() {
var t = make([]T, 3)
t[0].Bar = "hello"
t[1].Bar = "another"
t[1].Pint = "guiness"
t[2].Bar = "second"
y, err := yaml.Marshal(t)
if err != nil {
log.Fatalf("Marshal: %v", err)
}
fmt.Println(string(y))
}
Output:
- bar: hello
- bar: another
pint: guiness
- bar: second
If you want to keep the empty string like in your desired output then you can do this
package main
import (
"fmt"
"log"
yaml "gopkg.in/yaml.v2"
)
type S string
func (s *S) IsZero() bool {
return false
}
type T struct {
Bar string `yaml:"bar,omitempty"`
Pint *S `yaml:"pint,omitempty"`
}
func main() {
var t = make([]T, 3)
t[0].Bar = "hello"
t[1].Bar = "another"
p1 := S("guiness")
t[1].Pint = &p1
t[2].Bar = "second"
p2 := S("")
t[2].Pint = &p2
y, err := yaml.Marshal(t)
if err != nil {
log.Fatalf("Marshal: %v", err)
}
fmt.Println(string(y))
}
Output:
- bar: hello
- bar: another
pint: guiness
- bar: second
pint: ""
More info on yaml package: https://godoc.org/gopkg.in/yaml.v2