Go Go Value Object!
Inspired by my interest in domain driven design and Nicolò Pignatell's value object library for PHP I wanted to see if value objects could be implemented in Golang. Currently this is very much WIP with only two value objects: 1) a roman numeral 2) email address
Installation
go get github.com/codeinabox/go-go-valueobject
Usage
import (
"fmt"
"github.com/codeinabox/go-go-valueobject"
)
func main() {
email, err := valueobject.NewEmailAddress("joe@blogs.com")
fmt.Println(email.String())
differentEmail, err := valueobject.NewEmailAddress("mandy@blogs.com")
if email.Equals(differentEmail) == false {
fmt.Println("As expected the two emails are different")
}
}
Implementing your own value object
Implementing your own value object is easy, it just needs to adhere to the Value
interface eg
import (
"github.com/codeinabox/go-go-valueobject"
)
type Identifier struct {
value string
}
func NewIdentifier(value string) (Identifier, error) {
var n Identifier
n.value = value
return n, nil
}
func (n Identifier) String() string {
return n.value
}
func (n Identifier) Equals(value valueobject.Value) bool {
otherIdentifier, ok := value.(Identifier)
return ok && n.value == otherIdentifier.value
}
Reference
godoc
or http://godoc.org/github.com/codeinabox/go-go-valueobject