README
¶
Go Nullable
Nullable is specifically designed for json marshalling and unmarshalling but not limited to, where zero values have business logic meaning.
Examples
package main
import (
"fmt"
"github.com/steelshot/go-nullable"
)
func main() {
var greet nullable.Any[string]
if greet.Null() {
fmt.Println("greet is null after var declaration")
}
greet = nullable.Of("")
if greet.Null() {
fmt.Println("greet is null after zero value assignment")
}
greet = nullable.Of("Hello, World!")
if greet.Null() {
fmt.Println("greet is null after value assignment")
}
fmt.Printf(`greet value is "%s"`, greet)
// Output:
// greet is null after var declaration
// greet value is "Hello, World!"
}
Roadmap
- Aliases for builtin types
- Text & Binary Marshalling
- Support YAML, TOML and others without 3rd party dependencies
- API freeze & release 1.0.0
FAQ
Which GoLang version do I need?
As of the current release, the minimum required Go version is 1.18 which introduced Go generics
What is planned for 1.0.0?
As of the current release Go generics are in their infancy age. As Go generics grow and become more streamlined, features will be added, modified or removed if there is benefit to the module. Breaking changes before v1.0.0 are expected.
License
Documentation
¶
Overview ¶
Package nullable is specifically designed for json marshalling and unmarshalling but not limited to, where zero values have business logic meaning.
Example (NullableNestedStruct) ¶
var card nullable.Any[Card]
if card.Null() {
fmt.Println("card is null after var declaration")
}
if card.Value().Person.Null() {
fmt.Println("card.Person is null after card var declaration")
}
card = nullable.Of(Card{})
if card.Null() {
fmt.Println("card is null after zero value declaration")
}
if card.Value().Person.Null() {
fmt.Println("card.Person is null after card zero value declaration")
}
card = nullable.Of(Card{
ID: "card-id",
Person: nullable.Of(Person{
Name: "John Doe",
Age: 18,
}),
})
if card.Null() {
fmt.Println("card is null after value declaration")
}
if card.Value().Person.Null() {
fmt.Println("card.Person is null after card value declaration")
}
fmt.Printf(`card value is "%s"`, card)
Output: card is null after var declaration card.Person is null after card var declaration card.Person is null after card zero value declaration card value is "{card-id {John Doe 18}}"
Example (NullableString) ¶
var greet nullable.Any[string]
if greet.Null() {
fmt.Println("greet is null after var declaration")
}
greet = nullable.Of("")
if greet.Null() {
fmt.Println("greet is null after zero value assignment")
}
greet = nullable.Of("Hello, World!")
if greet.Null() {
fmt.Println("greet is null after value assignment")
}
fmt.Printf(`greet value is "%s"`, greet)
Output: greet is null after var declaration greet value is "Hello, World!"
Example (NullableStruct) ¶
var person nullable.Any[Person]
if person.Null() {
fmt.Println("person is null after var declaration")
}
person = nullable.Of(Person{})
if person.Null() {
fmt.Println("person is null after zero value assignment")
}
person = nullable.Of(Person{
Name: "John Doe",
Age: 18,
})
if person.Null() {
fmt.Println("person is null after value assignment")
}
fmt.Printf(`person value is "%s"`, person)
Output: person is null after var declaration person value is "{John Doe 18}"
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Any ¶ added in v0.2.0
type Any[T any] struct { // contains filtered or unexported fields }
Any holds a single value of type T BUG(golang) Golang currently (if ever?) has no type constraint that indicates that a type is json (un)marshalling compatible. If you use a json incompatible type like complex64, the marshal and unmarshal functions will always fail. BUG(steelshot) Currently the Any type does not implement text/binary (un)marshalling. YAML, TOML and other's (un)marshalling will not work, for the time being, You should implement your own types that embed Any with custom (un)marshalling.
func (Any[T]) MarshalJSON ¶ added in v0.2.0
MarshalJSON implements json.Marshaler
func (*Any[T]) UnmarshalJSON ¶ added in v0.2.0
UnmarshalJSON implements json.Unmarshaler
Notes ¶
Bugs ¶
Golang currently (if ever?) has no type constraint that indicates that a type is json (un)marshalling compatible. If you use a json incompatible type like complex64, the marshal and unmarshal functions will always fail.
Currently the Any type does not implement text/binary (un)marshalling. YAML, TOML and other's (un)marshalling will not work, for the time being, You should implement your own types that embed Any with custom (un)marshalling.
Source Files
Directories