Go Nullable with Generics

Go package simplifies nullable fields handling with Go Generics.

Package gonull provides a generic Nullable type for handling nullable values in a convenient way. This is useful when working with databases and JSON, where nullable values are common. Unlike other nullable libraries, gonull leverages Go's generics feature, enabling it to work seamlessly with any data type, making it more versatile and efficient.

Why gonull

Use of Go's generics allows for a single implementation that works with any data type.
Seamless integration with database/sql and JSON marshalling/unmarshalling.
Reduces boilerplate code and improves code readability.

Usage

go get github.com/LukaGiorgadze/gonull

Example

package main

import (
    "encoding/json"
    "fmt"

    "github.com/LukaGiorgadze/gonull"
)

type MyCustomInt int
type MyCustomFloat32 float32

type Person struct {
    Name    string
    Age     gonull.Nullable[MyCustomInt]
    Address gonull.Nullable[string]
    Height  gonull.Nullable[MyCustomFloat32]
}

func main() {
    jsonData := []byte(`{"Name":"Alice","Age":15,"Address":null,"Height":null}`)

    var person Person
    err := json.Unmarshal(jsonData, &person)
    if err != nil {
        panic(err)
    }
    fmt.Printf("Unmarshalled Person: %+v\n", person)

    marshalledData, err := json.Marshal(person)
    if err != nil {
        panic(err)
    }
    fmt.Printf("Marshalled JSON: %s\n", string(marshalledData))
}

Database example

type User struct {
    Name     gonull.Nullable[string]
    Age      gonull.Nullable[int]
}

func main() {
    // ...
    rows, err := db.Query("SELECT id, name, age FROM users")
    if err != nil {
        log.Fatal(err)
    }
    defer rows.Close()

    for rows.Next() {
        var user User
        err := rows.Scan(&user.Name, &user.Age)
        if err != nil {
            log.Fatal(err)
        }
        fmt.Printf("ID: %d, Name: %v, Age: %v\n", user.Name.Val, user.Age.Val)
    }
    // ...
}