lazy

Provides support for lazy initialization by generics in Go1.18

example 1

package main

import (
    "github.com/hymkor/go-lazy"
)

var s1 = lazy.New(func() string {
    println("s1 initialize")
    return "Foo"
})

func main() {
    println("start")
    println(s1.Value())
    println(s1.Value())
}

start
s1 initialize
Foo
Foo

example 2

Same as example 1. Light but long

package main

import (
    "github.com/hymkor/go-lazy"
)

var s1 = lazy.Of[string]{
    New: func() string {
        println("s1 initialize")
        return "Foo"
    },
}

func main() {
    println("start")
    println(s1.Value())
    println(s1.Value())
}

example 3

Two values version like "sync".OnceValues

package main

import (
    "github.com/hymkor/go-lazy"
)

var counter = 0

var s1 = lazy.Two[string, int]{
    New: func() (string, int) {
        println("s1 initialize")
        counter++
        return "Foo", counter
    },
}

func main() {
    println("start")
    println(s1.Values())
    println(s1.Values())
}

start
s1 initialize
Foo 1
Foo 1