go_bitwise_parsing.go

package main

import "fmt"

const step int = 8
const mask int = ^(-1 << step) // NOT(-1 << 8)

type RGB struct {
	Red    int
	Green  int
	Yellow int
}

func (rgb *RGB) score() int {
	binarySum := 0
	colors := []int{rgb.Red, rgb.Green, rgb.Yellow}

	for n, color := range colors {
		binarySum |= color << (step * n)
	}

	return binarySum
}

func getRgbFromScore(score int) RGB {
	return RGB{
		Red:    score >> (step * 0) & mask,
		Green:  score >> (step * 1) & mask,
		Yellow: score >> (step * 2) & mask,
	}
}

func main() {

	rgb1 := RGB{1,2,3}
	score1 := rgb1.score()

	fmt.Println(score1) // 197121
	fmt.Println(getRgbFromScore(score1)) // {1 2 3}


	rgb2 := RGB{3,2,1}
	score2 := rgb2.score()

	fmt.Println(score2) // 66051
	fmt.Println(getRgbFromScore(score2)) // {3 2 1}

}