Encode and Decode integers into []byte(inspired from a blog i couldn't find)

numbers.go

package main

import "fmt"

func main() {
	nums := []int{256, 2, 100, 122234456, 10024}
	fmt.Println(nums)
	buf := encodeNumbers(nums...)
	fmt.Println(buf)
	fmt.Println(decodeNumbers(buf))
}

// number - buf values...
// 1010101010101010 - none
// 101010101 - 10101010
// 00000010 - 10101010, 11010101
// 0 - 10101010, 11010101, 00000010
func encodeNumbers(nums ...int) (buf []byte) {
	for _, rem := range nums {
		// start decomposing
		for {
			// get last 7 bits
			v := rem & (0x7f)

			// shift rem 7 to left
			rem = rem >> 7

			// if rem == 0, append the bytes and return
			if rem == 0 {
				buf = append(buf, byte(v))
				break
			}

			// or the value with 8f so that we know we still have some bits to collect while decoding
			v = v | 0x80
			buf = append(buf, byte(v))
		}
	}

	return buf
}

func decodeNumbers(buf []byte) (nums []int) {
	var n, i int
	for _, b := range buf {
		// shift last 7 bits to number and then shift right and add to n.
		n += int(b&0x7f) << (7 * uint(i))

		// check if 8th bit is set to 0, if so, that was the end of the number
		if b&0x80 == 0 {
			nums = append(nums, n)
			n = 0
			i = 0
			continue
		}

		i++
	}

	return nums
}