merge sort using Golang

MergeSort.go

package main

import (
	"fmt"
)

var (
	list []int = []int{838, 23, 83, 64, 83, 23, 63, 90, 50, 20, 20, 4, 30, 5, 2, 50, 190, 19, 3, 70, 21, 3, 20, 28, 93, 39, 838, 23, 83, 64, 83, 23, 63, 90, 50, 20}
)

func main() {

	c := make(chan []int)
	go func() {
		c <- Merge(list)
	}()

	fmt.Println(<-c)
}

func join(l, r []int) []int {
	var out []int = make([]int, 0, len(l)+len(r))
	for len(l) > 0 || len(r) > 0 {
		if len(l) == 0 {
			return append(out, r...)
		} else if len(r) == 0 {
			return append(out, l...)
		} else if l[0] <= r[0] {
			out = append(out, l[0])
			l = l[1:]
		} else if l[0] > r[0] {
			out = append(out, r[0])
			r = r[1:]
		}
	}
	return out
}

func Merge(list []int) []int {
	var left, right <-chan []int
	if len(list) <= 1 {
		return list
	}

	left = makeChan(Merge, list[len(list)/2:len(list)])
	right = makeChan(Merge, list[:len(list)/2])

	return join(<-left, <-right)
}

func makeChan(a func([]int) []int, l []int) <-chan []int {
	c := make(chan []int)
	go func() { c <- a(l) }()
	return c
}