mergesort async with limit

gistfile1.go

func merge_sort_async(l []int, c chan []int) {
  if len(l) < 2 {
    c <- l
    return
  }
  if len(l) < 500 { //TUNE THIS NUMER AND DONT CREATE EXTRA WORK UNLESS IT'S BIGGER 
    c <- merge_sort(l)
    return
  }
  mid := len(l) / 2
  c1 := make(chan []int, 1)
  c2 := make(chan []int, 1)
  go merge_sort_async(l[:mid], c1)
  go merge_sort_async(l[mid:], c2)
  go func() { c <- merge(<-c1, <-c2) }()
}