// TraverseHori traverses the tree horizontally.
// It uses a queue. A FiFo structure.
// Inspired by www.geeksforgeeks.org/level-order-tree-traversal/
func traverseHori(lp interface{}) {
var queue = util.NewQueue(10)
lvlPrev := 0
for lp != nil {
lpn := lp.(NdX).Nd
lvl := lp.(NdX).Lvl
// print current
if lvl != lvlPrev { // new level => newline
fmt.Printf("\n%2v:\t", lvl)
lvlPrev = lvl
}
fmt.Printf("%8s ", lpn.Data)
// enqueue all children
for c := lpn.FirstChild; c != nil; c = c.NextSibling {
if c.Type == html.ElementNode {
queue.EnQueue(NdX{c, lvl + 1})
}
}
lp = queue.DeQueue()
}
}
// removeCommentsAndIntertagWhitespace employs horizontal traversal using a queue
func removeCommentsAndIntertagWhitespace(lp interface{}) {
var queue = util.NewQueue(10)
for lp != nil {
lpn := lp.(NdX).Nd
lvl := lp.(NdX).Lvl
for c := lpn.FirstChild; c != nil; c = c.NextSibling {
queue.EnQueue(NdX{c, lvl + 1})
}
// processing
if lpn.Type == html.CommentNode {
dom.RemoveNode(lpn)
}
// extinguish textnodes that do only formatting (spaces, tabs, line breaks)
if lpn.Type == html.TextNode && isSpacey(lpn.Data) {
dom.RemoveNode(lpn)
}
// next node
lp = queue.DeQueue()
}
}