Method pipes

tree.go:235–247

pipes draws the "| | |" pipes prefix. path is a slice of indexes leading to the current node. For example, the path [1, 3, 2] says that the current node is the 2nd child of the 3rd child of the 1st child of the root. last is the last "|" component in this grouping; it'll normally be "| " or "+- "

(path []int, last string)

// Note that for cases where path[1] == 0,
// we don't draw a pipe if len(path) > 2.
func (p *treeWriter) pipes(path []int, last string) {
	for depth, idx := range path {
		if depth == len(path)-1 {
			p.writeString(last)
		} else if idx == 0 {
			// First child of the parent at this layer.
			// Nothing to connect to above us.
			p.writeString("   ")
		} else {
			p.writeString("|  ")
		}
	}
}

func (p *treeWriter) writeString(s string) {
	_, err := io.WriteString(p.W, s)