good good study, day day up!

vendor/gopl.io/ch5/outline/main.go

@@ -0,0 +1,36 @@
+// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+
+// See page 123.
+
+// Outline prints the outline of an HTML document tree.
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"golang.org/x/net/html"
+)
+
+//!+
+func main() {
+	doc, err := html.Parse(os.Stdin)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "outline: %v\n", err)
+		os.Exit(1)
+	}
+	outline(nil, doc)
+}
+
+func outline(stack []string, n *html.Node) {
+	if n.Type == html.ElementNode {
+		stack = append(stack, n.Data) // push tag
+		fmt.Println(stack)
+	}
+	for c := n.FirstChild; c != nil; c = c.NextSibling {
+		outline(stack, c)
+	}
+}
+
+//!-