1//go:build errata

2

3package main

4

5// Convert eid html file, e.g. https://www.rfc-editor.org/errata/eid3192 to text with leading blank line for references.

6// See Makefile, run with "go run errata.go < eid.html >eid.txt"

7// I could not find a source for the text version of errata.

8

9import (

10 "bufio"

11 "fmt"

12 "log"

13 "os"

14

15 "golang.org/x/net/html"

16)

17

18func xcheckf(err error, format string, args ...any) {

19 if err != nil {

20 log.Fatalf("%s: %s", fmt.Sprintf(format, args...), err)

21 }

22}

23

24func main() {

25 log.SetFlags(0)

26 doc, err := html.Parse(os.Stdin)

27 xcheckf(err, "parsing html")

28 out := bufio.NewWriter(os.Stdout)

29 _, err = out.WriteString("\n") // First line for references.

30 xcheckf(err, "write")

31

32 // We will visit the html nodes. We skip <form>'s. We turn on text

33 // output when we encounter an h4, and we stop again when we see a div

34 // or form. This works at the moment, but may break in the future.

35 output := false

36 var walk func(*html.Node)

37 walk = func(n *html.Node) {

38 if n.Type == html.ElementNode {

39 if n.Data == "form" {

40 return

41 }

42 if !output && n.Data == "h4" {

43 output = true

44 } else if output && (n.Data == "div" || n.Data == "form") {

45 output = false

46 }

47 }

48 if output && n.Type == html.TextNode {

49 _, err := out.WriteString(n.Data)

50 xcheckf(err, "write")

51 }

52 for c := n.FirstChild; c != nil; c = c.NextSibling {

53 walk(c)

54 }

55 }

56 walk(doc)

57 err = out.Flush()

58 xcheckf(err, "flush")

59}

60