func fromHTMLToBNF(htmlFile string, w io.Writer) {
root := gs.WebPage{}.Load(htmlFile).Parse()
root.Descendants(td, class("code")).For(func(def *query.Node) {
for i, line := range def.Descendants(code, not(class("spaces"))).All() {
if i != 0 {
w.Write([]byte{'\t'})
}
if txt := line.Text(); txt != nil {
w.Write(bytes.TrimSpace([]byte(*txt)))
} else {
fmt.Sprintf("%#v", line)
}
w.Write([]byte{'\n'})
}
w.Write([]byte{'\n'})
})
}
