htmlAmp  = []byte("&")
	htmlLt   = []byte("<")
	htmlGt   = []byte(">")
	htmlNull = []byte("\uFFFD")
)

// HTMLEscape writes to w the escaped HTML equivalent of the plain text data b.
func HTMLEscape(w io.Writer, b []byte) {
	last := 0
	for i, c := range b {
		var html []byte
		switch c {
		case '\000':
			html = htmlNull
		case '"':
			html = htmlQuot
		case '\'':
			html = htmlApos