// Derived from https://play.golang.org/p/Dhmj7FORT5
const htmlSpaceAndASCIIAlnumBytes = "\x00\x36\x00\x00\x01\x00\xff\x03\xfe\xff\xff\x07\xfe\xff\xff\x07"

// isHTMLSpace is true iff c is a whitespace character per
// https://infra.spec.whatwg.org/#ascii-whitespace
func isHTMLSpace(c byte) bool {
	return (c <= 0x20) && 0 != (htmlSpaceAndASCIIAlnumBytes[c>>3]&(1<<uint(c&0x7)))
}

func isHTMLSpaceOrASCIIAlnum(c byte) bool {