Function escapeIndex

json/string.go:18–41

escapeIndex finds the index of the first char in `s` that requires escaping. A char requires escaping if it's outside of the range of [0x20, 0x7F] or if it includes a double quote or backslash. If the escapeHTML mode is enabled, the chars <, > and & also require escaping. If no chars in `s` require

(s string, escapeHTML bool)

// the chars <, > and & also require escaping. If no chars in `s` require
// escaping, the return value is -1.
func escapeIndex(s string, escapeHTML bool) int {
	chunks := stringToUint64(s)
	for _, n := range chunks {
		// combine masks before checking for the MSB of each byte. We include
		// `n` in the mask to check whether any of the *input* byte MSBs were
		// set (i.e. the byte was outside the ASCII range).
		mask := n | below(n, 0x20) | contains(n, '"') | contains(n, '\\')
		if escapeHTML {
			mask |= contains(n, '<') | contains(n, '>') | contains(n, '&')
		}
		if (mask & msb) != 0 {
			return bits.TrailingZeros64(mask&msb) / 8
		}
	}

	for i := len(chunks) * 8; i < len(s); i++ {
		c := s[i]
		if c < 0x20 || c > 0x7f || c == '"' || c == '\\' || (escapeHTML && (c == '<' || c == '>' || c == '&')) {
			return i
		}
	}

	return -1
}

func escapeByteRepr(b byte) byte {
	switch b {