# Escapes `self` from a JSON string to a Nit string
	#
	#     assert "\\\"string\\\"".json_to_nit_string == "\"string\""
	#     assert "\\nEscape\\t\\n".json_to_nit_string == "\nEscape\t\n"
	#     assert "\\u0041zu\\uD800\\uDFD3".json_to_nit_string == "Azu𐏓"
	private fun json_to_nit_string: String do
		var res = new FlatBuffer.with_capacity(byte_length)
		var i = 0
		var ln = self.length
		while i < ln do
			var char = self[i]
			if char == '\\' then
				i += 1
				char = self[i]
				if char == 'b' then
					char = 0x08.code_point
				else if char == 'f' then
					char = 0x0C.code_point
				else if char == 'n' then
					char = '\n'
				else if char == 'r' then
					char = '\r'
				else if char == 't' then
					char = '\t'
				else if char == 'u' then
					var u16_esc = from_utf16_digit(i + 1)
					char = u16_esc.code_point
					if char.is_surrogate and i + 10 < ln then
						if self[i + 5] == '\\' and self[i + 6] == 'u' then
							u16_esc <<= 16
							u16_esc += from_utf16_digit(i + 7)
							char = u16_esc.to_u32.from_utf16_surr.code_point
							i += 6
						else
							char = 0xFFFD.code_point
						end
					end
					i += 4
				end
				# `"`, `/` or `\` => Keep `char` as-is.
			end
			res.add char
			i += 1
		end
		return res.to_s
	end