prefix, suffix := b[:2816], b[2816:]

	testCases := []string{
		"PASS:",
		"PASS:\x00",
		"PASS:\x61",
		"PASS:\x61\x62\x63\xff\x00\x64",
		"PASS:\xff",
		"PASS:\xff\x00",
		"PASS:\xff\xff\xff\x00\xff\x00\x00\xff\xff\xff",

		"FAIL:\xff\x03",
		"FAIL:\xff\xd5",
		"FAIL:\xff\xff\xd5",
	}

	for _, tc := range testCases {
		want := tc[:5] == "PASS:"
		infix := tc[5:]

		data := []byte(nil)

		{"\xf7\x76\xa2\x22\xeb\x8a\x72\x61", -615126028225187231, true},
		{"\xff\xff\xff\xff\xf7\x76\xa2\x22\xeb\x8a\x72\x61", -615126028225187231, true},
		{"\x80\x7f\xff\xff\xff\xff\xff\xff\xff", math.MaxInt64, true},
		{"\x80\x80\x00\x00\x00\x00\x00\x00\x00", 0, false},
		{"\xff\x80\x00\x00\x00\x00\x00\x00\x00", math.MinInt64, true},
		{"\xff\x7f\xff\xff\xff\xff\xff\xff\xff", 0, false},
		{"\xf5\xec\xd1\xc7\x7e\x5f\x26\x48\x81\x9f\x8f\x9b", 0, false},

		"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +
		"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +
		"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +
		"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +
		"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +

		"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +
		"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +
		"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +
		"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +
		"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +

	{
		"1b esc stripped",
		8, 0, 1, '.', StripEscape,
		"\xff\xff",
		"",
	},

	{
		"1b esc",
		8, 0, 1, '.', 0,
		"\xff\xff",
		"\xff\xff",
	},

	{
		"1c esc stripped",
		8, 0, 1, '.', StripEscape,
		"\xff\t\xff",
		"\t",
	},

	{
		"1c esc",
		8, 0, 1, '.', 0,
		"\xff\t\xff",
		"\xff\t\xff",
	},

	{
		"1d esc stripped",

	{"d1884e711701ad81abe0c77a3b0ea12e19ba9af64077286c72fc602d", "abcdefg", "sha\x02\xc1\x05\x9e\xd86|\xd5\a0p\xdd\x17\xf7\x0eY9\xff\xc0\v1hX\x15\x11d\xf...

	{0x8ec0e7c835bf9cdf, 0x8a0825223ea6d221, "Discard medicine more than two years old.", "crc\x02s\xba\x84\x84\xbb\xcd]\xef\xc6\xc0\f\xac'\x11\x12\xd5", "crc\x02`&\x9aR\xe1\xb7\xfee\xfd%\xc0&\xa0R\xef\x95"},
	{0xc7db1759e2be5ab4, 0x8562c0ac2ab9a00d, "He who has a shady past knows that nice guys finish last.", "crc\x02s\xba\x84\x84\xbb\xcd]\xef\t\xcb\xd15X[r\t", "crc\x02`&\x9aR\xe1\xb7\xfee\a\x02\xe8|+\xc1\x06\xe3"},

		r       *Replacer
		in, out string
	}
	var testCases []testCase

	// str converts 0xff to "\xff". This isn't just string(b) since that converts to UTF-8.
	str := func(b byte) string {
		return string([]byte{b})
	}
	var s []string

	// inc maps "\x00"->"\x01", ..., "a"->"b", "b"->"c", ..., "\xff"->"\x00".
	s = nil
	for i := 0; i < 256; i++ {
		s = append(s, str(byte(i)), str(byte(i+1)))
	}

				buf = append(buf, lowerhex[r>>uint(s)&0xF])
			}
		}
	}
	return buf
}

// Quote returns a double-quoted Go string literal representing s. The
// returned string uses Go escape sequences (\t, \n, \xFF, \u0100) for
// control characters and non-printable characters as defined by
// [IsPrint].
func Quote(s string) string {
	return quoteWith(s, '"', false, false)
}

	`(a|b|))`,
	`(a|b`,
	`a|b)`,
	`(a|b))`,
	`[a-z`,
	`([a-z)`,
	`[a-z)`,
	`([a-z]))`,
	`x{1001}`,
	`x{9876543210}`,
	`x{2,1}`,
	`x{1,9876543210}`,
	"\xff", // Invalid UTF-8
	"[\xff]",
	"[\\\xff]",
	"\\\xff",
	`(?P<name>a`,
	`(?P<name>`,
	`(?P<name`,
	`(?P<x y>a)`,
	`(?P<>a)`,
	`(?<name>a`,
	`(?<name>`,
	`(?<name`,
	`(?<x y>a)`,
	`(?<>a)`,
	`[a-Z]`,