{`ab*`, "abbaab", build(3, 0, 3, 3, 4, 4, 6)},
	{`a(b*)`, "abbaab", build(3, 0, 3, 1, 3, 3, 4, 4, 4, 4, 6, 5, 6)},

	// fixed bugs
	{`ab$`, "cab", build(1, 1, 3)},
	{`axxb$`, "axxcb", nil},
	{`data`, "daXY data", build(1, 5, 9)},
	{`da(.)a$`, "daXY data", build(1, 5, 9, 7, 8)},
	{`zx+`, "zzx", build(1, 1, 3)},
	{`ab$`, "abcab", build(1, 3, 5)},
	{`(aa)*$`, "a", build(1, 1, 1, -1, -1)},

	fmt.Println(re.ReplaceAllString("-ab-axxb-", "T"))
	fmt.Println(re.ReplaceAllString("-ab-axxb-", "$1"))
	fmt.Println(re.ReplaceAllString("-ab-axxb-", "$1W"))
	fmt.Println(re.ReplaceAllString("-ab-axxb-", "${1}W"))

	re2 := regexp.MustCompile(`a(?P<1W>x*)b`)
	fmt.Printf("%s\n", re2.ReplaceAllString("-ab-axxb-", "$1W"))
	fmt.Println(re.ReplaceAllString("-ab-axxb-", "${1}W"))

	// Output:
	// -T-T-
	// --xx-