Golang多行正则表达式不起作用

Question

Why the the following multiline regex do not work, I expect to match the substring inside the tags. Other simples multiline matches worked correctly.

func main() {
    r := regexp.MustCompile(`(?m)<think>(.*)</think>`)
    const s = `That is 
    <think>
    FOOBAR
    </think>`
    fmt.Printf("%#v
", r.FindStringSubmatch(s))
}

https://play.golang.org/p/8C6u_0ca8w

Answer 1

By default, "." doesn't match newline. If you give the "s" flag, it does. I don't think you need "m".

Note that if there are multiple <think>...</think> in your string, the regexp will match everything between the first <think> and the last </think>. Using .*? will cause it to only match the contents of the first one.