Golang替换所有换行符

Question

Usually, when I'm replacing newlines I jump to Regexp, like in this PHP

preg_replace('/\R/u', "
", $String);

Because I know that to be a very durable way to replace any kind of Unicode newline (be it , , , etc.)

I was trying to something like this in Go as well, but I get

error parsing regexp: invalid escape sequence: \R

On this line

msg = regexp.MustCompilePOSIX("\\R").ReplaceAllString(html.EscapeString(msg), "<br>
")

I tried using (?:(?> )|\v) from https://stackoverflow.com/a/4389171/728236, but it looks like Go's regex implementation doesn't support that either, panicking with invalid or unsupported Perl syntax: '(?>'

What's a good, safe way to replace newlines in Go, Regex or not?

---

I see this answer here Golang: Issues replacing newlines in a string from a text file saying to use ? , but I'm hesitant to believe that it would get all Unicode newlines, mainly because of this question that has answer listing many more newline codepoints than the 3 that ? covers,

Answer 1

You may "decode" the \R pattern as

U+000DU+000A|[U+000AU+000BU+000CU+000DU+0085U+2028U+2029]

See the Java regex docs explaining the \R shorthand:

Linebreak matcher
\R  Any Unicode linebreak sequence, is equivalent to \u000D\u000A|[\u000A\u000B\u000C\u000D\u0085\u2028\u2029]

In Go, you may use the following:

func removeLBR(text string) string {
    re := regexp.MustCompile(`\x{000D}\x{000A}|[\x{000A}\x{000B}\x{000C}\x{000D}\x{0085}\x{2028}\x{2029}]`)
    return re.ReplaceAllString(text, ``)
}

Here is a Go demo.

Some of the Unicode codes can be replaced with regex escape sequences supported by Go regexp:

re := regexp.MustCompile(`
|[
\v\f\x{0085}\x{2028}\x{2029}]`)