stripansi: compile regex ondemand

Author: rsteube

third_party/github.com/acarl005/stripansi/stripansi.go

@@ -6,8 +6,11 @@ import (
 
 const ansi = "[\u001B\u009B][[\\]()#;?]*(?:(?:(?:[a-zA-Z\\d]*(?:;[a-zA-Z\\d]*)*)?\u0007)|(?:(?:\\d{1,4}(?:;\\d{0,4})*)?[\\dA-PRZcf-ntqry=><~]))"
 
-var re = regexp.MustCompile(ansi)
+var re *regexp.Regexp
 
 func Strip(str string) string {
+	if re == nil {
+		re = regexp.MustCompile(ansi)
+	}
 	return re.ReplaceAllString(str, "")
 }