package main
import (
"regexp"
"fmt"
)
func main() {
var re = regexp.MustCompile(`(?mi)\{\{(?:(?!\}\}).)*?default=(.*?)\}\}`)
var str = `It was a {{color, default=black}} and scary {{phase}}. As the {{animals, default=dogs}} {{make_sound, default=barked}} and the trees swayed {{setting, default=to the breeze}}, a {{size, default=}} {{monster, default=troll}} that emerged from the shadows.`
var substitution = "\1"
fmt.Println(re.ReplaceAllString(str, substitution))
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Golang, please visit: https://golang.org/pkg/regexp/