package main
import (
"regexp"
"fmt"
)
func main() {
var re = regexp.MustCompile(`(?m)\$\$((?:(?!\$\$).)+)\$\$`)
var str = `aaa $$123$$ c$ ddd
aaa $$123$$ c$ $$ddd$$
aaa $$12$3$$ c$ $$d$dd$$`
var substitution = "<a1>$1</a1>"
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/