package main
import (
"regexp"
"fmt"
)
func main() {
var re = regexp.MustCompile(`(?mi)^a\..*?\Kain't`)
var str = `For instance, if in the text below I wanted to replace "ain't" with "is not" for lines beginning "a." but not "b.":
a. This ain't a worm.
b. No, it ain't.
a. Ain't a snake, either.
b. No, ain't one of them.
a. ain't multiple ain't and more ain't
`
var substitution = "is not"
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/