package main
import (
"regexp"
"fmt"
)
func main() {
var re = regexp.MustCompile(`\b(first|second|third|fourth)(?=(?:\s*(?:,|and)\s*(?:first|second|third|fourth))*\s+section\b)`)
var str = `1. something first, other and then second, third and fourth section
2. something first and other and then second, third and fourth section
3. something first, second other and then second, third and fourth section
4. fourth section
5. something first, second, third and fourth section
`
for i, match := range re.FindAllString(str, -1) {
fmt.Println(match, "found at index", i)
}
}
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/