package main
import (
"regexp"
"fmt"
)
func main() {
var re = regexp.MustCompile(`(?m)([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}(\-[a-zA-Z]{1,50})?)`)
var str = `Should match
0.0.0
0.0.0-a
1.5.89-lorem
6.12.5-iPsUm
Mustn't match (even partially)
a.2.3 -> 'a' is not a number
1.5.89:lorem -> only '-' is valid to separate version and letters
1.2.3-4 -> '4' is not letter(s)
5.6.8.9 -> '9' is not letters and '.' used instead of '-'
8.k.2-j -> 'k' is not a number
7895.5.8 -> '7895' is 4 digit long, 3 is the max
`
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/