package main
import (
"regexp"
"fmt"
)
func main() {
var re = regexp.MustCompile(`(?m)^(?=(?:\b:?\w)*$)A?:?B?:?C?:?D?$`)
var str = `These should all match:
A
B
C
D
A:B
A:C
A:D
B:C
B:D
C:D
A:B:C
A:B:D
A:C:D
B:C:D
A:B:C:D
Meanwhile, these should not match.
A:
:C
ABC
A:BC
A::B
`
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/