package common import ( "math/big" "unicode" ) func IsDigit(s string) bool { for _, r := range s { if !unicode.IsDigit(r) { return false } } return true } func IsLower(s string) bool { for _, r := range s { if !unicode.IsLower(r) { return false } } return true } func IsUpper(s string) bool { for _, r := range s { if !(r >= 'A' && r <= 'Z') { return false } } return true } func IsPrime(i int) bool { return big.NewInt(int64(i)).ProbablyPrime(0) }