More flexible letter/symbol/nunmber combinations.

main.go

@@ -6,10 +6,16 @@ import (
 	"math/big"
 )
 
+type Generator func() (byte,error)
+
+
 var chars []byte = []byte("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789~`!@#$%^&*()_+-=[]{}\\|;:'\",./<>?")
 var letters []byte = chars[0:52]
 var digits []byte = chars[52:62]
+var letdig []byte = chars[0:62]
 var symbols []byte = chars[62:94]
+var digsym []byte = chars[52:94]
+var letsym []byte = []byte("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ~`!@#$%^&*()_+-=[]{}\\|;:'\",./<>?")
 
 func gen(s []byte) (byte,error) {
 	nBig, err := crand.Int(crand.Reader, big.NewInt(int64(len(s))))
@@ -32,11 +38,23 @@ func Symbol() (byte,error) {
 	return gen(symbols)
 }
 
+func LetterDigits() (byte,error) {
+	return gen(letdig)
+}
+
+func DigitsSymbols() (byte,error) {
+	return gen(digsym)
+}
+
+func LettersSymbols() (byte, error) {
+	return gen(letsym)
+}
+
 func Char() (byte,error) {
 	return gen(chars)
 }
 
-func Slice(f func() (byte,error), n int) ([]byte,error) {
+func Slice(f Generator, n int) ([]byte,error) {
 	ret := make([]byte,0)
 	for i := 0; i < n; i++ {
 		x,err := f()