before adding cryptoshuffler

pwgenerator/funcs_charset.go

@@ -1,5 +1,42 @@
 package pwgenerator
 
+/*
+	Has returns true if a CharSet contains char.
+
+	char can be one of: Char, byte, rune, or a string (of length 1).
+*/
+func (c *CharSet) Has(char interface{}) (contains bool, err error) {
+
+	var chkChar Char
+
+	switch t := char.(type) {
+	case Char:
+		chkChar = t
+	case byte:
+		chkChar = Char(t)
+	case rune:
+		chkChar = Char(t)
+	case string:
+		if len(t) != 1 {
+			err = ErrBadType
+			return
+		}
+		chkChar = Char(t[0])
+	default:
+		err = ErrBadType
+		return
+	}
+
+	for _, i := range *c {
+		if chkChar == i {
+			contains = true
+			break
+		}
+	}
+
+	return
+}
+
 // Len returns the length of a CharSet (needed for sort.Interface).
 func (c *CharSet) Len() (l int) {
 
@@ -23,7 +60,7 @@ func (c *CharSet) RandChar() (char Char, err error) {
 
 	var selectIdx int
 
-	if selectIdx, err = saferRandInt(len(*c) - 1); err != nil {
+	if selectIdx, err = saferRandInt(len(*c)); err != nil {
 		return
 	}