Implement some parts for loading data from a directory

valid.go

@@ -0,0 +1,52 @@
+package mailfull
+
+import (
+	"errors"
+	"regexp"
+)
+
+// Errors for incorrect format.
+var (
+	ErrInvalidDomainName        = errors.New("Domain: name incorrect format")
+	ErrInvalidAliasDomainName   = errors.New("AliasDomain: name incorrect format")
+	ErrInvalidAliasDomainTarget = errors.New("AliasDomain: target incorrect format")
+	ErrInvalidUserName          = errors.New("User: name incorrect format")
+	ErrInvalidAliasUserName     = errors.New("AliasUser: name incorrect format")
+	ErrInvalidAliasUserTarget   = errors.New("AliasUser: target incorrect format")
+	ErrInvalidCatchAllUserName  = errors.New("CatchAllUser: name incorrect format")
+)
+
+// validDomainName returns true if the input is correct format.
+func validDomainName(name string) bool {
+	return regexp.MustCompile(`^([A-Za-z0-9][A-Za-z0-9\-]{1,61}[A-Za-z0-9]\.)*[A-Za-z]+$`).MatchString(name)
+}
+
+// validAliasDomainName returns true if the input is correct format.
+func validAliasDomainName(name string) bool {
+	return regexp.MustCompile(`^([A-Za-z0-9][A-Za-z0-9\-]{1,61}[A-Za-z0-9]\.)*[A-Za-z]+$`).MatchString(name)
+}
+
+// validAliasDomainTarget returns true if the input is correct format.
+func validAliasDomainTarget(target string) bool {
+	return regexp.MustCompile(`^([A-Za-z0-9][A-Za-z0-9\-]{1,61}[A-Za-z0-9]\.)*[A-Za-z]+$`).MatchString(target)
+}
+
+// validUserName returns true if the input is correct format.
+func validUserName(name string) bool {
+	return regexp.MustCompile(`^[^\s]+$`).MatchString(name)
+}
+
+// validAliasUserName returns true if the input is correct format.
+func validAliasUserName(name string) bool {
+	return regexp.MustCompile(`^[^\s]+$`).MatchString(name)
+}
+
+// validAliasUserTarget returns true if the input is correct format.
+func validAliasUserTarget(target string) bool {
+	return regexp.MustCompile(`^[^\s]+@([A-Za-z0-9][A-Za-z0-9\-]{1,61}[A-Za-z0-9]\.)*[A-Za-z]+$`).MatchString(target)
+}
+
+// validCatchAllUserName returns true if the input is correct format.
+func validCatchAllUserName(name string) bool {
+	return regexp.MustCompile(`^[^\s]+$`).MatchString(name)
+}