1 files changed, 36 insertions, 0 deletions
diff --git a/phone.go b/phone.go
new file mode 100644
index 0000000..ff92cef
--- /dev/null
+++ b/phone.go
@@ -0,0 +1,36 @@
+package lulu
+
+import (
+	"fmt"
+	"regexp"
+)
+
+var phoneExpr = regexp.MustCompile(`^\+?[\d\s\-.\/()]{8,20}$`)
+
+type PhoneNumber string
+
+func ParsePhoneNumber(s string) (PhoneNumber, error) {
+	if phoneExpr.MatchString(s) {
+		return PhoneNumber(s), nil
+	}
+	return "", fmt.Errorf("malformed phone number %q; must fit pattern `%s`", s, phoneExpr.String())
+}
+
+// MustParsePhoneNumber is like ParsePhoneNumber but panics if the phone
+// number cannot be parsed.
+func MustParsePhoneNumber(s string) PhoneNumber {
+	n, err := ParsePhoneNumber(s)
+	if err != nil {
+		panic(fmt.Sprintf("lulu: ParsePhoneNumber(%q): %v", s, err))
+	}
+	return n
+}
+
+func (n *PhoneNumber) UnmarshalText(text []byte) error {
+	pn, err := ParsePhoneNumber(string(text))
+	if err != nil {
+		return err
+	}
+	*n = pn
+	return nil
+}