Pulled former jid package into main package. This time for real.

jid.go

@@ -0,0 +1,82 @@
+// Original taken from mellium.im/xmpp/jid and adjusted for my needs.
+
+package main
+
+import (
+	"errors"
+	"strings"
+	"unicode/utf8"
+)
+
+// MarshalJID checks that JIDs include localpart and serverpart
+// and return it marshalled. Shamelessly stolen from
+// mellium.im/xmpp/jid
+func MarshalJID(input string) (string, error) {
+
+	var (
+		err          error
+		localpart    string
+		domainpart   string
+		resourcepart string
+	)
+
+	s := input
+
+	// Remove any portion from the first '/' character to the end of the
+	// string (if there is a '/' character present).
+	sep := strings.Index(s, "/")
+
+	if sep == -1 {
+		resourcepart = ""
+	} else {
+		// If the resource part exists, make sure it isn't empty.
+		if sep == len(s)-1 {
+			return input, errors.New("Invalid JID" + input + ": The resourcepart must be larger than 0 bytes")
+		}
+		resourcepart = s[sep+1:]
+		s = s[:sep]
+	}
+
+	// Remove any portion from the beginning of the string to the first
+	// '@' character (if there is an '@' character present).
+
+	sep = strings.Index(s, "@")
+
+	switch {
+	case sep == -1:
+		// There is no @ sign, and therefore no localpart.
+		return input, errors.New("Invalid JID: " + input)
+	case sep == 0:
+		// The JID starts with an @ sign (invalid empty localpart)
+		err = errors.New("Invalid JID:" + input)
+		return input, err
+	default:
+		domainpart = s[sep+1:]
+		localpart = s[:sep]
+	}
+
+	// We'll throw out any trailing dots on domainparts, since they're ignored:
+	//
+	//    If the domainpart includes a final character considered to be a label
+	//    separator (dot) by [RFC1034], this character MUST be stripped from
+	//    the domainpart before the JID of which it is a part is used for the
+	//    purpose of routing an XML stanza, comparing against another JID, or
+	//    constructing an XMPP URI or IRI [RFC5122].  In particular, such a
+	//    character MUST be stripped before any other canonicalization steps
+	//    are taken.
+
+	domainpart = strings.TrimSuffix(domainpart, ".")
+
+	if !utf8.ValidString(localpart) || !utf8.ValidString(domainpart) || !utf8.ValidString(resourcepart) {
+		return input, errors.New("Invalid JID: " + input)
+	}
+
+	if localpart == "" || domainpart == "" {
+		return input, errors.New("Invalid JID: " + input)
+	}
+
+	if resourcepart == "" {
+		return localpart + "@" + domainpart, err
+	}
+	return localpart + "@" + domainpart + "/" + resourcepart, err
+}