Only use regex for hostname checks.

lib/compile/formats.js

@@ -70,7 +70,7 @@ formats.full = {
   'uri-template': URITEMPLATE,
   url: URL,
   email: /^[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?$/i,
-  hostname: hostname,
+  hostname: HOSTNAME,
   ipv4: /^(?:(?:25[0-5]|2[0-4]\d|[01]?\d\d?)\.){3}(?:25[0-5]|2[0-4]\d|[01]?\d\d?)$/,
   ipv6: /^\s*(?:(?:(?:[0-9a-f]{1,4}:){7}(?:[0-9a-f]{1,4}|:))|(?:(?:[0-9a-f]{1,4}:){6}(?::[0-9a-f]{1,4}|(?:(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(?:\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3})|:))|(?:(?:[0-9a-f]{1,4}:){5}(?:(?:(?::[0-9a-f]{1,4}){1,2})|:(?:(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(?:\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3})|:))|(?:(?:[0-9a-f]{1,4}:){4}(?:(?:(?::[0-9a-f]{1,4}){1,3})|(?:(?::[0-9a-f]{1,4})?:(?:(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(?:\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(?:(?:[0-9a-f]{1,4}:){3}(?:(?:(?::[0-9a-f]{1,4}){1,4})|(?:(?::[0-9a-f]{1,4}){0,2}:(?:(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(?:\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(?:(?:[0-9a-f]{1,4}:){2}(?:(?:(?::[0-9a-f]{1,4}){1,5})|(?:(?::[0-9a-f]{1,4}){0,3}:(?:(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(?:\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(?:(?:[0-9a-f]{1,4}:){1}(?:(?:(?::[0-9a-f]{1,4}){1,6})|(?:(?::[0-9a-f]{1,4}){0,4}:(?:(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(?:\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(?::(?:(?:(?::[0-9a-f]{1,4}){1,7})|(?:(?::[0-9a-f]{1,4}){0,5}:(?:(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(?:\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:)))(?:%.+)?\s*$/i,
   regex: regex,
@@ -123,15 +123,6 @@ function date_time(str) {
 }
 
 
-function hostname(str) {
-  // https://tools.ietf.org/html/rfc1034#section-3.5
-  // https://tools.ietf.org/html/rfc1123#section-2
-  // https://devblogs.microsoft.com/oldnewthing/?p=7873
-  // https://tools.ietf.org/html/rfc1034#section-3.1
-  return HOSTNAME.test(str);
-}
-
-
 var NOT_URI_FRAGMENT = /\/|:/;
 function uri(str) {
   // http://jmrware.com/articles/2009/uri_regexp/URI_regex.html + optional protocol + required "."