     [ port>> ] [ protocol>> protocol-port ] bi over =
     [ drop f ] when ;
 
+: ipv6-host ( host -- host/ipv6 ipv6? )
+    dup { [ "[" head? ] [ "]" tail? ] } 1&& [
+        1 swap [ length 1 - ] [ subseq ] bi t
+    ] [ f ] if ;
+
+: unparse-host ( url -- host )
+    host>> ipv6-host [ url-encode ] [ [ "[" "]" surround ] when ] bi* ;
+
 : unparse-host-part ( url -- )
     {
         [ unparse-username-password ]
-        [ host>> url-encode % ]
+        [ unparse-host % ]
         [ url-port [ ":" % # ] when* ]
         [ path>> "/" head? [ "/" % ] unless ]
     } cleave ;

query    = [^#]+           => [[ query>assoc ]]
anchor   = .+              => [[ url-decode ]]
hostname = [^/#?:]+        => [[ url-decode ]]
port     = [^/#?]+         => [[ url-decode parse-port ]]

auth     = username (":"~ password?)? "@"~
host     = hostname (":"~ port?)?

url      = (protocol ":"~)?
           ("//"~ auth? host?)?

! Copyright (C) 2008, 2011 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.

USING: accessors ascii assocs combinators
combinators.short-circuit fry io.pathnames io.sockets
io.sockets.secure kernel lexer linked-assocs make math
math.parser multiline namespaces peg.ebnf present sequences
sequences.generalizations splitting strings strings.parser
urls.encoding vocabs.loader ;
