.git - Unnamed repository; edit this file 'description' to name the repository.

diff options

Diffstat (limited to 'docs/doxygen/html')

0 files changed, 0 insertions, 0 deletions

ef='#n54'>54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898

=begin

= net/imap.rb

Copyright (C) 2000  Shugo Maeda <shugo@ruby-lang.org>

This library is distributed under the terms of the Ruby license.
You can freely distribute/modify this library.

== class Net::IMAP

Net::IMAP implements Internet Message Access Protocol (IMAP) clients.

=== Super Class

Object

=== Class Methods

: new(host, port = 143)
      Creates a new Net::IMAP object and connects it to the specified
      port on the named host.

: debug
      Returns the debug mode.

: debug = val
      Sets the debug mode.

: add_authenticator(auth_type, authenticator)
      Adds an authenticator for Net::IMAP#authenticate.

=== Methods

: greeting
      Returns an initial greeting response from the server.

: responses
      Returns recorded untagged responses.

      ex).
        imap.select("inbox")
        p imap.responses["EXISTS"][-1]
        #=> 2
        p imap.responses["UIDVALIDITY"][-1]
        #=> 968263756

: disconnect
      Disconnects from the server.

: capability
      Sends a CAPABILITY command, and returns a listing of
      capabilities that the server supports.

: noop
      Sends a NOOP command to the server. It does nothing.

: logout
      Sends a LOGOUT command to inform the server that the client is
      done with the connection.

: authenticate(auth_type, arg...)
      Sends an AUTEHNTICATE command to authenticate the client.
      The auth_type parameter is a string that represents
      the authentication mechanism to be used. Currently Net::IMAP
      supports "LOGIN" and "CRAM-MD5" for the auth_type.

      ex).
        imap.authenticate('LOGIN', user, password)

: login(user, password)
      Sends a LOGIN command to identify the client and carries
      the plaintext password authenticating this user.

: select(mailbox)
      Sends a SELECT command to select a mailbox so that messages
      in the mailbox can be accessed.

: examine(mailbox)
      Sends a EXAMINE command to select a mailbox so that messages
      in the mailbox can be accessed. However, the selected mailbox
      is identified as read-only.

: create(mailbox)
      Sends a CREATE command to create a new mailbox.

: delete(mailbox)
      Sends a DELETE command to remove the mailbox.

: rename(mailbox, newname)
      Sends a RENAME command to change the name of the mailbox to
      the newname.

: subscribe(mailbox)
      Sends a SUBSCRIBE command to add the specified mailbox name to
      the server's set of "active" or "subscribed" mailboxes.

: unsubscribe(mailbox)
      Sends a UNSUBSCRIBE command to remove the specified mailbox name
      from the server's set of "active" or "subscribed" mailboxes.

: list(refname, mailbox)
      Sends a LIST command, and returns a subset of names from
      the complete set of all names available to the client.

      ex).
        imap.create("foo/bar")
        imap.create("foo/baz")
        p imap.list("", "foo/%")
        #=> [#<Net::IMAP::MailboxList attr=[:NoSelect], delim="/", name="foo/">, #<Net::IMAP::MailboxList attr=[:NoInferiors, :Marked], delim="/", name="foo/bar">, #<Net::IMAP::MailboxList attr=[:NoInferiors], delim="/", name="foo/baz">]

: lsub(refname, mailbox)
      Sends a LSUB command, and returns a subset of names from the set
      of names that the user has declared as being "active" or
      "subscribed".

: status(mailbox, attr)
      Sends a STATUS command, and returns the status of the indicated
      mailbox.

      ex).
        p imap.status("inbox", ["MESSAGES", "RECENT"])
        #=> {"RECENT"=>0, "MESSAGES"=>44}

: append(mailbox, message, flags = nil, date_time = nil)
      Sends a APPEND command to append the message to the end of
      the mailbox.

      ex).
        imap.append("inbox", <<EOF.gsub(/\n/, "\r\n"), [:Seen], Time.now)
        Subject: hello
        From: shugo@ruby-lang.org
        To: shugo@ruby-lang.org
        
        hello world
        EOF

: check
      Sends a CHECK command to request a checkpoint of the currently
      selected mailbox.

: close
      Sends a CLOSE command to close the currently selected mailbox.
      The CLOSE command permanently removes from the mailbox all
      messages that have the \Deleted flag set.

: expunge
      Sends a EXPUNGE command to permanently remove from the currently
      selected mailbox all messages that have the \Deleted flag set.

: search(keys, charset = nil)
: uid_search(keys, charset = nil)
      Sends a SEARCH command to search the mailbox for messages that
      match the given searching criteria, and returns message sequence
      numbers (search) or unique identifiers (uid_search).

      ex).
        p imap.search(["SUBJECT", "hello"])
        #=> [1, 6, 7, 8]
        p imap.search('SUBJECT "hello"')
        #=> [1, 6, 7, 8]

: fetch(set, attr)
: uid_fetch(set, attr)
      Sends a FETCH command to retrieve data associated with a message
      in the mailbox. the set parameter is a number or an array of
      numbers or a Range object. the number is a message sequence
      number (fetch) or a unique identifier (uid_fetch).

      ex).
        p imap.fetch(6..8, "UID")
        #=> [#<Net::IMAP::FetchData seqno=6, attr={"UID"=>98}>, #<Net::IMAP::FetchData seqno=7, attr={"UID"=>99}>, #<Net::IMAP::FetchData seqno=8, attr={"UID"=>100}>]
        p imap.fetch(6, "BODY[HEADER.FIELDS (SUBJECT)]")
        #=> [#<Net::IMAP::FetchData seqno=6, attr={"BODY[HEADER.FIELDS (SUBJECT)]"=>"Subject: test\r\n\r\n"}>]
        data = imap.uid_fetch(98, ["RFC822.SIZE", "INTERNALDATE"])[0]
        p data.seqno
        #=> 6
        p data.attr["RFC822.SIZE"]
        #=> 611
        p data.attr["INTERNALDATE"]
        #=> "12-Oct-2000 22:40:59 +0900"
        p data.attr["UID"]
        #=> 98

: store(set, attr, flags)
: uid_store(set, attr, flags)
      Sends a STORE command to alter data associated with a message
      in the mailbox. the set parameter is a number or an array of
      numbers or a Range object. the number is a message sequence
      number (store) or a unique identifier (uid_store).

      ex).
        p imap.store(6..8, "+FLAGS", [:Deleted])
        #=> [#<Net::IMAP::FetchData seqno=6, attr={"FLAGS"=>[:Seen, :Deleted]}>, #<Net::IMAP::FetchData seqno=7, attr={"FLAGS"=>[:Seen, :Deleted]}>, #<Net::IMAP::FetchData seqno=8, attr={"FLAGS"=>[:Seen, :Deleted]}>]

: copy(set, mailbox)
: uid_copy(set, mailbox)
      Sends a COPY command to copy the specified message(s) to the end
      of the specified destination mailbox. the set parameter is
      a number or an array of numbers or a Range object. the number is
      a message sequence number (copy) or a unique identifier (uid_copy).

: sort(sort_keys, search_keys, charset)
: uid_sort(sort_keys, search_keys, charset)
      Sends a SORT command to sort messages in the mailbox.

      ex).
        p imap.sort(["FROM"], ["ALL"], "US-ASCII")
        #=> [1, 2, 3, 5, 6, 7, 8, 4, 9]
        p imap.sort(["DATE"], ["SUBJECT", "hello"], "US-ASCII")
        #=> [6, 7, 8, 1]

=end

require "socket"
require "md5"

module Net
  class IMAP
    attr_reader :greeting, :responses

    def self.debug
      return @@debug
    end

    def self.debug=(val)
      return @@debug = val
    end

    def self.add_authenticator(auth_type, authenticator)
      @@authenticators[auth_type] = authenticator
    end

    def disconnect
      @sock.close
    end

    def capability
      send_command("CAPABILITY")
      return @responses.delete("CAPABILITY")[-1]
    end

    def noop
      send_command("NOOP")
    end

    def logout
      send_command("LOGOUT")
    end

    def authenticate(auth_type, *args)
      auth_type = auth_type.upcase
      unless @@authenticators.has_key?(auth_type)
	raise ArgumentError,
	  format('unknown auth type - "%s"', auth_type)
      end
      authenticator = @@authenticators[auth_type].new(*args)
      send_command("AUTHENTICATE", auth_type) do |resp|
	if resp.instance_of?(ContinueRequest)
	  data = authenticator.process(resp.data.text.unpack("m")[0])
	  send_data([data].pack("m").chomp)
	end
      end
    end

    def login(user, password)
      send_command("LOGIN", user, password)
    end

    def select(mailbox)
      @responses.clear
      send_command("SELECT", mailbox)
    end

    def examine(mailbox)
      @responses.clear
      send_command("EXAMINE", mailbox)
    end

    def create(mailbox)
      send_command("CREATE", mailbox)
    end

    def delete(mailbox)
      send_command("DELETE", mailbox)
    end

    def rename(mailbox, newname)
      send_command("RENAME", mailbox, newname)
    end

    def subscribe(mailbox)
      send_command("SUBSCRIBE", mailbox)
    end

    def unsubscribe(mailbox)
      send_command("UNSUBSCRIBE", mailbox)
    end

    def list(refname, mailbox)
      send_command("LIST", refname, mailbox)
      return @responses.delete("LIST")
    end

    def lsub(refname, mailbox)
      send_command("LSUB", refname, mailbox)
      return @responses.delete("LSUB")
    end

    def status(mailbox, attr)
      send_command("STATUS", mailbox, attr)
      return @responses.delete("STATUS")[-1][1]
    end

    def append(mailbox, message, flags = nil, date_time = nil)
      args = []
      if flags
	args.push(flags)
      end
      args.push(date_time) if date_time
      args.push(Literal.new(message))
      send_command("APPEND", mailbox, *args)
    end

    def check
      send_command("CHECK")
    end

    def close
      send_command("CLOSE")
    end

    def expunge
      send_command("EXPUNGE")
      return @responses.delete("EXPUNGE")
    end

    def search(keys, charset = nil)
      return search_internal("SEARCH", keys, charset)
    end

    def uid_search(keys, charset = nil)
      return search_internal("UID SEARCH", keys, charset)
    end

    def fetch(set, attr)
      return fetch_internal("FETCH", set, attr)
    end

    def uid_fetch(set, attr)
      return fetch_internal("UID FETCH", set, attr)
    end

    def store(set, attr, flags)
      return store_internal("STORE", set, attr, flags)
    end

    def uid_store(set, attr, flags)
      return store_internal("UID STORE", set, attr, flags)
    end

    def copy(set, mailbox)
      copy_internal("COPY", set, mailbox)
    end

    def uid_copy(set, mailbox)
      copy_internal("UID COPY", set, mailbox)
    end

    def sort(sort_keys, search_keys, charset)
      return sort_internal("SORT", sort_keys, search_keys, charset)
    end

    def uid_sort(sort_keys, search_keys, charset)
      return sort_internal("UID SORT", sort_keys, search_keys, charset)
    end

    private

    CRLF = "\r\n"
    PORT = 143

    @@debug = false
    @@authenticators = {}

    def initialize(host, port = PORT)
      @host = host
      @port = port
      @tag_prefix = "RUBY"
      @tagno = 0
      @parser = ResponseParser.new
      @sock = TCPSocket.open(host, port)
      @responses = Hash.new([].freeze)
      @greeting = get_response
      if /\ABYE\z/ni =~ @greeting.name
	@sock.close
	raise ByeResponseError, resp[0]
      end
    end

    def send_command(cmd, *args, &block)
      tag = generate_tag
      data = args.collect {|i| format_data(i)}.join(" ")
      if data.length > 0
	put_line(tag + " " + cmd + " " + data)
      else
	put_line(tag + " " + cmd)
      end
      return get_all_responses(tag, cmd, &block)
    end

    def generate_tag
      @tagno += 1
      return format("%s%04d", @tag_prefix, @tagno)
    end

    def send_data(*args)
      data = args.collect {|i| format_data(i)}.join(" ")
      put_line(data)
    end

    def put_line(line)
      line = line + CRLF
      @sock.print(line)
      if @@debug
        $stderr.print(line.gsub(/^/n, "C: "))
      end
    end

    def get_all_responses(tag, cmd, &block)
      while resp = get_response
	if @@debug
	  $stderr.printf("R: %s\n", resp.inspect)
	end
	case resp
	when TaggedResponse
	  case resp.name
	  when /\A(?:NO)\z/ni
	    raise NoResponseError, resp.data.text
	  when /\A(?:BAD)\z/ni
	    raise BadResponseError, resp.data.text
	  else
	    return resp
	  end
	when UntaggedResponse
	  if /\ABYE\z/ni =~ resp.name &&
	      cmd != "LOGOUT"
	    raise ByeResponseError, resp.data.text
	  end
	  record_response(resp.name, resp.data)
	  if resp.data.instance_of?(ResponseText) &&
	      (code = resp.data.code)
	    record_response(code.name, code.data)
	  end
	end
	block.call(resp) if block
      end
    end

    def get_response
      buff = ""
      while true
	s = @sock.gets(CRLF)
	break unless s
	buff.concat(s)
	if /\{(\d+)\}\r\n/n =~ s
	  s = @sock.read($1.to_i)
	  buff.concat(s)
	else
	  break
	end
      end
      return nil if buff.length == 0
      if @@debug
        $stderr.print(buff.gsub(/^/n, "S: "))
      end
      return @parser.parse(buff)
    end

    def record_response(name, data)
      unless @responses.has_key?(name)
	@responses[name] = []
      end
      @responses[name].push(data)
    end

    def format_data(data)
      case data
      when nil
	return "NIL"
      when String
	return format_string(data)
      when Integer
	return format_number(data)
      when Array
	return format_list(data)
      when Time
	return format_time(data)
      when Symbol
	return format_symbol(data)
      else
	return data.format_data
      end
    end

    def format_string(str)
      case str
      when ""
	return '""'
      when /[\x80-\xff\r\n]/n
	# literal
	return "{" + str.length.to_s + "}" + CRLF + str
      when /[(){ \x00-\x1f\x7f%*"\\]/n
	# quoted string
	return '"' + str.gsub(/["\\]/n, "\\\\\\&") + '"'
      else
	# atom
	return str
      end
    end

    def format_number(num)
      if num < 0 || num >= 4294967296
	raise DataFormatError, num.to_s
      end
      return num.to_s
    end

    def format_list(list)
      contents = list.collect {|i| format_data(i)}.join(" ")
      return "(" + contents + ")"
    end

    DATE_MONTH = %w(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec)

    def format_time(time)
      t = time.dup.gmtime
      return format('"%2d-%3s-%4d %02d:%02d:%02d +0000"',
		    t.day, DATE_MONTH[t.month - 1], t.year,
		    t.hour, t.min, t.sec)
    end

    def format_symbol(symbol)
      return "\\" + symbol.to_s
    end

    def search_internal(cmd, keys, charset)
      if keys.instance_of?(String)
	keys = [RawData.new(keys)]
      else
	normalize_searching_criteria(keys)
      end
      if charset
	send_command(cmd, "CHARSET", charset, *keys)
      else
	send_command(cmd, *keys)
      end
      return @responses.delete("SEARCH")[-1]
    end

    def fetch_internal(cmd, set, attr)
      if attr.instance_of?(String)
	attr = RawData.new(attr)
      end
      @responses.delete("FETCH")
      send_command(cmd, MessageSet.new(set), attr)
      return @responses.delete("FETCH")
    end

    def store_internal(cmd, set, attr, flags)
      if attr.instance_of?(String)
	attr = RawData.new(attr)
      end
      @responses.delete("FETCH")
      send_command(cmd, MessageSet.new(set), attr, flags)
      return @responses.delete("FETCH")
    end

    def copy_internal(cmd, set, mailbox)
      send_command(cmd, MessageSet.new(set), mailbox)
    end

    def sort_internal(cmd, sort_keys, search_keys, charset)
      if search_keys.instance_of?(String)
	search_keys = [RawData.new(search_keys)]
      else
	normalize_searching_criteria(search_keys)
      end
      normalize_searching_criteria(search_keys)
      send_command(cmd, sort_keys, charset, *search_keys)
      return @responses.delete("SORT")[-1]
    end

    def normalize_searching_criteria(keys)
      keys.collect! do |i|
	case i
	when -1, Range, Array
	  MessageSet.new(i)
	else
	  i
	end
      end
    end

    class RawData
      def format_data
	return @data
      end

      private

      def initialize(data)
	@data = data
      end
    end

    class Atom
      def format_data
	return @data
      end

      private

      def initialize(data)
	@data = data
      end
    end

    class QuotedString
      def format_data
	return '"' + @data.gsub(/["\\]/n, "\\\\\\&") + '"'
      end

      private

      def initialize(data)
	@data = data
      end
    end

    class Literal
      def format_data
	return "{" + @data.length.to_s + "}" + CRLF + @data
      end

      private

      def initialize(data)
	@data = data
      end
    end

    class MessageSet
      def format_data
	return format_internal(@data)
      end

      private

      def initialize(data)
	@data = data
      end

      def format_internal(data)
	case data
	when "*"
	  return data
	when Integer
	  ensure_nz_number(data)
	  if data == -1
	    return "*"
	  else
	    return data.to_s
	  end
	when Range
	  return format_internal(data.first) +
	    ":" + format_internal(data.last)
	when Array
	  return data.collect {|i| format_internal(i)}.join(",")
	else
	  raise DataFormatError, data.inspect
	end
      end

      def ensure_nz_number(num)
	if num < -1 || num == 0 || num >= 4294967296
	  raise DataFormatError, num.inspect
	end
      end
    end

    ContinueRequest = Struct.new(:data, :raw_data)
    UntaggedResponse = Struct.new(:name, :data, :raw_data)
    TaggedResponse = Struct.new(:tag, :name, :data, :raw_data)
    ResponseText = Struct.new(:code, :text)
    ResponseCode = Struct.new(:name, :data)
    MailboxList = Struct.new(:attr, :delim, :name)
    StatusData = Struct.new(:mailbox, :attr)
    FetchData = Struct.new(:seqno, :attr)
    Envelope = Struct.new(:date, :subject, :from, :sender, :reply_to,
			  :to, :cc, :bcc, :in_reply_to, :message_id)
    Address = Struct.new(:name, :route, :mailbox, :host)
    ContentDisposition = Struct.new(:dsp_type, :param)

    class BodyTypeBasic < Struct.new(:media_type, :media_subtype,
				     :param, :content_id,
				     :description, :encoding, :size,
				     :md5, :disposition, :language,
				     :extension)
      def multipart?
	return false
      end
    end

    class BodyTypeText < Struct.new(:media_type, :media_subtype,
				    :param, :content_id,
				    :description, :encoding, :size,
				    :lines,
				    :md5, :disposition, :language,
				    :extension)
      def multipart?
	return false
      end
    end

    class BodyTypeMessage < Struct.new(:media_type, :media_subtype,
				       :param, :content_id,
				       :description, :encoding, :size,
				       :envelope, :body, :lines,
				       :md5, :disposition, :language,
				       :extension)
      def multipart?
	return false
      end
    end

    class BodyTypeMultipart < Struct.new(:media_type, :media_subtype,
					 :parts,
					 :param, :disposition, :language,
					 :extension)
      def multipart?
	return true
      end
    end

    class ResponseParser
      def parse(str)
	@str = str
	@pos = 0
	@lex_state = EXPR_BEG
	@token = nil
	return response
      end

      private

      EXPR_BEG		= :EXPR_BEG
      EXPR_DATA		= :EXPR_DATA
      EXPR_TEXT		= :EXPR_TEXT
      EXPR_RTEXT	= :EXPR_RTEXT
      EXPR_CTEXT	= :EXPR_CTEXT

      T_SPACE	= :SPACE
      T_NIL	= :NIL
      T_NUMBER	= :NUMBER
      T_ATOM	= :ATOM
      T_QUOTED	= :QUOTED
      T_LPAR	= :LPAR
      T_RPAR	= :RPAR
      T_BSLASH	= :BSLASH
      T_STAR	= :STAR
      T_LBRA	= :LBRA
      T_RBRA	= :RBRA
      T_LITERAL	= :LITERAL
      T_PLUS	= :PLUS
      T_PERCENT	= :PERCENT
      T_CRLF	= :CRLF
      T_EOF	= :EOF
      T_TEXT	= :TEXT

      BEG_REGEXP = /\G(?:\
(?# 1:	SPACE	)( )|\
(?# 2:	NIL	)(NIL)(?=[\x80-\xff(){ \x00-\x1f\x7f%*"\\\[\]+])|\
(?# 3:	NUMBER	)(\d+)(?=[\x80-\xff(){ \x00-\x1f\x7f%*"\\\[\]+])|\
(?# 4:	ATOM	)([^\x80-\xff(){ \x00-\x1f\x7f%*"\\\[\]+]+)|\
(?# 5:	QUOTED	)"((?:[^\x80-\xff\x00\r\n"\\]|\\["\\])*)"|\
(?# 6:	LPAR	)(\()|\
(?# 7:	RPAR	)(\))|\
(?# 8:	BSLASH	)(\\)|\
(?# 9:	STAR	)(\*)|\
(?# 10:	LBRA	)(\[)|\
(?# 11:	RBRA	)(\])|\
(?# 12:	LITERAL	)\{(\d+)\}\r\n|\
(?# 13:	PLUS	)(\+)|\
(?# 14:	PERCENT	)(%)|\
(?# 15:	CRLF	)(\r\n)|\
(?# 16:	EOF	)(\z))/ni

      DATA_REGEXP = /\G(?:\
(?# 1:	SPACE	)( )|\
(?# 2:	NIL	)(NIL)|\
(?# 3:	NUMBER	)(\d+)|\
(?# 4:	QUOTED	)"((?:[^\x80-\xff\x00\r\n"\\]|\\["\\])*)"|\
(?# 5:	LITERAL	)\{(\d+)\}\r\n|\
(?# 6:	LPAR	)(\()|\
(?# 7:	RPAR	)(\)))/ni

      TEXT_REGEXP = /\G(?:\
(?# 1:	TEXT	)([^\x00\x80-\xff\r\n]*))/ni

      RTEXT_REGEXP = /\G(?:\
(?# 1:	LBRA	)(\[)|\
(?# 2:	TEXT	)([^\x00\x80-\xff\r\n]*))/ni

      CTEXT_REGEXP = /\G(?:\
(?# 1:	TEXT	)([^\x00\x80-\xff\r\n\]]*))/ni

      Token = Struct.new(:symbol, :value)

      def response
	token = lookahead
	case token.symbol
	when T_PLUS
	  result = continue_req
	when T_STAR
	  result = response_untagged
	else
	  result = response_tagged
	end
	match(T_CRLF)
	match(T_EOF)
	return result
      end

      def continue_req
	match(T_PLUS)
	match(T_SPACE)
	return ContinueRequest.new(resp_text, @str)
      end

      def response_untagged
	match(T_STAR)
	match(T_SPACE)
	token = lookahead
	if token.symbol == T_NUMBER
	  return numeric_response
	elsif token.symbol == T_ATOM
	  case token.value
	  when /\A(?:OK|NO|BAD|BYE|PREAUTH)\z/ni
	    return response_cond
	  when /\A(?:FLAGS)\z/ni
	    return flags_response
	  when /\A(?:LIST|LSUB)\z/ni
	    return list_response
	  when /\A(?:SEARCH|SORT)\z/ni
	    return search_response
	  when /\A(?:STATUS)\z/ni
	    return status_response
	  when /\A(?:CAPABILITY)\z/ni
	    return capability_response
	  else
	    return text_response
	  end
	else
	  parse_error("unexpected token %s", token.symbol)
	end
      end

      def response_tagged
	tag = atom
	match(T_SPACE)
	token = match(T_ATOM)
	name = token.value.upcase
	match(T_SPACE)
	return TaggedResponse.new(tag, name, resp_text, @str)
      end

      def response_cond
	token = match(T_ATOM)
	name = token.value.upcase
	match(T_SPACE)
	return UntaggedResponse.new(name, resp_text, @str)
      end

      def numeric_response
	n = number
	match(T_SPACE)
	token = match(T_ATOM)
	name = token.value.upcase
	case name
	when "EXISTS", "RECENT", "EXPUNGE"
	  return UntaggedResponse.new(name, n, @str)
	when "FETCH"
	  shift_token
	  match(T_SPACE)
	  data = FetchData.new(n, msg_att)
	  return UntaggedResponse.new(name, data, @str)
	end
      end

      def msg_att
	match(T_LPAR)
	attr = {}
	while true
	  token = lookahead
	  case token.symbol
	  when T_RPAR
	    shift_token
	    break
	  when T_SPACE
	    shift_token
	    token = lookahead
	  end
	  case token.value
	  when /\A(?:ENVELOPE)\z/ni
	    name, val = envelope_data
	  when /\A(?:FLAGS)\z/ni
	    name, val = flags_data
	  when /\A(?:INTERNALDATE)\z/ni
	    name, val = internaldate_data
	  when /\A(?:RFC822(?:\.HEADER|\.TEXT)?)\z/ni
	    name, val = rfc822_text
	  when /\A(?:RFC822\.SIZE)\z/ni
	    name, val = rfc822_size
	  when /\A(?:BODY(?:STRUCTURE)?)\z/ni
	    name, val = body_data
	  when /\A(?:UID)\z/ni
	    name, val = uid_data
	  else
	    parse_error("unknown attribute `%s'", token.value)
	  end
	  attr[name] = val
	end
	return attr
      end

      def envelope_data
	token = match(T_ATOM)
	name = token.value.upcase
	match(T_SPACE)
	return name, envelope
      end

      def envelope
	@lex_state = EXPR_DATA
	match(T_LPAR)
	date = nstring
	match(T_SPACE)
	subject = nstring
	match(T_SPACE)
	from = address_list
	match(T_SPACE)
	sender = address_list
	match(T_SPACE)
	reply_to = address_list
	match(T_SPACE)
	to = address_list
	match(T_SPACE)
	cc = address_list
	match(T_SPACE)
	bcc = address_list
	match(T_SPACE)
	in_reply_to = nstring
	match(T_SPACE)
	message_id = nstring
	match(T_RPAR)
	@lex_state = EXPR_BEG
	return Envelope.new(date, subject, from, sender, reply_to,
			    to, cc, bcc, in_reply_to, message_id)
      end

      def flags_data
	token = match(T_ATOM)
	name = token.value.upcase
	match(T_SPACE)
	return name, flag_list
      end

      def internaldate_data
	token = match(T_ATOM)
	name = token.value.upcase
	match(T_SPACE)
	token = match(T_QUOTED)
	return name, token.value
      end

      def rfc822_text
	token = match(T_ATOM)
	name = token.value.upcase
	match(T_SPACE)
	return name, nstring
      end

      def rfc822_size
	token = match(T_ATOM)
	name = token.value.upcase
	match(T_SPACE)
	return name, number
      end

      def body_data
	token = match(T_ATOM)
	name = token.value.upcase
	token = lookahead
	if token.symbol == T_SPACE
	  shift_token
	  return name, body
	end
	name.concat(section)
	token = lookahead
	if token.symbol == T_ATOM
	  name.concat(token.value)
	  shift_token
	end
	match(T_SPACE)
	data = nstring
	return name, data
      end

      def body
	@lex_state = EXPR_DATA
	match(T_LPAR)
	token = lookahead
	if token.symbol == T_LPAR
	  result = body_type_mpart
	else
	  result = body_type_1part
	end
	match(T_RPAR)
	@lex_state = EXPR_BEG
	return result
      end

      def body_type_1part
	token = lookahead
	case token.value
	when /\A(?:TEXT)\z/ni
	  return body_type_text
	when /\A(?:MESSAGE)\z/ni
	  return body_type_msg
	else
	  return body_type_basic
	end
      end

      def body_type_basic
	mtype, msubtype = media_type
	match(T_SPACE)
	param, content_id, desc, enc, size = body_fields
	md5, disposition, language, extension = body_ext_1part
	return BodyTypeBasic.new(mtype, msubtype,
				 param, content_id,
				 desc, enc, size,
				 md5, disposition, language, extension)
      end

      def body_type_text
	mtype, msubtype = media_type
	match(T_SPACE)
	param, content_id, desc, enc, size = body_fields
	match(T_SPACE)
	lines = number
	md5, disposition, language, extension = body_ext_1part
	return BodyTypeText.new(mtype, msubtype,
				param, content_id,
				desc, enc, size,
				lines,
				md5, disposition, language, extension)
      end

      def body_type_msg
	mtype, msubtype = media_type
	match(T_SPACE)
	param, content_id, desc, enc, size = body_fields
	match(T_SPACE)
	env = envelope
	match(T_SPACE)
	b = body
	match(T_SPACE)
	lines = number
	md5, disposition, language, extension = body_ext_1part
	return BodyTypeMessage.new(mtype, msubtype,
				   param, content_id,
				   desc, enc, size,
				   env, b, lines,
				   md5, disposition, language, extension)
      end

      def body_type_mpart
	parts = []
	while true
	  token = lookahead
	  if token.symbol == T_SPACE
	    shift_token
	    break
	  end
	  parts.push(body)
	end
	mtype = "MULTIPART"
	msubtype = string.upcase
	param, disposition, language, extension = body_ext_mpart
	return BodyTypeMultipart.new(mtype, msubtype, parts,
				     param, disposition, language,
				     extension)
      end

      def media_type
	mtype = string.upcase
	match(T_SPACE)
	msubtype = string.upcase
	return mtype, msubtype
      end

      def body_fields
	param = body_fld_param
	match(T_SPACE)
	content_id = nstring
	match(T_SPACE)
	desc = nstring
	match(T_SPACE)
	enc = string.upcase
	match(T_SPACE)
	size = number
	return param, content_id, desc, enc, size
      end

      def body_fld_param
	token = lookahead
	if token.symbol == T_NIL
	  shift_token
	  return nil
	end
	match(T_LPAR)
	param = {}
	while true
	  token = lookahead
	  case token.symbol
	  when T_RPAR
	    shift_token
	    break
	  when T_SPACE
	    shift_token
	  end
	  name = string.upcase
	  match(T_SPACE)
	  val = string
	  param[name] = val
	end
	return param
      end

      def body_ext_1part
	token = lookahead
	if token.symbol == T_SPACE
	  shift_token
	else
	  return nil
	end
	md5 = nstring

	token = lookahead
	if token.symbol == T_SPACE
	  shift_token
	else
	  return md5
	end
	disposition = body_fld_dsp

	token = lookahead
	if token.symbol == T_SPACE
	  shift_token
	else
	  return md5, disposition
	end
	language = body_fld_lang

	token = lookahead
	if token.symbol == T_SPACE
	  shift_token
	else
	  return md5, disposition, language
	end

	extension = body_extensions
	return md5, disposition, language, extension
      end

      def body_ext_mpart
	token = lookahead
	if token.symbol == T_SPACE
	  shift_token
	else
	  return nil
	end
	param = body_fld_param

	token = lookahead
	if token.symbol == T_SPACE
	  shift_token
	else
	  return param
	end
	disposition = body_fld_dsp
	match(T_SPACE)
	language = body_fld_lang

	token = lookahead
	if token.symbol == T_SPACE
	  shift_token
	else
	  return param, disposition, language
	end

	extension = body_extensions
	return param, disposition, language, extension
      end

      def body_fld_dsp
	token = lookahead
	if token.symbol == T_NIL
	  shift_token
	  return nil
	end
	match(T_LPAR)
	dsp_type = string.upcase
	match(T_SPACE)
	param = body_fld_param
	match(T_RPAR)
	return ContentDisposition.new(dsp_type, param)
      end

      def body_fld_lang
	token = lookahead
	if token.symbol == T_LPAR
	  shift_token
	  result = []
	  while true
	    token = lookahead
	    case token.symbol
	    when T_RPAR
	      shift_token
	      return result
	    when T_SPACE
	      shift_token
	    end
	    result.push(string.upcase)
	  end
	else
	  lang = nstring
	  if lang
	    return lang.upcase
	  else
	    return lang
	  end
	end
      end

      def body_extensions
	result = []
	while true
	  token = lookahead
	  case token.symbol
	  when T_RPAR
	    return result
	  when T_SPACE
	    shift_token
	  end
	  result.push(body_extension)
	end
      end

      def body_extension
	token = lookahead
	case token.symbol
	when T_LPAR
	  shift_token
	  result = body_extensions
	  match(T_RPAR)
	  return result
	when T_NUMBER
	  return number
	else
	  return nstring
	end
      end

      def section
	str = ""
	token = match(T_LBRA)
	str.concat(token.value)
	token = match(T_ATOM, T_NUMBER, T_RBRA)
	if token.symbol == T_RBRA
	  str.concat(token.value)
	  return str
	end
	str.concat(token.value)
	token = lookahead
	if token.symbol == T_SPACE
	  shift_token
	  str.concat(token.value)
	  token = match(T_LPAR)
	  str.concat(token.value)
	  while true
	    token = lookahead
	    case token.symbol
	    when T_RPAR
	      str.concat(token.value)
	      shift_token
	      break
	    when T_SPACE
	      shift_token
	      str.concat(token.value)
	    end
	    str.concat(format_string(astring))
	  end
	end
	token = match(T_RBRA)
	str.concat(token.value)
	return str
      end

      def format_string(str)
	case str
	when ""
	  return '""'
	when /[\x80-\xff\r\n]/n
	  # literal
	  return "{" + str.length.to_s + "}" + CRLF + str
	when /[(){ \x00-\x1f\x7f%*"\\]/n
	  # quoted string
	  return '"' + str.gsub(/["\\]/n, "\\\\\\&") + '"'
	else
	  # atom
	  return str
	end
      end

      def uid_data
	token = match(T_ATOM)
	name = token.value.upcase
	match(T_SPACE)
	return name, number
      end

      def text_response
	token = match(T_ATOM)
	name = token.value.upcase
	match(T_SPACE)
	@lex_state = EXPR_TEXT
	token = match(T_TEXT)
	@lex_state = EXPR_BEG
	return UntaggedResponse.new(name, token.value)
      end

      def flags_response
	token = match(T_ATOM)
	name = token.value.upcase
	match(T_SPACE)
	return UntaggedResponse.new(name, flag_list, @str)
      end

      def list_response
	token = match(T_ATOM)
	name = token.value.upcase
	match(T_SPACE)
	return UntaggedResponse.new(name, mailbox_list, @str)
      end

      def mailbox_list
	attr = flag_list
	match(T_SPACE)
	token = match(T_QUOTED, T_NIL)
	if token.symbol == T_NIL
	  delim = nil
	else
	  delim = token.value
	end
	match(T_SPACE)
	name = astring
	return MailboxList.new(attr, delim, name)
      end

      def search_response
	token = match(T_ATOM)
	name = token.value.upcase
	token = lookahead
	if token.symbol == T_SPACE
	  shift_token
	  data = []
	  while true
	    token = lookahead
	    case token.symbol
	    when T_CRLF
	      break
	    when T_SPACE
	      shift_token
	    end
	    data.push(number)
	  end
	else
	  data = []
	end
	return UntaggedResponse.new(name, data, @str)
      end

      def status_response
	token = match(T_ATOM)
	name = token.value.upcase
	match(T_SPACE)
	mailbox = astring
	match(T_SPACE)
	match(T_LPAR)
	attr = {}
	while true
	  token = lookahead
	  case token.symbol
	  when T_RPAR
	    shift_token
	    break
	  when T_SPACE
	    shift_token
	  end
	  token = match(T_ATOM)
	  key = token.value.upcase
	  match(T_SPACE)
	  val = number
	  attr[key] = val
	end
	data = StatusData.new(mailbox, attr)
	return UntaggedResponse.new(name, data, @str)
      end

      def capability_response
	token = match(T_ATOM)
	name = token.value.upcase
	match(T_SPACE)
	data = []
	while true
	  token = lookahead
	  case token.symbol
	  when T_CRLF
	    break
	  when T_SPACE
	    shift_token
	  end
	  data.push(atom.upcase)
	end
	return UntaggedResponse.new(name, data, @str)
      end

      def resp_text
	@lex_state = EXPR_RTEXT
	token = lookahead
	if token.symbol == T_LBRA
	  code = resp_text_code
	else
	  code = nil
	end
	token = match(T_TEXT)
	@lex_state = EXPR_BEG
	return ResponseText.new(code, token.value)
      end

      def resp_text_code
	@lex_state = EXPR_BEG
	match(T_LBRA)
	token = match(T_ATOM)
	name = token.value.upcase
	case name
	when /\A(?:ALERT|PARSE|READ-ONLY|READ-WRITE|TRYCREATE)\z/n
	  result = ResponseCode.new(name, nil)
	when /\A(?:PERMANENTFLAGS)\z/n
	  match(T_SPACE)
	  result = ResponseCode.new(name, flag_list)
	when /\A(?:UIDVALIDITY|UIDNEXT|UNSEEN)\z/n
	  match(T_SPACE)
	  result = ResponseCode.new(name, number)
	end
	match(T_RBRA)
	@lex_state = EXPR_RTEXT
	return result
      end

      def address_list
	token = lookahead
	if token.symbol == T_NIL
	  shift_token
	  return nil
	else
	  result = []
	  match(T_LPAR)
	  while true
	    token = lookahead
	    case token.symbol
	    when T_RPAR
	      shift_token
	      break
	    when T_SPACE
	      shift_token
	    end
	    result.push(address)
	  end
	  return result
	end
      end

      ADDRESS_REGEXP = /\G\
(?# 1: NAME	)(?:NIL|"((?:[^\x80-\xff\x00\r\n"\\]|\\["\\])*)") \
(?# 2: ROUTE	)(?:NIL|"((?:[^\x80-\xff\x00\r\n"\\]|\\["\\])*)") \
(?# 3: MAILBOX	)(?:NIL|"((?:[^\x80-\xff\x00\r\n"\\]|\\["\\])*)") \
(?# 4: HOST	)(?:NIL|"((?:[^\x80-\xff\x00\r\n"\\]|\\["\\])*)")\
\)/ni

      def address
	match(T_LPAR)
	if @str.index(ADDRESS_REGEXP, @pos)
	  # address does not include literal.
	  @pos = $~.end(0)
	  name = $1
	  route = $2
	  mailbox = $3
	  host = $4
	  for s in [name, route, mailbox, host]
	    if s
	      s.gsub!(/\\(["\\])/n, "\\1")
	    end
	  end
	else
	  name = nstring
	  match(T_SPACE)
	  route = nstring
	  match(T_SPACE)
	  mailbox = nstring
	  match(T_SPACE)
	  host = nstring
	  match(T_RPAR)
	end
	return Address.new(name, route, mailbox, host)
      end

#        def flag_list
#  	result = []
#  	match(T_LPAR)
#  	while true
#  	  token = lookahead
#  	  case token.symbol
#  	  when T_RPAR
#  	    shift_token
#  	    break
#  	  when T_SPACE
#  	    shift_token
#  	  end
#  	  result.push(flag)
#  	end
#  	return result
#        end

#        def flag
#  	token = lookahead
#  	if token.symbol == T_BSLASH
#  	  shift_token
#  	  token = lookahead
#  	  if token.symbol == T_STAR
#  	    shift_token
#  	    return token.value.intern
#  	  else
#  	    return atom.intern
#  	  end
#  	else
#  	  return atom
#  	end
#        end

      FLAG_REGEXP = /\
(?# FLAG	)\\([^\x80-\xff(){ \x00-\x1f\x7f%"\\]+)|\
(?# ATOM	)([^\x80-\xff(){ \x00-\x1f\x7f%*"\\]+)/n

      def flag_list
	if @str.index(/\(([^)]*)\)/ni, @pos)
	  @pos = $~.end(0)
	  return $1.scan(FLAG_REGEXP).collect { |flag, atom|
	    atom || flag.intern
	  }
	else
	  parse_error("invalid flag list")
	end
      end

      def nstring
	token = lookahead
	if token.symbol == T_NIL
	  shift_token
	  return nil
	else
	  return string
	end
      end

      def astring
	token = lookahead
	if string_token?(token)
	  return string
	else
	  return atom
	end
      end

      def string
	token = match(T_QUOTED, T_LITERAL)


context:
space:
mode: