/usr/share/slib/xml-parse.scm is in slib 3b1-5.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 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 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 | ;;;;"xml-parse.scm" XML parsing and conversion to SXML (Scheme-XML)
;;; Copyright (C) 2007 Aubrey Jaffer
;;; 2007-04 jaffer: demacrofied from public-domain SSAX 5.1
;
;Permission to copy this software, to modify it, to redistribute it,
;to distribute modified versions, and to use it for any purpose is
;granted, subject to the following restrictions and understandings.
;
;1. Any copy made of this software must include this copyright notice
;in full.
;
;2. I have made no warranty or representation that the operation of
;this software will be error-free, and I am under no obligation to
;provide any services, by way of maintenance, update, or otherwise.
;
;3. In conjunction with products arising from the use of this
;material, there shall be no use of my name in any advertising,
;promotional, or sales literature without prior written consent in
;each case.
;;@code{(require 'xml-parse)} or @code{(require 'ssax)}
;;
;;@noindent
;;The XML standard document referred to in this module is@*
;;@url{http://www.w3.org/TR/1998/REC-xml-19980210.html}.
;;
;;@noindent
;;The present frameworks fully supports the XML Namespaces
;;Recommendation@*
;;@url{http://www.w3.org/TR/REC-xml-names}.
(require 'rev2-procedures) ; for substring-move-left!
(require 'string-search)
(require 'let-values)
(require 'values)
(require 'srfi-1) ; for fold-right, fold, cons*
;;@subsection String Glue
;;;; Three functions from SRFI-13
; procedure string-concatenate-reverse STRINGS [FINAL END]
(define (ssax:string-concatenate-reverse strs final end)
(if (null? strs) (substring final 0 end)
(let*
((total-len
(let loop ((len end) (lst strs))
(if (null? lst) len
(loop (+ len (string-length (car lst))) (cdr lst)))))
(result (make-string total-len)))
(let loop ((len end) (j total-len) (str final) (lst strs))
(substring-move-left! str 0 len result (- j len))
(if (null? lst) result
(loop (string-length (car lst)) (- j len)
(car lst) (cdr lst)))))))
; string-concatenate/shared STRING-LIST -> STRING
(define (ssax:string-concatenate/shared strs)
(cond ((null? strs) "") ; Test for the fast path first
((null? (cdr strs)) (car strs))
(else
(let*
((total-len
(let loop ((len (string-length (car strs))) (lst (cdr strs)))
(if (null? lst) len
(loop (+ len (string-length (car lst))) (cdr lst)))))
(result (make-string total-len)))
(let loop ((j 0) (str (car strs)) (lst (cdr strs)))
(substring-move-left! str 0 (string-length str) result j)
(if (null? lst) result
(loop (+ j (string-length str))
(car lst) (cdr lst))))))))
; string-concatenate-reverse/shared STRING-LIST [FINAL-STRING END] -> STRING
; We do not use the optional arguments of this procedure. Therefore,
; we do not implement them. See SRFI-13 for the complete
; implementation.
(define (ssax:string-concatenate-reverse/shared strs)
(cond ((null? strs) "") ; Test for the fast path first
((null? (cdr strs)) (car strs))
(else
(ssax:string-concatenate-reverse (cdr strs)
(car strs)
(string-length (car strs))))))
;;@args list-of-frags
;;
;;Given the list of fragments (some of which are text strings),
;;reverse the list and concatenate adjacent text strings. If
;;LIST-OF-FRAGS has zero or one element, the result of the procedure
;;is @code{equal?} to its argument.
(define (ssax:reverse-collect-str fragments)
(cond
((null? fragments) '()) ; a shortcut
((null? (cdr fragments)) fragments) ; see the comment above
(else
(let loop ((fragments fragments) (result '()) (strs '()))
(cond
((null? fragments)
(if (null? strs)
result
(cons (ssax:string-concatenate/shared strs) result)))
((string? (car fragments))
(loop (cdr fragments) result (cons (car fragments) strs)))
(else
(loop (cdr fragments)
(cons (car fragments)
(if (null? strs)
result
(cons (ssax:string-concatenate/shared strs) result)))
'())))))))
;;@args list-of-frags
;;
;;Given the list of fragments (some of which are text strings),
;;reverse the list and concatenate adjacent text strings while
;;dropping "unsignificant" whitespace, that is, whitespace in front,
;;behind and between elements. The whitespace that is included in
;;character data is not affected.
;;
;;Use this procedure to "intelligently" drop "insignificant"
;;whitespace in the parsed SXML. If the strict compliance with the
;;XML Recommendation regarding the whitespace is desired, use the
;;@code{ssax:reverse-collect-str} procedure instead.
(define (ssax:reverse-collect-str-drop-ws fragments)
;; Test if a string is made of only whitespace.
;; An empty string is considered made of whitespace as well
(define (string-whitespace? str)
(let ((len (string-length str)))
(cond ((zero? len) #t)
((= 1 len) (char-whitespace? (string-ref str 0)))
(else
(let loop ((i 0))
(or (>= i len)
(and (char-whitespace? (string-ref str i))
(loop (+ 1 i)))))))))
(cond
((null? fragments) '()) ; a shortcut
((null? (cdr fragments)) ; another shortcut
(if (and (string? (car fragments)) (string-whitespace? (car fragments)))
'() ; remove trailing ws
fragments))
(else
(let loop ((fragments fragments) (result '()) (strs '())
(all-whitespace? #t))
(cond
((null? fragments)
(if all-whitespace?
result ; remove leading ws
(cons (ssax:string-concatenate/shared strs) result)))
((string? (car fragments))
(loop (cdr fragments)
result
(cons (car fragments) strs)
(and all-whitespace? (string-whitespace? (car fragments)))))
(else
(loop (cdr fragments)
(cons (car fragments)
(if all-whitespace?
result
(cons (ssax:string-concatenate/shared strs) result)))
'()
#t)))))))
;;@subsection Character and Token Functions
;;
;;The following functions either skip, or build and return tokens,
;;according to inclusion or delimiting semantics. The list of
;;characters to expect, include, or to break at may vary from one
;;invocation of a function to another. This allows the functions to
;;easily parse even context-sensitive languages.
;;
;;Exceptions are mentioned specifically. The list of expected
;;characters (characters to skip until, or break-characters) may
;;include an EOF "character", which is coded as symbol *eof*
;;
;;The input stream to parse is specified as a PORT, which is the last
;;argument.
;;@args char-list string port
;;
;;Reads a character from the @3 and looks it up in the
;;@1 of expected characters. If the read character was
;;found among expected, it is returned. Otherwise, the
;;procedure writes a message using @2 as a comment
;;and quits.
(define (ssax:assert-current-char expected-chars comment port)
(let ((c (read-char port)))
(if (memv c expected-chars) c
(slib:error port "Wrong character " c
" (0x" (if (eof-object? c)
"*eof*"
(number->string (char->integer c) 16)) ") "
comment ". " expected-chars " expected"))))
;;@args char-list port
;;
;;Reads characters from the @2 and disregards them, as long as they
;;are mentioned in the @1. The first character (which may be EOF)
;;peeked from the stream that is @emph{not} a member of the @1 is
;;returned.
(define (ssax:skip-while skip-chars port)
(do ((c (peek-char port) (peek-char port)))
((not (memv c skip-chars)) c)
(read-char port)))
;;; Stream tokenizers
;;
;;Note: since we can't tell offhand how large the token being read is
;;going to be, we make a guess, pre-allocate a string, and grow it by
;;quanta if necessary. The quantum is always the length of the string
;;before it was extended the last time. Thus the algorithm does a
;;Fibonacci-type extension, which has been proven optimal.
;;
;;Size 32 turns out to be fairly good, on average. That policy is
;;good only when a Scheme system is multi-threaded with preemptive
;;scheduling, or when a Scheme system supports shared substrings. In
;;all the other cases, it's better for ssax:init-buffer to return the
;;same static buffer. ssax:next-token* functions return a copy (a
;;substring) of accumulated data, so the same buffer can be reused.
;;We shouldn't worry about an incoming token being too large:
;;ssax:next-token will use another chunk automatically. Still, the
;;best size for the static buffer is to allow most of the tokens to
;;fit in. Using a static buffer _dramatically_ reduces the amount of
;;produced garbage (e.g., during XML parsing).
;;@body
;;
;;Returns an initial buffer for @code{ssax:next-token*} procedures.
;;@0 may allocate a new buffer at each invocation.
(define (ssax:init-buffer) (make-string 32))
;;;(define ssax:init-buffer
;;; (let ((buffer (make-string 512)))
;;; (lambda () buffer)))
;;@args prefix-char-list break-char-list comment-string port
;;
;;Skips any number of the prefix characters (members of the @1), if
;;any, and reads the sequence of characters up to (but not including)
;;a break character, one of the @2.
;;
;;The string of characters thus read is returned. The break character
;;is left on the input stream. @2 may include the symbol @code{*eof*};
;;otherwise, EOF is fatal, generating an error message including a
;;specified @3.
(define (ssax:next-token prefix-skipped-chars break-chars comment port)
(let outer ((buffer (ssax:init-buffer)) (filled-buffer-l '())
(c (ssax:skip-while prefix-skipped-chars port)))
(let ((curr-buf-len (string-length buffer)))
(let loop ((i 0) (c c))
(cond
((memv c break-chars)
(if (null? filled-buffer-l) (substring buffer 0 i)
(ssax:string-concatenate-reverse filled-buffer-l buffer i)))
((eof-object? c)
(if (memq '*eof* break-chars) ; was EOF expected?
(if (null? filled-buffer-l) (substring buffer 0 i)
(ssax:string-concatenate-reverse filled-buffer-l buffer i))
(slib:error port "EOF while reading a token " comment)))
((>= i curr-buf-len)
(outer (make-string curr-buf-len)
(cons buffer filled-buffer-l) c))
(else
(string-set! buffer i c)
(read-char port) ; move to the next char
(loop (+ 1 i) (peek-char port))))))))
;;@noindent
;;@code{ssax:next-token-of} is similar to @code{ssax:next-token}
;;except that it implements an inclusion rather than delimiting
;;semantics.
;;@args inc-charset port
;;
;;Reads characters from the @2 that belong to the list of characters
;;@1. The reading stops at the first character which is not a member
;;of the set. This character is left on the stream. All the read
;;characters are returned in a string.
;;
;;@args pred port
;;
;;Reads characters from the @2 for which @var{pred} (a procedure of
;;one argument) returns non-#f. The reading stops at the first
;;character for which @var{pred} returns #f. That character is left
;;on the stream. All the results of evaluating of @var{pred} up to #f
;;are returned in a string.
;;
;;@var{pred} is a procedure that takes one argument (a character or
;;the EOF object) and returns a character or #f. The returned
;;character does not have to be the same as the input argument to the
;;@var{pred}. For example,
;;
;;@example
;;(ssax:next-token-of (lambda (c)
;; (cond ((eof-object? c) #f)
;; ((char-alphabetic? c) (char-downcase c))
;; (else #f)))
;; (current-input-port))
;;@end example
;;
;;will try to read an alphabetic token from the current input port,
;;and return it in lower case.
(define (ssax:next-token-of incl-list/pred port)
(let* ((buffer (ssax:init-buffer))
(curr-buf-len (string-length buffer)))
(if (procedure? incl-list/pred)
(let outer ((buffer buffer) (filled-buffer-l '()))
(let loop ((i 0))
(if (>= i curr-buf-len) ; make sure we have space
(outer (make-string curr-buf-len) (cons buffer filled-buffer-l))
(let ((c (incl-list/pred (peek-char port))))
(if c
(begin
(string-set! buffer i c)
(read-char port) ; move to the next char
(loop (+ 1 i)))
;; incl-list/pred decided it had had enough
(if (null? filled-buffer-l) (substring buffer 0 i)
(ssax:string-concatenate-reverse filled-buffer-l buffer i)))))))
;; incl-list/pred is a list of allowed characters
(let outer ((buffer buffer) (filled-buffer-l '()))
(let loop ((i 0))
(if (>= i curr-buf-len) ; make sure we have space
(outer (make-string curr-buf-len) (cons buffer filled-buffer-l))
(let ((c (peek-char port)))
(cond
((not (memv c incl-list/pred))
(if (null? filled-buffer-l) (substring buffer 0 i)
(ssax:string-concatenate-reverse filled-buffer-l buffer i)))
(else
(string-set! buffer i c)
(read-char port) ; move to the next char
(loop (+ 1 i))))))))
)))
;;@body
;;
;;Reads @1 characters from the @2, and returns them in a string. If
;;EOF is encountered before @1 characters are read, a shorter string
;;will be returned.
(define (ssax:read-string len port)
(define buffer (make-string len))
(do ((idx 0 (+ 1 idx)))
((>= idx len) idx)
(let ((chr (read-char port)))
(cond ((eof-object? byt)
(set! idx (+ -1 idx))
(set! len idx))
(else (string-set! buffer idx chr))))))
;;@subsection Data Types
;;
;;@table @code
;;
;;@item TAG-KIND
;;
;;A symbol @samp{START}, @samp{END}, @samp{PI}, @samp{DECL},
;;@samp{COMMENT}, @samp{CDSECT}, or @samp{ENTITY-REF} that identifies
;;a markup token
;;
;;@item UNRES-NAME
;;
;;a name (called GI in the XML Recommendation) as given in an XML
;;document for a markup token: start-tag, PI target, attribute name.
;;If a GI is an NCName, UNRES-NAME is this NCName converted into a
;;Scheme symbol. If a GI is a QName, @samp{UNRES-NAME} is a pair of
;;symbols: @code{(@var{PREFIX} . @var{LOCALPART})}.
;;
;;@item RES-NAME
;;
;;An expanded name, a resolved version of an @samp{UNRES-NAME}. For
;;an element or an attribute name with a non-empty namespace URI,
;;@samp{RES-NAME} is a pair of symbols,
;;@code{(@var{URI-SYMB} . @var{LOCALPART})}.
;;Otherwise, it's a single symbol.
;;
;;@item ELEM-CONTENT-MODEL
;;
;;A symbol:
;;@table @samp
;;@item ANY
;;anything goes, expect an END tag.
;;@item EMPTY-TAG
;;no content, and no END-tag is coming
;;@item EMPTY
;;no content, expect the END-tag as the next token
;;@item PCDATA
;;expect character data only, and no children elements
;;@item MIXED
;;@item ELEM-CONTENT
;;@end table
;;
;;@item URI-SYMB
;;
;;A symbol representing a namespace URI -- or other symbol chosen by
;;the user to represent URI. In the former case, @code{URI-SYMB} is
;;created by %-quoting of bad URI characters and converting the
;;resulting string into a symbol.
;;
;;@item NAMESPACES
;;
;;A list representing namespaces in effect. An element of the list
;;has one of the following forms:
;;
;;@table @code
;;
;;@item (@var{prefix} @var{uri-symb} . @var{uri-symb}) or
;;
;;@item (@var{prefix} @var{user-prefix} . @var{uri-symb})
;;@var{user-prefix} is a symbol chosen by the user to represent the URI.
;;
;;@item (#f @var{user-prefix} . @var{uri-symb})
;;Specification of the user-chosen prefix and a URI-SYMBOL.
;;
;;@item (*DEFAULT* @var{user-prefix} . @var{uri-symb})
;;Declaration of the default namespace
;;
;;@item (*DEFAULT* #f . #f)
;;Un-declaration of the default namespace. This notation
;;represents overriding of the previous declaration
;;
;;@end table
;;
;;A NAMESPACES list may contain several elements for the same @var{prefix}.
;;The one closest to the beginning of the list takes effect.
;;
;;@item ATTLIST
;;
;;An ordered collection of (@var{NAME} . @var{VALUE}) pairs, where
;;@var{NAME} is a RES-NAME or an UNRES-NAME. The collection is an ADT.
;;
;;@item STR-HANDLER
;;
;;A procedure of three arguments: @var{string1} @var{string2}
;;@var{seed} returning a new @var{seed}. The procedure is supposed to
;;handle a chunk of character data @var{string1} followed by a chunk
;;of character data @var{string2}. @var{string2} is a short string,
;;often @samp{"\n"} and even @samp{""}.
;;
;;@item ENTITIES
;;An assoc list of pairs:
;;@lisp
;; (@var{named-entity-name} . @var{named-entity-body})
;;@end lisp
;;
;;where @var{named-entity-name} is a symbol under which the entity was
;;declared, @var{named-entity-body} is either a string, or (for an
;;external entity) a thunk that will return an input port (from which
;;the entity can be read). @var{named-entity-body} may also be #f.
;;This is an indication that a @var{named-entity-name} is currently
;;being expanded. A reference to this @var{named-entity-name} will be
;;an error: violation of the WFC nonrecursion.
;;
;;@item XML-TOKEN
;;
;;This record represents a markup, which is, according to the XML
;;Recommendation, "takes the form of start-tags, end-tags,
;;empty-element tags, entity references, character references,
;;comments, CDATA section delimiters, document type declarations, and
;;processing instructions."
;;
;;@table @asis
;;@item kind
;;a TAG-KIND
;;@item head
;;an UNRES-NAME. For XML-TOKENs of kinds 'COMMENT and 'CDSECT, the
;;head is #f.
;;@end table
;;
;;For example,
;;@example
;;<P> => kind=START, head=P
;;</P> => kind=END, head=P
;;<BR/> => kind=EMPTY-EL, head=BR
;;<!DOCTYPE OMF ...> => kind=DECL, head=DOCTYPE
;;<?xml version="1.0"?> => kind=PI, head=xml
;;&my-ent; => kind=ENTITY-REF, head=my-ent
;;@end example
;;
;;Character references are not represented by xml-tokens as these
;;references are transparently resolved into the corresponding
;;characters.
;;
;;@item XML-DECL
;;
;;The record represents a datatype of an XML document: the list of
;;declared elements and their attributes, declared notations, list of
;;replacement strings or loading procedures for parsed general
;;entities, etc. Normally an XML-DECL record is created from a DTD or
;;an XML Schema, although it can be created and filled in in many
;;other ways (e.g., loaded from a file).
;;
;;@table @var
;;@item elems
;;an (assoc) list of decl-elem or #f. The latter instructs
;;the parser to do no validation of elements and attributes.
;;
;;@item decl-elem
;;declaration of one element:
;;
;;@code{(@var{elem-name} @var{elem-content} @var{decl-attrs})}
;;
;;@var{elem-name} is an UNRES-NAME for the element.
;;
;;@var{elem-content} is an ELEM-CONTENT-MODEL.
;;
;;@var{decl-attrs} is an @code{ATTLIST}, of
;;@code{(@var{attr-name} . @var{value})} associations.
;;
;;This element can declare a user procedure to handle parsing of an
;;element (e.g., to do a custom validation, or to build a hash of IDs
;;as they're encountered).
;;
;;@item decl-attr
;;an element of an @code{ATTLIST}, declaration of one attribute:
;;
;;@code{(@var{attr-name} @var{content-type} @var{use-type} @var{default-value})}
;;
;;@var{attr-name} is an UNRES-NAME for the declared attribute.
;;
;;@var{content-type} is a symbol: @code{CDATA}, @code{NMTOKEN},
;;@code{NMTOKENS}, @dots{} or a list of strings for the enumerated
;;type.
;;
;;@var{use-type} is a symbol: @code{REQUIRED}, @code{IMPLIED}, or
;;@code{FIXED}.
;;
;;@var{default-value} is a string for the default value, or #f if not
;;given.
;;
;;@end table
;;
;;@end table
;;see a function make-empty-xml-decl to make a XML declaration entry
;;suitable for a non-validating parsing.
;;We define xml-token simply as a pair.
(define (make-xml-token kind head) (cons kind head))
(define xml-token? pair?)
(define xml-token-kind car)
(define xml-token-head cdr)
;;@subsection Low-Level Parsers and Scanners
;;
;;@noindent
;;These procedures deal with primitive lexical units (Names,
;;whitespaces, tags) and with pieces of more generic productions.
;;Most of these parsers must be called in appropriate context. For
;;example, @code{ssax:complete-start-tag} must be called only when the
;;start-tag has been detected and its GI has been read.
(define char-return (integer->char 13))
(define ssax:S-chars (map integer->char '(32 10 9 13)))
;;@body
;;
;;Skip the S (whitespace) production as defined by
;;@example
;;[3] S ::= (#x20 | #x09 | #x0D | #x0A)
;;@end example
;;
;;@0 returns the first not-whitespace character it encounters while
;;scanning the @1. This character is left on the input stream.
(define (ssax:skip-S port)
(ssax:skip-while ssax:S-chars port))
;;Check to see if a-char may start a NCName
(define (ssax:ncname-starting-char? a-char)
(and (char? a-char)
(or (char-alphabetic? a-char)
(char=? #\_ a-char))))
;;@body
;;
;;Read a NCName starting from the current position in the @1 and
;;return it as a symbol.
;;
;;@example
;;[4] NameChar ::= Letter | Digit | '.' | '-' | '_' | ':'
;; | CombiningChar | Extender
;;[5] Name ::= (Letter | '_' | ':') (NameChar)*
;;@end example
;;
;;This code supports the XML Namespace Recommendation REC-xml-names,
;;which modifies the above productions as follows:
;;
;;@example
;;[4] NCNameChar ::= Letter | Digit | '.' | '-' | '_'
;; | CombiningChar | Extender
;;[5] NCName ::= (Letter | '_') (NCNameChar)*
;;@end example
;;
;;As the Rec-xml-names says,
;;
;;@quotation
;;"An XML document conforms to this specification if all other tokens
;;[other than element types and attribute names] in the document which
;;are required, for XML conformance, to match the XML production for
;;Name, match this specification's production for NCName."
;;@end quotation
;;
;;Element types and attribute names must match the production QName,
;;defined below.
(define (ssax:read-NCName port)
(let ((first-char (peek-char port)))
(or (ssax:ncname-starting-char? first-char)
(slib:error port "XMLNS [4] for '" first-char "'")))
(string->symbol (ssax:next-token-of (lambda (c)
(cond
((eof-object? c) #f)
((char-alphabetic? c) c)
((string-index "0123456789.-_" c) c)
(else #f)))
port)))
;;@body
;;
;;Read a (namespace-) Qualified Name, QName, from the current position
;;in @1; and return an UNRES-NAME.
;;
;;From REC-xml-names:
;;@example
;;[6] QName ::= (Prefix ':')? LocalPart
;;[7] Prefix ::= NCName
;;[8] LocalPart ::= NCName
;;@end example
(define (ssax:read-QName port)
(let ((prefix-or-localpart (ssax:read-NCName port)))
(case (peek-char port)
((#\:) ; prefix was given after all
(read-char port) ; consume the colon
(cons prefix-or-localpart (ssax:read-NCName port)))
(else prefix-or-localpart) ; Prefix was omitted
)))
;;The prefix of the pre-defined XML namespace
(define ssax:Prefix-XML (string->symbol "xml"))
;;An UNRES-NAME that is postulated to be larger than anything that can
;;occur in a well-formed XML document. ssax:name-compare enforces
;;this postulate.
(define ssax:largest-unres-name (cons (string->symbol "#LARGEST-SYMBOL")
(string->symbol "#LARGEST-SYMBOL")))
;;Compare one RES-NAME or an UNRES-NAME with the other.
;;Return a symbol '<, '>, or '= depending on the result of
;;the comparison.
;;Names without @var{prefix} are always smaller than those with the @var{prefix}.
(define ssax:name-compare
(letrec ((symbol-compare
(lambda (symb1 symb2)
(cond
((eq? symb1 symb2) '=)
((string<? (symbol->string symb1) (symbol->string symb2))
'<)
(else '>)))))
(lambda (name1 name2)
(cond
((symbol? name1) (if (symbol? name2) (symbol-compare name1 name2)
'<))
((symbol? name2) '>)
((eq? name2 ssax:largest-unres-name) '<)
((eq? name1 ssax:largest-unres-name) '>)
((eq? (car name1) (car name2)) ; prefixes the same
(symbol-compare (cdr name1) (cdr name2)))
(else (symbol-compare (car name1) (car name2)))))))
;;@args port
;;
;;This procedure starts parsing of a markup token. The current
;;position in the stream must be @samp{<}. This procedure scans
;;enough of the input stream to figure out what kind of a markup token
;;it is seeing. The procedure returns an XML-TOKEN structure
;;describing the token. Note, generally reading of the current markup
;;is not finished! In particular, no attributes of the start-tag
;;token are scanned.
;;
;;Here's a detailed break out of the return values and the position in
;;the PORT when that particular value is returned:
;;
;;@table @asis
;;
;;@item PI-token
;;
;;only PI-target is read. To finish the Processing-Instruction and
;;disregard it, call @code{ssax:skip-pi}. @code{ssax:read-attributes}
;;may be useful as well (for PIs whose content is attribute-value
;;pairs).
;;
;;@item END-token
;;
;;The end tag is read completely; the current position is right after
;;the terminating @samp{>} character.
;;
;;@item COMMENT
;;
;;is read and skipped completely. The current position is right after
;;@samp{-->} that terminates the comment.
;;
;;@item CDSECT
;;
;;The current position is right after @samp{<!CDATA[}. Use
;;@code{ssax:read-cdata-body} to read the rest.
;;
;;@item DECL
;;
;;We have read the keyword (the one that follows @samp{<!})
;;identifying this declaration markup. The current position is after
;;the keyword (usually a whitespace character)
;;
;;@item START-token
;;
;;We have read the keyword (GI) of this start tag. No attributes are
;;scanned yet. We don't know if this tag has an empty content either.
;;Use @code{ssax:complete-start-tag} to finish parsing of the token.
;;
;;@end table
(define ssax:read-markup-token ; procedure ssax:read-markup-token port
(let ()
;; we have read "<!-". Skip through the rest of the comment
;; Return the 'COMMENT token as an indication we saw a comment
;; and skipped it.
(define (skip-comment port)
(ssax:assert-current-char '(#\-) "XML [15], second dash" port)
(if (not (find-string-from-port? "-->" port))
(slib:error port "XML [15], no -->"))
(make-xml-token 'COMMENT #f))
;; we have read "<![" that must begin a CDATA section
(define (read-cdata port)
(define cdstr (ssax:read-string 6 port))
(if (not (string=? "CDATA[" cdstr))
(slib:error "expected 'CDATA[' but read " cdstr))
(make-xml-token 'CDSECT #f))
(lambda (port)
(ssax:assert-current-char '(#\<) "start of the token" port)
(case (peek-char port)
((#\/) (read-char port)
(let ((val (make-xml-token 'END (ssax:read-QName port))))
(ssax:skip-S port)
(ssax:assert-current-char '(#\>) "XML [42]" port)
val))
((#\?) (read-char port) (make-xml-token 'PI (ssax:read-NCName port)))
((#\!)
(read-char port)
(case (peek-char port)
((#\-) (read-char port) (skip-comment port))
((#\[) (read-char port) (read-cdata port))
(else (make-xml-token 'DECL (ssax:read-NCName port)))))
(else (make-xml-token 'START (ssax:read-QName port)))))))
;;@body
;;
;;The current position is inside a PI. Skip till the rest of the PI
(define (ssax:skip-pi port)
(if (not (find-string-from-port? "?>" port))
(slib:error port "Failed to find ?> terminating the PI")))
;;@body
;;
;;The current position is right after reading the PITarget. We read
;;the body of PI and return is as a string. The port will point to
;;the character right after @samp{?>} combination that terminates PI.
;;
;;@example
;;[16] PI ::= '<?' PITarget (S (Char* - (Char* '?>' Char*)))? '?>'
;;@end example
(define (ssax:read-pi-body-as-string port)
(ssax:skip-S port) ; skip WS after the PI target name
(ssax:string-concatenate/shared
(let loop ()
(let ((pi-fragment
(ssax:next-token '() '(#\?) "reading PI content" port)))
(read-char port)
(if (eqv? #\> (peek-char port))
(begin
(read-char port)
(cons pi-fragment '()))
(cons* pi-fragment "?" (loop)))))))
;;@body
;;
;;The current pos in the port is inside an internal DTD subset (e.g.,
;;after reading @samp{#\[} that begins an internal DTD subset) Skip
;;until the @samp{]>} combination that terminates this DTD.
(define (ssax:skip-internal-dtd port)
(slib:warn port "Internal DTD subset is not currently handled ")
(if (not (find-string-from-port? "]>" port))
(slib:error port
"Failed to find ]> terminating the internal DTD subset")))
;;@args port str-handler seed
;;
;;This procedure must be called after we have read a string
;;@samp{<![CDATA[} that begins a CDATA section. The current position
;;must be the first position of the CDATA body. This function reads
;;@emph{lines} of the CDATA body and passes them to a @2, a character
;;data consumer.
;;
;;@2 is a procedure taking arguments: @var{string1}, @var{string2},
;;and @var{seed}. The first @var{string1} argument to @2 never
;;contains a newline; the second @var{string2} argument often will.
;;On the first invocation of @2, @3 is the one passed to @0 as the
;;third argument. The result of this first invocation will be passed
;;as the @var{seed} argument to the second invocation of the line
;;consumer, and so on. The result of the last invocation of the @2 is
;;returned by the @0. Note a similarity to the fundamental @dfn{fold}
;;iterator.
;;
;;Within a CDATA section all characters are taken at their face value,
;;with three exceptions:
;;@itemize @bullet
;;@item
;;CR, LF, and CRLF are treated as line delimiters, and passed
;;as a single @samp{#\newline} to @2
;;
;;@item
;;@samp{]]>} combination is the end of the CDATA section.
;;@samp{>} is treated as an embedded @samp{>} character.
;;
;;@item
;;@samp{<} and @samp{&} are not specially recognized (and are
;;not expanded)!
;;
;;@end itemize
(define ssax:read-cdata-body
(let ((cdata-delimiters (list char-return #\newline #\] #\&)))
(lambda (port str-handler seed)
(let loop ((seed seed))
(let ((fragment (ssax:next-token '() cdata-delimiters "reading CDATA" port)))
;; that is, we're reading the char after the 'fragment'
(case (read-char port)
((#\newline) (loop (str-handler fragment #\newline seed)))
((#\])
(if (not (eqv? (peek-char port) #\]))
(loop (str-handler fragment "]" seed))
(let check-after-second-braket
((seed (if (string-null? fragment) seed
(str-handler fragment "" seed))))
(read-char port)
(case (peek-char port) ; after the second bracket
((#\>) (read-char port) seed) ; we have read "]]>"
((#\]) (check-after-second-braket
(str-handler "]" "" seed)))
(else (loop (str-handler "]]" "" seed)))))))
((#\&) ; Note that #\& within CDATA may stand for itself
(let ((ent-ref ; it does not have to start an entity ref
(ssax:next-token-of
(lambda (c)
(and (not (eof-object? c)) (char-alphabetic? c) c))
port)))
(cond ; replace ">" with #\>
((and (string=? "gt" ent-ref) (eqv? (peek-char port) #\;))
(read-char port)
(loop (str-handler fragment ">" seed)))
(else
(loop
(str-handler ent-ref ""
(str-handler fragment "&" seed)))))))
(else ; Must be CR: if the next char is #\newline, skip it
(if (eqv? (peek-char port) #\newline) (read-char port))
(loop (str-handler fragment #\newline seed)))
))))))
;;@body
;;
;;@example
;;[66] CharRef ::= '&#' [0-9]+ ';'
;; | '&#x' [0-9a-fA-F]+ ';'
;;@end example
;;
;;This procedure must be called after we we have read @samp{&#} that
;;introduces a char reference. The procedure reads this reference and
;;returns the corresponding char. The current position in PORT will
;;be after the @samp{;} that terminates the char reference.
;;
;;Faults detected:@*
;;WFC: XML-Spec.html#wf-Legalchar
;;
;;According to Section @cite{4.1 Character and Entity References}
;;of the XML Recommendation:
;;
;;@quotation
;;"[Definition: A character reference refers to a specific character
;;in the ISO/IEC 10646 character set, for example one not directly
;;accessible from available input devices.]"
;;@end quotation
;;
;;@c Therefore, we use a @code{ucscode->char} function to convert a
;;@c character code into the character -- *regardless* of the current
;;@c character encoding of the input stream.
(define (ssax:read-char-ref port)
(let* ((base (cond ((eqv? (peek-char port) #\x) (read-char port) 16)
(else 10)))
(name (ssax:next-token '() '(#\;) "XML [66]" port))
(char-code (string->number name base)))
(read-char port) ; read the terminating #\; char
(if (integer? char-code) (integer->char char-code)
(slib:error port "[wf-Legalchar] broken for '" name "'"))))
(define ssax:predefined-parsed-entities
`(
(,(string->symbol "amp") . "&")
(,(string->symbol "lt") . "<")
(,(string->symbol "gt") . ">")
(,(string->symbol "apos") . "'")
(,(string->symbol "quot") . "\"")
))
;;@body
;;
;;Expands and handles a parsed-entity reference.
;;
;;@2 is a symbol, the name of the parsed entity to expand.
;;@c entities - see ENTITIES
;;@4 is a procedure of arguments @var{port}, @var{entities}, and
;;@var{seed} that returns a seed.
;;@5 is called if the entity in question is a pre-declared entity.
;;
;;@0 returns the result returned by @4 or @5.
;;
;;Faults detected:@*
;;WFC: XML-Spec.html#wf-entdeclared@*
;;WFC: XML-Spec.html#norecursion
(define (ssax:handle-parsed-entity port name entities content-handler str-handler seed)
(cond ; First we check the list of the declared entities
((assq name entities) =>
(lambda (decl-entity)
(let ((ent-body (cdr decl-entity)) ; mark the list to prevent recursion
(new-entities (cons (cons name #f) entities)))
(cond
((string? ent-body)
(call-with-input-string ent-body
(lambda (port) (content-handler port new-entities seed))))
((procedure? ent-body)
(let ((port (ent-body)))
(define val (content-handler port new-entities seed))
(close-input-port port)
val))
(else
(slib:error port "[norecursion] broken for " name))))))
((assq name ssax:predefined-parsed-entities)
=> (lambda (decl-entity)
(str-handler (cdr decl-entity) "" seed)))
(else (slib:error port "[wf-entdeclared] broken for " name))))
;;;; The ATTLIST Abstract Data Type
;;; Currently is implemented as an assoc list sorted in the ascending
;;; order of NAMES.
(define attlist-fold fold)
(define attlist-null? null?)
(define attlist->alist identity)
(define (make-empty-attlist) '())
;;@body
;;
;;Add a @2 pair to the existing @1, preserving its sorted ascending
;;order; and return the new list. Return #f if a pair with the same
;;name already exists in @1
(define (attlist-add attlist name-value)
(if (null? attlist) (cons name-value attlist)
(case (ssax:name-compare (car name-value) (caar attlist))
((=) #f)
((<) (cons name-value attlist))
(else (cons (car attlist) (attlist-add (cdr attlist) name-value)))
)))
;;@body
;;
;;Given an non-null @1, return a pair of values: the top and the rest.
(define (attlist-remove-top attlist)
(values (car attlist) (cdr attlist)))
;;@args port entities
;;
;;This procedure reads and parses a production @dfn{Attribute}.
;;
;;@example
;;[41] Attribute ::= Name Eq AttValue
;;[10] AttValue ::= '"' ([^<&"] | Reference)* '"'
;; | "'" ([^<&'] | Reference)* "'"
;;[25] Eq ::= S? '=' S?
;;@end example
;;
;;The procedure returns an ATTLIST, of Name (as UNRES-NAME), Value (as
;;string) pairs. The current character on the @1 is a non-whitespace
;;character that is not an NCName-starting character.
;;
;;Note the following rules to keep in mind when reading an
;;@dfn{AttValue}:
;;@quotation
;;Before the value of an attribute is passed to the application or
;;checked for validity, the XML processor must normalize it as
;;follows:
;;
;;@itemize @bullet
;;@item
;;A character reference is processed by appending the referenced
;;character to the attribute value.
;;
;;@item
;;An entity reference is processed by recursively processing the
;;replacement text of the entity. The named entities @samp{amp},
;;@samp{lt}, @samp{gt}, @samp{quot}, and @samp{apos} are pre-declared.
;;
;;@item
;;A whitespace character (#x20, #x0D, #x0A, #x09) is processed by
;;appending #x20 to the normalized value, except that only a single
;;#x20 is appended for a "#x0D#x0A" sequence that is part of an
;;external parsed entity or the literal entity value of an internal
;;parsed entity.
;;
;;@item
;;Other characters are processed by appending them to the normalized
;;value.
;;
;;@end itemize
;;
;;@end quotation
;;
;;Faults detected:@*
;;WFC: XML-Spec.html#CleanAttrVals@*
;;WFC: XML-Spec.html#uniqattspec
(define ssax:read-attributes ; ssax:read-attributes port entities
(let ((value-delimeters (append '(#\< #\&) ssax:S-chars)))
;; Read the AttValue from the PORT up to the delimiter (which can
;; be a single or double-quote character, or even a symbol *eof*).
;; 'prev-fragments' is the list of string fragments, accumulated
;; so far, in reverse order. Return the list of fragments with
;; newly read fragments prepended.
(define (read-attrib-value delimiter port entities prev-fragments)
(let* ((new-fragments
(cons (ssax:next-token '() (cons delimiter value-delimeters)
"XML [10]" port)
prev-fragments))
(cterm (read-char port)))
(cond
((or (eof-object? cterm) (eqv? cterm delimiter))
new-fragments)
((eqv? cterm char-return) ; treat a CR and CRLF as a LF
(if (eqv? (peek-char port) #\newline) (read-char port))
(read-attrib-value delimiter port entities
(cons " " new-fragments)))
((memv cterm ssax:S-chars)
(read-attrib-value delimiter port entities
(cons " " new-fragments)))
((eqv? cterm #\&)
(cond
((eqv? (peek-char port) #\#)
(read-char port)
(read-attrib-value delimiter port entities
(cons (string (ssax:read-char-ref port)) new-fragments)))
(else
(read-attrib-value delimiter port entities
(read-named-entity port entities new-fragments)))))
(else (slib:error port "[CleanAttrVals] broken")))))
;; we have read "&" that introduces a named entity reference.
;; read this reference and return the result of normalizing of the
;; corresponding string (that is, read-attrib-value is applied to
;; the replacement text of the entity). The current position will
;; be after ";" that terminates the entity reference
(define (read-named-entity port entities fragments)
(let ((name (ssax:read-NCName port)))
(ssax:assert-current-char '(#\;) "XML [68]" port)
(ssax:handle-parsed-entity port name entities
(lambda (port entities fragments)
(read-attrib-value '*eof* port entities fragments))
(lambda (str1 str2 fragments)
(if (equal? "" str2) (cons str1 fragments)
(cons* str2 str1 fragments)))
fragments)))
(lambda (port entities)
(let loop ((attr-list (make-empty-attlist)))
(if (not (ssax:ncname-starting-char? (ssax:skip-S port))) attr-list
(let ((name (ssax:read-QName port)))
(ssax:skip-S port)
(ssax:assert-current-char '(#\=) "XML [25]" port)
(ssax:skip-S port)
(let ((delimiter
(ssax:assert-current-char '(#\' #\" ) "XML [10]" port)))
(loop
(or (attlist-add attr-list
(cons name
(ssax:string-concatenate-reverse/shared
(read-attrib-value delimiter port entities
'()))))
(slib:error port "[uniqattspec] broken for " name))))))))
))
;;@body
;;
;;Convert an @2 to a RES-NAME, given the appropriate @3 declarations.
;;The last parameter, @4, determines if the default namespace applies
;;(for instance, it does not for attribute names).
;;
;;Per REC-xml-names/#nsc-NSDeclared, the "xml" prefix is considered
;;pre-declared and bound to the namespace name
;;"http://www.w3.org/XML/1998/namespace".
;;
;;@0 tests for the namespace constraints:@*
;;@url{http://www.w3.org/TR/REC-xml-names/#nsc-NSDeclared}
(define (ssax:resolve-name port unres-name namespaces apply-default-ns?)
(cond
((pair? unres-name) ; it's a QNAME
(cons
(cond
((assq (car unres-name) namespaces) => cadr)
((eq? (car unres-name) ssax:Prefix-XML) ssax:Prefix-XML)
(else
(slib:error port "[nsc-NSDeclared] broken; prefix " (car unres-name))))
(cdr unres-name)))
(apply-default-ns? ; Do apply the default namespace, if any
(let ((default-ns (assq '*DEFAULT* namespaces)))
(if (and default-ns (cadr default-ns))
(cons (cadr default-ns) unres-name)
unres-name))) ; no default namespace declared
(else unres-name))) ; no prefix, don't apply the default-ns
;;Procedure: ssax:uri-string->symbol URI-STR
;;Convert a URI-STR to an appropriate symbol
(define ssax:uri-string->symbol string->symbol)
;;@args tag port elems entities namespaces
;;
;;Complete parsing of a start-tag markup. @0 must be called after the
;;start tag token has been read. @1 is an UNRES-NAME. @3 is an
;;instance of the ELEMS slot of XML-DECL; it can be #f to tell the
;;function to do @emph{no} validation of elements and their
;;attributes.
;;
;;@0 returns several values:
;;@itemize @bullet
;;@item ELEM-GI:
;;a RES-NAME.
;;@item ATTRIBUTES:
;;element's attributes, an ATTLIST of (RES-NAME . STRING) pairs.
;;The list does NOT include xmlns attributes.
;;@item NAMESPACES:
;;the input list of namespaces amended with namespace
;;(re-)declarations contained within the start-tag under parsing
;;@item ELEM-CONTENT-MODEL
;;@end itemize
;;
;;On exit, the current position in @2 will be the first character
;;after @samp{>} that terminates the start-tag markup.
;;
;;Faults detected:@*
;;VC: XML-Spec.html#enum@*
;;VC: XML-Spec.html#RequiredAttr@*
;;VC: XML-Spec.html#FixedAttr@*
;;VC: XML-Spec.html#ValueType@*
;;WFC: XML-Spec.html#uniqattspec (after namespaces prefixes are resolved)@*
;;VC: XML-Spec.html#elementvalid@*
;;WFC: REC-xml-names/#dt-NSName
;;
;;@emph{Note}: although XML Recommendation does not explicitly say it,
;;xmlns and xmlns: attributes don't have to be declared (although they
;;can be declared, to specify their default value).
(define ssax:complete-start-tag
(let ((xmlns (string->symbol "xmlns"))
(largest-dummy-decl-attr (list ssax:largest-unres-name #f #f #f)))
;; Scan through the attlist and validate it, against decl-attrs
;; Return an assoc list with added fixed or implied attrs.
;; Note that both attlist and decl-attrs are ATTLISTs, and therefore,
;; sorted
(define (validate-attrs port attlist decl-attrs)
;; Check to see decl-attr is not of use type REQUIRED. Add
;; the association with the default value, if any declared
(define (add-default-decl decl-attr result)
(let*-values
(((attr-name content-type use-type default-value)
(apply values decl-attr)))
(and (eq? use-type 'REQUIRED)
(slib:error port "[RequiredAttr] broken for" attr-name))
(if default-value
(cons (cons attr-name default-value) result)
result)))
(let loop ((attlist attlist) (decl-attrs decl-attrs) (result '()))
(if (attlist-null? attlist)
(attlist-fold add-default-decl result decl-attrs)
(let*-values
(((attr attr-others)
(attlist-remove-top attlist))
((decl-attr other-decls)
(if (attlist-null? decl-attrs)
(values largest-dummy-decl-attr decl-attrs)
(attlist-remove-top decl-attrs)))
)
(case (ssax:name-compare (car attr) (car decl-attr))
((<)
(if (or (eq? xmlns (car attr))
(and (pair? (car attr)) (eq? xmlns (caar attr))))
(loop attr-others decl-attrs (cons attr result))
(slib:error port "[ValueType] broken for " attr)))
((>)
(loop attlist other-decls
(add-default-decl decl-attr result)))
(else ; matched occurrence of an attr with its declaration
(let*-values
(((attr-name content-type use-type default-value)
(apply values decl-attr)))
;; Run some tests on the content of the attribute
(cond
((eq? use-type 'FIXED)
(or (equal? (cdr attr) default-value)
(slib:error port "[FixedAttr] broken for " attr-name)))
((eq? content-type 'CDATA) #t) ; everything goes
((pair? content-type)
(or (member (cdr attr) content-type)
(slib:error port "[enum] broken for " attr-name "="
(cdr attr))))
(else
(slib:warn port "declared content type " content-type
" not verified yet")))
(loop attr-others other-decls (cons attr result)))))
))))
;; Add a new namespace declaration to namespaces.
;; First we convert the uri-str to a uri-symbol and search namespaces for
;; an association (_ user-prefix . uri-symbol).
;; If found, we return the argument namespaces with an association
;; (prefix user-prefix . uri-symbol) prepended.
;; Otherwise, we prepend (prefix uri-symbol . uri-symbol)
(define (add-ns port prefix uri-str namespaces)
(and (equal? "" uri-str)
(slib:error port "[dt-NSName] broken for " prefix))
(let ((uri-symbol (ssax:uri-string->symbol uri-str)))
(let loop ((nss namespaces))
(cond
((null? nss)
(cons (cons* prefix uri-symbol uri-symbol) namespaces))
((eq? uri-symbol (cddar nss))
(cons (cons* prefix (cadar nss) uri-symbol) namespaces))
(else (loop (cdr nss)))))))
;; partition attrs into proper attrs and new namespace declarations
;; return two values: proper attrs and the updated namespace declarations
(define (adjust-namespace-decl port attrs namespaces)
(let loop ((attrs attrs) (proper-attrs '()) (namespaces namespaces))
(cond
((null? attrs) (values proper-attrs namespaces))
((eq? xmlns (caar attrs)) ; re-decl of the default namespace
(loop (cdr attrs) proper-attrs
(if (equal? "" (cdar attrs)) ; un-decl of the default ns
(cons (cons* '*DEFAULT* #f #f) namespaces)
(add-ns port '*DEFAULT* (cdar attrs) namespaces))))
((and (pair? (caar attrs)) (eq? xmlns (caaar attrs)))
(loop (cdr attrs) proper-attrs
(add-ns port (cdaar attrs) (cdar attrs) namespaces)))
(else
(loop (cdr attrs) (cons (car attrs) proper-attrs) namespaces)))))
;; The body of the function
(lambda (tag-head port elems entities namespaces)
(let*-values
(((attlist) (ssax:read-attributes port entities))
((empty-el-tag?)
(begin
(ssax:skip-S port)
(and
(eqv? #\/
(ssax:assert-current-char '(#\> #\/) "XML [40], XML [44], no '>'" port))
(ssax:assert-current-char '(#\>) "XML [44], no '>'" port))))
((elem-content decl-attrs) ; see xml-decl for their type
(if elems ; elements declared: validate!
(cond
((assoc tag-head elems) =>
(lambda (decl-elem) ; of type xml-decl::decl-elem
(values
(if empty-el-tag? 'EMPTY-TAG (cadr decl-elem))
(caddr decl-elem))))
(else
(slib:error port "[elementvalid] broken, no decl for " tag-head)))
(values ; non-validating parsing
(if empty-el-tag? 'EMPTY-TAG 'ANY)
#f) ; no attributes declared
))
((merged-attrs) (if decl-attrs (validate-attrs port attlist decl-attrs)
(attlist->alist attlist)))
((proper-attrs namespaces)
(adjust-namespace-decl port merged-attrs namespaces))
)
;; build the return value
(values
(ssax:resolve-name port tag-head namespaces #t)
(fold-right
(lambda (name-value attlist)
(or
(attlist-add attlist
(cons (ssax:resolve-name port (car name-value) namespaces #f)
(cdr name-value)))
(slib:error port "[uniqattspec] after NS expansion broken for "
name-value)))
(make-empty-attlist)
proper-attrs)
namespaces
elem-content)))))
;;@body
;;
;;Parses an ExternalID production:
;;
;;@example
;;[75] ExternalID ::= 'SYSTEM' S SystemLiteral
;; | 'PUBLIC' S PubidLiteral S SystemLiteral
;;[11] SystemLiteral ::= ('"' [^"]* '"') | ("'" [^']* "'")
;;[12] PubidLiteral ::= '"' PubidChar* '"'
;; | "'" (PubidChar - "'")* "'"
;;[13] PubidChar ::= #x20 | #x0D | #x0A | [a-zA-Z0-9]
;; | [-'()+,./:=?;!*#@@$_%]
;;@end example
;;
;;Call @0 when an ExternalID is expected; that is, the current
;;character must be either #\S or #\P that starts correspondingly a
;;SYSTEM or PUBLIC token. @0 returns the @var{SystemLiteral} as a
;;string. A @var{PubidLiteral} is disregarded if present.
(define (ssax:read-external-id port)
(let ((discriminator (ssax:read-NCName port)))
(ssax:assert-current-char ssax:S-chars "space after SYSTEM or PUBLIC" port)
(ssax:skip-S port)
(let ((delimiter
(ssax:assert-current-char '(#\' #\" ) "XML [11], XML [12]" port)))
(cond
((eq? discriminator (string->symbol "SYSTEM"))
(let ((val (ssax:next-token '() (list delimiter) "XML [11]" port)))
(read-char port) ; reading the closing delim
val))
((eq? discriminator (string->symbol "PUBLIC"))
(let loop ((c (read-char port)))
(cond
((eqv? c delimiter) c)
((eof-object? c)
(slib:error port "Unexpected EOF while skipping until " delimiter))
(else (loop (read-char port)))))
(ssax:assert-current-char ssax:S-chars "space after PubidLiteral" port)
(ssax:skip-S port)
(let* ((delimiter
(ssax:assert-current-char '(#\' #\" ) "XML [11]" port))
(systemid
(ssax:next-token '() (list delimiter) "XML [11]" port)))
(read-char port) ; reading the closing delim
systemid))
(else
(slib:error port "XML [75], " discriminator
" rather than SYSTEM or PUBLIC"))))))
;;@subsection Mid-Level Parsers and Scanners
;;
;;@noindent
;;These procedures parse productions corresponding to the whole
;;(document) entity or its higher-level pieces (prolog, root element,
;;etc).
;;@body
;;
;;Scan the Misc production in the context:
;;
;;@example
;;[1] document ::= prolog element Misc*
;;[22] prolog ::= XMLDecl? Misc* (doctypedec l Misc*)?
;;[27] Misc ::= Comment | PI | S
;;@end example
;;
;;Call @0 in the prolog or epilog contexts. In these contexts,
;;whitespaces are completely ignored. The return value from @0 is
;;either a PI-token, a DECL-token, a START token, or *EOF*. Comments
;;are ignored and not reported.
(define (ssax:scan-misc port)
(let loop ((c (ssax:skip-S port)))
(cond
((eof-object? c) c)
((not (char=? c #\<))
(slib:error port "XML [22], char '" c "' unexpected"))
(else
(let ((token (ssax:read-markup-token port)))
(case (xml-token-kind token)
((COMMENT) (loop (ssax:skip-S port)))
((PI DECL START) token)
(else
(slib:error port "XML [22], unexpected token of kind "
(xml-token-kind token)
))))))))
;;@args port expect-eof? str-handler iseed
;;
;;Read the character content of an XML document or an XML element.
;;
;;@example
;;[43] content ::=
;;(element | CharData | Reference | CDSect | PI | Comment)*
;;@end example
;;
;;To be more precise, @0 reads CharData, expands CDSect and character
;;entities, and skips comments. @0 stops at a named reference, EOF,
;;at the beginning of a PI, or a start/end tag.
;;
;;@2 is a boolean indicating if EOF is normal; i.e., the character
;;data may be terminated by the EOF. EOF is normal while processing a
;;parsed entity.
;;
;;@4 is an argument passed to the first invocation of @3.
;;
;;@0 returns two results: @var{seed} and @var{token}. The @var{seed}
;;is the result of the last invocation of @3, or the original @4 if @3
;;was never called.
;;
;;@var{token} can be either an eof-object (this can happen only if @2
;;was #t), or:
;;@itemize @bullet
;;
;;@item
;;an xml-token describing a START tag or an END-tag;
;;For a start token, the caller has to finish reading it.
;;
;;@item
;;an xml-token describing the beginning of a PI. It's up to an
;;application to read or skip through the rest of this PI;
;;
;;@item
;;an xml-token describing a named entity reference.
;;
;;@end itemize
;;
;;CDATA sections and character references are expanded inline and
;;never returned. Comments are silently disregarded.
;;
;;As the XML Recommendation requires, all whitespace in character data
;;must be preserved. However, a CR character (#x0D) must be
;;disregarded if it appears before a LF character (#x0A), or replaced
;;by a #x0A character otherwise. See Secs. 2.10 and 2.11 of the XML
;;Recommendation. See also the canonical XML Recommendation.
(define ssax:read-char-data
(let ((terminators-usual (list #\< #\& char-return))
(terminators-usual-eof (list #\< '*eof* #\& char-return))
(handle-fragment
(lambda (fragment str-handler seed)
(if (string-null? fragment) seed
(str-handler fragment "" seed)))))
(lambda (port expect-eof? str-handler seed)
;; Very often, the first character we encounter is #\<
;; Therefore, we handle this case in a special, fast path
(if (eqv? #\< (peek-char port))
;; The fast path
(let ((token (ssax:read-markup-token port)))
(case (xml-token-kind token)
((START END) ; The most common case
(values seed token))
((CDSECT)
(let ((seed (ssax:read-cdata-body port str-handler seed)))
(ssax:read-char-data port expect-eof? str-handler seed)))
((COMMENT)
(ssax:read-char-data port expect-eof? str-handler seed))
(else
(values seed token))))
;; The slow path
(let ((char-data-terminators
(if expect-eof? terminators-usual-eof terminators-usual)))
(let loop ((seed seed))
(let* ((fragment
(ssax:next-token '() char-data-terminators
"reading char data" port))
(term-char (peek-char port)) ; one of char-data-terminators
)
(if (eof-object? term-char)
(values
(handle-fragment fragment str-handler seed)
term-char)
(case term-char
((#\<)
(let ((token (ssax:read-markup-token port)))
(case (xml-token-kind token)
((CDSECT)
(loop
(ssax:read-cdata-body port str-handler
(handle-fragment fragment str-handler seed))))
((COMMENT)
(loop (handle-fragment fragment str-handler seed)))
(else
(values
(handle-fragment fragment str-handler seed)
token)))))
((#\&)
(read-char port)
(case (peek-char port)
((#\#) (read-char port)
(loop (str-handler fragment
(string (ssax:read-char-ref port))
seed)))
(else
(let ((name (ssax:read-NCName port)))
(ssax:assert-current-char '(#\;) "XML [68]" port)
(values
(handle-fragment fragment str-handler seed)
(make-xml-token 'ENTITY-REF name))))))
(else ; This must be a CR character
(read-char port)
(if (eqv? (peek-char port) #\newline)
(read-char port))
(loop (str-handler fragment (string #\newline) seed))))
))))))))
;;@body
;;
;;Make sure that @1 is of anticipated @2 and has anticipated @3. Note
;;that the @3 argument may actually be a pair of two symbols,
;;Namespace-URI or the prefix, and of the localname. If the assertion
;;fails, @4 is evaluated by passing it three arguments: @1 @2 @3. The
;;result of @4 is returned.
(define (ssax:assert-token token kind gi error-cont)
(or (and (xml-token? token)
(eq? kind (xml-token-kind token))
(equal? gi (xml-token-head token)))
(error-cont token kind gi)))
;;@subsection High-level Parsers
;;
;;These procedures are to instantiate a SSAX parser. A user can
;;instantiate the parser to do the full validation, or no validation,
;;or any particular validation. The user specifies which PI he wants
;;to be notified about. The user tells what to do with the parsed
;;character and element data. The latter handlers determine if the
;;parsing follows a SAX or a DOM model.
;;@args my-pi-handlers
;;
;;Create a parser to parse and process one Processing Element (PI).
;;
;;@1 is an association list of pairs
;;@code{(@var{pi-tag} . @var{pi-handler})} where @var{pi-tag} is an
;;NCName symbol, the PI target; and @var{pi-handler} is a procedure
;;taking arguments @var{port}, @var{pi-tag}, and @var{seed}.
;;
;;@var{pi-handler} should read the rest of the PI up to and including
;;the combination @samp{?>} that terminates the PI. The handler
;;should return a new seed. One of the @var{pi-tag}s may be the
;;symbol @code{*DEFAULT*}. The corresponding handler will handle PIs
;;that no other handler will. If the *DEFAULT* @var{pi-tag} is not
;;specified, @0 will assume the default handler that skips the body of
;;the PI.
;;
;;@0 returns a procedure of arguments @var{port}, @var{pi-tag}, and
;;@var{seed}; that will parse the current PI according to @1.
(define (ssax:make-pi-parser handlers)
(lambda (port target seed)
(define pair (assv target handlers))
(or pair (set! pair (assv '*DEFAULT* handlers)))
(cond ((not pair)
(slib:warn port "Skipping PI: " target #\newline)
(ssax:skip-pi port)
seed)
(else ((cdr pair) port target seed)))))
;;syntax: ssax:make-elem-parser
;; my-new-level-seed my-finish-element my-char-data-handler my-pi-handlers
;;@body
;;
;;Create a parser to parse and process one element, including its
;;character content or children elements. The parser is typically
;;applied to the root element of a document.
;;
;;@table @asis
;;
;;@item @1
;;is a procedure taking arguments:
;;
;;@var{elem-gi} @var{attributes} @var{namespaces} @var{expected-content} @var{seed}
;;
;;where @var{elem-gi} is a RES-NAME of the element about to be
;;processed.
;;
;;@1 is to generate the seed to be passed to handlers that process the
;;content of the element.
;;
;;@item @2
;;is a procedure taking arguments:
;;
;;@var{elem-gi} @var{attributes} @var{namespaces} @var{parent-seed} @var{seed}
;;
;;@2 is called when parsing of @var{elem-gi} is finished.
;;The @var{seed} is the result from the last content parser (or
;;from @1 if the element has the empty content).
;;@var{parent-seed} is the same seed as was passed to @1.
;;@2 is to generate a seed that will be the result
;;of the element parser.
;;
;;@item @3
;;is a STR-HANDLER as described in Data Types above.
;;
;;@item @4
;;is as described for @code{ssax:make-pi-handler} above.
;;
;;@end table
;;
;;The generated parser is a procedure taking arguments:
;;
;;@var{start-tag-head} @var{port} @var{elems} @var{entities} @var{namespaces} @var{preserve-ws?} @var{seed}
;;
;;The procedure must be called after the start tag token has been
;;read. @var{start-tag-head} is an UNRES-NAME from the start-element
;;tag. ELEMS is an instance of ELEMS slot of XML-DECL.
;;
;;Faults detected:@*
;;VC: XML-Spec.html#elementvalid@*
;;WFC: XML-Spec.html#GIMatch
(define (ssax:make-elem-parser my-new-level-seed my-finish-element
my-char-data-handler my-pi-handlers)
(lambda (start-tag-head port elems entities namespaces preserve-ws? seed)
(define xml-space-gi (cons ssax:Prefix-XML
(string->symbol "space")))
(let handle-start-tag ((start-tag-head start-tag-head)
(port port) (entities entities)
(namespaces namespaces)
(preserve-ws? preserve-ws?) (parent-seed seed))
(let*-values
(((elem-gi attributes namespaces expected-content)
(ssax:complete-start-tag start-tag-head port elems
entities namespaces))
((seed)
(my-new-level-seed elem-gi attributes
namespaces expected-content parent-seed)))
(case expected-content
((EMPTY-TAG)
(my-finish-element
elem-gi attributes namespaces parent-seed seed))
((EMPTY) ; The end tag must immediately follow
(ssax:assert-token (and (eqv? #\< (ssax:skip-S port))
(ssax:read-markup-token port))
'END
start-tag-head
(lambda (token exp-kind exp-head)
(slib:error port "[elementvalid] broken for " token
" while expecting "
exp-kind exp-head)))
(my-finish-element
elem-gi attributes namespaces parent-seed seed))
(else ; reading the content...
(let ((preserve-ws? ; inherit or set the preserve-ws? flag
(cond ((assoc xml-space-gi attributes) =>
(lambda (name-value)
(equal? "preserve" (cdr name-value))))
(else preserve-ws?))))
(let loop ((port port) (entities entities)
(expect-eof? #f) (seed seed))
(let*-values
(((seed term-token)
(ssax:read-char-data port expect-eof?
my-char-data-handler seed)))
(if (eof-object? term-token)
seed
(case (xml-token-kind term-token)
((END)
(ssax:assert-token term-token 'END start-tag-head
(lambda (token exp-kind exp-head)
(slib:error port "[GIMatch] broken for "
term-token " while expecting "
exp-kind exp-head)))
(my-finish-element
elem-gi attributes namespaces parent-seed seed))
((PI)
(let ((seed
((ssax:make-pi-parser my-pi-handlers)
port (xml-token-head term-token) seed)))
(loop port entities expect-eof? seed)))
((ENTITY-REF)
(let ((seed
(ssax:handle-parsed-entity
port (xml-token-head term-token)
entities
(lambda (port entities seed)
(loop port entities #t seed))
my-char-data-handler
seed))) ; keep on reading the content after ent
(loop port entities expect-eof? seed)))
((START) ; Start of a child element
(if (eq? expected-content 'PCDATA)
(slib:error port "[elementvalid] broken for "
elem-gi
" with char content only; unexpected token "
term-token))
;; Do other validation of the element content
(let ((seed
(handle-start-tag
(xml-token-head term-token)
port entities namespaces
preserve-ws? seed)))
(loop port entities expect-eof? seed)))
(else
(slib:error port "XML [43] broken for "
term-token))))))))
)))
))
;;This is ssax:make-parser with all the (specialization) handlers given
;;as positional arguments. It is called by ssax:make-parser, see below
(define (ssax:make-parser/positional-args
*handler-DOCTYPE
*handler-UNDECL-ROOT
*handler-DECL-ROOT
*handler-NEW-LEVEL-SEED
*handler-FINISH-ELEMENT
*handler-CHAR-DATA-HANDLER
*handler-PROCESSING-INSTRUCTIONS)
(lambda (port seed)
;; We must've just scanned the DOCTYPE token. Handle the
;; doctype declaration and exit to
;; scan-for-significant-prolog-token-2, and eventually, to the
;; element parser.
(define (handle-decl port token-head seed)
(or (eq? (string->symbol "DOCTYPE") token-head)
(slib:error port "XML [22], expected DOCTYPE declaration, found "
token-head))
(ssax:assert-current-char ssax:S-chars "XML [28], space after DOCTYPE" port)
(ssax:skip-S port)
(let*-values
(((docname) (ssax:read-QName port))
((systemid)
(and (ssax:ncname-starting-char? (ssax:skip-S port))
(ssax:read-external-id port)))
((internal-subset?)
(begin
(ssax:skip-S port)
(eqv? #\[
(ssax:assert-current-char '(#\> #\[)
"XML [28], end-of-DOCTYPE" port))))
((elems entities namespaces seed)
(*handler-DOCTYPE port docname systemid internal-subset? seed)))
(scan-for-significant-prolog-token-2 port elems entities namespaces
seed)))
;; Scan the leading PIs until we encounter either a doctype
;; declaration or a start token (of the root element). In the
;; latter two cases, we exit to the appropriate continuation
(define (scan-for-significant-prolog-token-1 port seed)
(let ((token (ssax:scan-misc port)))
(if (eof-object? token)
(slib:error port "XML [22], unexpected EOF")
(case (xml-token-kind token)
((PI)
(let ((seed
((ssax:make-pi-parser *handler-PROCESSING-INSTRUCTIONS)
port (xml-token-head token) seed)))
(scan-for-significant-prolog-token-1 port seed)))
((DECL) (handle-decl port (xml-token-head token) seed))
((START)
(let*-values
(((elems entities namespaces seed)
(*handler-UNDECL-ROOT (xml-token-head token) seed)))
(element-parser (xml-token-head token) port elems
entities namespaces #f seed)))
(else (slib:error port "XML [22], unexpected markup "
token))))))
;; Scan PIs after the doctype declaration, till we encounter
;; the start tag of the root element. After that we exit
;; to the element parser
(define (scan-for-significant-prolog-token-2 port elems entities namespaces seed)
(let ((token (ssax:scan-misc port)))
(if (eof-object? token)
(slib:error port "XML [22], unexpected EOF")
(case (xml-token-kind token)
((PI)
(let ((seed ((ssax:make-pi-parser *handler-PROCESSING-INSTRUCTIONS)
port (xml-token-head token) seed)))
(scan-for-significant-prolog-token-2 port elems entities
namespaces seed)))
((START)
(element-parser (xml-token-head token) port elems
entities namespaces #f
(*handler-DECL-ROOT (xml-token-head token) seed)))
(else (slib:error port "XML [22], unexpected markup "
token))))))
;; A procedure start-tag-head port elems entities namespaces
;; preserve-ws? seed
(define element-parser
(ssax:make-elem-parser *handler-NEW-LEVEL-SEED
*handler-FINISH-ELEMENT
*handler-CHAR-DATA-HANDLER
*handler-PROCESSING-INSTRUCTIONS))
;; Get the ball rolling ...
(scan-for-significant-prolog-token-1 port seed)
))
(define DOCTYPE 'DOCTYPE)
(define UNDECL-ROOT 'UNDECL-ROOT)
(define DECL-ROOT 'DECL-ROOT)
(define NEW-LEVEL-SEED 'NEW-LEVEL-SEED)
(define FINISH-ELEMENT 'FINISH-ELEMENT)
(define CHAR-DATA-HANDLER 'CHAR-DATA-HANDLER)
(define PROCESSING-INSTRUCTIONS 'PROCESSING-INSTRUCTIONS)
;;@args user-handler-tag user-handler ...
;;
;;Create an XML parser, an instance of the XML parsing framework.
;;This will be a SAX, a DOM, or a specialized parser depending on the
;;supplied user-handlers.
;;
;;@0 takes an even number of arguments; @1 is a symbol that identifies
;;a procedure (or association list for @code{PROCESSING-INSTRUCTIONS})
;;(@2) that follows the tag. Given below are tags and signatures of
;;the corresponding procedures. Not all tags have to be specified.
;;If some are omitted, reasonable defaults will apply.
;;
;;@table @samp
;;
;;@item DOCTYPE
;;handler-procedure: @var{port} @var{docname} @var{systemid} @var{internal-subset?} @var{seed}
;;
;;If @var{internal-subset?} is #t, the current position in the port is
;;right after we have read @samp{[} that begins the internal DTD
;;subset. We must finish reading of this subset before we return (or
;;must call @code{skip-internal-dtd} if we aren't interested in
;;reading it). @var{port} at exit must be at the first symbol after
;;the whole DOCTYPE declaration.
;;
;;The handler-procedure must generate four values:
;;@quotation
;;@var{elems} @var{entities} @var{namespaces} @var{seed}
;;@end quotation
;;
;;@var{elems} is as defined for the ELEMS slot of XML-DECL. It may be
;;#f to switch off validation. @var{namespaces} will typically
;;contain @var{user-prefix}es for selected @var{uri-symb}s. The
;;default handler-procedure skips the internal subset, if any, and
;;returns @code{(values #f '() '() seed)}.
;;
;;@item UNDECL-ROOT
;;procedure: @var{elem-gi} @var{seed}
;;
;;where @var{elem-gi} is an UNRES-NAME of the root element. This
;;procedure is called when an XML document under parsing contains
;;@emph{no} DOCTYPE declaration.
;;
;;The handler-procedure, as a DOCTYPE handler procedure above,
;;must generate four values:
;;@quotation
;;@var{elems} @var{entities} @var{namespaces} @var{seed}
;;@end quotation
;;
;;The default handler-procedure returns (values #f '() '() seed)
;;
;;@item DECL-ROOT
;;procedure: @var{elem-gi} @var{seed}
;;
;;where @var{elem-gi} is an UNRES-NAME of the root element. This
;;procedure is called when an XML document under parsing does contains
;;the DOCTYPE declaration. The handler-procedure must generate a new
;;@var{seed} (and verify that the name of the root element matches the
;;doctype, if the handler so wishes). The default handler-procedure
;;is the identity function.
;;
;;@item NEW-LEVEL-SEED
;;procedure: see ssax:make-elem-parser, my-new-level-seed
;;
;;@item FINISH-ELEMENT
;;procedure: see ssax:make-elem-parser, my-finish-element
;;
;;@item CHAR-DATA-HANDLER
;;procedure: see ssax:make-elem-parser, my-char-data-handler
;;
;;@item PROCESSING-INSTRUCTIONS
;;association list as is passed to @code{ssax:make-pi-parser}.
;;The default value is '()
;;
;;@end table
;;
;;The generated parser is a procedure of arguments @var{port} and
;;@var{seed}.
;;
;;This procedure parses the document prolog and then exits to an
;;element parser (created by @code{ssax:make-elem-parser}) to handle
;;the rest.
;;
;;@example
;;[1] document ::= prolog element Misc*
;;[22] prolog ::= XMLDecl? Misc* (doctypedec | Misc*)?
;;[27] Misc ::= Comment | PI | S
;;[28] doctypedecl ::= '<!DOCTYPE' S Name (S ExternalID)? S?
;; ('[' (markupdecl | PEReference | S)* ']' S?)? '>'
;;[29] markupdecl ::= elementdecl | AttlistDecl
;; | EntityDecl
;; | NotationDecl | PI
;; | Comment
;;@end example
(define ssax:make-parser
(let ((descriptors
`((DOCTYPE
,(lambda (port docname systemid internal-subset? seed)
(cond (internal-subset?
(ssax:skip-internal-dtd port)))
(slib:warn port "DOCTYPE DECL " docname " "
systemid " found and skipped")
(values #f '() '() seed)
))
(UNDECL-ROOT
,(lambda (elem-gi seed) (values #f '() '() seed)))
(DECL-ROOT
,(lambda (elem-gi seed) seed))
(NEW-LEVEL-SEED) ; required
(FINISH-ELEMENT) ; required
(CHAR-DATA-HANDLER) ; required
(PROCESSING-INSTRUCTIONS ())
)))
(lambda proplist
(define count 0)
(if (odd? (length proplist))
(slib:error 'ssax:make-parser "takes even number of arguments"
proplist))
(let ((posititional-args
(map (lambda (spec)
(define ptail (member (car spec) proplist))
(cond ((and ptail (odd? (length ptail)))
(slib:error 'ssax:make-parser 'bad 'argument ptail))
(ptail
(set! count (+ 1 count))
(cadr ptail))
((not (null? (cdr spec)))
(cadr spec))
(else
(slib:error
'ssax:make-parser 'missing (car spec) 'property))))
descriptors)))
(if (= count (quotient (length proplist) 2))
(apply ssax:make-parser/positional-args posititional-args)
(slib:error 'ssax:make-parser 'extra 'arguments proplist))))))
;;@subsection Parsing XML to SXML
;;@body
;;
;;This is an instance of the SSAX parser that returns an SXML
;;representation of the XML document to be read from @1. @2 is a list
;;of @code{(@var{user-prefix} . @var{uri-string})} that assigns
;;@var{user-prefix}es to certain namespaces identified by particular
;;@var{uri-string}s. It may be an empty list. @0 returns an SXML
;;tree. The port points out to the first character after the root
;;element.
(define (ssax:xml->sxml port namespace-prefix-assig)
(define namespaces
(map (lambda (el) (cons* #f (car el) (ssax:uri-string->symbol (cdr el))))
namespace-prefix-assig))
(define (RES-NAME->SXML res-name)
(string->symbol
(string-append
(symbol->string (car res-name))
":"
(symbol->string (cdr res-name)))))
(let ((result
(reverse
((ssax:make-parser
'DOCTYPE
(lambda (port docname systemid internal-subset? seed)
(cond (internal-subset?
(ssax:skip-internal-dtd port)))
(slib:warn port "DOCTYPE DECL " docname " "
systemid " found and skipped")
(values #f '() namespaces seed))
'NEW-LEVEL-SEED
(lambda (elem-gi attributes namespaces expected-content seed)
'())
'FINISH-ELEMENT
(lambda (elem-gi attributes namespaces parent-seed seed)
(define nseed (ssax:reverse-collect-str-drop-ws seed))
(define attrs
(attlist-fold
(lambda (attr accum)
(cons (list (if (symbol? (car attr))
(car attr)
(RES-NAME->SXML (car attr)))
(cdr attr))
accum))
'() attributes))
(cons (cons (if (symbol? elem-gi)
elem-gi
(RES-NAME->SXML elem-gi))
(if (null? attrs)
nseed
(cons (cons '@ attrs) nseed)))
parent-seed))
'CHAR-DATA-HANDLER
(lambda (string1 string2 seed)
(if (string-null? string2)
(cons string1 seed)
(cons* string2 string1 seed)))
'UNDECL-ROOT
(lambda (elem-gi seed)
(values #f '() namespaces seed))
'PROCESSING-INSTRUCTIONS
(list
(cons '*DEFAULT*
(lambda (port pi-tag seed)
(cons (list '*PROCESSING-INSTRUCTIONS*
pi-tag
(ssax:read-pi-body-as-string port))
seed))))
)
port
'()))))
(cons '*TOP*
(if (null? namespace-prefix-assig)
result
(cons
(list '@ (cons '*NAMESPACES*
(map (lambda (ns) (list (car ns) (cdr ns)))
namespace-prefix-assig)))
result)))))
|