Source file src/pkg/encoding/xml/xml.go
1 // Copyright 2009 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
4
5 // Package xml implements a simple XML 1.0 parser that
6 // understands XML name spaces.
7 package xml
8
9 // References:
10 // Annotated XML spec: http://www.xml.com/axml/testaxml.htm
11 // XML name spaces: http://www.w3.org/TR/REC-xml-names/
12
13 // TODO(rsc):
14 // Test error handling.
15
16 import (
17 "bufio"
18 "bytes"
19 "fmt"
20 "io"
21 "strconv"
22 "strings"
23 "unicode"
24 "unicode/utf8"
25 )
26
27 // A SyntaxError represents a syntax error in the XML input stream.
28 type SyntaxError struct {
29 Msg string
30 Line int
31 }
32
33 func (e *SyntaxError) Error() string {
34 return "XML syntax error on line " + strconv.Itoa(e.Line) + ": " + e.Msg
35 }
36
37 // A Name represents an XML name (Local) annotated
38 // with a name space identifier (Space).
39 // In tokens returned by Decoder.Token, the Space identifier
40 // is given as a canonical URL, not the short prefix used
41 // in the document being parsed.
42 type Name struct {
43 Space, Local string
44 }
45
46 // An Attr represents an attribute in an XML element (Name=Value).
47 type Attr struct {
48 Name Name
49 Value string
50 }
51
52 // A Token is an interface holding one of the token types:
53 // StartElement, EndElement, CharData, Comment, ProcInst, or Directive.
54 type Token interface{}
55
56 // A StartElement represents an XML start element.
57 type StartElement struct {
58 Name Name
59 Attr []Attr
60 }
61
62 func (e StartElement) Copy() StartElement {
63 attrs := make([]Attr, len(e.Attr))
64 copy(attrs, e.Attr)
65 e.Attr = attrs
66 return e
67 }
68
69 // An EndElement represents an XML end element.
70 type EndElement struct {
71 Name Name
72 }
73
74 // A CharData represents XML character data (raw text),
75 // in which XML escape sequences have been replaced by
76 // the characters they represent.
77 type CharData []byte
78
79 func makeCopy(b []byte) []byte {
80 b1 := make([]byte, len(b))
81 copy(b1, b)
82 return b1
83 }
84
85 func (c CharData) Copy() CharData { return CharData(makeCopy(c)) }
86
87 // A Comment represents an XML comment of the form <!--comment-->.
88 // The bytes do not include the <!-- and --> comment markers.
89 type Comment []byte
90
91 func (c Comment) Copy() Comment { return Comment(makeCopy(c)) }
92
93 // A ProcInst represents an XML processing instruction of the form <?target inst?>
94 type ProcInst struct {
95 Target string
96 Inst []byte
97 }
98
99 func (p ProcInst) Copy() ProcInst {
100 p.Inst = makeCopy(p.Inst)
101 return p
102 }
103
104 // A Directive represents an XML directive of the form <!text>.
105 // The bytes do not include the <! and > markers.
106 type Directive []byte
107
108 func (d Directive) Copy() Directive { return Directive(makeCopy(d)) }
109
110 // CopyToken returns a copy of a Token.
111 func CopyToken(t Token) Token {
112 switch v := t.(type) {
113 case CharData:
114 return v.Copy()
115 case Comment:
116 return v.Copy()
117 case Directive:
118 return v.Copy()
119 case ProcInst:
120 return v.Copy()
121 case StartElement:
122 return v.Copy()
123 }
124 return t
125 }
126
127 // A Decoder represents an XML parser reading a particular input stream.
128 // The parser assumes that its input is encoded in UTF-8.
129 type Decoder struct {
130 // Strict defaults to true, enforcing the requirements
131 // of the XML specification.
132 // If set to false, the parser allows input containing common
133 // mistakes:
134 // * If an element is missing an end tag, the parser invents
135 // end tags as necessary to keep the return values from Token
136 // properly balanced.
137 // * In attribute values and character data, unknown or malformed
138 // character entities (sequences beginning with &) are left alone.
139 //
140 // Setting:
141 //
142 // d.Strict = false;
143 // d.AutoClose = HTMLAutoClose;
144 // d.Entity = HTMLEntity
145 //
146 // creates a parser that can handle typical HTML.
147 Strict bool
148
149 // When Strict == false, AutoClose indicates a set of elements to
150 // consider closed immediately after they are opened, regardless
151 // of whether an end element is present.
152 AutoClose []string
153
154 // Entity can be used to map non-standard entity names to string replacements.
155 // The parser behaves as if these standard mappings are present in the map,
156 // regardless of the actual map content:
157 //
158 // "lt": "<",
159 // "gt": ">",
160 // "amp": "&",
161 // "apos": "'",
162 // "quot": `"`,
163 Entity map[string]string
164
165 // CharsetReader, if non-nil, defines a function to generate
166 // charset-conversion readers, converting from the provided
167 // non-UTF-8 charset into UTF-8. If CharsetReader is nil or
168 // returns an error, parsing stops with an error. One of the
169 // the CharsetReader's result values must be non-nil.
170 CharsetReader func(charset string, input io.Reader) (io.Reader, error)
171
172 r io.ByteReader
173 buf bytes.Buffer
174 saved *bytes.Buffer
175 stk *stack
176 free *stack
177 needClose bool
178 toClose Name
179 nextToken Token
180 nextByte int
181 ns map[string]string
182 err error
183 line int
184 tmp [32]byte
185 }
186
187 // NewDecoder creates a new XML parser reading from r.
188 func NewDecoder(r io.Reader) *Decoder {
189 d := &Decoder{
190 ns: make(map[string]string),
191 nextByte: -1,
192 line: 1,
193 Strict: true,
194 }
195 d.switchToReader(r)
196 return d
197 }
198
199 // Token returns the next XML token in the input stream.
200 // At the end of the input stream, Token returns nil, io.EOF.
201 //
202 // Slices of bytes in the returned token data refer to the
203 // parser's internal buffer and remain valid only until the next
204 // call to Token. To acquire a copy of the bytes, call CopyToken
205 // or the token's Copy method.
206 //
207 // Token expands self-closing elements such as <br/>
208 // into separate start and end elements returned by successive calls.
209 //
210 // Token guarantees that the StartElement and EndElement
211 // tokens it returns are properly nested and matched:
212 // if Token encounters an unexpected end element,
213 // it will return an error.
214 //
215 // Token implements XML name spaces as described by
216 // http://www.w3.org/TR/REC-xml-names/. Each of the
217 // Name structures contained in the Token has the Space
218 // set to the URL identifying its name space when known.
219 // If Token encounters an unrecognized name space prefix,
220 // it uses the prefix as the Space rather than report an error.
221 func (d *Decoder) Token() (t Token, err error) {
222 if d.nextToken != nil {
223 t = d.nextToken
224 d.nextToken = nil
225 } else if t, err = d.RawToken(); err != nil {
226 return
227 }
228
229 if !d.Strict {
230 if t1, ok := d.autoClose(t); ok {
231 d.nextToken = t
232 t = t1
233 }
234 }
235 switch t1 := t.(type) {
236 case StartElement:
237 // In XML name spaces, the translations listed in the
238 // attributes apply to the element name and
239 // to the other attribute names, so process
240 // the translations first.
241 for _, a := range t1.Attr {
242 if a.Name.Space == "xmlns" {
243 v, ok := d.ns[a.Name.Local]
244 d.pushNs(a.Name.Local, v, ok)
245 d.ns[a.Name.Local] = a.Value
246 }
247 if a.Name.Space == "" && a.Name.Local == "xmlns" {
248 // Default space for untagged names
249 v, ok := d.ns[""]
250 d.pushNs("", v, ok)
251 d.ns[""] = a.Value
252 }
253 }
254
255 d.translate(&t1.Name, true)
256 for i := range t1.Attr {
257 d.translate(&t1.Attr[i].Name, false)
258 }
259 d.pushElement(t1.Name)
260 t = t1
261
262 case EndElement:
263 d.translate(&t1.Name, true)
264 if !d.popElement(&t1) {
265 return nil, d.err
266 }
267 t = t1
268 }
269 return
270 }
271
272 // Apply name space translation to name n.
273 // The default name space (for Space=="")
274 // applies only to element names, not to attribute names.
275 func (d *Decoder) translate(n *Name, isElementName bool) {
276 switch {
277 case n.Space == "xmlns":
278 return
279 case n.Space == "" && !isElementName:
280 return
281 case n.Space == "" && n.Local == "xmlns":
282 return
283 }
284 if v, ok := d.ns[n.Space]; ok {
285 n.Space = v
286 }
287 }
288
289 func (d *Decoder) switchToReader(r io.Reader) {
290 // Get efficient byte at a time reader.
291 // Assume that if reader has its own
292 // ReadByte, it's efficient enough.
293 // Otherwise, use bufio.
294 if rb, ok := r.(io.ByteReader); ok {
295 d.r = rb
296 } else {
297 d.r = bufio.NewReader(r)
298 }
299 }
300
301 // Parsing state - stack holds old name space translations
302 // and the current set of open elements. The translations to pop when
303 // ending a given tag are *below* it on the stack, which is
304 // more work but forced on us by XML.
305 type stack struct {
306 next *stack
307 kind int
308 name Name
309 ok bool
310 }
311
312 const (
313 stkStart = iota
314 stkNs
315 )
316
317 func (d *Decoder) push(kind int) *stack {
318 s := d.free
319 if s != nil {
320 d.free = s.next
321 } else {
322 s = new(stack)
323 }
324 s.next = d.stk
325 s.kind = kind
326 d.stk = s
327 return s
328 }
329
330 func (d *Decoder) pop() *stack {
331 s := d.stk
332 if s != nil {
333 d.stk = s.next
334 s.next = d.free
335 d.free = s
336 }
337 return s
338 }
339
340 // Record that we are starting an element with the given name.
341 func (d *Decoder) pushElement(name Name) {
342 s := d.push(stkStart)
343 s.name = name
344 }
345
346 // Record that we are changing the value of ns[local].
347 // The old value is url, ok.
348 func (d *Decoder) pushNs(local string, url string, ok bool) {
349 s := d.push(stkNs)
350 s.name.Local = local
351 s.name.Space = url
352 s.ok = ok
353 }
354
355 // Creates a SyntaxError with the current line number.
356 func (d *Decoder) syntaxError(msg string) error {
357 return &SyntaxError{Msg: msg, Line: d.line}
358 }
359
360 // Record that we are ending an element with the given name.
361 // The name must match the record at the top of the stack,
362 // which must be a pushElement record.
363 // After popping the element, apply any undo records from
364 // the stack to restore the name translations that existed
365 // before we saw this element.
366 func (d *Decoder) popElement(t *EndElement) bool {
367 s := d.pop()
368 name := t.Name
369 switch {
370 case s == nil || s.kind != stkStart:
371 d.err = d.syntaxError("unexpected end element </" + name.Local + ">")
372 return false
373 case s.name.Local != name.Local:
374 if !d.Strict {
375 d.needClose = true
376 d.toClose = t.Name
377 t.Name = s.name
378 return true
379 }
380 d.err = d.syntaxError("element <" + s.name.Local + "> closed by </" + name.Local + ">")
381 return false
382 case s.name.Space != name.Space:
383 d.err = d.syntaxError("element <" + s.name.Local + "> in space " + s.name.Space +
384 "closed by </" + name.Local + "> in space " + name.Space)
385 return false
386 }
387
388 // Pop stack until a Start is on the top, undoing the
389 // translations that were associated with the element we just closed.
390 for d.stk != nil && d.stk.kind != stkStart {
391 s := d.pop()
392 if s.ok {
393 d.ns[s.name.Local] = s.name.Space
394 } else {
395 delete(d.ns, s.name.Local)
396 }
397 }
398
399 return true
400 }
401
402 // If the top element on the stack is autoclosing and
403 // t is not the end tag, invent the end tag.
404 func (d *Decoder) autoClose(t Token) (Token, bool) {
405 if d.stk == nil || d.stk.kind != stkStart {
406 return nil, false
407 }
408 name := strings.ToLower(d.stk.name.Local)
409 for _, s := range d.AutoClose {
410 if strings.ToLower(s) == name {
411 // This one should be auto closed if t doesn't close it.
412 et, ok := t.(EndElement)
413 if !ok || et.Name.Local != name {
414 return EndElement{d.stk.name}, true
415 }
416 break
417 }
418 }
419 return nil, false
420 }
421
422 // RawToken is like Token but does not verify that
423 // start and end elements match and does not translate
424 // name space prefixes to their corresponding URLs.
425 func (d *Decoder) RawToken() (Token, error) {
426 if d.err != nil {
427 return nil, d.err
428 }
429 if d.needClose {
430 // The last element we read was self-closing and
431 // we returned just the StartElement half.
432 // Return the EndElement half now.
433 d.needClose = false
434 return EndElement{d.toClose}, nil
435 }
436
437 b, ok := d.getc()
438 if !ok {
439 return nil, d.err
440 }
441
442 if b != '<' {
443 // Text section.
444 d.ungetc(b)
445 data := d.text(-1, false)
446 if data == nil {
447 return nil, d.err
448 }
449 return CharData(data), nil
450 }
451
452 if b, ok = d.mustgetc(); !ok {
453 return nil, d.err
454 }
455 switch b {
456 case '/':
457 // </: End element
458 var name Name
459 if name, ok = d.nsname(); !ok {
460 if d.err == nil {
461 d.err = d.syntaxError("expected element name after </")
462 }
463 return nil, d.err
464 }
465 d.space()
466 if b, ok = d.mustgetc(); !ok {
467 return nil, d.err
468 }
469 if b != '>' {
470 d.err = d.syntaxError("invalid characters between </" + name.Local + " and >")
471 return nil, d.err
472 }
473 return EndElement{name}, nil
474
475 case '?':
476 // <?: Processing instruction.
477 // TODO(rsc): Should parse the <?xml declaration to make sure
478 // the version is 1.0 and the encoding is UTF-8.
479 var target string
480 if target, ok = d.name(); !ok {
481 if d.err == nil {
482 d.err = d.syntaxError("expected target name after <?")
483 }
484 return nil, d.err
485 }
486 d.space()
487 d.buf.Reset()
488 var b0 byte
489 for {
490 if b, ok = d.mustgetc(); !ok {
491 return nil, d.err
492 }
493 d.buf.WriteByte(b)
494 if b0 == '?' && b == '>' {
495 break
496 }
497 b0 = b
498 }
499 data := d.buf.Bytes()
500 data = data[0 : len(data)-2] // chop ?>
501
502 if target == "xml" {
503 enc := procInstEncoding(string(data))
504 if enc != "" && enc != "utf-8" && enc != "UTF-8" {
505 if d.CharsetReader == nil {
506 d.err = fmt.Errorf("xml: encoding %q declared but Decoder.CharsetReader is nil", enc)
507 return nil, d.err
508 }
509 newr, err := d.CharsetReader(enc, d.r.(io.Reader))
510 if err != nil {
511 d.err = fmt.Errorf("xml: opening charset %q: %v", enc, err)
512 return nil, d.err
513 }
514 if newr == nil {
515 panic("CharsetReader returned a nil Reader for charset " + enc)
516 }
517 d.switchToReader(newr)
518 }
519 }
520 return ProcInst{target, data}, nil
521
522 case '!':
523 // <!: Maybe comment, maybe CDATA.
524 if b, ok = d.mustgetc(); !ok {
525 return nil, d.err
526 }
527 switch b {
528 case '-': // <!-
529 // Probably <!-- for a comment.
530 if b, ok = d.mustgetc(); !ok {
531 return nil, d.err
532 }
533 if b != '-' {
534 d.err = d.syntaxError("invalid sequence <!- not part of <!--")
535 return nil, d.err
536 }
537 // Look for terminator.
538 d.buf.Reset()
539 var b0, b1 byte
540 for {
541 if b, ok = d.mustgetc(); !ok {
542 return nil, d.err
543 }
544 d.buf.WriteByte(b)
545 if b0 == '-' && b1 == '-' && b == '>' {
546 break
547 }
548 b0, b1 = b1, b
549 }
550 data := d.buf.Bytes()
551 data = data[0 : len(data)-3] // chop -->
552 return Comment(data), nil
553
554 case '[': // <![
555 // Probably <![CDATA[.
556 for i := 0; i < 6; i++ {
557 if b, ok = d.mustgetc(); !ok {
558 return nil, d.err
559 }
560 if b != "CDATA["[i] {
561 d.err = d.syntaxError("invalid <![ sequence")
562 return nil, d.err
563 }
564 }
565 // Have <![CDATA[. Read text until ]]>.
566 data := d.text(-1, true)
567 if data == nil {
568 return nil, d.err
569 }
570 return CharData(data), nil
571 }
572
573 // Probably a directive: <!DOCTYPE ...>, <!ENTITY ...>, etc.
574 // We don't care, but accumulate for caller. Quoted angle
575 // brackets do not count for nesting.
576 d.buf.Reset()
577 d.buf.WriteByte(b)
578 inquote := uint8(0)
579 depth := 0
580 for {
581 if b, ok = d.mustgetc(); !ok {
582 return nil, d.err
583 }
584 if inquote == 0 && b == '>' && depth == 0 {
585 break
586 }
587 d.buf.WriteByte(b)
588 switch {
589 case b == inquote:
590 inquote = 0
591
592 case inquote != 0:
593 // in quotes, no special action
594
595 case b == '\'' || b == '"':
596 inquote = b
597
598 case b == '>' && inquote == 0:
599 depth--
600
601 case b == '<' && inquote == 0:
602 depth++
603 }
604 }
605 return Directive(d.buf.Bytes()), nil
606 }
607
608 // Must be an open element like <a href="foo">
609 d.ungetc(b)
610
611 var (
612 name Name
613 empty bool
614 attr []Attr
615 )
616 if name, ok = d.nsname(); !ok {
617 if d.err == nil {
618 d.err = d.syntaxError("expected element name after <")
619 }
620 return nil, d.err
621 }
622
623 attr = make([]Attr, 0, 4)
624 for {
625 d.space()
626 if b, ok = d.mustgetc(); !ok {
627 return nil, d.err
628 }
629 if b == '/' {
630 empty = true
631 if b, ok = d.mustgetc(); !ok {
632 return nil, d.err
633 }
634 if b != '>' {
635 d.err = d.syntaxError("expected /> in element")
636 return nil, d.err
637 }
638 break
639 }
640 if b == '>' {
641 break
642 }
643 d.ungetc(b)
644
645 n := len(attr)
646 if n >= cap(attr) {
647 nattr := make([]Attr, n, 2*cap(attr))
648 copy(nattr, attr)
649 attr = nattr
650 }
651 attr = attr[0 : n+1]
652 a := &attr[n]
653 if a.Name, ok = d.nsname(); !ok {
654 if d.err == nil {
655 d.err = d.syntaxError("expected attribute name in element")
656 }
657 return nil, d.err
658 }
659 d.space()
660 if b, ok = d.mustgetc(); !ok {
661 return nil, d.err
662 }
663 if b != '=' {
664 if d.Strict {
665 d.err = d.syntaxError("attribute name without = in element")
666 return nil, d.err
667 } else {
668 d.ungetc(b)
669 a.Value = a.Name.Local
670 }
671 } else {
672 d.space()
673 data := d.attrval()
674 if data == nil {
675 return nil, d.err
676 }
677 a.Value = string(data)
678 }
679 }
680 if empty {
681 d.needClose = true
682 d.toClose = name
683 }
684 return StartElement{name, attr}, nil
685 }
686
687 func (d *Decoder) attrval() []byte {
688 b, ok := d.mustgetc()
689 if !ok {
690 return nil
691 }
692 // Handle quoted attribute values
693 if b == '"' || b == '\'' {
694 return d.text(int(b), false)
695 }
696 // Handle unquoted attribute values for strict parsers
697 if d.Strict {
698 d.err = d.syntaxError("unquoted or missing attribute value in element")
699 return nil
700 }
701 // Handle unquoted attribute values for unstrict parsers
702 d.ungetc(b)
703 d.buf.Reset()
704 for {
705 b, ok = d.mustgetc()
706 if !ok {
707 return nil
708 }
709 // http://www.w3.org/TR/REC-html40/intro/sgmltut.html#h-3.2.2
710 if 'a' <= b && b <= 'z' || 'A' <= b && b <= 'Z' ||
711 '0' <= b && b <= '9' || b == '_' || b == ':' || b == '-' {
712 d.buf.WriteByte(b)
713 } else {
714 d.ungetc(b)
715 break
716 }
717 }
718 return d.buf.Bytes()
719 }
720
721 // Skip spaces if any
722 func (d *Decoder) space() {
723 for {
724 b, ok := d.getc()
725 if !ok {
726 return
727 }
728 switch b {
729 case ' ', '\r', '\n', '\t':
730 default:
731 d.ungetc(b)
732 return
733 }
734 }
735 }
736
737 // Read a single byte.
738 // If there is no byte to read, return ok==false
739 // and leave the error in d.err.
740 // Maintain line number.
741 func (d *Decoder) getc() (b byte, ok bool) {
742 if d.err != nil {
743 return 0, false
744 }
745 if d.nextByte >= 0 {
746 b = byte(d.nextByte)
747 d.nextByte = -1
748 } else {
749 b, d.err = d.r.ReadByte()
750 if d.err != nil {
751 return 0, false
752 }
753 if d.saved != nil {
754 d.saved.WriteByte(b)
755 }
756 }
757 if b == '\n' {
758 d.line++
759 }
760 return b, true
761 }
762
763 // Return saved offset.
764 // If we did ungetc (nextByte >= 0), have to back up one.
765 func (d *Decoder) savedOffset() int {
766 n := d.saved.Len()
767 if d.nextByte >= 0 {
768 n--
769 }
770 return n
771 }
772
773 // Must read a single byte.
774 // If there is no byte to read,
775 // set d.err to SyntaxError("unexpected EOF")
776 // and return ok==false
777 func (d *Decoder) mustgetc() (b byte, ok bool) {
778 if b, ok = d.getc(); !ok {
779 if d.err == io.EOF {
780 d.err = d.syntaxError("unexpected EOF")
781 }
782 }
783 return
784 }
785
786 // Unread a single byte.
787 func (d *Decoder) ungetc(b byte) {
788 if b == '\n' {
789 d.line--
790 }
791 d.nextByte = int(b)
792 }
793
794 var entity = map[string]int{
795 "lt": '<',
796 "gt": '>',
797 "amp": '&',
798 "apos": '\'',
799 "quot": '"',
800 }
801
802 // Read plain text section (XML calls it character data).
803 // If quote >= 0, we are in a quoted string and need to find the matching quote.
804 // If cdata == true, we are in a <![CDATA[ section and need to find ]]>.
805 // On failure return nil and leave the error in d.err.
806 func (d *Decoder) text(quote int, cdata bool) []byte {
807 var b0, b1 byte
808 var trunc int
809 d.buf.Reset()
810 Input:
811 for {
812 b, ok := d.getc()
813 if !ok {
814 if cdata {
815 if d.err == io.EOF {
816 d.err = d.syntaxError("unexpected EOF in CDATA section")
817 }
818 return nil
819 }
820 break Input
821 }
822
823 // <![CDATA[ section ends with ]]>.
824 // It is an error for ]]> to appear in ordinary text.
825 if b0 == ']' && b1 == ']' && b == '>' {
826 if cdata {
827 trunc = 2
828 break Input
829 }
830 d.err = d.syntaxError("unescaped ]]> not in CDATA section")
831 return nil
832 }
833
834 // Stop reading text if we see a <.
835 if b == '<' && !cdata {
836 if quote >= 0 {
837 d.err = d.syntaxError("unescaped < inside quoted string")
838 return nil
839 }
840 d.ungetc('<')
841 break Input
842 }
843 if quote >= 0 && b == byte(quote) {
844 break Input
845 }
846 if b == '&' && !cdata {
847 // Read escaped character expression up to semicolon.
848 // XML in all its glory allows a document to define and use
849 // its own character names with <!ENTITY ...> directives.
850 // Parsers are required to recognize lt, gt, amp, apos, and quot
851 // even if they have not been declared. That's all we allow.
852 var i int
853 for i = 0; i < len(d.tmp); i++ {
854 var ok bool
855 d.tmp[i], ok = d.getc()
856 if !ok {
857 if d.err == io.EOF {
858 d.err = d.syntaxError("unexpected EOF")
859 }
860 return nil
861 }
862 c := d.tmp[i]
863 if c == ';' {
864 break
865 }
866 if 'a' <= c && c <= 'z' ||
867 'A' <= c && c <= 'Z' ||
868 '0' <= c && c <= '9' ||
869 c == '_' || c == '#' {
870 continue
871 }
872 d.ungetc(c)
873 break
874 }
875 s := string(d.tmp[0:i])
876 if i >= len(d.tmp) {
877 if !d.Strict {
878 b0, b1 = 0, 0
879 d.buf.WriteByte('&')
880 d.buf.Write(d.tmp[0:i])
881 continue Input
882 }
883 d.err = d.syntaxError("character entity expression &" + s + "... too long")
884 return nil
885 }
886 var haveText bool
887 var text string
888 if i >= 2 && s[0] == '#' {
889 var n uint64
890 var err error
891 if i >= 3 && s[1] == 'x' {
892 n, err = strconv.ParseUint(s[2:], 16, 64)
893 } else {
894 n, err = strconv.ParseUint(s[1:], 10, 64)
895 }
896 if err == nil && n <= unicode.MaxRune {
897 text = string(n)
898 haveText = true
899 }
900 } else {
901 if r, ok := entity[s]; ok {
902 text = string(r)
903 haveText = true
904 } else if d.Entity != nil {
905 text, haveText = d.Entity[s]
906 }
907 }
908 if !haveText {
909 if !d.Strict {
910 b0, b1 = 0, 0
911 d.buf.WriteByte('&')
912 d.buf.Write(d.tmp[0:i])
913 continue Input
914 }
915 d.err = d.syntaxError("invalid character entity &" + s + ";")
916 return nil
917 }
918 d.buf.Write([]byte(text))
919 b0, b1 = 0, 0
920 continue Input
921 }
922 d.buf.WriteByte(b)
923 b0, b1 = b1, b
924 }
925 data := d.buf.Bytes()
926 data = data[0 : len(data)-trunc]
927
928 // Inspect each rune for being a disallowed character.
929 buf := data
930 for len(buf) > 0 {
931 r, size := utf8.DecodeRune(buf)
932 if r == utf8.RuneError && size == 1 {
933 d.err = d.syntaxError("invalid UTF-8")
934 return nil
935 }
936 buf = buf[size:]
937 if !isInCharacterRange(r) {
938 d.err = d.syntaxError(fmt.Sprintf("illegal character code %U", r))
939 return nil
940 }
941 }
942
943 // Must rewrite \r and \r\n into \n.
944 w := 0
945 for r := 0; r < len(data); r++ {
946 b := data[r]
947 if b == '\r' {
948 if r+1 < len(data) && data[r+1] == '\n' {
949 continue
950 }
951 b = '\n'
952 }
953 data[w] = b
954 w++
955 }
956 return data[0:w]
957 }
958
959 // Decide whether the given rune is in the XML Character Range, per
960 // the Char production of http://www.xml.com/axml/testaxml.htm,
961 // Section 2.2 Characters.
962 func isInCharacterRange(r rune) (inrange bool) {
963 return r == 0x09 ||
964 r == 0x0A ||
965 r == 0x0D ||
966 r >= 0x20 && r <= 0xDF77 ||
967 r >= 0xE000 && r <= 0xFFFD ||
968 r >= 0x10000 && r <= 0x10FFFF
969 }
970
971 // Get name space name: name with a : stuck in the middle.
972 // The part before the : is the name space identifier.
973 func (d *Decoder) nsname() (name Name, ok bool) {
974 s, ok := d.name()
975 if !ok {
976 return
977 }
978 i := strings.Index(s, ":")
979 if i < 0 {
980 name.Local = s
981 } else {
982 name.Space = s[0:i]
983 name.Local = s[i+1:]
984 }
985 return name, true
986 }
987
988 // Get name: /first(first|second)*/
989 // Do not set d.err if the name is missing (unless unexpected EOF is received):
990 // let the caller provide better context.
991 func (d *Decoder) name() (s string, ok bool) {
992 var b byte
993 if b, ok = d.mustgetc(); !ok {
994 return
995 }
996
997 // As a first approximation, we gather the bytes [A-Za-z_:.-\x80-\xFF]*
998 if b < utf8.RuneSelf && !isNameByte(b) {
999 d.ungetc(b)
1000 return "", false
1001 }
1002 d.buf.Reset()
1003 d.buf.WriteByte(b)
1004 for {
1005 if b, ok = d.mustgetc(); !ok {
1006 return
1007 }
1008 if b < utf8.RuneSelf && !isNameByte(b) {
1009 d.ungetc(b)
1010 break
1011 }
1012 d.buf.WriteByte(b)
1013 }
1014
1015 // Then we check the characters.
1016 s = d.buf.String()
1017 for i, c := range s {
1018 if !unicode.Is(first, c) && (i == 0 || !unicode.Is(second, c)) {
1019 d.err = d.syntaxError("invalid XML name: " + s)
1020 return "", false
1021 }
1022 }
1023 return s, true
1024 }
1025
1026 func isNameByte(c byte) bool {
1027 return 'A' <= c && c <= 'Z' ||
1028 'a' <= c && c <= 'z' ||
1029 '0' <= c && c <= '9' ||
1030 c == '_' || c == ':' || c == '.' || c == '-'
1031 }
1032
1033 // These tables were generated by cut and paste from Appendix B of
1034 // the XML spec at http://www.xml.com/axml/testaxml.htm
1035 // and then reformatting. First corresponds to (Letter | '_' | ':')
1036 // and second corresponds to NameChar.
1037
1038 var first = &unicode.RangeTable{
1039 R16: []unicode.Range16{
1040 {0x003A, 0x003A, 1},
1041 {0x0041, 0x005A, 1},
1042 {0x005F, 0x005F, 1},
1043 {0x0061, 0x007A, 1},
1044 {0x00C0, 0x00D6, 1},
1045 {0x00D8, 0x00F6, 1},
1046 {0x00F8, 0x00FF, 1},
1047 {0x0100, 0x0131, 1},
1048 {0x0134, 0x013E, 1},
1049 {0x0141, 0x0148, 1},
1050 {0x014A, 0x017E, 1},
1051 {0x0180, 0x01C3, 1},
1052 {0x01CD, 0x01F0, 1},
1053 {0x01F4, 0x01F5, 1},
1054 {0x01FA, 0x0217, 1},
1055 {0x0250, 0x02A8, 1},
1056 {0x02BB, 0x02C1, 1},
1057 {0x0386, 0x0386, 1},
1058 {0x0388, 0x038A, 1},
1059 {0x038C, 0x038C, 1},
1060 {0x038E, 0x03A1, 1},
1061 {0x03A3, 0x03CE, 1},
1062 {0x03D0, 0x03D6, 1},
1063 {0x03DA, 0x03E0, 2},
1064 {0x03E2, 0x03F3, 1},
1065 {0x0401, 0x040C, 1},
1066 {0x040E, 0x044F, 1},
1067 {0x0451, 0x045C, 1},
1068 {0x045E, 0x0481, 1},
1069 {0x0490, 0x04C4, 1},
1070 {0x04C7, 0x04C8, 1},
1071 {0x04CB, 0x04CC, 1},
1072 {0x04D0, 0x04EB, 1},
1073 {0x04EE, 0x04F5, 1},
1074 {0x04F8, 0x04F9, 1},
1075 {0x0531, 0x0556, 1},
1076 {0x0559, 0x0559, 1},
1077 {0x0561, 0x0586, 1},
1078 {0x05D0, 0x05EA, 1},
1079 {0x05F0, 0x05F2, 1},
1080 {0x0621, 0x063A, 1},
1081 {0x0641, 0x064A, 1},
1082 {0x0671, 0x06B7, 1},
1083 {0x06BA, 0x06BE, 1},
1084 {0x06C0, 0x06CE, 1},
1085 {0x06D0, 0x06D3, 1},
1086 {0x06D5, 0x06D5, 1},
1087 {0x06E5, 0x06E6, 1},
1088 {0x0905, 0x0939, 1},
1089 {0x093D, 0x093D, 1},
1090 {0x0958, 0x0961, 1},
1091 {0x0985, 0x098C, 1},
1092 {0x098F, 0x0990, 1},
1093 {0x0993, 0x09A8, 1},
1094 {0x09AA, 0x09B0, 1},
1095 {0x09B2, 0x09B2, 1},
1096 {0x09B6, 0x09B9, 1},
1097 {0x09DC, 0x09DD, 1},
1098 {0x09DF, 0x09E1, 1},
1099 {0x09F0, 0x09F1, 1},
1100 {0x0A05, 0x0A0A, 1},
1101 {0x0A0F, 0x0A10, 1},
1102 {0x0A13, 0x0A28, 1},
1103 {0x0A2A, 0x0A30, 1},
1104 {0x0A32, 0x0A33, 1},
1105 {0x0A35, 0x0A36, 1},
1106 {0x0A38, 0x0A39, 1},
1107 {0x0A59, 0x0A5C, 1},
1108 {0x0A5E, 0x0A5E, 1},
1109 {0x0A72, 0x0A74, 1},
1110 {0x0A85, 0x0A8B, 1},
1111 {0x0A8D, 0x0A8D, 1},
1112 {0x0A8F, 0x0A91, 1},
1113 {0x0A93, 0x0AA8, 1},
1114 {0x0AAA, 0x0AB0, 1},
1115 {0x0AB2, 0x0AB3, 1},
1116 {0x0AB5, 0x0AB9, 1},
1117 {0x0ABD, 0x0AE0, 0x23},
1118 {0x0B05, 0x0B0C, 1},
1119 {0x0B0F, 0x0B10, 1},
1120 {0x0B13, 0x0B28, 1},
1121 {0x0B2A, 0x0B30, 1},
1122 {0x0B32, 0x0B33, 1},
1123 {0x0B36, 0x0B39, 1},
1124 {0x0B3D, 0x0B3D, 1},
1125 {0x0B5C, 0x0B5D, 1},
1126 {0x0B5F, 0x0B61, 1},
1127 {0x0B85, 0x0B8A, 1},
1128 {0x0B8E, 0x0B90, 1},
1129 {0x0B92, 0x0B95, 1},
1130 {0x0B99, 0x0B9A, 1},
1131 {0x0B9C, 0x0B9C, 1},
1132 {0x0B9E, 0x0B9F, 1},
1133 {0x0BA3, 0x0BA4, 1},
1134 {0x0BA8, 0x0BAA, 1},
1135 {0x0BAE, 0x0BB5, 1},
1136 {0x0BB7, 0x0BB9, 1},
1137 {0x0C05, 0x0C0C, 1},
1138 {0x0C0E, 0x0C10, 1},
1139 {0x0C12, 0x0C28, 1},
1140 {0x0C2A, 0x0C33, 1},
1141 {0x0C35, 0x0C39, 1},
1142 {0x0C60, 0x0C61, 1},
1143 {0x0C85, 0x0C8C, 1},
1144 {0x0C8E, 0x0C90, 1},
1145 {0x0C92, 0x0CA8, 1},
1146 {0x0CAA, 0x0CB3, 1},
1147 {0x0CB5, 0x0CB9, 1},
1148 {0x0CDE, 0x0CDE, 1},
1149 {0x0CE0, 0x0CE1, 1},
1150 {0x0D05, 0x0D0C, 1},
1151 {0x0D0E, 0x0D10, 1},
1152 {0x0D12, 0x0D28, 1},
1153 {0x0D2A, 0x0D39, 1},
1154 {0x0D60, 0x0D61, 1},
1155 {0x0E01, 0x0E2E, 1},
1156 {0x0E30, 0x0E30, 1},
1157 {0x0E32, 0x0E33, 1},
1158 {0x0E40, 0x0E45, 1},
1159 {0x0E81, 0x0E82, 1},
1160 {0x0E84, 0x0E84, 1},
1161 {0x0E87, 0x0E88, 1},
1162 {0x0E8A, 0x0E8D, 3},
1163 {0x0E94, 0x0E97, 1},
1164 {0x0E99, 0x0E9F, 1},
1165 {0x0EA1, 0x0EA3, 1},
1166 {0x0EA5, 0x0EA7, 2},
1167 {0x0EAA, 0x0EAB, 1},
1168 {0x0EAD, 0x0EAE, 1},
1169 {0x0EB0, 0x0EB0, 1},
1170 {0x0EB2, 0x0EB3, 1},
1171 {0x0EBD, 0x0EBD, 1},
1172 {0x0EC0, 0x0EC4, 1},
1173 {0x0F40, 0x0F47, 1},
1174 {0x0F49, 0x0F69, 1},
1175 {0x10A0, 0x10C5, 1},
1176 {0x10D0, 0x10F6, 1},
1177 {0x1100, 0x1100, 1},
1178 {0x1102, 0x1103, 1},
1179 {0x1105, 0x1107, 1},
1180 {0x1109, 0x1109, 1},
1181 {0x110B, 0x110C, 1},
1182 {0x110E, 0x1112, 1},
1183 {0x113C, 0x1140, 2},
1184 {0x114C, 0x1150, 2},
1185 {0x1154, 0x1155, 1},
1186 {0x1159, 0x1159, 1},
1187 {0x115F, 0x1161, 1},
1188 {0x1163, 0x1169, 2},
1189 {0x116D, 0x116E, 1},
1190 {0x1172, 0x1173, 1},
1191 {0x1175, 0x119E, 0x119E - 0x1175},
1192 {0x11A8, 0x11AB, 0x11AB - 0x11A8},
1193 {0x11AE, 0x11AF, 1},
1194 {0x11B7, 0x11B8, 1},
1195 {0x11BA, 0x11BA, 1},
1196 {0x11BC, 0x11C2, 1},
1197 {0x11EB, 0x11F0, 0x11F0 - 0x11EB},
1198 {0x11F9, 0x11F9, 1},
1199 {0x1E00, 0x1E9B, 1},
1200 {0x1EA0, 0x1EF9, 1},
1201 {0x1F00, 0x1F15, 1},
1202 {0x1F18, 0x1F1D, 1},
1203 {0x1F20, 0x1F45, 1},
1204 {0x1F48, 0x1F4D, 1},
1205 {0x1F50, 0x1F57, 1},
1206 {0x1F59, 0x1F5B, 0x1F5B - 0x1F59},
1207 {0x1F5D, 0x1F5D, 1},
1208 {0x1F5F, 0x1F7D, 1},
1209 {0x1F80, 0x1FB4, 1},
1210 {0x1FB6, 0x1FBC, 1},
1211 {0x1FBE, 0x1FBE, 1},
1212 {0x1FC2, 0x1FC4, 1},
1213 {0x1FC6, 0x1FCC, 1},
1214 {0x1FD0, 0x1FD3, 1},
1215 {0x1FD6, 0x1FDB, 1},
1216 {0x1FE0, 0x1FEC, 1},
1217 {0x1FF2, 0x1FF4, 1},
1218 {0x1FF6, 0x1FFC, 1},
1219 {0x2126, 0x2126, 1},
1220 {0x212A, 0x212B, 1},
1221 {0x212E, 0x212E, 1},
1222 {0x2180, 0x2182, 1},
1223 {0x3007, 0x3007, 1},
1224 {0x3021, 0x3029, 1},
1225 {0x3041, 0x3094, 1},
1226 {0x30A1, 0x30FA, 1},
1227 {0x3105, 0x312C, 1},
1228 {0x4E00, 0x9FA5, 1},
1229 {0xAC00, 0xD7A3, 1},
1230 },
1231 }
1232
1233 var second = &unicode.RangeTable{
1234 R16: []unicode.Range16{
1235 {0x002D, 0x002E, 1},
1236 {0x0030, 0x0039, 1},
1237 {0x00B7, 0x00B7, 1},
1238 {0x02D0, 0x02D1, 1},
1239 {0x0300, 0x0345, 1},
1240 {0x0360, 0x0361, 1},
1241 {0x0387, 0x0387, 1},
1242 {0x0483, 0x0486, 1},
1243 {0x0591, 0x05A1, 1},
1244 {0x05A3, 0x05B9, 1},
1245 {0x05BB, 0x05BD, 1},
1246 {0x05BF, 0x05BF, 1},
1247 {0x05C1, 0x05C2, 1},
1248 {0x05C4, 0x0640, 0x0640 - 0x05C4},
1249 {0x064B, 0x0652, 1},
1250 {0x0660, 0x0669, 1},
1251 {0x0670, 0x0670, 1},
1252 {0x06D6, 0x06DC, 1},
1253 {0x06DD, 0x06DF, 1},
1254 {0x06E0, 0x06E4, 1},
1255 {0x06E7, 0x06E8, 1},
1256 {0x06EA, 0x06ED, 1},
1257 {0x06F0, 0x06F9, 1},
1258 {0x0901, 0x0903, 1},
1259 {0x093C, 0x093C, 1},
1260 {0x093E, 0x094C, 1},
1261 {0x094D, 0x094D, 1},
1262 {0x0951, 0x0954, 1},
1263 {0x0962, 0x0963, 1},
1264 {0x0966, 0x096F, 1},
1265 {0x0981, 0x0983, 1},
1266 {0x09BC, 0x09BC, 1},
1267 {0x09BE, 0x09BF, 1},
1268 {0x09C0, 0x09C4, 1},
1269 {0x09C7, 0x09C8, 1},
1270 {0x09CB, 0x09CD, 1},
1271 {0x09D7, 0x09D7, 1},
1272 {0x09E2, 0x09E3, 1},
1273 {0x09E6, 0x09EF, 1},
1274 {0x0A02, 0x0A3C, 0x3A},
1275 {0x0A3E, 0x0A3F, 1},
1276 {0x0A40, 0x0A42, 1},
1277 {0x0A47, 0x0A48, 1},
1278 {0x0A4B, 0x0A4D, 1},
1279 {0x0A66, 0x0A6F, 1},
1280 {0x0A70, 0x0A71, 1},
1281 {0x0A81, 0x0A83, 1},
1282 {0x0ABC, 0x0ABC, 1},
1283 {0x0ABE, 0x0AC5, 1},
1284 {0x0AC7, 0x0AC9, 1},
1285 {0x0ACB, 0x0ACD, 1},
1286 {0x0AE6, 0x0AEF, 1},
1287 {0x0B01, 0x0B03, 1},
1288 {0x0B3C, 0x0B3C, 1},
1289 {0x0B3E, 0x0B43, 1},
1290 {0x0B47, 0x0B48, 1},
1291 {0x0B4B, 0x0B4D, 1},
1292 {0x0B56, 0x0B57, 1},
1293 {0x0B66, 0x0B6F, 1},
1294 {0x0B82, 0x0B83, 1},
1295 {0x0BBE, 0x0BC2, 1},
1296 {0x0BC6, 0x0BC8, 1},
1297 {0x0BCA, 0x0BCD, 1},
1298 {0x0BD7, 0x0BD7, 1},
1299 {0x0BE7, 0x0BEF, 1},
1300 {0x0C01, 0x0C03, 1},
1301 {0x0C3E, 0x0C44, 1},
1302 {0x0C46, 0x0C48, 1},
1303 {0x0C4A, 0x0C4D, 1},
1304 {0x0C55, 0x0C56, 1},
1305 {0x0C66, 0x0C6F, 1},
1306 {0x0C82, 0x0C83, 1},
1307 {0x0CBE, 0x0CC4, 1},
1308 {0x0CC6, 0x0CC8, 1},
1309 {0x0CCA, 0x0CCD, 1},
1310 {0x0CD5, 0x0CD6, 1},
1311 {0x0CE6, 0x0CEF, 1},
1312 {0x0D02, 0x0D03, 1},
1313 {0x0D3E, 0x0D43, 1},
1314 {0x0D46, 0x0D48, 1},
1315 {0x0D4A, 0x0D4D, 1},
1316 {0x0D57, 0x0D57, 1},
1317 {0x0D66, 0x0D6F, 1},
1318 {0x0E31, 0x0E31, 1},
1319 {0x0E34, 0x0E3A, 1},
1320 {0x0E46, 0x0E46, 1},
1321 {0x0E47, 0x0E4E, 1},
1322 {0x0E50, 0x0E59, 1},
1323 {0x0EB1, 0x0EB1, 1},
1324 {0x0EB4, 0x0EB9, 1},
1325 {0x0EBB, 0x0EBC, 1},
1326 {0x0EC6, 0x0EC6, 1},
1327 {0x0EC8, 0x0ECD, 1},
1328 {0x0ED0, 0x0ED9, 1},
1329 {0x0F18, 0x0F19, 1},
1330 {0x0F20, 0x0F29, 1},
1331 {0x0F35, 0x0F39, 2},
1332 {0x0F3E, 0x0F3F, 1},
1333 {0x0F71, 0x0F84, 1},
1334 {0x0F86, 0x0F8B, 1},
1335 {0x0F90, 0x0F95, 1},
1336 {0x0F97, 0x0F97, 1},
1337 {0x0F99, 0x0FAD, 1},
1338 {0x0FB1, 0x0FB7, 1},
1339 {0x0FB9, 0x0FB9, 1},
1340 {0x20D0, 0x20DC, 1},
1341 {0x20E1, 0x3005, 0x3005 - 0x20E1},
1342 {0x302A, 0x302F, 1},
1343 {0x3031, 0x3035, 1},
1344 {0x3099, 0x309A, 1},
1345 {0x309D, 0x309E, 1},
1346 {0x30FC, 0x30FE, 1},
1347 },
1348 }
1349
1350 // HTMLEntity is an entity map containing translations for the
1351 // standard HTML entity characters.
1352 var HTMLEntity = htmlEntity
1353
1354 var htmlEntity = map[string]string{
1355 /*
1356 hget http://www.w3.org/TR/html4/sgml/entities.html |
1357 ssam '
1358 ,y /\>/ x/\<(.|\n)+/ s/\n/ /g
1359 ,x v/^\<!ENTITY/d
1360 ,s/\<!ENTITY ([^ ]+) .*U\+([0-9A-F][0-9A-F][0-9A-F][0-9A-F]) .+/ "\1": "\\u\2",/g
1361 '
1362 */
1363 "nbsp": "\u00A0",
1364 "iexcl": "\u00A1",
1365 "cent": "\u00A2",
1366 "pound": "\u00A3",
1367 "curren": "\u00A4",
1368 "yen": "\u00A5",
1369 "brvbar": "\u00A6",
1370 "sect": "\u00A7",
1371 "uml": "\u00A8",
1372 "copy": "\u00A9",
1373 "ordf": "\u00AA",
1374 "laquo": "\u00AB",
1375 "not": "\u00AC",
1376 "shy": "\u00AD",
1377 "reg": "\u00AE",
1378 "macr": "\u00AF",
1379 "deg": "\u00B0",
1380 "plusmn": "\u00B1",
1381 "sup2": "\u00B2",
1382 "sup3": "\u00B3",
1383 "acute": "\u00B4",
1384 "micro": "\u00B5",
1385 "para": "\u00B6",
1386 "middot": "\u00B7",
1387 "cedil": "\u00B8",
1388 "sup1": "\u00B9",
1389 "ordm": "\u00BA",
1390 "raquo": "\u00BB",
1391 "frac14": "\u00BC",
1392 "frac12": "\u00BD",
1393 "frac34": "\u00BE",
1394 "iquest": "\u00BF",
1395 "Agrave": "\u00C0",
1396 "Aacute": "\u00C1",
1397 "Acirc": "\u00C2",
1398 "Atilde": "\u00C3",
1399 "Auml": "\u00C4",
1400 "Aring": "\u00C5",
1401 "AElig": "\u00C6",
1402 "Ccedil": "\u00C7",
1403 "Egrave": "\u00C8",
1404 "Eacute": "\u00C9",
1405 "Ecirc": "\u00CA",
1406 "Euml": "\u00CB",
1407 "Igrave": "\u00CC",
1408 "Iacute": "\u00CD",
1409 "Icirc": "\u00CE",
1410 "Iuml": "\u00CF",
1411 "ETH": "\u00D0",
1412 "Ntilde": "\u00D1",
1413 "Ograve": "\u00D2",
1414 "Oacute": "\u00D3",
1415 "Ocirc": "\u00D4",
1416 "Otilde": "\u00D5",
1417 "Ouml": "\u00D6",
1418 "times": "\u00D7",
1419 "Oslash": "\u00D8",
1420 "Ugrave": "\u00D9",
1421 "Uacute": "\u00DA",
1422 "Ucirc": "\u00DB",
1423 "Uuml": "\u00DC",
1424 "Yacute": "\u00DD",
1425 "THORN": "\u00DE",
1426 "szlig": "\u00DF",
1427 "agrave": "\u00E0",
1428 "aacute": "\u00E1",
1429 "acirc": "\u00E2",
1430 "atilde": "\u00E3",
1431 "auml": "\u00E4",
1432 "aring": "\u00E5",
1433 "aelig": "\u00E6",
1434 "ccedil": "\u00E7",
1435 "egrave": "\u00E8",
1436 "eacute": "\u00E9",
1437 "ecirc": "\u00EA",
1438 "euml": "\u00EB",
1439 "igrave": "\u00EC",
1440 "iacute": "\u00ED",
1441 "icirc": "\u00EE",
1442 "iuml": "\u00EF",
1443 "eth": "\u00F0",
1444 "ntilde": "\u00F1",
1445 "ograve": "\u00F2",
1446 "oacute": "\u00F3",
1447 "ocirc": "\u00F4",
1448 "otilde": "\u00F5",
1449 "ouml": "\u00F6",
1450 "divide": "\u00F7",
1451 "oslash": "\u00F8",
1452 "ugrave": "\u00F9",
1453 "uacute": "\u00FA",
1454 "ucirc": "\u00FB",
1455 "uuml": "\u00FC",
1456 "yacute": "\u00FD",
1457 "thorn": "\u00FE",
1458 "yuml": "\u00FF",
1459 "fnof": "\u0192",
1460 "Alpha": "\u0391",
1461 "Beta": "\u0392",
1462 "Gamma": "\u0393",
1463 "Delta": "\u0394",
1464 "Epsilon": "\u0395",
1465 "Zeta": "\u0396",
1466 "Eta": "\u0397",
1467 "Theta": "\u0398",
1468 "Iota": "\u0399",
1469 "Kappa": "\u039A",
1470 "Lambda": "\u039B",
1471 "Mu": "\u039C",
1472 "Nu": "\u039D",
1473 "Xi": "\u039E",
1474 "Omicron": "\u039F",
1475 "Pi": "\u03A0",
1476 "Rho": "\u03A1",
1477 "Sigma": "\u03A3",
1478 "Tau": "\u03A4",
1479 "Upsilon": "\u03A5",
1480 "Phi": "\u03A6",
1481 "Chi": "\u03A7",
1482 "Psi": "\u03A8",
1483 "Omega": "\u03A9",
1484 "alpha": "\u03B1",
1485 "beta": "\u03B2",
1486 "gamma": "\u03B3",
1487 "delta": "\u03B4",
1488 "epsilon": "\u03B5",
1489 "zeta": "\u03B6",
1490 "eta": "\u03B7",
1491 "theta": "\u03B8",
1492 "iota": "\u03B9",
1493 "kappa": "\u03BA",
1494 "lambda": "\u03BB",
1495 "mu": "\u03BC",
1496 "nu": "\u03BD",
1497 "xi": "\u03BE",
1498 "omicron": "\u03BF",
1499 "pi": "\u03C0",
1500 "rho": "\u03C1",
1501 "sigmaf": "\u03C2",
1502 "sigma": "\u03C3",
1503 "tau": "\u03C4",
1504 "upsilon": "\u03C5",
1505 "phi": "\u03C6",
1506 "chi": "\u03C7",
1507 "psi": "\u03C8",
1508 "omega": "\u03C9",
1509 "thetasym": "\u03D1",
1510 "upsih": "\u03D2",
1511 "piv": "\u03D6",
1512 "bull": "\u2022",
1513 "hellip": "\u2026",
1514 "prime": "\u2032",
1515 "Prime": "\u2033",
1516 "oline": "\u203E",
1517 "frasl": "\u2044",
1518 "weierp": "\u2118",
1519 "image": "\u2111",
1520 "real": "\u211C",
1521 "trade": "\u2122",
1522 "alefsym": "\u2135",
1523 "larr": "\u2190",
1524 "uarr": "\u2191",
1525 "rarr": "\u2192",
1526 "darr": "\u2193",
1527 "harr": "\u2194",
1528 "crarr": "\u21B5",
1529 "lArr": "\u21D0",
1530 "uArr": "\u21D1",
1531 "rArr": "\u21D2",
1532 "dArr": "\u21D3",
1533 "hArr": "\u21D4",
1534 "forall": "\u2200",
1535 "part": "\u2202",
1536 "exist": "\u2203",
1537 "empty": "\u2205",
1538 "nabla": "\u2207",
1539 "isin": "\u2208",
1540 "notin": "\u2209",
1541 "ni": "\u220B",
1542 "prod": "\u220F",
1543 "sum": "\u2211",
1544 "minus": "\u2212",
1545 "lowast": "\u2217",
1546 "radic": "\u221A",
1547 "prop": "\u221D",
1548 "infin": "\u221E",
1549 "ang": "\u2220",
1550 "and": "\u2227",
1551 "or": "\u2228",
1552 "cap": "\u2229",
1553 "cup": "\u222A",
1554 "int": "\u222B",
1555 "there4": "\u2234",
1556 "sim": "\u223C",
1557 "cong": "\u2245",
1558 "asymp": "\u2248",
1559 "ne": "\u2260",
1560 "equiv": "\u2261",
1561 "le": "\u2264",
1562 "ge": "\u2265",
1563 "sub": "\u2282",
1564 "sup": "\u2283",
1565 "nsub": "\u2284",
1566 "sube": "\u2286",
1567 "supe": "\u2287",
1568 "oplus": "\u2295",
1569 "otimes": "\u2297",
1570 "perp": "\u22A5",
1571 "sdot": "\u22C5",
1572 "lceil": "\u2308",
1573 "rceil": "\u2309",
1574 "lfloor": "\u230A",
1575 "rfloor": "\u230B",
1576 "lang": "\u2329",
1577 "rang": "\u232A",
1578 "loz": "\u25CA",
1579 "spades": "\u2660",
1580 "clubs": "\u2663",
1581 "hearts": "\u2665",
1582 "diams": "\u2666",
1583 "quot": "\u0022",
1584 "amp": "\u0026",
1585 "lt": "\u003C",
1586 "gt": "\u003E",
1587 "OElig": "\u0152",
1588 "oelig": "\u0153",
1589 "Scaron": "\u0160",
1590 "scaron": "\u0161",
1591 "Yuml": "\u0178",
1592 "circ": "\u02C6",
1593 "tilde": "\u02DC",
1594 "ensp": "\u2002",
1595 "emsp": "\u2003",
1596 "thinsp": "\u2009",
1597 "zwnj": "\u200C",
1598 "zwj": "\u200D",
1599 "lrm": "\u200E",
1600 "rlm": "\u200F",
1601 "ndash": "\u2013",
1602 "mdash": "\u2014",
1603 "lsquo": "\u2018",
1604 "rsquo": "\u2019",
1605 "sbquo": "\u201A",
1606 "ldquo": "\u201C",
1607 "rdquo": "\u201D",
1608 "bdquo": "\u201E",
1609 "dagger": "\u2020",
1610 "Dagger": "\u2021",
1611 "permil": "\u2030",
1612 "lsaquo": "\u2039",
1613 "rsaquo": "\u203A",
1614 "euro": "\u20AC",
1615 }
1616
1617 // HTMLAutoClose is the set of HTML elements that
1618 // should be considered to close automatically.
1619 var HTMLAutoClose = htmlAutoClose
1620
1621 var htmlAutoClose = []string{
1622 /*
1623 hget http://www.w3.org/TR/html4/loose.dtd |
1624 9 sed -n 's/<!ELEMENT (.*) - O EMPTY.+/ "\1",/p' | tr A-Z a-z
1625 */
1626 "basefont",
1627 "br",
1628 "area",
1629 "link",
1630 "img",
1631 "param",
1632 "hr",
1633 "input",
1634 "col ",
1635 "frame",
1636 "isindex",
1637 "base",
1638 "meta",
1639 }
1640
1641 var (
1642 esc_quot = []byte(""") // shorter than """
1643 esc_apos = []byte("'") // shorter than "'"
1644 esc_amp = []byte("&")
1645 esc_lt = []byte("<")
1646 esc_gt = []byte(">")
1647 )
1648
1649 // Escape writes to w the properly escaped XML equivalent
1650 // of the plain text data s.
1651 func Escape(w io.Writer, s []byte) {
1652 var esc []byte
1653 last := 0
1654 for i, c := range s {
1655 switch c {
1656 case '"':
1657 esc = esc_quot
1658 case '\'':
1659 esc = esc_apos
1660 case '&':
1661 esc = esc_amp
1662 case '<':
1663 esc = esc_lt
1664 case '>':
1665 esc = esc_gt
1666 default:
1667 continue
1668 }
1669 w.Write(s[last:i])
1670 w.Write(esc)
1671 last = i + 1
1672 }
1673 w.Write(s[last:])
1674 }
1675
1676 // procInstEncoding parses the `encoding="..."` or `encoding='...'`
1677 // value out of the provided string, returning "" if not found.
1678 func procInstEncoding(s string) string {
1679 // TODO: this parsing is somewhat lame and not exact.
1680 // It works for all actual cases, though.
1681 idx := strings.Index(s, "encoding=")
1682 if idx == -1 {
1683 return ""
1684 }
1685 v := s[idx+len("encoding="):]
1686 if v == "" {
1687 return ""
1688 }
1689 if v[0] != '\'' && v[0] != '"' {
1690 return ""
1691 }
1692 idx = strings.IndexRune(v[1:], rune(v[0]))
1693 if idx == -1 {
1694 return ""
1695 }
1696 return v[1 : idx+1]
1697 }