Profile of /project/perl/lib/HTML/Parser.pm

File	/project/perl/lib/HTML/Parser.pm
Statements Executed	9236
Statement Execution Time	179ms

Subroutines — ordered by exclusive time
Calls	P	F	Exclusive Time	Inclusive Time	Subroutine
461	1	1	97.4ms	142ms	HTML::Parser::::initHTML::Parser::init
2766	6	2	25.5ms	25.5ms	HTML::Parser::::handlerHTML::Parser::handler (xsub)
461	1	1	18.0ms	160ms	HTML::Parser::::newHTML::Parser::new
461	1	2	7.42ms	7.42ms	HTML::Parser::::_alloc_pstateHTML::Parser::_alloc_pstate (xsub)
922	1	2	6.65ms	6.65ms	HTML::Parser::::CORE:matchHTML::Parser::CORE:match (opcode)
461	1	2	5.15ms	5.15ms	HTML::Parser::::ignore_elementsHTML::Parser::ignore_elements (xsub)
7	1	2	283µs	986µs	HTML::Parser::::parseHTML::Parser::parse (xsub)
7	1	2	48µs	48µs	HTML::Parser::::eofHTML::Parser::eof (xsub)
0	0	0	0s	0s	HTML::Parser::::BEGINHTML::Parser::BEGIN
0	0	0	0s	0s	HTML::Parser::::__ANON__[:54]HTML::Parser::__ANON__[:54]
0	0	0	0s	0s	HTML::Parser::::__ANON__[:60]HTML::Parser::__ANON__[:60]
0	0	0	0s	0s	HTML::Parser::::netscape_buggy_commentHTML::Parser::netscape_buggy_comment
0	0	0	0s	0s	HTML::Parser::::parse_fileHTML::Parser::parse_file
0	0	0	0s	0s	HTML::Parser::::textHTML::Parser::text

Call graph for these subroutines as a Graphviz dot language file.

Line	State ments	Time on line	Calls	Time in subs	Code
1					package HTML::Parser;
2
3					# Copyright 1996-2007, Gisle Aas.
4					# Copyright 1999-2000, Michael A. Chase.
5					#
6					# This library is free software; you can redistribute it and/or
7					# modify it under the same terms as Perl itself.
8
9	3	107µs	1	27µs	use strict; # spent 27µs making 1 call to strict::import
10	3	1.41ms	1	240µs	use vars qw($VERSION @ISA); # spent 240µs making 1 call to vars::import
11
12	1	6µs			$VERSION = '3.56'; # $Date: 2007/01/12 09:18:31 $
13
14	1	6µs			require HTML::Entities;
15
16	1	4µs			require XSLoader;
17	1	16.9ms	1	16.8ms	XSLoader::load('HTML::Parser', $VERSION); # spent 16.8ms making 1 call to XSLoader::load
18
19					sub new
20					# spent 160ms (18.0+142) within HTML::Parser::new which was called 461 times, avg 347µs/call: # 461 times (18.0ms+142ms) by HTML::HeadParser::new at line 103 of HTML/HeadParser.pm, avg 347µs/call {
21	1383	17.5ms			my $class = shift;
22					my $self = bless {}, $class;
23					return $self->init(@_); # spent 142ms making 461 calls to HTML::Parser::init, avg 308µs/call
24					}
25
26
27					sub init
28					# spent 142ms (97.4+44.7) within HTML::Parser::init which was called 461 times, avg 308µs/call: # 461 times (97.4ms+44.7ms) by HTML::Parser::new at line 23, avg 308µs/call {
29	4149	47.1ms			my $self = shift;
30					$self->_alloc_pstate; # spent 7.42ms making 461 calls to HTML::Parser::_alloc_pstate, avg 16µs/call
31
32					my %arg = @_;
33					my $api_version = delete $arg{api_version} \|\| (@_ ? 3 : 2);
34					if ($api_version >= 4) {
35					require Carp;
36					Carp::croak("API version $api_version not supported " .
37					"by HTML::Parser $VERSION");
38					}
39
40	2766	62.9ms			if ($api_version < 3) {
41					# Set up method callbacks compatible with HTML-Parser-2.xx
42					$self->handler(text => "text", "self,text,is_cdata"); # spent 5.89ms making 461 calls to HTML::Parser::handler, avg 13µs/call
43					$self->handler(end => "end", "self,tagname,text"); # spent 4.13ms making 461 calls to HTML::Parser::handler, avg 9µs/call
44					$self->handler(process => "process", "self,token0,text"); # spent 3.98ms making 461 calls to HTML::Parser::handler, avg 9µs/call
45					$self->handler(start => "start", # spent 4.47ms making 461 calls to HTML::Parser::handler, avg 10µs/call
46					"self,tagname,attr,attrseq,text");
47
48					$self->handler(comment =>
49					sub {
50					my($self, $tokens) = @_;
51					for (@$tokens) {
52					$self->comment($_);
53					}
54					}, "self,tokens"); # spent 3.52ms making 461 calls to HTML::Parser::handler, avg 8µs/call
55
56					$self->handler(declaration =>
57					sub {
58					my $self = shift;
59					$self->declaration(substr($_[0], 2, -1));
60					}, "self,text"); # spent 3.48ms making 461 calls to HTML::Parser::handler, avg 8µs/call
61					}
62
63					if (my $h = delete $arg{handlers}) {
64					$h = {@$h} if ref($h) eq "ARRAY";
65					while (my($event, $cb) = each %$h) {
66					$self->handler($event => @$cb);
67					}
68					}
69
70					# In the end we try to assume plain attribute or handler
71					while (my($option, $val) = each %arg) {
72	922	32.7ms	922	6.65ms	if ($option =~ /^(\w+)_h$/) { # spent 6.65ms making 922 calls to HTML::Parser::CORE:match, avg 7µs/call
73					$self->handler($1 => @$val);
74					}
75					elsif ($option =~ /^(text\|start\|end\|process\|declaration\|comment)$/) {
76					require Carp;
77					Carp::croak("Bad constructor option '$option'");
78					}
79					else {
80					$self->$option($val); # spent 5.15ms making 461 calls to HTML::Parser::ignore_elements, avg 11µs/call
81					}
82					}
83
84					return $self;
85					}
86
87
88					sub parse_file
89					{
90					my($self, $file) = @_;
91					my $opened;
92					if (!ref($file) && ref(\$file) ne "GLOB") {
93					# Assume $file is a filename
94					local(*F);
95					open(F, $file) \|\| return undef;
96					binmode(F); # should we? good for byte counts
97					$opened++;
98					$file = *F;
99					}
100					my $chunk = '';
101					while (read($file, $chunk, 512)) {
102					$self->parse($chunk) \|\| last;
103					}
104					close($file) if $opened;
105					$self->eof;
106					}
107
108
109					sub netscape_buggy_comment # legacy
110					{
111					my $self = shift;
112					require Carp;
113					Carp::carp("netscape_buggy_comment() is deprecated. " .
114					"Please use the strict_comment() method instead");
115					my $old = !$self->strict_comment;
116					$self->strict_comment(!shift) if @_;
117					return $old;
118					}
119
120					# set up method stubs
121					sub text { }
122	1	9µs			*start = \&text;
123	1	5µs			*end = \&text;
124	1	6µs			*comment = \&text;
125	1	4µs			*declaration = \&text;
126	1	5µs			*process = \&text;
127
128	1	26µs			1;
129
130					__END__
131
132
133					=head1 NAME
134
135					HTML::Parser - HTML parser class
136
137					=head1 SYNOPSIS
138
139					use HTML::Parser ();
140
141					# Create parser object
142					$p = HTML::Parser->new( api_version => 3,
143					start_h => [\&start, "tagname, attr"],
144					end_h => [\&end, "tagname"],
145					marked_sections => 1,
146					);
147
148					# Parse document text chunk by chunk
149					$p->parse($chunk1);
150					$p->parse($chunk2);
151					#...
152					$p->eof; # signal end of document
153
154					# Parse directly from file
155					$p->parse_file("foo.html");
156					# or
157					open(my $fh, "<:utf8", "foo.html") \|\| die;
158					$p->parse_file($fh);
159
160					=head1 DESCRIPTION
161
162					Objects of the C<HTML::Parser> class will recognize markup and
163					separate it from plain text (alias data content) in HTML
164					documents. As different kinds of markup and text are recognized, the
165					corresponding event handlers are invoked.
166
167					C<HTML::Parser> is not a generic SGML parser. We have tried to
168					make it able to deal with the HTML that is actually "out there", and
169					it normally parses as closely as possible to the way the popular web
170					browsers do it instead of strictly following one of the many HTML
171					specifications from W3C. Where there is disagreement, there is often
172					an option that you can enable to get the official behaviour.
173
174					The document to be parsed may be supplied in arbitrary chunks. This
175					makes on-the-fly parsing as documents are received from the network
176					possible.
177
178					If event driven parsing does not feel right for your application, you
179					might want to use C<HTML::PullParser>. This is an C<HTML::Parser>
180					subclass that allows a more conventional program structure.
181
182
183					=head1 METHODS
184
185					The following method is used to construct a new C<HTML::Parser> object:
186
187					=over
188
189					=item $p = HTML::Parser->new( %options_and_handlers )
190
191					This class method creates a new C<HTML::Parser> object and
192					returns it. Key/value argument pairs may be provided to assign event
193					handlers or initialize parser options. The handlers and parser
194					options can also be set or modified later by the method calls described below.
195
196					If a top level key is in the form "<event>_h" (e.g., "text_h") then it
197					assigns a handler to that event, otherwise it initializes a parser
198					option. The event handler specification value must be an array
199					reference. Multiple handlers may also be assigned with the 'handlers
200					=> [%handlers]' option. See examples below.
201
202					If new() is called without any arguments, it will create a parser that
203					uses callback methods compatible with version 2 of C<HTML::Parser>.
204					See the section on "version 2 compatibility" below for details.
205
206					The special constructor option 'api_version => 2' can be used to
207					initialize version 2 callbacks while still setting other options and
208					handlers. The 'api_version => 3' option can be used if you don't want
209					to set any options and don't want to fall back to v2 compatible
210					mode.
211
212					Examples:
213
214					$p = HTML::Parser->new(api_version => 3,
215					text_h => [ sub {...}, "dtext" ]);
216
217					This creates a new parser object with a text event handler subroutine
218					that receives the original text with general entities decoded.
219
220					$p = HTML::Parser->new(api_version => 3,
221					start_h => [ 'my_start', "self,tokens" ]);
222
223					This creates a new parser object with a start event handler method
224					that receives the $p and the tokens array.
225
226					$p = HTML::Parser->new(api_version => 3,
227					handlers => { text => [\@array, "event,text"],
228					comment => [\@array, "event,text"],
229					});
230
231					This creates a new parser object that stores the event type and the
232					original text in @array for text and comment events.
233
234					=back
235
236					The following methods feed the HTML document
237					to the C<HTML::Parser> object:
238
239					=over
240
241					=item $p->parse( $string )
242
243					Parse $string as the next chunk of the HTML document. The return
244					value is normally a reference to the parser object (i.e. $p).
245					Handlers invoked should not attempt to modify the $string in-place until
246					$p->parse returns.
247
248					If an invoked event handler aborts parsing by calling $p->eof, then
249					$p->parse() will return a FALSE value.
250
251					=item $p->parse( $code_ref )
252
253					If a code reference is passed as the argument to be parsed, then the
254					chunks to be parsed are obtained by invoking this function repeatedly.
255					Parsing continues until the function returns an empty (or undefined)
256					result. When this happens $p->eof is automatically signaled.
257
258					Parsing will also abort if one of the event handlers calls $p->eof.
259
260					The effect of this is the same as:
261
262					while (1) {
263					my $chunk = &$code_ref();
264					if (!defined($chunk) \|\| !length($chunk)) {
265					$p->eof;
266					return $p;
267					}
268					$p->parse($chunk) \|\| return undef;
269					}
270
271					But it is more efficient as this loop runs internally in XS code.
272
273					=item $p->parse_file( $file )
274
275					Parse text directly from a file. The $file argument can be a
276					filename, an open file handle, or a reference to an open file
277					handle.
278
279					If $file contains a filename and the file can't be opened, then the
280					method returns an undefined value and $! tells why it failed.
281					Otherwise the return value is a reference to the parser object.
282
283					If a file handle is passed as the $file argument, then the file will
284					normally be read until EOF, but not closed.
285
286					If an invoked event handler aborts parsing by calling $p->eof,
287					then $p->parse_file() may not have read the entire file.
288
289					On systems with multi-byte line terminators, the values passed for the
290					offset and length argspecs may be too low if parse_file() is called on
291					a file handle that is not in binary mode.
292
293					If a filename is passed in, then parse_file() will open the file in
294					binary mode.
295
296					=item $p->eof
297
298					Signals the end of the HTML document. Calling the $p->eof method
299					outside a handler callback will flush any remaining buffered text
300					(which triggers the C<text> event if there is any remaining text).
301
302					Calling $p->eof inside a handler will terminate parsing at that point
303					and cause $p->parse to return a FALSE value. This also terminates
304					parsing by $p->parse_file().
305
306					After $p->eof has been called, the parse() and parse_file() methods
307					can be invoked to feed new documents with the parser object.
308
309					The return value from eof() is a reference to the parser object.
310
311					=back
312
313
314					Most parser options are controlled by boolean attributes.
315					Each boolean attribute is enabled by calling the corresponding method
316					with a TRUE argument and disabled with a FALSE argument. The
317					attribute value is left unchanged if no argument is given. The return
318					value from each method is the old attribute value.
319
320					Methods that can be used to get and/or set parser options are:
321
322					=over
323
324					=item $p->attr_encoded
325
326					=item $p->attr_encoded( $bool )
327
328					By default, the C<attr> and C<@attr> argspecs will have general
329					entities for attribute values decoded. Enabling this attribute leaves
330					entities alone.
331
332					=item $p->boolean_attribute_value( $val )
333
334					This method sets the value reported for boolean attributes inside HTML
335					start tags. By default, the name of the attribute is also used as its
336					value. This affects the values reported for C<tokens> and C<attr>
337					argspecs.
338
339					=item $p->case_sensitive
340
341					=item $p->case_sensitive( $bool )
342
343					By default, tagnames and attribute names are down-cased. Enabling this
344					attribute leaves them as found in the HTML source document.
345
346					=item $p->closing_plaintext
347
348					=item $p->closing_plaintext( $bool )
349
350					By default, "plaintext" element can never be closed. Everything up to
351					the end of the document is parsed in CDATA mode. This historical
352					behaviour is what at least MSIE does. Enabling this attribute makes
353					closing "</plaintext>" tag effective and the parsing process will resume
354					after seeing this tag. This emulates gecko-based browsers.
355
356					=item $p->empty_element_tags
357
358					=item $p->empty_element_tags( $bool )
359
360					By default, empty element tags are not recognized as such and the "/"
361					before ">" is just treated like a normal name character (unless
362					C<strict_names> is enabled). Enabling this attribute make
363					C<HTML::Parser> recognize these tags.
364
365					Empty element tags look like start tags, but end with the character
366					sequence "/>" instead of ">". When recognized by C<HTML::Parser> they
367					cause an artificial end event in addition to the start event. The
368					C<text> for the artificial end event will be empty and the C<tokenpos>
369					array will be undefined even though the the token array will have one
370					element containing the tag name.
371
372					=item $p->marked_sections
373
374					=item $p->marked_sections( $bool )
375
376					By default, section markings like <![CDATA[...]]> are treated like
377					ordinary text. When this attribute is enabled section markings are
378					honoured.
379
380					There are currently no events associated with the marked section
381					markup, but the text can be returned as C<skipped_text>.
382
383					=item $p->strict_comment
384
385					=item $p->strict_comment( $bool )
386
387					By default, comments are terminated by the first occurrence of "-->".
388					This is the behaviour of most popular browsers (like Mozilla, Opera and
389					MSIE), but it is not correct according to the official HTML
390					standard. Officially, you need an even number of "--" tokens before
391					the closing ">" is recognized and there may not be anything but
392					whitespace between an even and an odd "--".
393
394					The official behaviour is enabled by enabling this attribute.
395
396					Enabling of 'strict_comment' also disables recognizing these forms as
397					comments:
398
399					</ comment>
400					<! comment>
401
402
403					=item $p->strict_end
404
405					=item $p->strict_end( $bool )
406
407					By default, attributes and other junk are allowed to be present on end tags in a
408					manner that emulates MSIE's behaviour.
409
410					The official behaviour is enabled with this attribute. If enabled,
411					only whitespace is allowed between the tagname and the final ">".
412
413					=item $p->strict_names
414
415					=item $p->strict_names( $bool )
416
417					By default, almost anything is allowed in tag and attribute names.
418					This is the behaviour of most popular browsers and allows us to parse
419					some broken tags with invalid attribute values like:
420
421					<IMG SRC=newprevlstGr.gif ALT=[PREV LIST] BORDER=0>
422
423					By default, "LIST]" is parsed as a boolean attribute, not as
424					part of the ALT value as was clearly intended. This is also what
425					Mozilla sees.
426
427					The official behaviour is enabled by enabling this attribute. If
428					enabled, it will cause the tag above to be reported as text
429					since "LIST]" is not a legal attribute name.
430
431					=item $p->unbroken_text
432
433					=item $p->unbroken_text( $bool )
434
435					By default, blocks of text are given to the text handler as soon as
436					possible (but the parser takes care always to break text at a
437					boundary between whitespace and non-whitespace so single words and
438					entities can always be decoded safely). This might create breaks that
439					make it hard to do transformations on the text. When this attribute is
440					enabled, blocks of text are always reported in one piece. This will
441					delay the text event until the following (non-text) event has been
442					recognized by the parser.
443
444					Note that the C<offset> argspec will give you the offset of the first
445					segment of text and C<length> is the combined length of the segments.
446					Since there might be ignored tags in between, these numbers can't be
447					used to directly index in the original document file.
448
449					=item $p->utf8_mode
450
451					=item $p->utf8_mode( $bool )
452
453					Enable this option when parsing raw undecoded UTF-8. This tells the
454					parser that the entities expanded for strings reported by C<attr>,
455					C<@attr> and C<dtext> should be expanded as decoded UTF-8 so they end
456					up compatible with the surrounding text.
457
458					If C<utf8_mode> is enabled then it is an error to pass strings
459					containing characters with code above 255 to the parse() method, and
460					the parse() method will croak if you try.
461
462					Example: The Unicode character "\x{2665}" is "\xE2\x99\xA5" when UTF-8
463					encoded. The character can also be represented by the entity
464					"&hearts;" or "&#x2665". If we feed the parser:
465
466					$p->parse("\xE2\x99\xA5&hearts;");
467
468					then C<dtext> will be reported as "\xE2\x99\xA5\x{2665}" without
469					C<utf8_mode> enabled, but as "\xE2\x99\xA5\xE2\x99\xA5" when enabled.
470					The later string is what you want.
471
472					This option is only available with perl-5.8 or better.
473
474					=item $p->xml_mode
475
476					=item $p->xml_mode( $bool )
477
478					Enabling this attribute changes the parser to allow some XML
479					constructs. This enables the behaviour controlled by individually by
480					the C<case_sensitive>, C<empty_element_tags>, C<strict_names> and
481					C<xml_pic> attributes and also suppresses special treatment of
482					elements that are parsed as CDATA for HTML.
483
484					=item $p->xml_pic
485
486					=item $p->xml_pic( $bool )
487
488					By default, I<processing instructions> are terminated by ">". When
489					this attribute is enabled, processing instructions are terminated by
490					"?>" instead.
491
492					=back
493
494					As markup and text is recognized, handlers are invoked. The following
495					method is used to set up handlers for different events:
496
497					=over
498
499					=item $p->handler( event => \&subroutine, $argspec )
500
501					=item $p->handler( event => $method_name, $argspec )
502
503					=item $p->handler( event => \@accum, $argspec )
504
505					=item $p->handler( event => "" );
506
507					=item $p->handler( event => undef );
508
509					=item $p->handler( event );
510
511					This method assigns a subroutine, method, or array to handle an event.
512
513					Event is one of C<text>, C<start>, C<end>, C<declaration>, C<comment>,
514					C<process>, C<start_document>, C<end_document> or C<default>.
515
516					The C<\&subroutine> is a reference to a subroutine which is called to handle
517					the event.
518
519					The C<$method_name> is the name of a method of $p which is called to handle
520					the event.
521
522					The C<@accum> is an array that will hold the event information as
523					sub-arrays.
524
525					If the second argument is "", the event is ignored.
526					If it is undef, the default handler is invoked for the event.
527
528					The C<$argspec> is a string that describes the information to be reported
529					for the event. Any requested information that does not apply to a
530					specific event is passed as C<undef>. If argspec is omitted, then it
531					is left unchanged.
532
533					The return value from $p->handler is the old callback routine or a
534					reference to the accumulator array.
535
536					Any return values from handler callback routines/methods are always
537					ignored. A handler callback can request parsing to be aborted by
538					invoking the $p->eof method. A handler callback is not allowed to
539					invoke the $p->parse() or $p->parse_file() method. An exception will
540					be raised if it tries.
541
542					Examples:
543
544					$p->handler(start => "start", 'self, attr, attrseq, text' );
545
546					This causes the "start" method of object $p to be called for 'start' events.
547					The callback signature is $p->start(\%attr, \@attr_seq, $text).
548
549					$p->handler(start => \&start, 'attr, attrseq, text' );
550
551					This causes subroutine start() to be called for 'start' events.
552					The callback signature is start(\%attr, \@attr_seq, $text).
553
554					$p->handler(start => \@accum, '"S", attr, attrseq, text' );
555
556					This causes 'start' event information to be saved in @accum.
557					The array elements will be ['S', \%attr, \@attr_seq, $text].
558
559					$p->handler(start => "");
560
561					This causes 'start' events to be ignored. It also suppresses
562					invocations of any default handler for start events. It is in most
563					cases equivalent to $p->handler(start => sub {}), but is more
564					efficient. It is different from the empty-sub-handler in that
565					C<skipped_text> is not reset by it.
566
567					$p->handler(start => undef);
568
569					This causes no handler to be associated with start events.
570					If there is a default handler it will be invoked.
571
572					=back
573
574					Filters based on tags can be set up to limit the number of events
575					reported. The main bottleneck during parsing is often the huge number
576					of callbacks made from the parser. Applying filters can improve
577					performance significantly.
578
579					The following methods control filters:
580
581					=over
582
583					=item $p->ignore_elements( @tags )
584
585					Both the C<start> event and the C<end> event as well as any events that
586					would be reported in between are suppressed. The ignored elements can
587					contain nested occurrences of itself. Example:
588
589					$p->ignore_elements(qw(script style));
590
591					The C<script> and C<style> tags will always nest properly since their
592					content is parsed in CDATA mode. For most other tags
593					C<ignore_elements> must be used with caution since HTML is often not
594					I<well formed>.
595
596					=item $p->ignore_tags( @tags )
597
598					Any C<start> and C<end> events involving any of the tags given are
599					suppressed. To reset the filter (i.e. don't suppress any C<start> and
600					C<end> events), call C<ignore_tags> without an argument.
601
602					=item $p->report_tags( @tags )
603
604					Any C<start> and C<end> events involving any of the tags I<not> given
605					are suppressed. To reset the filter (i.e. report all C<start> and
606					C<end> events), call C<report_tags> without an argument.
607
608					=back
609
610					Internally, the system has two filter lists, one for C<report_tags>
611					and one for C<ignore_tags>, and both filters are applied. This
612					effectively gives C<ignore_tags> precedence over C<report_tags>.
613
614					Examples:
615
616					$p->ignore_tags(qw(style));
617					$p->report_tags(qw(script style));
618
619					results in only C<script> events being reported.
620
621					=head2 Argspec
622
623					Argspec is a string containing a comma-separated list that describes
624					the information reported by the event. The following argspec
625					identifier names can be used:
626
627					=over
628
629					=item C<attr>
630
631					Attr causes a reference to a hash of attribute name/value pairs to be
632					passed.
633
634					Boolean attributes' values are either the value set by
635					$p->boolean_attribute_value, or the attribute name if no value has been
636					set by $p->boolean_attribute_value.
637
638					This passes undef except for C<start> events.
639
640					Unless C<xml_mode> or C<case_sensitive> is enabled, the attribute
641					names are forced to lower case.
642
643					General entities are decoded in the attribute values and
644					one layer of matching quotes enclosing the attribute values is removed.
645
646					The Unicode character set is assumed for entity decoding. With Perl
647					version 5.6 or earlier only the Latin-1 range is supported, and
648					entities for characters outside the range 0..255 are left unchanged.
649
650					=item C<@attr>
651
652					Basically the same as C<attr>, but keys and values are passed as
653					individual arguments and the original sequence of the attributes is
654					kept. The parameters passed will be the same as the @attr calculated
655					here:
656
657					@attr = map { $_ => $attr->{$_} } @$attrseq;
658
659					assuming $attr and $attrseq here are the hash and array passed as the
660					result of C<attr> and C<attrseq> argspecs.
661
662					This passes no values for events besides C<start>.
663
664					=item C<attrseq>
665
666					Attrseq causes a reference to an array of attribute names to be
667					passed. This can be useful if you want to walk the C<attr> hash in
668					the original sequence.
669
670					This passes undef except for C<start> events.
671
672					Unless C<xml_mode> or C<case_sensitive> is enabled, the attribute
673					names are forced to lower case.
674
675					=item C<column>
676
677					Column causes the column number of the start of the event to be passed.
678					The first column on a line is 0.
679
680					=item C<dtext>
681
682					Dtext causes the decoded text to be passed. General entities are
683					automatically decoded unless the event was inside a CDATA section or
684					was between literal start and end tags (C<script>, C<style>,
685					C<xmp>, and C<plaintext>).
686
687					The Unicode character set is assumed for entity decoding. With Perl
688					version 5.6 or earlier only the Latin-1 range is supported, and
689					entities for characters outside the range 0..255 are left unchanged.
690
691					This passes undef except for C<text> events.
692
693					=item C<event>
694
695					Event causes the event name to be passed.
696
697					The event name is one of C<text>, C<start>, C<end>, C<declaration>,
698					C<comment>, C<process>, C<start_document> or C<end_document>.
699
700					=item C<is_cdata>
701
702					Is_cdata causes a TRUE value to be passed if the event is inside a CDATA
703					section or between literal start and end tags (C<script>,
704					C<style>, C<xmp>, and C<plaintext>).
705
706					if the flag is FALSE for a text event, then you should normally
707					either use C<dtext> or decode the entities yourself before the text is
708					processed further.
709
710					=item C<length>
711
712					Length causes the number of bytes of the source text of the event to
713					be passed.
714
715					=item C<line>
716
717					Line causes the line number of the start of the event to be passed.
718					The first line in the document is 1. Line counting doesn't start
719					until at least one handler requests this value to be reported.
720
721					=item C<offset>
722
723					Offset causes the byte position in the HTML document of the start of
724					the event to be passed. The first byte in the document has offset 0.
725
726					=item C<offset_end>
727
728					Offset_end causes the byte position in the HTML document of the end of
729					the event to be passed. This is the same as C<offset> + C<length>.
730
731					=item C<self>
732
733					Self causes the current object to be passed to the handler. If the
734					handler is a method, this must be the first element in the argspec.
735
736					An alternative to passing self as an argspec is to register closures
737					that capture $self by themselves as handlers. Unfortunately this
738					creates circular references which prevent the HTML::Parser object
739					from being garbage collected. Using the C<self> argspec avoids this
740					problem.
741
742					=item C<skipped_text>
743
744					Skipped_text returns the concatenated text of all the events that have
745					been skipped since the last time an event was reported. Events might
746					be skipped because no handler is registered for them or because some
747					filter applies. Skipped text also includes marked section markup,
748					since there are no events that can catch it.
749
750					If an C<"">-handler is registered for an event, then the text for this
751					event is not included in C<skipped_text>. Skipped text both before
752					and after the C<"">-event is included in the next reported
753					C<skipped_text>.
754
755					=item C<tag>
756
757					Same as C<tagname>, but prefixed with "/" if it belongs to an C<end>
758					event and "!" for a declaration. The C<tag> does not have any prefix
759					for C<start> events, and is in this case identical to C<tagname>.
760
761					=item C<tagname>
762
763					This is the element name (or I<generic identifier> in SGML jargon) for
764					start and end tags. Since HTML is case insensitive, this name is
765					forced to lower case to ease string matching.
766
767					Since XML is case sensitive, the tagname case is not changed when
768					C<xml_mode> is enabled. The same happens if the C<case_sensitive> attribute
769					is set.
770
771					The declaration type of declaration elements is also passed as a tagname,
772					even if that is a bit strange.
773					In fact, in the current implementation tagname is
774					identical to C<token0> except that the name may be forced to lower case.
775
776					=item C<token0>
777
778					Token0 causes the original text of the first token string to be
779					passed. This should always be the same as $tokens->[0].
780
781					For C<declaration> events, this is the declaration type.
782
783					For C<start> and C<end> events, this is the tag name.
784
785					For C<process> and non-strict C<comment> events, this is everything
786					inside the tag.
787
788					This passes undef if there are no tokens in the event.
789
790					=item C<tokenpos>
791
792					Tokenpos causes a reference to an array of token positions to be
793					passed. For each string that appears in C<tokens>, this array
794					contains two numbers. The first number is the offset of the start of
795					the token in the original C<text> and the second number is the length
796					of the token.
797
798					Boolean attributes in a C<start> event will have (0,0) for the
799					attribute value offset and length.
800
801					This passes undef if there are no tokens in the event (e.g., C<text>)
802					and for artificial C<end> events triggered by empty element tags.
803
804					If you are using these offsets and lengths to modify C<text>, you
805					should either work from right to left, or be very careful to calculate
806					the changes to the offsets.
807
808					=item C<tokens>
809
810					Tokens causes a reference to an array of token strings to be passed.
811					The strings are exactly as they were found in the original text,
812					no decoding or case changes are applied.
813
814					For C<declaration> events, the array contains each word, comment, and
815					delimited string starting with the declaration type.
816
817					For C<comment> events, this contains each sub-comment. If
818					$p->strict_comments is disabled, there will be only one sub-comment.
819
820					For C<start> events, this contains the original tag name followed by
821					the attribute name/value pairs. The values of boolean attributes will
822					be either the value set by $p->boolean_attribute_value, or the
823					attribute name if no value has been set by
824					$p->boolean_attribute_value.
825
826					For C<end> events, this contains the original tag name (always one token).
827
828					For C<process> events, this contains the process instructions (always one
829					token).
830
831					This passes C<undef> for C<text> events.
832
833					=item C<text>
834
835					Text causes the source text (including markup element delimiters) to be
836					passed.
837
838					=item C<undef>
839
840					Pass an undefined value. Useful as padding where the same handler
841					routine is registered for multiple events.
842
843					=item C<'...'>
844
845					A literal string of 0 to 255 characters enclosed
846					in single (') or double (") quotes is passed as entered.
847
848					=back
849
850					The whole argspec string can be wrapped up in C<'@{...}'> to signal
851					that the resulting event array should be flattened. This only makes a
852					difference if an array reference is used as the handler target.
853					Consider this example:
854
855					$p->handler(text => [], 'text');
856					$p->handler(text => [], '@{text}']);
857
858					With two text events; C<"foo">, C<"bar">; then the first example will end
859					up with [["foo"], ["bar"]] and the second with ["foo", "bar"] in
860					the handler target array.
861
862
863					=head2 Events
864
865					Handlers for the following events can be registered:
866
867					=over
868
869					=item C<comment>
870
871					This event is triggered when a markup comment is recognized.
872
873					Example:
874
875					<!-- This is a comment -- -- So is this -->
876
877					=item C<declaration>
878
879					This event is triggered when a I<markup declaration> is recognized.
880
881					For typical HTML documents, the only declaration you are
882					likely to find is <!DOCTYPE ...>.
883
884					Example:
885
886					<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
887					"http://www.w3.org/TR/html40/strict.dtd">
888
889					DTDs inside <!DOCTYPE ...> will confuse HTML::Parser.
890
891					=item C<default>
892
893					This event is triggered for events that do not have a specific
894					handler. You can set up a handler for this event to catch stuff you
895					did not want to catch explicitly.
896
897					=item C<end>
898
899					This event is triggered when an end tag is recognized.
900
901					Example:
902
903					</A>
904
905					=item C<end_document>
906
907					This event is triggered when $p->eof is called and after any remaining
908					text is flushed. There is no document text associated with this event.
909
910					=item C<process>
911
912					This event is triggered when a processing instructions markup is
913					recognized.
914
915					The format and content of processing instructions are system and
916					application dependent.
917
918					Examples:
919
920					<? HTML processing instructions >
921					<? XML processing instructions ?>
922
923					=item C<start>
924
925					This event is triggered when a start tag is recognized.
926
927					Example:
928
929					<A HREF="http://www.perl.com/">
930
931					=item C<start_document>
932
933					This event is triggered before any other events for a new document. A
934					handler for it can be used to initialize stuff. There is no document
935					text associated with this event.
936
937					=item C<text>
938
939					This event is triggered when plain text (characters) is recognized.
940					The text may contain multiple lines. A sequence of text may be broken
941					between several text events unless $p->unbroken_text is enabled.
942
943					The parser will make sure that it does not break a word or a sequence
944					of whitespace between two text events.
945
946					=back
947
948					=head2 Unicode
949
950					The C<HTML::Parser> can parse Unicode strings when running under
951					perl-5.8 or better. If Unicode is passed to $p->parse() then chunks
952					of Unicode will be reported to the handlers. The offset and length
953					argspecs will also report their position in terms of characters.
954
955					It is safe to parse raw undecoded UTF-8 if you either avoid decoding
956					entities and make sure to not use I<argspecs> that do, or enable the
957					C<utf8_mode> for the parser. Parsing of undecoded UTF-8 might be
958					useful when parsing from a file where you need the reported offsets
959					and lengths to match the byte offsets in the file.
960
961					If a filename is passed to $p->parse_file() then the file will be read
962					in binary mode. This will be fine if the file contains only ASCII or
963					Latin-1 characters. If the file contains UTF-8 encoded text then care
964					must be taken when decoding entities as described in the previous
965					paragraph, but better is to open the file with the UTF-8 layer so that
966					it is decoded properly:
967
968					open(my $fh, "<:utf8", "index.html") \|\| die "...: $!";
969					$p->parse_file($fh);
970
971					If the file contains text encoded in a charset besides ASCII, Latin-1
972					or UTF-8 then decoding will always be needed.
973
974					=head1 VERSION 2 COMPATIBILITY
975
976					When an C<HTML::Parser> object is constructed with no arguments, a set
977					of handlers is automatically provided that is compatible with the old
978					HTML::Parser version 2 callback methods.
979
980					This is equivalent to the following method calls:
981
982					$p->handler(start => "start", "self, tagname, attr, attrseq, text");
983					$p->handler(end => "end", "self, tagname, text");
984					$p->handler(text => "text", "self, text, is_cdata");
985					$p->handler(process => "process", "self, token0, text");
986					$p->handler(comment =>
987					sub {
988					my($self, $tokens) = @_;
989					for (@$tokens) {$self->comment($_);}},
990					"self, tokens");
991					$p->handler(declaration =>
992					sub {
993					my $self = shift;
994					$self->declaration(substr($_[0], 2, -1));},
995					"self, text");
996
997					Setting up these handlers can also be requested with the "api_version =>
998					2" constructor option.
999
1000					=head1 SUBCLASSING
1001
1002					The C<HTML::Parser> class is subclassable. Parser objects are plain
1003					hashes and C<HTML::Parser> reserves only hash keys that start with
1004					"_hparser". The parser state can be set up by invoking the init()
1005					method, which takes the same arguments as new().
1006
1007					=head1 EXAMPLES
1008
1009					The first simple example shows how you might strip out comments from
1010					an HTML document. We achieve this by setting up a comment handler that
1011					does nothing and a default handler that will print out anything else:
1012
1013					use HTML::Parser;
1014					HTML::Parser->new(default_h => [sub { print shift }, 'text'],
1015					comment_h => [""],
1016					)->parse_file(shift \|\| die) \|\| die $!;
1017
1018					An alternative implementation is:
1019
1020					use HTML::Parser;
1021					HTML::Parser->new(end_document_h => [sub { print shift },
1022					'skipped_text'],
1023					comment_h => [""],
1024					)->parse_file(shift \|\| die) \|\| die $!;
1025
1026					This will in most cases be much more efficient since only a single
1027					callback will be made.
1028
1029					The next example prints out the text that is inside the <title>
1030					element of an HTML document. Here we start by setting up a start
1031					handler. When it sees the title start tag it enables a text handler
1032					that prints any text found and an end handler that will terminate
1033					parsing as soon as the title end tag is seen:
1034
1035					use HTML::Parser ();
1036
1037					sub start_handler
1038					{
1039					return if shift ne "title";
1040					my $self = shift;
1041					$self->handler(text => sub { print shift }, "dtext");
1042					$self->handler(end => sub { shift->eof if shift eq "title"; },
1043					"tagname,self");
1044					}
1045
1046					my $p = HTML::Parser->new(api_version => 3);
1047					$p->handler( start => \&start_handler, "tagname,self");
1048					$p->parse_file(shift \|\| die) \|\| die $!;
1049					print "\n";
1050
1051					More examples are found in the F<eg/> directory of the C<HTML-Parser>
1052					distribution: the program C<hrefsub> shows how you can edit all links
1053					found in a document; the program C<htextsub> shows how to edit the text only; the
1054					program C<hstrip> shows how you can strip out certain tags/elements
1055					and/or attributes; and the program C<htext> show how to obtain the
1056					plain text, but not any script/style content.
1057
1058					You can browse the F<eg/> directory online from the I<[Browse]> link on
1059					the http://search.cpan.org/~gaas/HTML-Parser/ page.
1060
1061					=head1 BUGS
1062
1063					The <style> and <script> sections do not end with the first "</", but
1064					need the complete corresponding end tag. The standard behaviour is
1065					not really practical.
1066
1067					When the I<strict_comment> option is enabled, we still recognize
1068					comments where there is something other than whitespace between even
1069					and odd "--" markers.
1070
1071					Once $p->boolean_attribute_value has been set, there is no way to
1072					restore the default behaviour.
1073
1074					There is currently no way to get both quote characters
1075					into the same literal argspec.
1076
1077					Empty tags, e.g. "<>" and "</>", are not recognized. SGML allows them
1078					to repeat the previous start tag or close the previous start tag
1079					respectively.
1080
1081					NET tags, e.g. "code/.../" are not recognized. This is SGML
1082					shorthand for "<code>...</code>".
1083
1084					Unclosed start or end tags, e.g. "<tt<b>...</b</tt>" are not
1085					recognized.
1086
1087					=head1 DIAGNOSTICS
1088
1089					The following messages may be produced by HTML::Parser. The notation
1090					in this listing is the same as used in L<perldiag>:
1091
1092					=over
1093
1094					=item Not a reference to a hash
1095
1096					(F) The object blessed into or subclassed from HTML::Parser is not a
1097					hash as required by the HTML::Parser methods.
1098
1099					=item Bad signature in parser state object at %p
1100
1101					(F) The _hparser_xs_state element does not refer to a valid state structure.
1102					Something must have changed the internal value
1103					stored in this hash element, or the memory has been overwritten.
1104
1105					=item _hparser_xs_state element is not a reference
1106
1107					(F) The _hparser_xs_state element has been destroyed.
1108
1109					=item Can't find '_hparser_xs_state' element in HTML::Parser hash
1110
1111					(F) The _hparser_xs_state element is missing from the parser hash.
1112					It was either deleted, or not created when the object was created.
1113
1114					=item API version %s not supported by HTML::Parser %s
1115
1116					(F) The constructor option 'api_version' with an argument greater than
1117					or equal to 4 is reserved for future extensions.
1118
1119					=item Bad constructor option '%s'
1120
1121					(F) An unknown constructor option key was passed to the new() or
1122					init() methods.
1123
1124					=item Parse loop not allowed
1125
1126					(F) A handler invoked the parse() or parse_file() method.
1127					This is not permitted.
1128
1129					=item marked sections not supported
1130
1131					(F) The $p->marked_sections() method was invoked in a HTML::Parser
1132					module that was compiled without support for marked sections.
1133
1134					=item Unknown boolean attribute (%d)
1135
1136					(F) Something is wrong with the internal logic that set up aliases for
1137					boolean attributes.
1138
1139					=item Only code or array references allowed as handler
1140
1141					(F) The second argument for $p->handler must be either a subroutine
1142					reference, then name of a subroutine or method, or a reference to an
1143					array.
1144
1145					=item No handler for %s events
1146
1147					(F) The first argument to $p->handler must be a valid event name; i.e. one
1148					of "start", "end", "text", "process", "declaration" or "comment".
1149
1150					=item Unrecognized identifier %s in argspec
1151
1152					(F) The identifier is not a known argspec name.
1153					Use one of the names mentioned in the argspec section above.
1154
1155					=item Literal string is longer than 255 chars in argspec
1156
1157					(F) The current implementation limits the length of literals in
1158					an argspec to 255 characters. Make the literal shorter.
1159
1160					=item Backslash reserved for literal string in argspec
1161
1162					(F) The backslash character "\" is not allowed in argspec literals.
1163					It is reserved to permit quoting inside a literal in a later version.
1164
1165					=item Unterminated literal string in argspec
1166
1167					(F) The terminating quote character for a literal was not found.
1168
1169					=item Bad argspec (%s)
1170
1171					(F) Only identifier names, literals, spaces and commas
1172					are allowed in argspecs.
1173
1174					=item Missing comma separator in argspec
1175
1176					(F) Identifiers in an argspec must be separated with ",".
1177
1178					=item Parsing of undecoded UTF-8 will give garbage when decoding entities
1179
1180					(W) The first chunk parsed appears to contain undecoded UTF-8 and one
1181					or more argspecs that decode entities are used for the callback
1182					handlers.
1183
1184					The result of decoding will be a mix of encoded and decoded characters
1185					for any entities that expand to characters with code above 127. This
1186					is not a good thing.
1187
1188					The solution is to use the Encode::encode_utf8() on the data before
1189					feeding it to the $p->parse(). For $p->parse_file() pass a file that
1190					has been opened in ":utf8" mode.
1191
1192					The parser can process raw undecoded UTF-8 sanely if the C<utf8_mode>
1193					is enabled or if the "attr", "@attr" or "dtext" argspecs is avoided.
1194
1195					=item Parsing string decoded with wrong endianess
1196
1197					(W) The first character in the document is U+FFFE. This is not a
1198					legal Unicode character but a byte swapped BOM. The result of parsing
1199					will likely be garbage.
1200
1201					=item Parsing of undecoded UTF-32
1202
1203					(W) The parser found the Unicode UTF-32 BOM signature at the start
1204					of the document. The result of parsing will likely be garbage.
1205
1206					=item Parsing of undecoded UTF-16
1207
1208					(W) The parser found the Unicode UTF-16 BOM signature at the start of
1209					the document. The result of parsing will likely be garbage.
1210
1211					=back
1212
1213					=head1 SEE ALSO
1214
1215					L<HTML::Entities>, L<HTML::PullParser>, L<HTML::TokeParser>, L<HTML::HeadParser>,
1216					L<HTML::LinkExtor>, L<HTML::Form>
1217
1218					L<HTML::TreeBuilder> (part of the I<HTML-Tree> distribution)
1219
1220					http://www.w3.org/TR/html4
1221
1222					More information about marked sections and processing instructions may
1223					be found at C<http://www.sgml.u-net.com/book/sgml-8.htm>.
1224
1225					=head1 COPYRIGHT
1226
1227					Copyright 1996-2007 Gisle Aas. All rights reserved.
1228					Copyright 1999-2000 Michael A. Chase. All rights reserved.
1229
1230					This library is free software; you can redistribute it and/or
1231					modify it under the same terms as Perl itself.
1232
1233					=cut
					# spent 6.65ms within HTML::Parser::CORE:match which was called 922 times, avg 7µs/call: # 922 times (6.65ms+0s) by HTML::Parser::init at line 72 of HTML/Parser.pm, avg 7µs/call sub HTML::Parser::CORE:match; # xsub
					# spent 7.42ms within HTML::Parser::_alloc_pstate which was called 461 times, avg 16µs/call: # 461 times (7.42ms+0s) by HTML::Parser::init at line 30 of HTML/Parser.pm, avg 16µs/call sub HTML::Parser::_alloc_pstate; # xsub
					# spent 48µs within HTML::Parser::eof which was called 7 times, avg 7µs/call: # 7 times (48µs+0s) by HTML::HeadParser::text at line 216 of HTML/HeadParser.pm, avg 7µs/call sub HTML::Parser::eof; # xsub
					# spent 25.5ms within HTML::Parser::handler which was called 2766 times, avg 9µs/call: # 461 times (5.89ms+0s) by HTML::Parser::init at line 42 of HTML/Parser.pm, avg 13µs/call # 461 times (4.47ms+0s) by HTML::Parser::init at line 45 of HTML/Parser.pm, avg 10µs/call # 461 times (4.13ms+0s) by HTML::Parser::init at line 43 of HTML/Parser.pm, avg 9µs/call # 461 times (3.98ms+0s) by HTML::Parser::init at line 44 of HTML/Parser.pm, avg 9µs/call # 461 times (3.52ms+0s) by HTML::Parser::init at line 54 of HTML/Parser.pm, avg 8µs/call # 461 times (3.48ms+0s) by HTML::Parser::init at line 60 of HTML/Parser.pm, avg 8µs/call sub HTML::Parser::handler; # xsub
					# spent 5.15ms within HTML::Parser::ignore_elements which was called 461 times, avg 11µs/call: # 461 times (5.15ms+0s) by HTML::Parser::init at line 80 of HTML/Parser.pm, avg 11µs/call sub HTML::Parser::ignore_elements; # xsub
					# spent 986µs (283+703) within HTML::Parser::parse which was called 7 times, avg 141µs/call: # 7 times (283µs+703µs) by LWP::Protocol::collect at line 114 of LWP/Protocol.pm, avg 141µs/call sub HTML::Parser::parse; # xsub