yatra / vendor / masterminds / html5 / src / HTML5 / Parser / Scanner.php

Scanner.php in Yatra – Travel Booking & Tour Operator Software trunk, at vendor/masterminds/html5/src/HTML5/Parser/Scanner.php

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1	<?php
2
3	namespace Masterminds\HTML5\Parser;
4
5	use Masterminds\HTML5\Exception;
6
7	/**
8	* The scanner scans over a given data input to react appropriately to characters.
9	*/
10	class Scanner
11	{
12	const CHARS_HEX = 'abcdefABCDEF01234567890';
13	const CHARS_ALNUM = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890';
14	const CHARS_ALPHA = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
15
16	/**
17	* The string data we're parsing.
18	*/
19	private $data;
20
21	/**
22	* The current integer byte position we are in $data.
23	*/
24	private $char;
25
26	/**
27	* Length of $data; when $char === $data, we are at the end-of-file.
28	*/
29	private $EOF;
30
31	/**
32	* Parse errors.
33	*/
34	public $errors = array();
35
36	/**
37	* Create a new Scanner.
38	*
39	* @param string $data Data to parse.
40	* @param string $encoding The encoding to use for the data.
41	*
42	* @throws Exception If the given data cannot be encoded to UTF-8.
43	*/
44	public function __construct($data, $encoding = 'UTF-8')
45	{
46	if ($data instanceof InputStream) {
47	@trigger_error('InputStream objects are deprecated since version 2.4 and will be removed in 3.0. Use strings instead.', E_USER_DEPRECATED);
48	$data = (string) $data;
49	}
50
51	$data = UTF8Utils::convertToUTF8($data, $encoding);
52
53	// There is good reason to question whether it makes sense to
54	// do this here, since most of these checks are done during
55	// parsing, and since this check doesn't actually do anything.
56	$this->errors = UTF8Utils::checkForIllegalCodepoints($data);
57
58	$data = $this->replaceLinefeeds($data);
59
60	$this->data = $data;
61	$this->char = 0;
62	$this->EOF = strlen($data);
63	}
64
65	/**
66	* Check if upcomming chars match the given sequence.
67	*
68	* This will read the stream for the $sequence. If it's
69	* found, this will return true. If not, return false.
70	* Since this unconsumes any chars it reads, the caller
71	* will still need to read the next sequence, even if
72	* this returns true.
73	*
74	* Example: $this->scanner->sequenceMatches('</script>') will
75	* see if the input stream is at the start of a
76	* '</script>' string.
77	*
78	* @param string $sequence
79	* @param bool $caseSensitive
80	*
81	* @return bool
82	*/
83	public function sequenceMatches($sequence, $caseSensitive = true)
84	{
85	$portion = substr($this->data, $this->char, strlen($sequence));
86
87	return $caseSensitive ? $portion === $sequence : 0 === strcasecmp($portion, $sequence);
88	}
89
90	/**
91	* Get the current position.
92	*
93	* @return int The current intiger byte position.
94	*/
95	public function position()
96	{
97	return $this->char;
98	}
99
100	/**
101	* Take a peek at the next character in the data.
102	*
103	* @return string The next character.
104	*/
105	public function peek()
106	{
107	if (($this->char + 1) < $this->EOF) {
108	return $this->data[$this->char + 1];
109	}
110
111	return false;
112	}
113
114	/**
115	* Get the next character.
116	* Note: This advances the pointer.
117	*
118	* @return string The next character.
119	*/
120	public function next()
121	{
122	++$this->char;
123
124	if ($this->char < $this->EOF) {
125	return $this->data[$this->char];
126	}
127
128	return false;
129	}
130
131	/**
132	* Get the current character.
133	* Note, this does not advance the pointer.
134	*
135	* @return string The current character.
136	*/
137	public function current()
138	{
139	if ($this->char < $this->EOF) {
140	return $this->data[$this->char];
141	}
142
143	return false;
144	}
145
146	/**
147	* Silently consume N chars.
148	*
149	* @param int $count
150	*/
151	public function consume($count = 1)
152	{
153	$this->char += $count;
154	}
155
156	/**
157	* Unconsume some of the data.
158	* This moves the data pointer backwards.
159	*
160	* @param int $howMany The number of characters to move the pointer back.
161	*/
162	public function unconsume($howMany = 1)
163	{
164	if (($this->char - $howMany) >= 0) {
165	$this->char -= $howMany;
166	}
167	}
168
169	/**
170	* Get the next group of that contains hex characters.
171	* Note, along with getting the characters the pointer in the data will be
172	* moved as well.
173	*
174	* @return string The next group that is hex characters.
175	*/
176	public function getHex()
177	{
178	return $this->doCharsWhile(static::CHARS_HEX);
179	}
180
181	/**
182	* Get the next group of characters that are ASCII Alpha characters.
183	* Note, along with getting the characters the pointer in the data will be
184	* moved as well.
185	*
186	* @return string The next group of ASCII alpha characters.
187	*/
188	public function getAsciiAlpha()
189	{
190	return $this->doCharsWhile(static::CHARS_ALPHA);
191	}
192
193	/**
194	* Get the next group of characters that are ASCII Alpha characters and numbers.
195	* Note, along with getting the characters the pointer in the data will be
196	* moved as well.
197	*
198	* @return string The next group of ASCII alpha characters and numbers.
199	*/
200	public function getAsciiAlphaNum()
201	{
202	return $this->doCharsWhile(static::CHARS_ALNUM);
203	}
204
205	/**
206	* Get the next group of numbers.
207	* Note, along with getting the characters the pointer in the data will be
208	* moved as well.
209	*
210	* @return string The next group of numbers.
211	*/
212	public function getNumeric()
213	{
214	return $this->doCharsWhile('0123456789');
215	}
216
217	/**
218	* Consume whitespace.
219	* Whitespace in HTML5 is: formfeed, tab, newline, space.
220	*
221	* @return int The length of the matched whitespaces.
222	*/
223	public function whitespace()
224	{
225	if ($this->char >= $this->EOF) {
226	return false;
227	}
228
229	$len = strspn($this->data, "\n\t\f ", $this->char);
230
231	$this->char += $len;
232
233	return $len;
234	}
235
236	/**
237	* Returns the current line that is being consumed.
238	*
239	* @return int The current line number.
240	*/
241	public function currentLine()
242	{
243	if (empty($this->EOF) \|\| 0 === $this->char) {
244	return 1;
245	}
246
247	// Add one to $this->char because we want the number for the next
248	// byte to be processed.
249	return substr_count($this->data, "\n", 0, min($this->char, $this->EOF)) + 1;
250	}
251
252	/**
253	* Read chars until something in the mask is encountered.
254	*
255	* @param string $mask
256	*
257	* @return mixed
258	*/
259	public function charsUntil($mask)
260	{
261	return $this->doCharsUntil($mask);
262	}
263
264	/**
265	* Read chars as long as the mask matches.
266	*
267	* @param string $mask
268	*
269	* @return int
270	*/
271	public function charsWhile($mask)
272	{
273	return $this->doCharsWhile($mask);
274	}
275
276	/**
277	* Returns the current column of the current line that the tokenizer is at.
278	*
279	* Newlines are column 0. The first char after a newline is column 1.
280	*
281	* @return int The column number.
282	*/
283	public function columnOffset()
284	{
285	// Short circuit for the first char.
286	if (0 === $this->char) {
287	return 0;
288	}
289
290	// strrpos is weird, and the offset needs to be negative for what we
291	// want (i.e., the last \n before $this->char). This needs to not have
292	// one (to make it point to the next character, the one we want the
293	// position of) added to it because strrpos's behaviour includes the
294	// final offset byte.
295	$backwardFrom = $this->char - 1 - strlen($this->data);
296	$lastLine = strrpos($this->data, "\n", $backwardFrom);
297
298	// However, for here we want the length up until the next byte to be
299	// processed, so add one to the current byte ($this->char).
300	if (false !== $lastLine) {
301	$findLengthOf = substr($this->data, $lastLine + 1, $this->char - 1 - $lastLine);
302	} else {
303	// After a newline.
304	$findLengthOf = substr($this->data, 0, $this->char);
305	}
306
307	return UTF8Utils::countChars($findLengthOf);
308	}
309
310	/**
311	* Get all characters until EOF.
312	*
313	* This consumes characters until the EOF.
314	*
315	* @return int The number of characters remaining.
316	*/
317	public function remainingChars()
318	{
319	if ($this->char < $this->EOF) {
320	$data = substr($this->data, $this->char);
321	$this->char = $this->EOF;
322
323	return $data;
324	}
325
326	return ''; // false;
327	}
328
329	/**
330	* Replace linefeed characters according to the spec.
331	*
332	* @param $data
333	*
334	* @return string
335	*/
336	private function replaceLinefeeds($data)
337	{
338	/*
339	* U+000D CARRIAGE RETURN (CR) characters and U+000A LINE FEED (LF) characters are treated specially.
340	* Any CR characters that are followed by LF characters must be removed, and any CR characters not
341	* followed by LF characters must be converted to LF characters. Thus, newlines in HTML DOMs are
342	* represented by LF characters, and there are never any CR characters in the input to the tokenization
343	* stage.
344	*/
345	$crlfTable = array(
346	"\0" => "\xEF\xBF\xBD",
347	"\r\n" => "\n",
348	"\r" => "\n",
349	);
350
351	return strtr($data, $crlfTable);
352	}
353
354	/**
355	* Read to a particular match (or until $max bytes are consumed).
356	*
357	* This operates on byte sequences, not characters.
358	*
359	* Matches as far as possible until we reach a certain set of bytes
360	* and returns the matched substring.
361	*
362	* @param string $bytes Bytes to match.
363	* @param int $max Maximum number of bytes to scan.
364	*
365	* @return mixed Index or false if no match is found. You should use strong
366	* equality when checking the result, since index could be 0.
367	*/
368	private function doCharsUntil($bytes, $max = null)
369	{
370	if ($this->char >= $this->EOF) {
371	return false;
372	}
373
374	if (0 === $max \|\| $max) {
375	$len = strcspn($this->data, $bytes, $this->char, $max);
376	} else {
377	$len = strcspn($this->data, $bytes, $this->char);
378	}
379
380	$string = (string) substr($this->data, $this->char, $len);
381	$this->char += $len;
382
383	return $string;
384	}
385
386	/**
387	* Returns the string so long as $bytes matches.
388	*
389	* Matches as far as possible with a certain set of bytes
390	* and returns the matched substring.
391	*
392	* @param string $bytes A mask of bytes to match. If ANY byte in this mask matches the
393	* current char, the pointer advances and the char is part of the
394	* substring.
395	* @param int $max The max number of chars to read.
396	*
397	* @return string
398	*/
399	private function doCharsWhile($bytes, $max = null)
400	{
401	if ($this->char >= $this->EOF) {
402	return false;
403	}
404
405	if (0 === $max \|\| $max) {
406	$len = strspn($this->data, $bytes, $this->char, $max);
407	} else {
408	$len = strspn($this->data, $bytes, $this->char);
409	}
410
411	$string = (string) substr($this->data, $this->char, $len);
412	$this->char += $len;
413
414	return $string;
415	}
416	}
417