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1"""CSS selector parser."""
2from __future__ import annotations
3import re
4from functools import lru_cache
5from . import util
6from . import css_match as cm
7from . import css_types as ct
8from .util import SelectorSyntaxError
9import warnings
10from typing import Match, Any, Iterator, Iterable, cast
11from dataclasses import dataclass
12from collections import UserDict
13import threading
15RE_LOCK = threading.Lock()
16SEL_LOCK = threading.RLock()
18UNICODE_REPLACEMENT_CHAR = 0xFFFD
20SELECTOR_LIMIT = 8192
22# Simple pseudo classes that take no parameters
23PSEUDO_SIMPLE = {
24 ":any-link",
25 ":empty",
26 ":first-child",
27 ":first-of-type",
28 ":in-range",
29 ":open",
30 ":out-of-range",
31 ":last-child",
32 ":last-of-type",
33 ":link",
34 ":only-child",
35 ":only-of-type",
36 ":root",
37 ':checked',
38 ':default',
39 ':disabled',
40 ':enabled',
41 ':indeterminate',
42 ':optional',
43 ':placeholder-shown',
44 ':read-only',
45 ':read-write',
46 ':required',
47 ':scope',
48 ':defined',
49 ':muted'
50}
52# Supported, simple pseudo classes that match nothing in the Soup Sieve environment
53PSEUDO_SIMPLE_NO_MATCH = {
54 ':active',
55 ':autofill',
56 ':buffering',
57 ':current',
58 ':focus',
59 ':focus-visible',
60 ':focus-within',
61 ':fullscreen',
62 ':future',
63 ':host',
64 ':hover',
65 ':local-link',
66 ':past',
67 ':paused',
68 ':picture-in-picture',
69 ':playing',
70 ':popover-open',
71 ':seeking',
72 ':stalled',
73 ':target',
74 ':target-within',
75 ':user-invalid',
76 ':volume-locked',
77 ':visited'
78}
80# Complex pseudo classes that take selector lists
81PSEUDO_COMPLEX = {
82 ':contains',
83 ':-soup-contains',
84 ':-soup-contains-own',
85 ':has',
86 ':is',
87 ':matches',
88 ':not',
89 ':where'
90}
92PSEUDO_COMPLEX_NO_MATCH = {
93 ':current',
94 ':host',
95 ':host-context'
96}
98# Complex pseudo classes that take very specific parameters and are handled special
99PSEUDO_SPECIAL = {
100 ':dir',
101 ':lang',
102 ':nth-child',
103 ':nth-last-child',
104 ':nth-last-of-type',
105 ':nth-of-type'
106}
108PSEUDO_SUPPORTED = PSEUDO_SIMPLE | PSEUDO_SIMPLE_NO_MATCH | PSEUDO_COMPLEX | PSEUDO_COMPLEX_NO_MATCH | PSEUDO_SPECIAL
110# Sub-patterns parts
111# Whitespace
112NEWLINE = r'(?:\r\n|(?!\r\n)[\n\f\r])'
113WS = fr'(?:[ \t]|{NEWLINE})'
114# Comments
115COMMENTS = r'(?:/\*(?:[^*]|\*(?!/))*\*/)'
116# Whitespace with comments included
117WSC = fr'(?:{WS}|{COMMENTS})'
118# CSS escapes
119CSS_ESCAPES = fr'(?:\\(?:[a-f0-9]{{1,6}}{WS}?|[^\r\n\f]|$))'
120CSS_STRING_ESCAPES = fr'(?:\\(?:[a-f0-9]{{1,6}}{WS}?|[^\r\n\f]|$|{NEWLINE}))'
121# CSS Identifier
122IDENTIFIER = fr'''
123(?:(?:--|-?(?:[^\x00-\x2f\x30-\x40\x5B-\x5E\x60\x7B-\x9f]|{CSS_ESCAPES}))
124(?:[^\x00-\x2c\x2e\x2f\x3A-\x40\x5B-\x5E\x60\x7B-\x9f]|{CSS_ESCAPES})*)
125'''
126# `nth` content
127NTH = fr'(?:[-+])?(?:[0-9]+n?|n)(?:(?<=n){WSC}*(?:[-+]){WSC}*(?:[0-9]+))?'
128# Value: quoted string or identifier
129VALUE = fr'''(?:"(?:\\(?:.|{NEWLINE})|[^\\"\r\n\f])*?"|'(?:\\(?:.|{NEWLINE})|[^\\'\r\n\f])*?'|{IDENTIFIER})'''
130# Attribute value comparison. `!=` is handled special as it is non-standard.
131ATTR = fr'(?:{WSC}*(?P<cmp>[!~^|*$]?=){WSC}*(?P<value>{VALUE})(?:{WSC}*(?P<case>[is]))?)?{WSC}*'
133# Selector patterns
134# IDs (`#id`)
135PAT_ID = fr'\#{IDENTIFIER}'
136# Classes (`.class`)
137PAT_CLASS = fr'\.{IDENTIFIER}'
138# Prefix:Tag (`prefix|tag`)
139PAT_TAG = fr'(?P<tag_ns>(?:{IDENTIFIER}|\*)?\|)?(?P<tag_name>{IDENTIFIER}|\*)'
140# Attributes (`[attr]`, `[attr=value]`, etc.)
141PAT_ATTR = fr'\[{WSC}*(?P<attr_ns>(?:{IDENTIFIER}|\*)?\|)?(?P<attr_name>{IDENTIFIER}){ATTR}\]'
142# Pseudo class (`:pseudo-class`, `:pseudo-class(`)
143PAT_PSEUDO_CLASS = fr'(?P<name>:{IDENTIFIER})(?P<open>\({WSC}*)?'
144# Pseudo class special patterns. Matches `:pseudo-class(` for special case pseudo classes.
145PAT_PSEUDO_CLASS_SPECIAL = fr'(?P<name>:{IDENTIFIER})(?P<open>\({WSC}*)'
146# Custom pseudo class (`:--custom-pseudo`)
147PAT_PSEUDO_CLASS_CUSTOM = fr'(?P<name>:(?=--){IDENTIFIER})'
148# Nesting ampersand selector. Matches `&`
149PAT_AMP = r'&'
150# Closing pseudo group (`)`)
151PAT_PSEUDO_CLOSE = fr'{WSC}*\)'
152# Pseudo element (`::pseudo-element`)
153PAT_PSEUDO_ELEMENT = fr':{PAT_PSEUDO_CLASS}'
154# At rule (`@page`, etc.) (not supported)
155PAT_AT_RULE = fr'@P{IDENTIFIER}'
156# Pseudo class `nth-child` (`:nth-child(an+b [of S]?)`, `:first-child`, etc.)
157PAT_PSEUDO_NTH_CHILD = fr'''
158(?P<pseudo_nth_child>{PAT_PSEUDO_CLASS_SPECIAL}
159(?P<nth_child>{NTH}|even|odd))(?:{WSC}*\)|(?P<of>{COMMENTS}*{WS}{WSC}*of{COMMENTS}*{WS}{WSC}*))
160'''
161# Pseudo class `nth-of-type` (`:nth-of-type(an+b)`, `:first-of-type`, etc.)
162PAT_PSEUDO_NTH_TYPE = fr'''
163(?P<pseudo_nth_type>{PAT_PSEUDO_CLASS_SPECIAL}
164(?P<nth_type>{NTH}|even|odd)){WSC}*\)
165'''
166# Pseudo class language (`:lang("*-de", en)`)
167PAT_PSEUDO_LANG = fr'{PAT_PSEUDO_CLASS_SPECIAL}(?P<values>{VALUE}(?:{WSC}*,{WSC}*{VALUE})*){WSC}*\)'
168# Pseudo class direction (`:dir(ltr)`)
169PAT_PSEUDO_DIR = fr'{PAT_PSEUDO_CLASS_SPECIAL}(?P<dir>ltr|rtl){WSC}*\)'
170# Combining characters (`>`, `~`, ` `, `+`, `,`)
171PAT_COMBINE = fr'{WSC}*?(?P<relation>[,+>~]|{WS}(?![,+>~])){WSC}*'
172# Extra: Contains (`:contains(text)`)
173PAT_PSEUDO_CONTAINS = fr'{PAT_PSEUDO_CLASS_SPECIAL}(?P<values>{VALUE}(?:{WSC}*,{WSC}*{VALUE})*){WSC}*\)'
175# Regular expressions
176# CSS escape pattern
177RE_CSS_ESC = re.compile(fr'(?:(\\[a-f0-9]{{1,6}}{WSC}?)|(\\[^\r\n\f])|(\\$))', re.I)
178RE_CSS_STR_ESC = re.compile(fr'(?:(\\[a-f0-9]{{1,6}}{WS}?)|(\\[^\r\n\f])|(\\$)|(\\{NEWLINE}))', re.I)
179# Pattern to break up `nth` specifiers
180RE_NTH = re.compile(fr'(?P<s1>[-+])?(?P<a>[0-9]+n?|n)(?:(?<=n){WSC}*(?P<s2>[-+]){WSC}*(?P<b>[0-9]+))?', re.I)
181# Pattern to iterate multiple values.
182RE_VALUES = re.compile(fr'(?:(?P<value>{VALUE})|(?P<split>{WSC}*,{WSC}*))', re.X)
183# Whitespace checks
184RE_WS = re.compile(WS)
185RE_WS_BEGIN = re.compile(fr'^{WSC}*')
186RE_WS_END = re.compile(fr'^(?:[ \t]|(?:\n\r|(?!\n\r)[\n\f\r])|{COMMENTS})*')
187RE_CUSTOM = re.compile(fr'^{PAT_PSEUDO_CLASS_CUSTOM}$', re.X)
188RE_PSEUDO_CLASS_SPECIAL = re.compile(PAT_PSEUDO_CLASS_SPECIAL, re.I | re.X | re.U)
189RE_PSEUDO_IGNORE = re.compile(PAT_PSEUDO_CLASS, re.X | re.I | re.U)
191QUOTED = ("'", '"')
193# Constants
194# List split token
195COMMA_COMBINATOR = ','
196# Relation token for descendant
197WS_COMBINATOR = " "
199# Parse flags
200FLG_PSEUDO = 0x01
201FLG_NOT = 0x02
202FLG_RELATIVE = 0x04
203FLG_DEFAULT = 0x08
204FLG_HTML = 0x10
205FLG_INDETERMINATE = 0x20
206FLG_OPEN = 0x40
207FLG_IN_RANGE = 0x80
208FLG_OUT_OF_RANGE = 0x100
209FLG_PLACEHOLDER_SHOWN = 0x200
210FLG_FORGIVE = 0x400
212# Maximum cached patterns to store
213_MAXCACHE = 500
216@lru_cache(maxsize=_MAXCACHE)
217def _cached_css_compile(
218 pattern: str,
219 namespaces: ct.Namespaces | None,
220 custom: ct.CustomSelectors | None,
221 ignore: tuple[str] | None = None,
222 flags: int = 0
223) -> cm.SoupSieve:
224 """Cached CSS compile."""
226 custom_selectors = process_custom(custom)
227 return cm.SoupSieve(
228 pattern,
229 CSSParser(
230 pattern,
231 custom=custom_selectors,
232 ignore=ignore,
233 flags=flags
234 ).process_selectors(),
235 namespaces,
236 custom,
237 flags
238 )
241def _purge_cache() -> None:
242 """Purge the cache."""
244 _cached_css_compile.cache_clear()
247def process_custom(custom: ct.CustomSelectors | None) -> dict[str, str | ct.SelectorList]:
248 """Process custom."""
250 custom_selectors = {}
251 if custom is not None:
252 for key, value in custom.items():
253 name = util.lower(key)
254 if RE_CUSTOM.match(name) is None:
255 raise SelectorSyntaxError(f"The name '{name}' is not a valid custom pseudo-class name")
256 if name in custom_selectors:
257 raise KeyError(f"The custom selector '{name}' has already been registered")
258 custom_selectors[css_unescape(name)] = value
259 return custom_selectors
262def css_unescape(content: str) -> str:
263 """
264 Unescape CSS value.
266 Strings allow for spanning the value on multiple strings by escaping a new line.
267 """
269 def replace(m: Match[str]) -> str:
270 """Replace with the appropriate substitute."""
272 if m.group(1):
273 codepoint = int(m.group(1)[1:], 16)
274 if codepoint == 0:
275 codepoint = UNICODE_REPLACEMENT_CHAR
276 value = chr(codepoint)
277 elif m.group(2):
278 value = m.group(2)[1:]
279 elif m.group(3):
280 value = '\ufffd'
281 else:
282 value = ''
284 return value
286 quoted = content.startswith(QUOTED)
287 return (RE_CSS_STR_ESC if quoted else RE_CSS_ESC).sub(
288 replace,
289 content[1:-1] if quoted else content
290 )
293def escape(ident: str) -> str:
294 """Escape identifier."""
296 string = []
297 length = len(ident)
298 start_dash = length > 0 and ident[0] == '-'
299 if length == 1 and start_dash:
300 # Need to escape identifier that is a single `-` with no other characters
301 string.append(f'\\{ident}')
302 else:
303 for index, c in enumerate(ident):
304 codepoint = ord(c)
305 if codepoint == 0x00:
306 string.append('\ufffd')
307 elif (0x01 <= codepoint <= 0x1F) or codepoint == 0x7F:
308 string.append(f'\\{codepoint:x} ')
309 elif (index == 0 or (start_dash and index == 1)) and (0x30 <= codepoint <= 0x39):
310 string.append(f'\\{codepoint:x} ')
311 elif (
312 codepoint in (0x2D, 0x5F) or codepoint >= 0x80 or (0x30 <= codepoint <= 0x39) or
313 (0x30 <= codepoint <= 0x39) or (0x41 <= codepoint <= 0x5A) or (0x61 <= codepoint <= 0x7A)
314 ):
315 string.append(c)
316 else:
317 string.append(f'\\{c}')
318 return ''.join(string)
321class SelectorPattern:
322 """Selector pattern."""
324 def __init__(self, name: str, pattern: str) -> None:
325 """Initialize."""
327 self.name = name
328 self.pattern = pattern
329 self._re_pattern: re.Pattern[str] | None = None
331 @property
332 def re_pattern(self) -> re.Pattern[str]:
333 """Retrieve the compiled regular expression pattern."""
335 with RE_LOCK:
336 if self._re_pattern is None:
337 self._re_pattern = re.compile(self.pattern, re.I | re.X | re.U)
338 return self._re_pattern
340 def get_name(self) -> str:
341 """Get name."""
343 return self.name
345 def match(self, selector: str, index: int, flags: int) -> Match[str] | None:
346 """Match the selector."""
348 return self.re_pattern.match(selector, index)
351class SpecialPseudoPattern(SelectorPattern):
352 """Selector pattern."""
354 def __init__(self, patterns: tuple[tuple[str, tuple[str, ...], str, type[SelectorPattern]], ...]) -> None:
355 """Initialize."""
357 self.patterns = {}
358 for p in patterns:
359 name = p[0]
360 pattern = p[3](name, p[2])
361 for pseudo in p[1]:
362 self.patterns[pseudo] = pattern
364 self.matched_name = None # type: SelectorPattern | None
366 def get_name(self) -> str:
367 """Get name."""
369 return '' if self.matched_name is None else self.matched_name.get_name()
371 def match(self, selector: str, index: int, flags: int) -> Match[str] | None:
372 """Match the selector."""
374 pseudo = None
375 m = RE_PSEUDO_CLASS_SPECIAL.match(selector, index)
376 if m:
377 name = util.lower(css_unescape(m.group('name')))
378 pattern = self.patterns.get(name)
379 if pattern:
380 pseudo = pattern.match(selector, index, flags)
381 if pseudo:
382 self.matched_name = pattern
384 return pseudo
387class _Selector:
388 """
389 Intermediate selector class.
391 This stores selector data for a compound selector as we are acquiring them.
392 Once we are done collecting the data for a compound selector, we freeze
393 the data in an object that can be pickled and hashed.
394 """
396 def __init__(self, **kwargs: Any) -> None:
397 """Initialize."""
399 self.tag = kwargs.get('tag', None) # type: ct.SelectorTag | None
400 self.ids = kwargs.get('ids', []) # type: list[str]
401 self.classes = kwargs.get('classes', []) # type: list[str]
402 self.attributes = kwargs.get('attributes', []) # type: list[ct.SelectorAttribute]
403 self.nth = kwargs.get('nth', []) # type: list[ct.SelectorNth]
404 self.selectors = kwargs.get('selectors', []) # type: list[ct.SelectorList]
405 self.relations = kwargs.get('relations', []) # type: list[_Selector]
406 self.rel_type = kwargs.get('rel_type', None) # type: str | None
407 self.contains = kwargs.get('contains', []) # type: list[ct.SelectorContains]
408 self.lang = kwargs.get('lang', []) # type: list[ct.SelectorLang]
409 self.flags = kwargs.get('flags', 0) # type: int
410 self.no_match = kwargs.get('no_match', False) # type: bool
412 def _freeze_relations(self, relations: list[_Selector]) -> ct.SelectorList:
413 """Freeze relation."""
415 if relations:
416 sel = relations[0]
417 sel.relations.extend(relations[1:])
418 return ct.SelectorList([sel.freeze()])
419 else:
420 return ct.SelectorList()
422 def freeze(self) -> ct.Selector | ct.SelectorNull:
423 """Freeze self."""
425 if self.no_match:
426 return ct.Null
427 else:
428 return ct.Selector(
429 self.tag,
430 tuple(self.ids),
431 tuple(self.classes),
432 tuple(self.attributes),
433 tuple(self.nth),
434 tuple(self.selectors),
435 self._freeze_relations(self.relations),
436 self.rel_type,
437 tuple(self.contains),
438 tuple(self.lang),
439 self.flags
440 )
442 def __str__(self) -> str: # pragma: no cover
443 """String representation."""
445 return (
446 f'_Selector(tag={self.tag!r}, ids={self.ids!r}, classes={self.classes!r}, attributes={self.attributes!r}, '
447 f'nth={self.nth!r}, selectors={self.selectors!r}, relations={self.relations!r}, '
448 f'rel_type={self.rel_type!r}, contains={self.contains!r}, lang={self.lang!r}, flags={self.flags!r}, '
449 f'no_match={self.no_match!r})'
450 )
452 __repr__ = __str__
455@dataclass
456class CSSPattern:
457 """A CSS pattern that hasn't been processed by `CSSParser` yet."""
459 selector: str
460 flags: int
463class PseudoSelectorMap(UserDict[str, CSSPattern | ct.SelectorList]):
464 """Pseudo selector map."""
466 def __setitem__(self, key: str, value: CSSPattern | ct.SelectorList) -> None:
467 """Set item."""
469 self.data[key] = value
471 def __getitem__(self, key: str) -> ct.SelectorList:
472 """Get item."""
474 with SEL_LOCK:
475 value = self.data[key]
476 if isinstance(value, CSSPattern):
477 value = CSSParser(value.selector).process_selectors(flags=value.flags)
478 self.data[key] = value
480 return value
483# CSS pattern for `:link` and `:any-link`
484CSS_LINK = CSSPattern('html|*:is(a, area)[href]', FLG_PSEUDO | FLG_HTML)
485# CSS pattern for `:checked`
486CSS_CHECKED = CSSPattern(
487 '''
488 html|*:is(input[type=checkbox], input[type=radio])[checked], html|option[selected]
489 ''',
490 FLG_PSEUDO | FLG_HTML
491)
492# CSS pattern for `:default` (must compile CSS_CHECKED first)
493CSS_DEFAULT = CSSPattern(
494 '''
495 :checked,
497 /*
498 This pattern must be at the end.
499 Special logic is applied to the last selector.
500 */
501 html|form html|*:is(button, input)[type="submit"]
502 ''',
503 FLG_PSEUDO | FLG_HTML | FLG_DEFAULT
504)
505# CSS pattern for `:indeterminate`
506CSS_INDETERMINATE = CSSPattern(
507 '''
508 html|input[type="checkbox"][indeterminate],
509 html|input[type="radio"]:is(:not([name]), [name=""]):not([checked]),
510 html|progress:not([value]),
512 /*
513 This pattern must be at the end.
514 Special logic is applied to the last selector.
515 */
516 html|input[type="radio"][name]:not([name='']):not([checked])
517 ''',
518 FLG_PSEUDO | FLG_HTML | FLG_INDETERMINATE
519)
520# CSS pattern for `:disabled`
521CSS_DISABLED = CSSPattern(
522 '''
523 html|*:is(input:not([type=hidden]), button, select, textarea, fieldset, optgroup, option, fieldset)[disabled],
524 html|optgroup[disabled] > html|option,
525 html|fieldset[disabled] > html|*:is(input:not([type=hidden]), button, select, textarea, fieldset),
526 html|fieldset[disabled] >
527 html|*:not(legend:nth-of-type(1)) html|*:is(input:not([type=hidden]), button, select, textarea, fieldset)
528 ''',
529 FLG_PSEUDO | FLG_HTML
530)
531# CSS pattern for `:enabled`
532CSS_ENABLED = CSSPattern(
533 '''
534 html|*:is(input:not([type=hidden]), button, select, textarea, fieldset, optgroup, option, fieldset):not(:disabled)
535 ''',
536 FLG_PSEUDO | FLG_HTML
537)
538# CSS pattern for `:required`
539CSS_REQUIRED = CSSPattern('html|*:is(input, textarea, select)[required]', FLG_PSEUDO | FLG_HTML)
540# CSS pattern for `:optional`
541CSS_OPTIONAL = CSSPattern('html|*:is(input, textarea, select):not([required])', FLG_PSEUDO | FLG_HTML)
542# CSS pattern for `:placeholder-shown`
543CSS_PLACEHOLDER_SHOWN = CSSPattern(
544 '''
545 html|input:is(
546 :not([type]),
547 [type=""],
548 [type=text],
549 [type=search],
550 [type=url],
551 [type=tel],
552 [type=email],
553 [type=password],
554 [type=number]
555 )[placeholder]:not([placeholder='']):is(:not([value]), [value=""]),
556 html|textarea[placeholder]:not([placeholder=''])
557 ''',
558 FLG_PSEUDO | FLG_HTML | FLG_PLACEHOLDER_SHOWN
559)
560# CSS pattern for `:read-write` (CSS_DISABLED must be compiled first)
561CSS_READ_WRITE = CSSPattern(
562 '''
563 html|*:is(
564 textarea,
565 input:is(
566 :not([type]),
567 [type=""],
568 [type=text],
569 [type=search],
570 [type=url],
571 [type=tel],
572 [type=email],
573 [type=number],
574 [type=password],
575 [type=date],
576 [type=datetime-local],
577 [type=month],
578 [type=time],
579 [type=week]
580 )
581 ):not([readonly], :disabled),
582 html|*:is([contenteditable=""], [contenteditable="true" i])
583 ''',
584 FLG_PSEUDO | FLG_HTML
585)
586# CSS pattern for `:read-only`
587CSS_READ_ONLY = CSSPattern('html|*:not(:read-write)', FLG_PSEUDO | FLG_HTML)
588# CSS pattern for `:in-range`
589CSS_IN_RANGE = CSSPattern(
590 '''
591 html|input:is(
592 [type="date"],
593 [type="month"],
594 [type="week"],
595 [type="time"],
596 [type="datetime-local"],
597 [type="number"],
598 [type="range"]
599 ):is(
600 [min],
601 [max]
602 )
603 ''',
604 FLG_PSEUDO | FLG_HTML | FLG_IN_RANGE
605)
606# CSS pattern for `:out-of-range`
607CSS_OUT_OF_RANGE = CSSPattern(
608 '''
609 html|input:is(
610 [type="date"],
611 [type="month"],
612 [type="week"],
613 [type="time"],
614 [type="datetime-local"],
615 [type="number"],
616 [type="range"]
617 ):is(
618 [min],
619 [max]
620 )
621 ''',
622 FLG_PSEUDO | FLG_HTML | FLG_OUT_OF_RANGE
623)
624# CSS pattern for :open
625CSS_OPEN = CSSPattern('html|*:is(details, dialog)[open]', FLG_PSEUDO | FLG_HTML)
626# CSS pattern for :muted
627CSS_MUTED = CSSPattern('html|*:is(video, audio)[muted]', FLG_PSEUDO | FLG_HTML)
628# CSS pattern default for `:nth-child` "of S" feature
629CSS_NTH_OF_S_DEFAULT = CSSPattern("*|*", FLG_PSEUDO)
632class CSSParser:
633 """Parse CSS selectors."""
635 CSS_TOKENS = (
636 SelectorPattern("pseudo_close", PAT_PSEUDO_CLOSE),
637 SpecialPseudoPattern(
638 (
639 (
640 "pseudo_contains",
641 (':contains', ':-soup-contains', ':-soup-contains-own'),
642 PAT_PSEUDO_CONTAINS,
643 SelectorPattern
644 ),
645 ("pseudo_nth_child", (':nth-child', ':nth-last-child'), PAT_PSEUDO_NTH_CHILD, SelectorPattern),
646 ("pseudo_nth_type", (':nth-of-type', ':nth-last-of-type'), PAT_PSEUDO_NTH_TYPE, SelectorPattern),
647 ("pseudo_lang", (':lang',), PAT_PSEUDO_LANG, SelectorPattern),
648 ("pseudo_dir", (':dir',), PAT_PSEUDO_DIR, SelectorPattern)
649 )
650 ),
651 SelectorPattern("pseudo_class_custom", PAT_PSEUDO_CLASS_CUSTOM),
652 SelectorPattern("pseudo_class", PAT_PSEUDO_CLASS),
653 SelectorPattern("pseudo_element", PAT_PSEUDO_ELEMENT),
654 SelectorPattern("amp", PAT_AMP),
655 SelectorPattern("at_rule", PAT_AT_RULE),
656 SelectorPattern("id", PAT_ID),
657 SelectorPattern("class", PAT_CLASS),
658 SelectorPattern("tag", PAT_TAG),
659 SelectorPattern("attribute", PAT_ATTR),
660 SelectorPattern("combine", PAT_COMBINE)
661 )
663 # Pseudos that expand to selectors
664 PSEUDO_SELECTORS = PseudoSelectorMap(
665 {
666 ':link': CSS_LINK,
667 ':any-link': CSS_LINK,
668 ':checked': CSS_CHECKED,
669 ':default': CSS_DEFAULT,
670 ':indeterminate': CSS_INDETERMINATE,
671 ':disabled': CSS_DISABLED,
672 ':enabled': CSS_ENABLED,
673 ':required': CSS_REQUIRED,
674 ':muted': CSS_MUTED,
675 ':open': CSS_OPEN,
676 ':optional': CSS_OPTIONAL,
677 ':read-only': CSS_READ_ONLY,
678 ':read-write': CSS_READ_WRITE,
679 ':in-range': CSS_IN_RANGE,
680 ':out-of-range': CSS_OUT_OF_RANGE,
681 ':placeholder-shown': CSS_PLACEHOLDER_SHOWN,
682 '<nth-of-s>': CSS_NTH_OF_S_DEFAULT
683 }
684 )
686 def __init__(
687 self,
688 selector: str,
689 *,
690 custom: dict[str, str | ct.SelectorList] | None = None,
691 ignore: Iterable[str] | None = None,
692 flags: int = 0
693 ) -> None:
694 """Initialize."""
696 self.pattern = selector.replace('\x00', '\ufffd')
697 self.flags = flags
698 self.debug = self.flags & util.DEBUG
699 self.custom = {} if custom is None else custom
700 self.ignore = frozenset([] if ignore is None else ignore)
701 self.count = 0
703 def increment_count(self, increment: int = 1) -> None:
704 """Check the current selector count."""
706 self.count += increment
707 if self.count > SELECTOR_LIMIT:
708 raise ValueError(f'Selector exceeds pseudo-class nesting limit of {SELECTOR_LIMIT}')
710 def parse_attribute_selector(self, sel: _Selector, m: Match[str], has_selector: bool) -> bool:
711 """Create attribute selector from the returned regex match."""
713 inverse = False
714 op = m.group('cmp')
715 case = util.lower(m.group('case')) if m.group('case') else None
716 ns = css_unescape(m.group('attr_ns')[:-1]) if m.group('attr_ns') else ''
717 attr = css_unescape(m.group('attr_name'))
718 is_type = False
719 pattern2 = None
720 value = ''
722 if case:
723 flags = (re.I if case == 'i' else 0) | re.DOTALL
724 elif util.lower(attr) == 'type':
725 flags = re.I | re.DOTALL
726 is_type = True
727 else:
728 flags = re.DOTALL
730 if op:
731 value = css_unescape(m.group('value'))
733 if not op:
734 # Attribute name
735 pattern = None
736 elif op.startswith('^'):
737 # Value start with
738 # `^=` should match nothing if the value is empty, so use `(?!)` which cannot be matched.
739 value = r'(?!)' if not value else re.escape(value)
740 pattern = re.compile(r'^%s.*' % value, flags)
741 elif op.startswith('$'):
742 # Value ends with
743 # `$=` should match nothing if the value is empty, so use `(?!)` which cannot be matched.
744 value = r'(?!)' if not value else re.escape(value)
745 pattern = re.compile(r'.*?%s$' % value, flags)
746 elif op.startswith('*'):
747 # Value contains
748 # `*=` should match nothing if the value is empty, so use `(?!)` which cannot be matched.
749 value = r'(?!)' if not value else re.escape(value)
750 pattern = re.compile(r'.*?%s.*' % value, flags)
751 elif op.startswith('~'):
752 # Value contains word within space separated list
753 # `*~` should match nothing if the value is empty, so use `(?!)` which cannot be matched.
754 value = r'(?!)' if not value or RE_WS.search(value) else re.escape(value)
755 pattern = re.compile(r'.*?(?:(?<=^)|(?<=[ \t\r\n\f]))%s(?=(?:[ \t\r\n\f]|$)).*' % value, flags)
756 elif op.startswith('|'):
757 # Value starts with word in dash separated list
758 pattern = re.compile(r'^%s(?:-.*)?$' % re.escape(value), flags)
759 else:
760 # Value matches
761 pattern = re.compile(r'^%s$' % re.escape(value), flags)
762 if op.startswith('!'):
763 # Equivalent to `:not([attr=value])`
764 inverse = True
765 if is_type and pattern:
766 pattern2 = re.compile(pattern.pattern)
768 # Append the attribute selector
769 sel_attr = ct.SelectorAttribute(attr, ns, pattern, pattern2)
770 if inverse:
771 # If we are using `!=`, we need to nest the pattern under a `:not()`.
772 sub_sel = _Selector()
773 sub_sel.attributes.append(sel_attr)
774 not_list = ct.SelectorList([sub_sel.freeze()], True, False)
775 sel.selectors.append(not_list)
776 else:
777 sel.attributes.append(sel_attr)
779 has_selector = True
780 return has_selector
782 def parse_tag_pattern(self, sel: _Selector, m: Match[str], has_selector: bool) -> bool:
783 """Parse tag pattern from regex match."""
785 prefix = css_unescape(m.group('tag_ns')[:-1]) if m.group('tag_ns') else None
786 tag = css_unescape(m.group('tag_name'))
787 sel.tag = ct.SelectorTag(tag, prefix)
788 has_selector = True
789 return has_selector
791 def parse_pseudo_class_custom(self, sel: _Selector, m: Match[str], has_selector: bool) -> bool:
792 """
793 Parse custom pseudo class alias.
795 Compile custom selectors as we need them. When compiling a custom selector,
796 set it to `None` in the dictionary so we can avoid an infinite loop.
797 """
799 pseudo = util.lower(css_unescape(m.group('name')))
800 selector = self.custom.get(pseudo)
801 if selector is None:
802 raise SelectorSyntaxError(
803 f"Undefined custom selector '{pseudo}' found at position {m.end(0)}",
804 self.pattern,
805 m.end(0)
806 )
808 if not isinstance(selector, ct.SelectorList):
809 del self.custom[pseudo]
810 selector = CSSParser(
811 selector, custom=self.custom, flags=self.flags, ignore=self.ignore
812 ).process_selectors(flags=FLG_PSEUDO)
813 self.custom[pseudo] = selector
815 self.increment_count(selector.count)
816 sel.selectors.append(selector)
817 has_selector = True
818 return has_selector
820 def parse_pseudo_class(
821 self,
822 sel: _Selector,
823 m: Match[str],
824 has_selector: bool,
825 iselector: Iterator[tuple[str, Match[str]]],
826 is_html: bool
827 ) -> tuple[bool, bool]:
828 """Parse pseudo class."""
830 complex_pseudo = False
831 pseudo = util.lower(css_unescape(m.group('name')))
832 if m.group('open'):
833 complex_pseudo = True
834 if complex_pseudo and pseudo in PSEUDO_COMPLEX:
835 has_selector = self.parse_pseudo_open(sel, pseudo, has_selector, iselector, m.end(0))
836 elif not complex_pseudo and pseudo in PSEUDO_SIMPLE:
837 if pseudo == ':root':
838 sel.flags |= ct.SEL_ROOT
839 elif pseudo == ':defined':
840 sel.flags |= ct.SEL_DEFINED
841 is_html = True
842 elif pseudo == ':scope':
843 sel.flags |= ct.SEL_SCOPE
844 elif pseudo == ':empty':
845 sel.flags |= ct.SEL_EMPTY
846 elif pseudo in self.PSEUDO_SELECTORS:
847 pseudo_selector = self.PSEUDO_SELECTORS[pseudo]
848 self.increment_count(pseudo_selector.count)
849 sel.selectors.append(pseudo_selector)
850 elif pseudo == ':first-child':
851 sel.nth.append(ct.SelectorNth(0, False, 1, False, False, ct.SelectorList()))
852 elif pseudo == ':last-child':
853 sel.nth.append(ct.SelectorNth(0, False, 1, False, True, ct.SelectorList()))
854 elif pseudo == ':first-of-type':
855 sel.nth.append(ct.SelectorNth(0, False, 1, True, False, ct.SelectorList()))
856 elif pseudo == ':last-of-type':
857 sel.nth.append(ct.SelectorNth(0, False, 1, True, True, ct.SelectorList()))
858 elif pseudo == ':only-child':
859 sel.nth.extend(
860 [
861 ct.SelectorNth(0, False, 1, False, False, ct.SelectorList()),
862 ct.SelectorNth(0, False, 1, False, True, ct.SelectorList())
863 ]
864 )
865 elif pseudo == ':only-of-type':
866 sel.nth.extend(
867 [
868 ct.SelectorNth(0, False, 1, True, False, ct.SelectorList()),
869 ct.SelectorNth(0, False, 1, True, True, ct.SelectorList())
870 ]
871 )
872 has_selector = True
873 elif complex_pseudo and pseudo in PSEUDO_COMPLEX_NO_MATCH:
874 self.parse_selectors(iselector, m.end(0), FLG_PSEUDO | FLG_OPEN)
875 sel.no_match = True
876 has_selector = True
877 elif not complex_pseudo and pseudo in PSEUDO_SIMPLE_NO_MATCH:
878 sel.no_match = True
879 has_selector = True
880 elif pseudo in PSEUDO_SUPPORTED:
881 raise SelectorSyntaxError(
882 f"Invalid syntax for pseudo class '{pseudo}'",
883 self.pattern,
884 m.start(0)
885 )
886 else:
887 raise SelectorSyntaxError(
888 f"'{pseudo}' was detected as a pseudo-class and is either unsupported or invalid. "
889 "If the syntax was not intended to be recognized as a pseudo-class, please escape the colon.",
890 self.pattern,
891 m.start(0)
892 )
894 return has_selector, is_html
896 def parse_pseudo_nth(
897 self,
898 sel: _Selector,
899 m: Match[str],
900 has_selector: bool,
901 iselector: Iterator[tuple[str, Match[str]]]
902 ) -> bool:
903 """Parse `nth` pseudo."""
905 mdict = m.groupdict()
906 if mdict.get('pseudo_nth_child'):
907 postfix = '_child'
908 else:
909 postfix = '_type'
910 mdict['name'] = util.lower(css_unescape(mdict['name']))
911 content = util.lower(mdict.get('nth' + postfix))
912 if content == 'even':
913 # 2n
914 s1 = 2
915 s2 = 0
916 var = True
917 elif content == 'odd':
918 # 2n+1
919 s1 = 2
920 s2 = 1
921 var = True
922 else:
923 nth_parts = cast(Match[str], RE_NTH.match(content))
924 _s1 = '-' if nth_parts.group('s1') and nth_parts.group('s1') == '-' else ''
925 _s2 = ''
926 a = nth_parts.group('a')
927 var = a.endswith('n')
928 if a.startswith('n'):
929 _s1 += '1'
930 elif var:
931 _s1 += a[:-1]
932 else:
933 _s2 = _s1 + a
934 _s1 = ''
935 if nth_parts.group('s2') and nth_parts.group('s2') == '-':
936 _s2 = '-'
937 if nth_parts.group('b'):
938 _s2 += nth_parts.group('b')
939 s1 = int(_s1, 10) if _s1 else 0
940 s2 = int(_s2, 10) if _s2 else 0
942 pseudo_sel = mdict['name']
943 if postfix == '_child':
944 if m.group('of'):
945 # Parse the rest of `of S`.
946 nth_sel = self.parse_selectors(iselector, m.end(0), FLG_PSEUDO | FLG_OPEN)
947 else:
948 # Use default `*|*` for `of S`.
949 nth_sel = self.PSEUDO_SELECTORS['<nth-of-s>']
950 self.increment_count(nth_sel.count)
951 if pseudo_sel == ':nth-child':
952 sel.nth.append(ct.SelectorNth(s1, var, s2, False, False, nth_sel))
953 elif pseudo_sel == ':nth-last-child':
954 sel.nth.append(ct.SelectorNth(s1, var, s2, False, True, nth_sel))
955 else:
956 if pseudo_sel == ':nth-of-type':
957 sel.nth.append(ct.SelectorNth(s1, var, s2, True, False, ct.SelectorList()))
958 elif pseudo_sel == ':nth-last-of-type':
959 sel.nth.append(ct.SelectorNth(s1, var, s2, True, True, ct.SelectorList()))
960 has_selector = True
961 return has_selector
963 def parse_pseudo_open(
964 self,
965 sel: _Selector,
966 name: str,
967 has_selector: bool,
968 iselector: Iterator[tuple[str, Match[str]]],
969 index: int
970 ) -> bool:
971 """Parse pseudo with opening bracket."""
973 flags = FLG_PSEUDO | FLG_OPEN
974 if name == ':not':
975 flags |= FLG_NOT
976 elif name == ':has':
977 flags |= FLG_RELATIVE
978 elif name in (':where', ':is'):
979 flags |= FLG_FORGIVE
981 sel.selectors.append(self.parse_selectors(iselector, index, flags))
982 has_selector = True
984 return has_selector
986 def parse_has_combinator(
987 self,
988 sel: _Selector,
989 m: Match[str],
990 has_selector: bool,
991 selectors: list[_Selector],
992 rel_type: str,
993 index: int
994 ) -> tuple[bool, _Selector, str]:
995 """Parse combinator tokens."""
997 combinator = m.group('relation').strip()
998 if not combinator:
999 combinator = WS_COMBINATOR
1000 if combinator == COMMA_COMBINATOR:
1001 if not has_selector:
1002 raise SelectorSyntaxError(
1003 f"The combinator '{combinator}' at position {index}, must have a selector before it",
1004 self.pattern,
1005 index
1006 )
1007 sel.rel_type = rel_type
1008 selectors[-1].relations.append(sel)
1009 rel_type = ":" + WS_COMBINATOR
1010 selectors.append(_Selector())
1011 else:
1012 if has_selector:
1013 # End the current selector and associate the leading combinator with this selector.
1014 sel.rel_type = rel_type
1015 selectors[-1].relations.append(sel)
1016 elif rel_type[1:] != WS_COMBINATOR:
1017 # It's impossible to have two whitespace combinators after each other as the patterns
1018 # will gobble up trailing whitespace. It is also impossible to have a whitespace
1019 # combinator after any other kind for the same reason. But we could have
1020 # multiple non-whitespace combinators. So if the current combinator is not a whitespace,
1021 # then we've hit the multiple combinator case, so we should fail.
1022 raise SelectorSyntaxError(
1023 f'The multiple combinators at position {index}',
1024 self.pattern,
1025 index
1026 )
1028 # Set the leading combinator for the next selector.
1029 rel_type = ':' + combinator
1031 sel = _Selector()
1032 has_selector = False
1033 return has_selector, sel, rel_type
1035 def parse_combinator(
1036 self,
1037 sel: _Selector,
1038 m: Match[str],
1039 has_selector: bool,
1040 selectors: list[_Selector],
1041 relations: list[_Selector],
1042 is_pseudo: bool,
1043 is_forgive: bool,
1044 index: int
1045 ) -> tuple[bool, _Selector]:
1046 """Parse combinator tokens."""
1048 combinator = m.group('relation').strip()
1049 if not combinator:
1050 combinator = WS_COMBINATOR
1051 if not has_selector:
1052 if not is_forgive or combinator != COMMA_COMBINATOR:
1053 raise SelectorSyntaxError(
1054 f"The combinator '{combinator}' at position {index}, must have a selector before it",
1055 self.pattern,
1056 index
1057 )
1059 # If we are in a forgiving pseudo class, just make the selector a "no match"
1060 if combinator == COMMA_COMBINATOR:
1061 self.increment_count()
1062 del relations[:]
1063 else:
1064 if combinator == COMMA_COMBINATOR:
1065 if not sel.tag and not is_pseudo:
1066 # Implied `*`
1067 sel.tag = ct.SelectorTag('*', None)
1068 sel.relations.extend(relations)
1069 selectors.append(sel)
1070 del relations[:]
1071 else:
1072 sel.relations.extend(relations)
1073 sel.rel_type = combinator
1074 del relations[:]
1075 relations.append(sel)
1077 sel = _Selector()
1078 has_selector = False
1080 return has_selector, sel
1082 def parse_class_id(self, sel: _Selector, m: Match[str], has_selector: bool) -> bool:
1083 """Parse HTML classes and ids."""
1085 selector = m.group(0)
1086 if selector.startswith('.'):
1087 sel.classes.append(css_unescape(selector[1:]))
1088 else:
1089 sel.ids.append(css_unescape(selector[1:]))
1090 has_selector = True
1091 return has_selector
1093 def parse_pseudo_contains(self, sel: _Selector, m: Match[str], has_selector: bool) -> bool:
1094 """Parse contains."""
1096 pseudo = util.lower(css_unescape(m.group('name')))
1097 if pseudo == ":contains":
1098 warnings.warn( # noqa: B028
1099 "The pseudo class ':contains' is deprecated, ':-soup-contains' should be used moving forward.",
1100 FutureWarning
1101 )
1102 contains_own = pseudo == ":-soup-contains-own"
1103 patterns = [
1104 css_unescape(token.group('value'))
1105 for token in RE_VALUES.finditer(m.group('values'))
1106 if not token.group('split')
1107 ]
1108 sel.contains.append(ct.SelectorContains(patterns, contains_own))
1109 has_selector = True
1110 return has_selector
1112 def parse_pseudo_lang(self, sel: _Selector, m: Match[str], has_selector: bool) -> bool:
1113 """Parse pseudo language."""
1115 patterns = [
1116 css_unescape(token.group('value'))
1117 for token in RE_VALUES.finditer(m.group('values'))
1118 if not token.group('split')
1119 ]
1120 sel.lang.append(ct.SelectorLang(patterns))
1121 has_selector = True
1123 return has_selector
1125 def parse_pseudo_dir(self, sel: _Selector, m: Match[str], has_selector: bool) -> bool:
1126 """Parse pseudo direction."""
1128 value = ct.SEL_DIR_LTR if util.lower(m.group('dir')) == 'ltr' else ct.SEL_DIR_RTL
1129 sel.flags |= value
1130 has_selector = True
1131 return has_selector
1133 def parse_selectors(
1134 self,
1135 iselector: Iterator[tuple[str, Match[str]]],
1136 index: int = 0,
1137 flags: int = 0
1138 ) -> ct.SelectorList:
1139 """Parse selectors."""
1141 # Initialize important variables
1142 sel = _Selector()
1143 selectors = []
1144 has_selector = False
1145 closed = False
1146 relations = [] # type: list[_Selector]
1147 rel_type = ":" + WS_COMBINATOR
1148 count = self.count
1150 # Setup various flags
1151 is_open = bool(flags & FLG_OPEN)
1152 is_pseudo = bool(flags & FLG_PSEUDO)
1153 is_relative = bool(flags & FLG_RELATIVE)
1154 is_not = bool(flags & FLG_NOT)
1155 is_html = bool(flags & FLG_HTML)
1156 is_default = bool(flags & FLG_DEFAULT)
1157 is_indeterminate = bool(flags & FLG_INDETERMINATE)
1158 is_in_range = bool(flags & FLG_IN_RANGE)
1159 is_out_of_range = bool(flags & FLG_OUT_OF_RANGE)
1160 is_placeholder_shown = bool(flags & FLG_PLACEHOLDER_SHOWN)
1161 is_forgive = bool(flags & FLG_FORGIVE)
1163 # Print out useful debug stuff
1164 if self.debug: # pragma: no cover
1165 if is_pseudo:
1166 print(' is_pseudo: True')
1167 if is_open:
1168 print(' is_open: True')
1169 if is_relative:
1170 print(' is_relative: True')
1171 if is_not:
1172 print(' is_not: True')
1173 if is_html:
1174 print(' is_html: True')
1175 if is_default:
1176 print(' is_default: True')
1177 if is_indeterminate:
1178 print(' is_indeterminate: True')
1179 if is_in_range:
1180 print(' is_in_range: True')
1181 if is_out_of_range:
1182 print(' is_out_of_range: True')
1183 if is_placeholder_shown:
1184 print(' is_placeholder_shown: True')
1185 if is_forgive:
1186 print(' is_forgive: True')
1188 # The algorithm for relative selectors require an initial selector in the selector list
1189 if is_relative:
1190 selectors.append(_Selector())
1192 try:
1193 while True:
1194 key, m = next(iselector)
1196 if key not in ('combine', 'pseudo_close'):
1197 self.increment_count()
1199 # Handle parts
1200 if self.ignore:
1201 mi = RE_PSEUDO_IGNORE.match(m.group(0))
1202 if mi is not None and mi.group('name').lower() in self.ignore:
1203 raise SelectorSyntaxError(
1204 f"The selector '{mi.group('name')}' at position {m.start(0)}, has been disallowed",
1205 self.pattern,
1206 m.start(0)
1207 )
1208 if key == "at_rule":
1209 raise NotImplementedError(f"At-rules found at position {m.start(0)}")
1210 elif key == "amp":
1211 sel.flags |= ct.SEL_SCOPE
1212 has_selector = True
1213 elif key == 'pseudo_class_custom':
1214 has_selector = self.parse_pseudo_class_custom(sel, m, has_selector)
1215 elif key == 'pseudo_class':
1216 has_selector, is_html = self.parse_pseudo_class(sel, m, has_selector, iselector, is_html)
1217 elif key == 'pseudo_element':
1218 raise NotImplementedError(f"Pseudo-element found at position {m.start(0)}")
1219 elif key == 'pseudo_contains':
1220 has_selector = self.parse_pseudo_contains(sel, m, has_selector)
1221 elif key in ('pseudo_nth_type', 'pseudo_nth_child'):
1222 has_selector = self.parse_pseudo_nth(sel, m, has_selector, iselector)
1223 elif key == 'pseudo_lang':
1224 has_selector = self.parse_pseudo_lang(sel, m, has_selector)
1225 elif key == 'pseudo_dir':
1226 has_selector = self.parse_pseudo_dir(sel, m, has_selector)
1227 # Currently only supports HTML
1228 is_html = True
1229 elif key == 'pseudo_close':
1230 if not has_selector:
1231 if not is_forgive:
1232 raise SelectorSyntaxError(
1233 f"Expected a selector at position {m.start(0)}",
1234 self.pattern,
1235 m.start(0)
1236 )
1237 sel.no_match = True
1238 if is_open:
1239 closed = True
1240 break
1241 else:
1242 raise SelectorSyntaxError(
1243 f"Unmatched pseudo-class close at position {m.start(0)}",
1244 self.pattern,
1245 m.start(0)
1246 )
1247 elif key == 'combine':
1248 if is_relative:
1249 has_selector, sel, rel_type = self.parse_has_combinator(
1250 sel, m, has_selector, selectors, rel_type, index
1251 )
1252 else:
1253 has_selector, sel = self.parse_combinator(
1254 sel, m, has_selector, selectors, relations, is_pseudo, is_forgive, index
1255 )
1256 elif key == 'attribute':
1257 has_selector = self.parse_attribute_selector(sel, m, has_selector)
1258 elif key == 'tag':
1259 if has_selector:
1260 raise SelectorSyntaxError(
1261 f"Tag name found at position {m.start(0)} instead of at the start",
1262 self.pattern,
1263 m.start(0)
1264 )
1265 has_selector = self.parse_tag_pattern(sel, m, has_selector)
1266 elif key in ('class', 'id'):
1267 has_selector = self.parse_class_id(sel, m, has_selector)
1269 index = m.end(0)
1270 except StopIteration:
1271 pass
1273 # Handle selectors that are not closed
1274 if is_open and not closed:
1275 raise SelectorSyntaxError(
1276 f"Unclosed pseudo-class at position {index}",
1277 self.pattern,
1278 index
1279 )
1281 # Cleanup completed selector piece
1282 if has_selector:
1283 if not sel.tag and not is_pseudo:
1284 # Implied `*`
1285 sel.tag = ct.SelectorTag('*', None)
1286 if is_relative:
1287 sel.rel_type = rel_type
1288 selectors[-1].relations.append(sel)
1289 else:
1290 sel.relations.extend(relations)
1291 del relations[:]
1292 selectors.append(sel)
1294 # Forgive empty slots in pseudo-classes that have lists (and are forgiving)
1295 elif is_forgive and (not selectors or not relations):
1296 # Handle normal pseudo-classes with empty slots like `:is()` etc.
1297 self.increment_count()
1298 sel.no_match = True
1299 del relations[:]
1300 selectors.append(sel)
1301 has_selector = True
1303 if not has_selector:
1304 # We will always need to finish a selector when `:has()` is used as it leads with combining.
1305 # May apply to others as well.
1306 raise SelectorSyntaxError(
1307 f'Expected a selector at position {index}',
1308 self.pattern,
1309 index
1310 )
1312 # Some patterns require additional logic, such as default. We try to make these the
1313 # last pattern, and append the appropriate flag to that selector which communicates
1314 # to the matcher what additional logic is required.
1315 if is_default:
1316 selectors[-1].flags = ct.SEL_DEFAULT
1317 if is_indeterminate:
1318 selectors[-1].flags = ct.SEL_INDETERMINATE
1319 if is_in_range:
1320 selectors[-1].flags = ct.SEL_IN_RANGE
1321 if is_out_of_range:
1322 selectors[-1].flags = ct.SEL_OUT_OF_RANGE
1323 if is_placeholder_shown:
1324 selectors[-1].flags = ct.SEL_PLACEHOLDER_SHOWN
1326 # Return selector list
1327 return ct.SelectorList([s.freeze() for s in selectors], is_not, is_html, self.count - count)
1329 def selector_iter(self, pattern: str) -> Iterator[tuple[str, Match[str]]]:
1330 """Iterate selector tokens."""
1332 # Ignore whitespace and comments at start and end of pattern
1333 m = RE_WS_BEGIN.search(pattern)
1334 index = m.end(0) if m else 0
1335 m = RE_WS_END.search(pattern[::-1])
1336 offset = m.end(0) if m else 0
1337 end = len(pattern) - (1 + offset)
1339 if self.debug: # pragma: no cover
1340 print(f'## PARSING: {pattern!r}')
1341 while index <= end:
1342 m = None
1343 for v in self.CSS_TOKENS:
1344 m = v.match(pattern, index, self.flags)
1345 if m:
1346 name = v.get_name()
1347 if self.debug: # pragma: no cover
1348 print(f"TOKEN: '{name}' --> {m.group(0)!r} at position {m.start(0)}")
1349 index = m.end(0)
1350 yield name, m
1351 break
1352 if m is None:
1353 c = pattern[index]
1354 # If the character represents the start of one of the known selector types,
1355 # throw an exception mentioning that the known selector type is in error;
1356 # otherwise, report the invalid character.
1357 if c == '[':
1358 msg = f"Malformed attribute selector at position {index}"
1359 elif c == '.':
1360 msg = f"Malformed class selector at position {index}"
1361 elif c == '#':
1362 msg = f"Malformed id selector at position {index}"
1363 elif c == ':':
1364 msg = f"Malformed pseudo-class selector at position {index}"
1365 else:
1366 msg = f"Invalid character {c!r} position {index}"
1367 raise SelectorSyntaxError(msg, self.pattern, index)
1368 if self.debug: # pragma: no cover
1369 print('## END PARSING')
1371 def process_selectors(self, index: int = 0, flags: int = 0) -> ct.SelectorList:
1372 """Process selectors."""
1374 return self.parse_selectors(self.selector_iter(self.pattern), index, flags)