-
-
Notifications
You must be signed in to change notification settings - Fork 34.4k
Expand file tree
/
Copy path_header_value_parser.py
More file actions
3009 lines (2615 loc) · 105 KB
/
_header_value_parser.py
File metadata and controls
3009 lines (2615 loc) · 105 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
"""Header value parser implementing various email-related RFC parsing rules.
The parsing methods defined in this module implement various email related
parsing rules. Principal among them is RFC 5322, which is the followon
to RFC 2822 and primarily a clarification of the former. It also implements
RFC 2047 encoded word decoding.
RFC 5322 goes to considerable trouble to maintain backward compatibility with
RFC 822 in the parse phase, while cleaning up the structure on the generation
phase. This parser supports correct RFC 5322 generation by tagging white space
as folding white space only when folding is allowed in the non-obsolete rule
sets. Actually, the parser is even more generous when accepting input than RFC
5322 mandates, following the spirit of Postel's Law, which RFC 5322 encourages.
Where possible deviations from the standard are annotated on the 'defects'
attribute of tokens that deviate.
The general structure of the parser follows RFC 5322, and uses its terminology
where there is a direct correspondence. Where the implementation requires a
somewhat different structure than that used by the formal grammar, new terms
that mimic the closest existing terms are used. Thus, it really helps to have
a copy of RFC 5322 handy when studying this code.
Input to the parser is a string that has already been unfolded according to
RFC 5322 rules. According to the RFC this unfolding is the very first step, and
this parser leaves the unfolding step to a higher level message parser, which
will have already detected the line breaks that need unfolding while
determining the beginning and end of each header.
The output of the parser is a TokenList object, which is a list subclass. A
TokenList is a recursive data structure. The terminal nodes of the structure
are Terminal objects, which are subclasses of str. These do not correspond
directly to terminal objects in the formal grammar, but are instead more
practical higher level combinations of true terminals.
All TokenList and Terminal objects have a 'value' attribute, which produces the
semantically meaningful value of that part of the parse subtree. The value of
all whitespace tokens (no matter how many sub-tokens they may contain) is a
single space, as per the RFC rules. This includes 'CFWS', which is herein
included in the general class of whitespace tokens. There is one exception to
the rule that whitespace tokens are collapsed into single spaces in values: in
the value of a 'bare-quoted-string' (a quoted-string with no leading or
trailing whitespace), any whitespace that appeared between the quotation marks
is preserved in the returned value. Note that in all Terminal strings quoted
pairs are turned into their unquoted values.
All TokenList and Terminal objects also have a string value, which attempts to
be a "canonical" representation of the RFC-compliant form of the substring that
produced the parsed subtree, including minimal use of quoted pair quoting.
Whitespace runs are not collapsed.
Comment tokens also have a 'content' attribute providing the string found
between the parens (including any nested comments) with whitespace preserved.
All TokenList and Terminal objects have a 'defects' attribute which is a
possibly empty list all of the defects found while creating the token. Defects
may appear on any token in the tree, and a composite list of all defects in the
subtree is available through the 'all_defects' attribute of any node. (For
Terminal notes x.defects == x.all_defects.)
Each object in a parse tree is called a 'token', and each has a 'token_type'
attribute that gives the name from the RFC 5322 grammar that it represents.
Not all RFC 5322 nodes are produced, and there is one non-RFC 5322 node that
may be produced: 'ptext'. A 'ptext' is a string of printable ascii characters.
It is returned in place of lists of (ctext/quoted-pair) and
(qtext/quoted-pair).
XXX: provide complete list of token types.
"""
import re
import sys
import urllib # For urllib.parse.unquote
from string import hexdigits
from operator import itemgetter
from email import _encoded_words as _ew
from email import errors
from email import utils
#
# Useful constants and functions
#
WSP = set(' \t')
CFWS_LEADER = WSP | set('(')
SPECIALS = set(r'()<>@,:;.\"[]')
ATOM_ENDS = SPECIALS | WSP
DOT_ATOM_ENDS = ATOM_ENDS - set('.')
# '.', '"', and '(' do not end phrases in order to support obs-phrase
PHRASE_ENDS = SPECIALS - set('."(')
TSPECIALS = (SPECIALS | set('/?=')) - set('.')
TOKEN_ENDS = TSPECIALS | WSP
ASPECIALS = TSPECIALS | set("*'%")
ATTRIBUTE_ENDS = ASPECIALS | WSP
EXTENDED_ATTRIBUTE_ENDS = ATTRIBUTE_ENDS - set('%')
NLSET = {'\n', '\r'}
SPECIALSNL = SPECIALS | NLSET
def quote_string(value):
return '"'+str(value).replace('\\', '\\\\').replace('"', r'\"')+'"'
# Match a RFC 2047 word, looks like =?utf-8?q?someword?=
rfc2047_matcher = re.compile(r'''
=\? # literal =?
[^?]* # charset
\? # literal ?
[qQbB] # literal 'q' or 'b', case insensitive
\? # literal ?
.*? # encoded word
\?= # literal ?=
''', re.VERBOSE | re.MULTILINE)
#
# TokenList and its subclasses
#
class TokenList(list):
token_type = None
syntactic_break = True
ew_combine_allowed = True
def __init__(self, *args, **kw):
super().__init__(*args, **kw)
self.defects = []
def __str__(self):
return ''.join(str(x) for x in self)
def __repr__(self):
return '{}({})'.format(self.__class__.__name__,
super().__repr__())
@property
def value(self):
return ''.join(x.value for x in self if x.value)
@property
def all_defects(self):
return sum((x.all_defects for x in self), self.defects)
def startswith_fws(self):
return self[0].startswith_fws()
@property
def as_ew_allowed(self):
"""True if all top level tokens of this part may be RFC2047 encoded."""
return all(part.as_ew_allowed for part in self)
@property
def comments(self):
comments = []
for token in self:
comments.extend(token.comments)
return comments
def fold(self, *, policy):
return _refold_parse_tree(self, policy=policy)
def pprint(self, indent=''):
print(self.ppstr(indent=indent))
def ppstr(self, indent=''):
return '\n'.join(self._pp(indent=indent))
def _pp(self, indent=''):
yield '{}{}/{}('.format(
indent,
self.__class__.__name__,
self.token_type)
for token in self:
if not hasattr(token, '_pp'):
yield (indent + ' !! invalid element in token '
'list: {!r}'.format(token))
else:
yield from token._pp(indent+' ')
if self.defects:
extra = ' Defects: {}'.format(self.defects)
else:
extra = ''
yield '{}){}'.format(indent, extra)
class WhiteSpaceTokenList(TokenList):
@property
def value(self):
return ' '
@property
def comments(self):
return [x.content for x in self if x.token_type=='comment']
class UnstructuredTokenList(TokenList):
token_type = 'unstructured'
class Phrase(TokenList):
token_type = 'phrase'
class Word(TokenList):
token_type = 'word'
class CFWSList(WhiteSpaceTokenList):
token_type = 'cfws'
class Atom(TokenList):
token_type = 'atom'
class Token(TokenList):
token_type = 'token'
encode_as_ew = False
class EncodedWord(TokenList):
token_type = 'encoded-word'
cte = None
charset = None
lang = None
class QuotedString(TokenList):
token_type = 'quoted-string'
@property
def content(self):
for x in self:
if x.token_type == 'bare-quoted-string':
return x.value
@property
def quoted_value(self):
res = []
for x in self:
if x.token_type == 'bare-quoted-string':
res.append(str(x))
else:
res.append(x.value)
return ''.join(res)
@property
def stripped_value(self):
for token in self:
if token.token_type == 'bare-quoted-string':
return token.value
class BareQuotedString(QuotedString):
token_type = 'bare-quoted-string'
def __str__(self):
return quote_string(''.join(str(x) for x in self))
@property
def value(self):
return ''.join(str(x) for x in self)
class Comment(WhiteSpaceTokenList):
token_type = 'comment'
def __str__(self):
return ''.join(sum([
["("],
[self.quote(x) for x in self],
[")"],
], []))
def quote(self, value):
if value.token_type == 'comment':
return str(value)
return str(value).replace('\\', '\\\\').replace(
'(', r'\(').replace(
')', r'\)')
@property
def content(self):
return ''.join(str(x) for x in self)
@property
def comments(self):
return [self.content]
class AddressList(TokenList):
token_type = 'address-list'
@property
def addresses(self):
return [x for x in self if x.token_type=='address']
@property
def mailboxes(self):
return sum((x.mailboxes
for x in self if x.token_type=='address'), [])
@property
def all_mailboxes(self):
return sum((x.all_mailboxes
for x in self if x.token_type=='address'), [])
class Address(TokenList):
token_type = 'address'
@property
def display_name(self):
if self[0].token_type == 'group':
return self[0].display_name
@property
def mailboxes(self):
if self[0].token_type == 'mailbox':
return [self[0]]
elif self[0].token_type == 'invalid-mailbox':
return []
return self[0].mailboxes
@property
def all_mailboxes(self):
if self[0].token_type == 'mailbox':
return [self[0]]
elif self[0].token_type == 'invalid-mailbox':
return [self[0]]
return self[0].all_mailboxes
class MailboxList(TokenList):
token_type = 'mailbox-list'
@property
def mailboxes(self):
return [x for x in self if x.token_type=='mailbox']
@property
def all_mailboxes(self):
return [x for x in self
if x.token_type in ('mailbox', 'invalid-mailbox')]
class GroupList(TokenList):
token_type = 'group-list'
@property
def mailboxes(self):
if not self or self[0].token_type != 'mailbox-list':
return []
return self[0].mailboxes
@property
def all_mailboxes(self):
if not self or self[0].token_type != 'mailbox-list':
return []
return self[0].all_mailboxes
class Group(TokenList):
token_type = "group"
@property
def mailboxes(self):
if self[2].token_type != 'group-list':
return []
return self[2].mailboxes
@property
def all_mailboxes(self):
if self[2].token_type != 'group-list':
return []
return self[2].all_mailboxes
@property
def display_name(self):
return self[0].display_name
class NameAddr(TokenList):
token_type = 'name-addr'
@property
def display_name(self):
if len(self) == 1:
return None
return self[0].display_name
@property
def local_part(self):
return self[-1].local_part
@property
def domain(self):
return self[-1].domain
@property
def route(self):
return self[-1].route
@property
def addr_spec(self):
return self[-1].addr_spec
class AngleAddr(TokenList):
token_type = 'angle-addr'
@property
def local_part(self):
for x in self:
if x.token_type == 'addr-spec':
return x.local_part
@property
def domain(self):
for x in self:
if x.token_type == 'addr-spec':
return x.domain
@property
def route(self):
for x in self:
if x.token_type == 'obs-route':
return x.domains
@property
def addr_spec(self):
for x in self:
if x.token_type == 'addr-spec':
if x.local_part:
return x.addr_spec
else:
return quote_string(x.local_part) + x.addr_spec
else:
return '<>'
class ObsRoute(TokenList):
token_type = 'obs-route'
@property
def domains(self):
return [x.domain for x in self if x.token_type == 'domain']
class Mailbox(TokenList):
token_type = 'mailbox'
@property
def display_name(self):
if self[0].token_type == 'name-addr':
return self[0].display_name
@property
def local_part(self):
return self[0].local_part
@property
def domain(self):
return self[0].domain
@property
def route(self):
if self[0].token_type == 'name-addr':
return self[0].route
@property
def addr_spec(self):
return self[0].addr_spec
class InvalidMailbox(TokenList):
token_type = 'invalid-mailbox'
@property
def display_name(self):
return None
local_part = domain = route = addr_spec = display_name
class Domain(TokenList):
token_type = 'domain'
as_ew_allowed = False
@property
def domain(self):
return ''.join(super().value.split())
class DotAtom(TokenList):
token_type = 'dot-atom'
class DotAtomText(TokenList):
token_type = 'dot-atom-text'
as_ew_allowed = True
class NoFoldLiteral(TokenList):
token_type = 'no-fold-literal'
as_ew_allowed = False
class AddrSpec(TokenList):
token_type = 'addr-spec'
as_ew_allowed = False
@property
def local_part(self):
return self[0].local_part
@property
def domain(self):
if len(self) < 3:
return None
return self[-1].domain
@property
def value(self):
if len(self) < 3:
return self[0].value
return self[0].value.rstrip()+self[1].value+self[2].value.lstrip()
@property
def addr_spec(self):
nameset = set(self.local_part)
if len(nameset) > len(nameset-DOT_ATOM_ENDS):
lp = quote_string(self.local_part)
else:
lp = self.local_part
if self.domain is not None:
return lp + '@' + self.domain
return lp
class ObsLocalPart(TokenList):
token_type = 'obs-local-part'
as_ew_allowed = False
class DisplayName(Phrase):
token_type = 'display-name'
ew_combine_allowed = False
@property
def display_name(self):
res = TokenList(self)
if len(res) == 0:
return res.value
if res[0].token_type == 'cfws':
res.pop(0)
else:
if res[0][0].token_type == 'cfws':
res[0] = TokenList(res[0][1:])
if res[-1].token_type == 'cfws':
res.pop()
else:
if res[-1][-1].token_type == 'cfws':
res[-1] = TokenList(res[-1][:-1])
return res.value
@property
def value(self):
quote = False
if self.defects:
quote = True
else:
for x in self:
if x.token_type == 'quoted-string':
quote = True
if len(self) != 0 and quote:
pre = post = ''
if self[0].token_type=='cfws' or self[0][0].token_type=='cfws':
pre = ' '
if self[-1].token_type=='cfws' or self[-1][-1].token_type=='cfws':
post = ' '
return pre+quote_string(self.display_name)+post
else:
return super().value
class LocalPart(TokenList):
token_type = 'local-part'
as_ew_allowed = False
@property
def value(self):
if self[0].token_type == "quoted-string":
return self[0].quoted_value
else:
return self[0].value
@property
def local_part(self):
# Strip whitespace from front, back, and around dots.
res = [DOT]
last = DOT
last_is_tl = False
for tok in self[0] + [DOT]:
if tok.token_type == 'cfws':
continue
if (last_is_tl and tok.token_type == 'dot' and
last[-1].token_type == 'cfws'):
res[-1] = TokenList(last[:-1])
is_tl = isinstance(tok, TokenList)
if (is_tl and last.token_type == 'dot' and
tok[0].token_type == 'cfws'):
res.append(TokenList(tok[1:]))
else:
res.append(tok)
last = res[-1]
last_is_tl = is_tl
res = TokenList(res[1:-1])
return res.value
class DomainLiteral(TokenList):
token_type = 'domain-literal'
as_ew_allowed = False
@property
def domain(self):
return ''.join(super().value.split())
@property
def ip(self):
for x in self:
if x.token_type == 'ptext':
return x.value
class MIMEVersion(TokenList):
token_type = 'mime-version'
major = None
minor = None
class Parameter(TokenList):
token_type = 'parameter'
sectioned = False
extended = False
charset = 'us-ascii'
@property
def section_number(self):
# Because the first token, the attribute (name) eats CFWS, the second
# token is always the section if there is one.
return self[1].number if self.sectioned else 0
@property
def param_value(self):
# This is part of the "handle quoted extended parameters" hack.
for token in self:
if token.token_type == 'value':
return token.stripped_value
if token.token_type == 'quoted-string':
for token in token:
if token.token_type == 'bare-quoted-string':
for token in token:
if token.token_type == 'value':
return token.stripped_value
return ''
class InvalidParameter(Parameter):
token_type = 'invalid-parameter'
class Attribute(TokenList):
token_type = 'attribute'
@property
def stripped_value(self):
for token in self:
if token.token_type.endswith('attrtext'):
return token.value
class Section(TokenList):
token_type = 'section'
number = None
class Value(TokenList):
token_type = 'value'
@property
def stripped_value(self):
token = self[0]
if token.token_type == 'cfws':
token = self[1]
if token.token_type.endswith(
('quoted-string', 'attribute', 'extended-attribute')):
return token.stripped_value
return self.value
class MimeParameters(TokenList):
token_type = 'mime-parameters'
syntactic_break = False
@property
def params(self):
# The RFC specifically states that the ordering of parameters is not
# guaranteed and may be reordered by the transport layer. So we have
# to assume the RFC 2231 pieces can come in any order. However, we
# output them in the order that we first see a given name, which gives
# us a stable __str__.
params = {} # Using order preserving dict from Python 3.7+
for token in self:
if not token.token_type.endswith('parameter'):
continue
if token[0].token_type != 'attribute':
continue
name = token[0].value.strip()
if name not in params:
params[name] = []
params[name].append((token.section_number, token))
for name, parts in params.items():
parts = sorted(parts, key=itemgetter(0))
first_param = parts[0][1]
charset = first_param.charset
# Our arbitrary error recovery is to ignore duplicate parameters,
# to use appearance order if there are duplicate rfc 2231 parts,
# and to ignore gaps. This mimics the error recovery of get_param.
if not first_param.extended and len(parts) > 1:
if parts[1][0] == 0:
parts[1][1].defects.append(errors.InvalidHeaderDefect(
'duplicate parameter name; duplicate(s) ignored'))
parts = parts[:1]
# Else assume the *0* was missing...note that this is different
# from get_param, but we registered a defect for this earlier.
value_parts = []
i = 0
for section_number, param in parts:
if section_number != i:
# We could get fancier here and look for a complete
# duplicate extended parameter and ignore the second one
# seen. But we're not doing that. The old code didn't.
if not param.extended:
param.defects.append(errors.InvalidHeaderDefect(
'duplicate parameter name; duplicate ignored'))
continue
else:
param.defects.append(errors.InvalidHeaderDefect(
"inconsistent RFC2231 parameter numbering"))
i += 1
value = param.param_value
if param.extended:
try:
value = urllib.parse.unquote_to_bytes(value)
except UnicodeEncodeError:
# source had surrogate escaped bytes. What we do now
# is a bit of an open question. I'm not sure this is
# the best choice, but it is what the old algorithm did
value = urllib.parse.unquote(value, encoding='latin-1')
else:
try:
value = value.decode(charset, 'surrogateescape')
except LookupError:
# XXX: there should really be a custom defect for
# unknown character set to make it easy to find,
# because otherwise unknown charset is a silent
# failure.
value = value.decode('us-ascii', 'surrogateescape')
if utils._has_surrogates(value):
param.defects.append(errors.UndecodableBytesDefect())
value_parts.append(value)
value = ''.join(value_parts)
yield name, value
def __str__(self):
params = []
for name, value in self.params:
if value:
params.append('{}={}'.format(name, quote_string(value)))
else:
params.append(name)
params = '; '.join(params)
return ' ' + params if params else ''
class ParameterizedHeaderValue(TokenList):
# Set this false so that the value doesn't wind up on a new line even
# if it and the parameters would fit there but not on the first line.
syntactic_break = False
@property
def params(self):
for token in reversed(self):
if token.token_type == 'mime-parameters':
return token.params
return {}
class ContentType(ParameterizedHeaderValue):
token_type = 'content-type'
as_ew_allowed = False
maintype = 'text'
subtype = 'plain'
class ContentDisposition(ParameterizedHeaderValue):
token_type = 'content-disposition'
as_ew_allowed = False
content_disposition = None
class ContentTransferEncoding(TokenList):
token_type = 'content-transfer-encoding'
as_ew_allowed = False
cte = '7bit'
class HeaderLabel(TokenList):
token_type = 'header-label'
as_ew_allowed = False
class MsgID(TokenList):
token_type = 'msg-id'
as_ew_allowed = False
def fold(self, policy):
# message-id tokens may not be folded.
return str(self) + policy.linesep
class MessageID(MsgID):
token_type = 'message-id'
class InvalidMessageID(MessageID):
token_type = 'invalid-message-id'
class Header(TokenList):
token_type = 'header'
#
# Terminal classes and instances
#
class Terminal(str):
as_ew_allowed = True
ew_combine_allowed = True
syntactic_break = True
def __new__(cls, value, token_type):
self = super().__new__(cls, value)
self.token_type = token_type
self.defects = []
return self
def __repr__(self):
return "{}({})".format(self.__class__.__name__, super().__repr__())
def pprint(self):
print(self.__class__.__name__ + '/' + self.token_type)
@property
def all_defects(self):
return list(self.defects)
def _pp(self, indent=''):
return ["{}{}/{}({}){}".format(
indent,
self.__class__.__name__,
self.token_type,
super().__repr__(),
'' if not self.defects else ' {}'.format(self.defects),
)]
def pop_trailing_ws(self):
# This terminates the recursion.
return None
@property
def comments(self):
return []
def __getnewargs__(self):
return(str(self), self.token_type)
class WhiteSpaceTerminal(Terminal):
@property
def value(self):
return ' '
def startswith_fws(self):
return True
class ValueTerminal(Terminal):
@property
def value(self):
return self
def startswith_fws(self):
return False
class EWWhiteSpaceTerminal(WhiteSpaceTerminal):
@property
def value(self):
return ''
def __str__(self):
return ''
class _InvalidEwError(errors.HeaderParseError):
"""Invalid encoded word found while parsing headers."""
# XXX these need to become classes and used as instances so
# that a program can't change them in a parse tree and screw
# up other parse trees. Maybe should have tests for that, too.
DOT = ValueTerminal('.', 'dot')
ListSeparator = ValueTerminal(',', 'list-separator')
RouteComponentMarker = ValueTerminal('@', 'route-component-marker')
#
# Parser
#
# Parse strings according to RFC822/2047/2822/5322 rules.
#
# This is a stateless parser. Each get_XXX function accepts a string and
# returns either a Terminal or a TokenList representing the RFC object named
# by the method and a string containing the remaining unparsed characters
# from the input. Thus a parser method consumes the next syntactic construct
# of a given type and returns a token representing the construct plus the
# unparsed remainder of the input string.
#
# For example, if the first element of a structured header is a 'phrase',
# then:
#
# phrase, value = get_phrase(value)
#
# returns the complete phrase from the start of the string value, plus any
# characters left in the string after the phrase is removed.
_wsp_splitter = re.compile(r'([{}]+)'.format(''.join(WSP))).split
_non_atom_end_matcher = re.compile(r"[^{}]+".format(
re.escape(''.join(ATOM_ENDS)))).match
_non_printable_finder = re.compile(r"[\x00-\x20\x7F]").findall
_non_token_end_matcher = re.compile(r"[^{}]+".format(
re.escape(''.join(TOKEN_ENDS)))).match
_non_attribute_end_matcher = re.compile(r"[^{}]+".format(
re.escape(''.join(ATTRIBUTE_ENDS)))).match
_non_extended_attribute_end_matcher = re.compile(r"[^{}]+".format(
re.escape(''.join(EXTENDED_ATTRIBUTE_ENDS)))).match
def _validate_xtext(xtext):
"""If input token contains ASCII non-printables, register a defect."""
non_printables = _non_printable_finder(xtext)
if non_printables:
xtext.defects.append(errors.NonPrintableDefect(non_printables))
if utils._has_surrogates(xtext):
xtext.defects.append(errors.UndecodableBytesDefect(
"Non-ASCII characters found in header token"))
def _get_ptext_to_endchars(value, endchars):
"""Scan printables/quoted-pairs until endchars and return unquoted ptext.