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1+
2+/*
3+ * Introduction
4+ * ************
5+ *
6+ * The following notes assume that you are familiar with the YAML specification
7+ * (http://yaml.org/spec/cvs/current.html). We mostly follow it, although in
8+ * some cases we are less restrictive that it requires.
9+ *
10+ * The process of transforming a YAML stream into a sequence of events is
11+ * divided on two steps: Scanning and Parsing.
12+ *
13+ * The Scanner transforms the input stream into a sequence of tokens, while the
14+ * parser transform the sequence of tokens produced by the Scanner into a
15+ * sequence of parsing events.
16+ *
17+ * The Scanner is rather clever and complicated. The Parser, on the contrary,
18+ * is a straightforward implementation of a recursive-descendant parser (or,
19+ * LL(1) parser, as it is usually called).
20+ *
21+ * Actually there are two issues of Scanning that might be called "clever", the
22+ * rest is quite straightforward. The issues are "block collection start" and
23+ * "simple keys". Both issues are explained below in details.
24+ *
25+ * Here the Scanning step is explained and implemented. We start with the list
26+ * of all the tokens produced by the Scanner together with short descriptions.
27+ *
28+ * Now, tokens:
29+ *
30+ * STREAM-START(encoding) # The stream start.
31+ * STREAM-END # The stream end.
32+ * VERSION-DIRECTIVE(major,minor) # The '%YAML' directive.
33+ * TAG-DIRECTIVE(handle,prefix) # The '%TAG' directive.
34+ * DOCUMENT-START # '---'
35+ * DOCUMENT-END # '...'
36+ * BLOCK-SEQUENCE-START # Indentation increase denoting a block
37+ * BLOCK-MAPPING-START # sequence or a block mapping.
38+ * BLOCK-END # Indentation decrease.
39+ * FLOW-SEQUENCE-START # '['
40+ * FLOW-SEQUENCE-END # ']'
41+ * BLOCK-SEQUENCE-START # '{'
42+ * BLOCK-SEQUENCE-END # '}'
43+ * BLOCK-ENTRY # '-'
44+ * FLOW-ENTRY # ','
45+ * KEY # '?' or nothing (simple keys).
46+ * VALUE # ':'
47+ * ALIAS(anchor) # '*anchor'
48+ * ANCHOR(anchor) # '&anchor'
49+ * TAG(handle,suffix) # '!handle!suffix'
50+ * SCALAR(value,style) # A scalar.
51+ *
52+ * The following two tokens are "virtual" tokens denoting the beginning and the
53+ * end of the stream:
54+ *
55+ * STREAM-START(encoding)
56+ * STREAM-END
57+ *
58+ * We pass the information about the input stream encoding with the
59+ * STREAM-START token.
60+ *
61+ * The next two tokens are responsible for tags:
62+ *
63+ * VERSION-DIRECTIVE(major,minor)
64+ * TAG-DIRECTIVE(handle,prefix)
65+ *
66+ * Example:
67+ *
68+ * %YAML 1.1
69+ * %TAG ! !foo
70+ * %TAG !yaml! tag:yaml.org,2002:
71+ * ---
72+ *
73+ * The correspoding sequence of tokens:
74+ *
75+ * STREAM-START(utf-8)
76+ * VERSION-DIRECTIVE(1,1)
77+ * TAG-DIRECTIVE("!","!foo")
78+ * TAG-DIRECTIVE("!yaml","tag:yaml.org,2002:")
79+ * DOCUMENT-START
80+ * STREAM-END
81+ *
82+ * Note that the VERSION-DIRECTIVE and TAG-DIRECTIVE tokens occupy a whole
83+ * line.
84+ *
85+ * The document start and end indicators are represented by:
86+ *
87+ * DOCUMENT-START
88+ * DOCUMENT-END
89+ *
90+ * Note that if a YAML stream contains an implicit document (without '---'
91+ * and '...' indicators), no DOCUMENT-START and DOCUMENT-END tokens will be
92+ * produced.
93+ *
94+ * In the following examples, we present whole documents together with the
95+ * produced tokens.
96+ *
97+ * 1. An implicit document:
98+ *
99+ * 'a scalar'
100+ *
101+ * Tokens:
102+ *
103+ * STREAM-START(utf-8)
104+ * SCALAR("a scalar",single-quoted)
105+ * STREAM-END
106+ *
107+ * 2. An explicit document:
108+ *
109+ * ---
110+ * 'a scalar'
111+ * ...
112+ *
113+ * Tokens:
114+ *
115+ * STREAM-START(utf-8)
116+ * DOCUMENT-START
117+ * SCALAR("a scalar",single-quoted)
118+ * DOCUMENT-END
119+ * STREAM-END
120+ *
121+ * 3. Several documents in a stream:
122+ *
123+ * 'a scalar'
124+ * ---
125+ * 'another scalar'
126+ * ---
127+ * 'yet another scalar'
128+ *
129+ * Tokens:
130+ *
131+ * STREAM-START(utf-8)
132+ * SCALAR("a scalar",single-quoted)
133+ * DOCUMENT-START
134+ * SCALAR("another scalar",single-quoted)
135+ * DOCUMENT-START
136+ * SCALAR("yet another scalar",single-quoted)
137+ * STREAM-END
138+ *
139+ * We have already introduced the SCALAR token above. The following tokens are
140+ * used to describe aliases, anchors, tag, and scalars:
141+ *
142+ * ALIAS(anchor)
143+ * ANCHOR(anchor)
144+ * TAG(handle,suffix)
145+ * SCALAR(value,style)
146+ *
147+ * The following series of examples illustrate the usage of these tokens:
148+ *
149+ * 1. A recursive sequence:
150+ *
151+ * &A [ *A ]
152+ *
153+ * Tokens:
154+ *
155+ * STREAM-START(utf-8)
156+ * ANCHOR("A")
157+ * FLOW-SEQUENCE-START
158+ * ALIAS("A")
159+ * FLOW-SEQUENCE-END
160+ * STREAM-END
161+ *
162+ * 2. A tagged scalar:
163+ *
164+ * !!float "3.14" # A good approximation.
165+ *
166+ * Tokens:
167+ *
168+ * STREAM-START(utf-8)
169+ * TAG("!!","float")
170+ * SCALAR("3.14",double-quoted)
171+ * STREAM-END
172+ *
173+ * 3. Various scalar styles:
174+ *
175+ * --- # Implicit empty plain scalars do not produce tokens.
176+ * --- a plain scalar
177+ * --- 'a single-quoted scalar'
178+ * --- "a double-quoted scalar"
179+ * --- |-
180+ * a literal scalar
181+ * --- >-
182+ * a folded
183+ * scalar
184+ *
185+ * Tokens:
186+ *
187+ * STREAM-START(utf-8)
188+ * DOCUMENT-START
189+ * DOCUMENT-START
190+ * SCALAR("a plain scalar",plain)
191+ * DOCUMENT-START
192+ * SCALAR("a single-quoted scalar",single-quoted)
193+ * DOCUMENT-START
194+ * SCALAR("a double-quoted scalar",double-quoted)
195+ * DOCUMENT-START
196+ * SCALAR("a literal scalar",literal)
197+ * DOCUMENT-START
198+ * SCALAR("a folded scalar",folded)
199+ * STREAM-END
200+ *
201+ * Now it's time to review collection-related tokens. We will start with
202+ * flow collections:
203+ *
204+ * FLOW-SEQUENCE-START
205+ * FLOW-SEQUENCE-END
206+ * FLOW-MAPPING-START
207+ * FLOW-MAPPING-END
208+ * FLOW-ENTRY
209+ * KEY
210+ * VALUE
211+ *
212+ * The tokens FLOW-SEQUENCE-START, FLOW-SEQUENCE-END, FLOW-MAPPING-START, and
213+ * FLOW-MAPPING-END represent the indicators '[', ']', '{', and '}'
214+ * correspondingly. FLOW-ENTRY represent the ',' indicator. Finally the
215+ * indicators '?' and ':', which are used for denoting mapping keys and values,
216+ * are represented by the KEY and VALUE tokens.
217+ *
218+ * The following examples show flow collections:
219+ *
220+ * 1. A flow sequence:
221+ *
222+ * [item 1, item 2, item 3]
223+ *
224+ * Tokens:
225+ *
226+ * STREAM-START(utf-8)
227+ * FLOW-SEQUENCE-START
228+ * SCALAR("item 1",plain)
229+ * FLOW-ENTRY
230+ * SCALAR("item 2",plain)
231+ * FLOW-ENTRY
232+ * SCALAR("item 3",plain)
233+ * FLOW-SEQUENCE-END
234+ * STREAM-END
235+ *
236+ * 2. A flow mapping:
237+ *
238+ * {
239+ * a simple key: a value, # Note that the KEY token is produced.
240+ * ? a complex key: another value,
241+ * }
242+ *
243+ * Tokens:
244+ *
245+ * STREAM-START(utf-8)
246+ * FLOW-MAPPING-START
247+ * KEY
248+ * SCALAR("a simple key",plain)
249+ * VALUE
250+ * SCALAR("a value",plain)
251+ * FLOW-ENTRY
252+ * KEY
253+ * SCALAR("a complex key",plain)
254+ * VALUE
255+ * SCALAR("another value",plain)
256+ * FLOW-ENTRY
257+ * FLOW-MAPPING-END
258+ * STREAM-END
259+ *
260+ * A simple key is a key which is not denoted by the '?' indicator. Note that
261+ * the Scanner still produce the KEY token whenever it encounters a simple key.
262+ *
263+ * For scanning block collections, the following tokens are used (note that we
264+ * repeat KEY and VALUE here):
265+ *
266+ * BLOCK-SEQUENCE-START
267+ * BLOCK-MAPPING-START
268+ * BLOCK-END
269+ * BLOCK-ENTRY
270+ * KEY
271+ * VALUE
272+ *
273+ * The tokens BLOCK-SEQUENCE-START and BLOCK-MAPPING-START denote indentation
274+ * increase that precedes a block collection (cf. the INDENT token in Python).
275+ * The token BLOCK-END denote indentation decrease that ends a block collection
276+ * (cf. the DEDENT token in Python). However YAML has some syntax pecularities
277+ * that makes detections of these tokens more complex.
278+ *
279+ * The tokens BLOCK-ENTRY, KEY, and VALUE are used to represent the indicators
280+ * '-', '?', and ':' correspondingly.
281+ *
282+ * The following examples show how the tokens BLOCK-SEQUENCE-START,
283+ * BLOCK-MAPPING-START, and BLOCK-END are emitted by the Scanner:
284+ *
285+ * 1. Block sequences:
286+ *
287+ * - item 1
288+ * - item 2
289+ * -
290+ * - item 3.1
291+ * - item 3.2
292+ * -
293+ * key 1: value 1
294+ * key 2: value 2
295+ *
296+ * Tokens:
297+ *
298+ * STREAM-START(utf-8)
299+ * BLOCK-SEQUENCE-START
300+ * BLOCK-ENTRY
301+ * SCALAR("item 1",plain)
302+ * BLOCK-ENTRY
303+ * SCALAR("item 2",plain)
304+ * BLOCK-ENTRY
305+ * BLOCK-SEQUENCE-START
306+ * BLOCK-ENTRY
307+ * SCALAR("item 3.1",plain)
308+ * BLOCK-ENTRY
309+ * SCALAR("item 3.2",plain)
310+ * BLOCK-END
311+ * BLOCK-ENTRY
312+ * BLOCK-MAPPING-START
313+ * KEY
314+ * SCALAR("key 1",plain)
315+ * VALUE
316+ * SCALAR("value 1",plain)
317+ * KEY
318+ * SCALAR("key 2",plain)
319+ * VALUE
320+ * SCALAR("value 2",plain)
321+ * BLOCK-END
322+ * BLOCK-END
323+ * STREAM-END
324+ *
325+ * 2. Block mappings:
326+ *
327+ * a simple key: a value # The KEY token is produced here.
328+ * ? a complex key
329+ * : another value
330+ * a mapping:
331+ * key 1: value 1
332+ * key 2: value 2
333+ * a sequence:
334+ * - item 1
335+ * - item 2
336+ *
337+ * Tokens:
338+ *
339+ * STREAM-START(utf-8)
340+ * BLOCK-MAPPING-START
341+ * KEY
342+ * SCALAR("a simple key",plain)
343+ * VALUE
344+ * SCALAR("a value",plain)
345+ * KEY
346+ * SCALAR("a complex key",plain)
347+ * VALUE
348+ * SCALAR("another value",plain)
349+ * KEY
350+ * SCALAR("a mapping",plain)
351+ * BLOCK-MAPPING-START
352+ * KEY
353+ * SCALAR("key 1",plain)
354+ * VALUE
355+ * SCALAR("value 1",plain)
356+ * KEY
357+ * SCALAR("key 2",plain)
358+ * VALUE
359+ * SCALAR("value 2",plain)
360+ * BLOCK-END
361+ * KEY
362+ * SCALAR("a sequence",plain)
363+ * VALUE
364+ * BLOCK-SEQUENCE-START
365+ * BLOCK-ENTRY
366+ * SCALAR("item 1",plain)
367+ * BLOCK-ENTRY
368+ * SCALAR("item 2",plain)
369+ * BLOCK-END
370+ * BLOCK-END
371+ * STREAM-END
372+ *
373+ * YAML does not always require to start a new block collection from a new
374+ * line. If the current line contains only '-', '?', and ':' indicators, a new
375+ * block collection may start at the current line. The following examples
376+ * illustrate this case:
377+ *
378+ * 1. Collections in a sequence:
379+ *
380+ * - - item 1
381+ * - item 2
382+ * - key 1: value 1
383+ * key 2: value 2
384+ * - ? complex key
385+ * : complex value
386+ *
387+ * Tokens:
388+ *
389+ * STREAM-START(utf-8)
390+ * BLOCK-SEQUENCE-START
391+ * BLOCK-ENTRY
392+ * BLOCK-SEQUENCE-START
393+ * BLOCK-ENTRY
394+ * SCALAR("item 1",plain)
395+ * BLOCK-ENTRY
396+ * SCALAR("item 2",plain)
397+ * BLOCK-END
398+ * BLOCK-ENTRY
399+ * BLOCK-MAPPING-START
400+ * KEY
401+ * SCALAR("key 1",plain)
402+ * VALUE
403+ * SCALAR("value 1",plain)
404+ * KEY
405+ * SCALAR("key 2",plain)
406+ * VALUE
407+ * SCALAR("value 2",plain)
408+ * BLOCK-END
409+ * BLOCK-ENTRY
410+ * BLOCK-MAPPING-START
411+ * KEY
412+ * SCALAR("complex key")
413+ * VALUE
414+ * SCALAR("complex value")
415+ * BLOCK-END
416+ * BLOCK-END
417+ * STREAM-END
418+ *
419+ * 2. Collections in a mapping:
420+ *
421+ * ? a sequence
422+ * : - item 1
423+ * - item 2
424+ * ? a mapping
425+ * : key 1: value 1
426+ * key 2: value 2
427+ *
428+ * Tokens:
429+ *
430+ * STREAM-START(utf-8)
431+ * BLOCK-MAPPING-START
432+ * KEY
433+ * SCALAR("a sequence",plain)
434+ * VALUE
435+ * BLOCK-SEQUENCE-START
436+ * BLOCK-ENTRY
437+ * SCALAR("item 1",plain)
438+ * BLOCK-ENTRY
439+ * SCALAR("item 2",plain)
440+ * BLOCK-END
441+ * KEY
442+ * SCALAR("a mapping",plain)
443+ * VALUE
444+ * BLOCK-MAPPING-START
445+ * KEY
446+ * SCALAR("key 1",plain)
447+ * VALUE
448+ * SCALAR("value 1",plain)
449+ * KEY
450+ * SCALAR("key 2",plain)
451+ * VALUE
452+ * SCALAR("value 2",plain)
453+ * BLOCK-END
454+ * BLOCK-END
455+ * STREAM-END
456+ *
457+ * YAML also permits non-indented sequences if they are included into a block
458+ * mapping. In this case, the token BLOCK-SEQUENCE-START is not produced:
459+ *
460+ * key:
461+ * - item 1 # BLOCK-SEQUENCE-START is NOT produced here.
462+ * - item 2
463+ *
464+ * Tokens:
465+ *
466+ * STREAM-START(utf-8)
467+ * BLOCK-MAPPING-START
468+ * KEY
469+ * SCALAR("key",plain)
470+ * VALUE
471+ * BLOCK-ENTRY
472+ * SCALAR("item 1",plain)
473+ * BLOCK-ENTRY
474+ * SCALAR("item 2",plain)
475+ * BLOCK-END
476+ */
477+
478+#include "yaml_private.h"
479+
480+/*
481+ * Ensure that the buffer contains the required number of characters.
482+ * Return 1 on success, 0 on failure (reader error or memory error).
483+ */
484+
485+#define CACHE(parser,length) \
486+ (parser->unread >= (length) \
487+ ? 1 \
488+ : yaml_parser_update_buffer(parser, (length)))
489+
490+/*
491+ * Advance the buffer pointer.
492+ */
493+
494+#define SKIP(parser) \
495+ (parser->mark.index ++, \
496+ parser->mark.column ++, \
497+ parser->unread --, \
498+ parser->buffer.pointer += WIDTH(parser->buffer))
499+
500+#define SKIP_LINE(parser) \
501+ (IS_CRLF(parser->buffer) ? \
502+ (parser->mark.index += 2, \
503+ parser->mark.column = 0, \
504+ parser->mark.line ++, \
505+ parser->unread -= 2, \
506+ parser->buffer.pointer += 2) : \
507+ IS_BREAK(parser->buffer) ? \
508+ (parser->mark.index ++, \
509+ parser->mark.column = 0, \
510+ parser->mark.line ++, \
511+ parser->unread --, \
512+ parser->buffer.pointer += WIDTH(parser->buffer)) : 0)
513+
514+/*
515+ * Copy a character to a string buffer and advance pointers.
516+ */
517+
518+#define READ(parser,string) \
519+ (STRING_EXTEND(parser,string) ? \
520+ (COPY(string,parser->buffer), \
521+ parser->mark.index ++, \
522+ parser->mark.column ++, \
523+ parser->unread --, \
524+ 1) : 0)
525+
526+/*
527+ * Copy a line break character to a string buffer and advance pointers.
528+ */
529+
530+#define READ_LINE(parser,string) \
531+ (STRING_EXTEND(parser,string) ? \
532+ (((CHECK_AT(parser->buffer,'\r',0) \
533+ && CHECK_AT(parser->buffer,'\n',1)) ? /* CR LF -> LF */ \
534+ (*((string).pointer++) = (yaml_char_t) '\n', \
535+ parser->buffer.pointer += 2, \
536+ parser->mark.index += 2, \
537+ parser->mark.column = 0, \
538+ parser->mark.line ++, \
539+ parser->unread -= 2) : \
540+ (CHECK_AT(parser->buffer,'\r',0) \
541+ || CHECK_AT(parser->buffer,'\n',0)) ? /* CR|LF -> LF */ \
542+ (*((string).pointer++) = (yaml_char_t) '\n', \
543+ parser->buffer.pointer ++, \
544+ parser->mark.index ++, \
545+ parser->mark.column = 0, \
546+ parser->mark.line ++, \
547+ parser->unread --) : \
548+ (CHECK_AT(parser->buffer,'\xC2',0) \
549+ && CHECK_AT(parser->buffer,'\x85',1)) ? /* NEL -> LF */ \
550+ (*((string).pointer++) = (yaml_char_t) '\n', \
551+ parser->buffer.pointer += 2, \
552+ parser->mark.index ++, \
553+ parser->mark.column = 0, \
554+ parser->mark.line ++, \
555+ parser->unread --) : \
556+ (CHECK_AT(parser->buffer,'\xE2',0) && \
557+ CHECK_AT(parser->buffer,'\x80',1) && \
558+ (CHECK_AT(parser->buffer,'\xA8',2) || \
559+ CHECK_AT(parser->buffer,'\xA9',2))) ? /* LS|PS -> LS|PS */ \
560+ (*((string).pointer++) = *(parser->buffer.pointer++), \
561+ *((string).pointer++) = *(parser->buffer.pointer++), \
562+ *((string).pointer++) = *(parser->buffer.pointer++), \
563+ parser->mark.index ++, \
564+ parser->mark.column = 0, \
565+ parser->mark.line ++, \
566+ parser->unread --) : 0), \
567+ 1) : 0)
568+
569+/*
570+ * Public API declarations.
571+ */
572+
573+YAML_DECLARE(int)
574+yaml_parser_scan(yaml_parser_t *parser, yaml_token_t *token);
575+
576+/*
577+ * Error handling.
578+ */
579+
580+static int
581+yaml_parser_set_scanner_error(yaml_parser_t *parser, const char *context,
582+ yaml_mark_t context_mark, const char *problem);
583+
584+/*
585+ * High-level token API.
586+ */
587+
588+YAML_DECLARE(int)
589+yaml_parser_fetch_more_tokens(yaml_parser_t *parser);
590+
591+static int
592+yaml_parser_fetch_next_token(yaml_parser_t *parser);
593+
594+/*
595+ * Potential simple keys.
596+ */
597+
598+static int
599+yaml_parser_stale_simple_keys(yaml_parser_t *parser);
600+
601+static int
602+yaml_parser_save_simple_key(yaml_parser_t *parser);
603+
604+static int
605+yaml_parser_remove_simple_key(yaml_parser_t *parser);
606+
607+static int
608+yaml_parser_increase_flow_level(yaml_parser_t *parser);
609+
610+static int
611+yaml_parser_decrease_flow_level(yaml_parser_t *parser);
612+
613+/*
614+ * Indentation treatment.
615+ */
616+
617+static int
618+yaml_parser_roll_indent(yaml_parser_t *parser, ptrdiff_t column,
619+ ptrdiff_t number, yaml_token_type_t type, yaml_mark_t mark);
620+
621+static int
622+yaml_parser_unroll_indent(yaml_parser_t *parser, ptrdiff_t column);
623+
624+/*
625+ * Token fetchers.
626+ */
627+
628+static int
629+yaml_parser_fetch_stream_start(yaml_parser_t *parser);
630+
631+static int
632+yaml_parser_fetch_stream_end(yaml_parser_t *parser);
633+
634+static int
635+yaml_parser_fetch_directive(yaml_parser_t *parser);
636+
637+static int
638+yaml_parser_fetch_document_indicator(yaml_parser_t *parser,
639+ yaml_token_type_t type);
640+
641+static int
642+yaml_parser_fetch_flow_collection_start(yaml_parser_t *parser,
643+ yaml_token_type_t type);
644+
645+static int
646+yaml_parser_fetch_flow_collection_end(yaml_parser_t *parser,
647+ yaml_token_type_t type);
648+
649+static int
650+yaml_parser_fetch_flow_entry(yaml_parser_t *parser);
651+
652+static int
653+yaml_parser_fetch_block_entry(yaml_parser_t *parser);
654+
655+static int
656+yaml_parser_fetch_key(yaml_parser_t *parser);
657+
658+static int
659+yaml_parser_fetch_value(yaml_parser_t *parser);
660+
661+static int
662+yaml_parser_fetch_anchor(yaml_parser_t *parser, yaml_token_type_t type);
663+
664+static int
665+yaml_parser_fetch_tag(yaml_parser_t *parser);
666+
667+static int
668+yaml_parser_fetch_block_scalar(yaml_parser_t *parser, int literal);
669+
670+static int
671+yaml_parser_fetch_flow_scalar(yaml_parser_t *parser, int single);
672+
673+static int
674+yaml_parser_fetch_plain_scalar(yaml_parser_t *parser);
675+
676+/*
677+ * Token scanners.
678+ */
679+
680+static int
681+yaml_parser_scan_to_next_token(yaml_parser_t *parser);
682+
683+static int
684+yaml_parser_scan_directive(yaml_parser_t *parser, yaml_token_t *token);
685+
686+static int
687+yaml_parser_scan_directive_name(yaml_parser_t *parser,
688+ yaml_mark_t start_mark, yaml_char_t **name);
689+
690+static int
691+yaml_parser_scan_version_directive_value(yaml_parser_t *parser,
692+ yaml_mark_t start_mark, int *major, int *minor);
693+
694+static int
695+yaml_parser_scan_version_directive_number(yaml_parser_t *parser,
696+ yaml_mark_t start_mark, int *number);
697+
698+static int
699+yaml_parser_scan_tag_directive_value(yaml_parser_t *parser,
700+ yaml_mark_t mark, yaml_char_t **handle, yaml_char_t **prefix);
701+
702+static int
703+yaml_parser_scan_anchor(yaml_parser_t *parser, yaml_token_t *token,
704+ yaml_token_type_t type);
705+
706+static int
707+yaml_parser_scan_tag(yaml_parser_t *parser, yaml_token_t *token);
708+
709+static int
710+yaml_parser_scan_tag_handle(yaml_parser_t *parser, int directive,
711+ yaml_mark_t start_mark, yaml_char_t **handle);
712+
713+static int
714+yaml_parser_scan_tag_uri(yaml_parser_t *parser, int directive,
715+ yaml_char_t *head, yaml_mark_t start_mark, yaml_char_t **uri);
716+
717+static int
718+yaml_parser_scan_uri_escapes(yaml_parser_t *parser, int directive,
719+ yaml_mark_t start_mark, yaml_string_t *string);
720+
721+static int
722+yaml_parser_scan_block_scalar(yaml_parser_t *parser, yaml_token_t *token,
723+ int literal);
724+
725+static int
726+yaml_parser_scan_block_scalar_breaks(yaml_parser_t *parser,
727+ int *indent, yaml_string_t *breaks,
728+ yaml_mark_t start_mark, yaml_mark_t *end_mark);
729+
730+static int
731+yaml_parser_scan_flow_scalar(yaml_parser_t *parser, yaml_token_t *token,
732+ int single);
733+
734+static int
735+yaml_parser_scan_plain_scalar(yaml_parser_t *parser, yaml_token_t *token);
736+
737+/*
738+ * Get the next token.
739+ */
740+
741+YAML_DECLARE(int)
742+yaml_parser_scan(yaml_parser_t *parser, yaml_token_t *token)
743+{
744+ assert(parser); /* Non-NULL parser object is expected. */
745+ assert(token); /* Non-NULL token object is expected. */
746+
747+ /* Erase the token object. */
748+
749+ memset(token, 0, sizeof(yaml_token_t));
750+
751+ /* No tokens after STREAM-END or error. */
752+
753+ if (parser->stream_end_produced || parser->error) {
754+ return 1;
755+ }
756+
757+ /* Ensure that the tokens queue contains enough tokens. */
758+
759+ if (!parser->token_available) {
760+ if (!yaml_parser_fetch_more_tokens(parser))
761+ return 0;
762+ }
763+
764+ /* Fetch the next token from the queue. */
765+
766+ *token = DEQUEUE(parser, parser->tokens);
767+ parser->token_available = 0;
768+ parser->tokens_parsed ++;
769+
770+ if (token->type == YAML_STREAM_END_TOKEN) {
771+ parser->stream_end_produced = 1;
772+ }
773+
774+ return 1;
775+}
776+
777+/*
778+ * Set the scanner error and return 0.
779+ */
780+
781+static int
782+yaml_parser_set_scanner_error(yaml_parser_t *parser, const char *context,
783+ yaml_mark_t context_mark, const char *problem)
784+{
785+ parser->error = YAML_SCANNER_ERROR;
786+ parser->context = context;
787+ parser->context_mark = context_mark;
788+ parser->problem = problem;
789+ parser->problem_mark = parser->mark;
790+
791+ return 0;
792+}
793+
794+/*
795+ * Ensure that the tokens queue contains at least one token which can be
796+ * returned to the Parser.
797+ */
798+
799+YAML_DECLARE(int)
800+yaml_parser_fetch_more_tokens(yaml_parser_t *parser)
801+{
802+ int need_more_tokens;
803+
804+ /* While we need more tokens to fetch, do it. */
805+
806+ while (1)
807+ {
808+ /*
809+ * Check if we really need to fetch more tokens.
810+ */
811+
812+ need_more_tokens = 0;
813+
814+ if (parser->tokens.head == parser->tokens.tail)
815+ {
816+ /* Queue is empty. */
817+
818+ need_more_tokens = 1;
819+ }
820+ else
821+ {
822+ yaml_simple_key_t *simple_key;
823+
824+ /* Check if any potential simple key may occupy the head position. */
825+
826+ if (!yaml_parser_stale_simple_keys(parser))
827+ return 0;
828+
829+ for (simple_key = parser->simple_keys.start;
830+ simple_key != parser->simple_keys.top; simple_key++) {
831+ if (simple_key->possible
832+ && simple_key->token_number == parser->tokens_parsed) {
833+ need_more_tokens = 1;
834+ break;
835+ }
836+ }
837+ }
838+
839+ /* We are finished. */
840+
841+ if (!need_more_tokens)
842+ break;
843+
844+ /* Fetch the next token. */
845+
846+ if (!yaml_parser_fetch_next_token(parser))
847+ return 0;
848+ }
849+
850+ parser->token_available = 1;
851+
852+ return 1;
853+}
854+
855+/*
856+ * The dispatcher for token fetchers.
857+ */
858+
859+static int
860+yaml_parser_fetch_next_token(yaml_parser_t *parser)
861+{
862+ /* Ensure that the buffer is initialized. */
863+
864+ if (!CACHE(parser, 1))
865+ return 0;
866+
867+ /* Check if we just started scanning. Fetch STREAM-START then. */
868+
869+ if (!parser->stream_start_produced)
870+ return yaml_parser_fetch_stream_start(parser);
871+
872+ /* Eat whitespaces and comments until we reach the next token. */
873+
874+ if (!yaml_parser_scan_to_next_token(parser))
875+ return 0;
876+
877+ /* Remove obsolete potential simple keys. */
878+
879+ if (!yaml_parser_stale_simple_keys(parser))
880+ return 0;
881+
882+ /* Check the indentation level against the current column. */
883+
884+ if (!yaml_parser_unroll_indent(parser, parser->mark.column))
885+ return 0;
886+
887+ /*
888+ * Ensure that the buffer contains at least 4 characters. 4 is the length
889+ * of the longest indicators ('--- ' and '... ').
890+ */
891+
892+ if (!CACHE(parser, 4))
893+ return 0;
894+
895+ /* Is it the end of the stream? */
896+
897+ if (IS_Z(parser->buffer))
898+ return yaml_parser_fetch_stream_end(parser);
899+
900+ /* Is it a directive? */
901+
902+ if (parser->mark.column == 0 && CHECK(parser->buffer, '%'))
903+ return yaml_parser_fetch_directive(parser);
904+
905+ /* Is it the document start indicator? */
906+
907+ if (parser->mark.column == 0
908+ && CHECK_AT(parser->buffer, '-', 0)
909+ && CHECK_AT(parser->buffer, '-', 1)
910+ && CHECK_AT(parser->buffer, '-', 2)
911+ && IS_BLANKZ_AT(parser->buffer, 3))
912+ return yaml_parser_fetch_document_indicator(parser,
913+ YAML_DOCUMENT_START_TOKEN);
914+
915+ /* Is it the document end indicator? */
916+
917+ if (parser->mark.column == 0
918+ && CHECK_AT(parser->buffer, '.', 0)
919+ && CHECK_AT(parser->buffer, '.', 1)
920+ && CHECK_AT(parser->buffer, '.', 2)
921+ && IS_BLANKZ_AT(parser->buffer, 3))
922+ return yaml_parser_fetch_document_indicator(parser,
923+ YAML_DOCUMENT_END_TOKEN);
924+
925+ /* Is it the flow sequence start indicator? */
926+
927+ if (CHECK(parser->buffer, '['))
928+ return yaml_parser_fetch_flow_collection_start(parser,
929+ YAML_FLOW_SEQUENCE_START_TOKEN);
930+
931+ /* Is it the flow mapping start indicator? */
932+
933+ if (CHECK(parser->buffer, '{'))
934+ return yaml_parser_fetch_flow_collection_start(parser,
935+ YAML_FLOW_MAPPING_START_TOKEN);
936+
937+ /* Is it the flow sequence end indicator? */
938+
939+ if (CHECK(parser->buffer, ']'))
940+ return yaml_parser_fetch_flow_collection_end(parser,
941+ YAML_FLOW_SEQUENCE_END_TOKEN);
942+
943+ /* Is it the flow mapping end indicator? */
944+
945+ if (CHECK(parser->buffer, '}'))
946+ return yaml_parser_fetch_flow_collection_end(parser,
947+ YAML_FLOW_MAPPING_END_TOKEN);
948+
949+ /* Is it the flow entry indicator? */
950+
951+ if (CHECK(parser->buffer, ','))
952+ return yaml_parser_fetch_flow_entry(parser);
953+
954+ /* Is it the block entry indicator? */
955+
956+ if (CHECK(parser->buffer, '-') && IS_BLANKZ_AT(parser->buffer, 1))
957+ return yaml_parser_fetch_block_entry(parser);
958+
959+ /* Is it the key indicator? */
960+
961+ if (CHECK(parser->buffer, '?')
962+ && (parser->flow_level || IS_BLANKZ_AT(parser->buffer, 1)))
963+ return yaml_parser_fetch_key(parser);
964+
965+ /* Is it the value indicator? */
966+
967+ if (CHECK(parser->buffer, ':')
968+ && (parser->flow_level || IS_BLANKZ_AT(parser->buffer, 1)))
969+ return yaml_parser_fetch_value(parser);
970+
971+ /* Is it an alias? */
972+
973+ if (CHECK(parser->buffer, '*'))
974+ return yaml_parser_fetch_anchor(parser, YAML_ALIAS_TOKEN);
975+
976+ /* Is it an anchor? */
977+
978+ if (CHECK(parser->buffer, '&'))
979+ return yaml_parser_fetch_anchor(parser, YAML_ANCHOR_TOKEN);
980+
981+ /* Is it a tag? */
982+
983+ if (CHECK(parser->buffer, '!'))
984+ return yaml_parser_fetch_tag(parser);
985+
986+ /* Is it a literal scalar? */
987+
988+ if (CHECK(parser->buffer, '|') && !parser->flow_level)
989+ return yaml_parser_fetch_block_scalar(parser, 1);
990+
991+ /* Is it a folded scalar? */
992+
993+ if (CHECK(parser->buffer, '>') && !parser->flow_level)
994+ return yaml_parser_fetch_block_scalar(parser, 0);
995+
996+ /* Is it a single-quoted scalar? */
997+
998+ if (CHECK(parser->buffer, '\''))
999+ return yaml_parser_fetch_flow_scalar(parser, 1);
1000+
1001+ /* Is it a double-quoted scalar? */
1002+
1003+ if (CHECK(parser->buffer, '"'))
1004+ return yaml_parser_fetch_flow_scalar(parser, 0);
1005+
1006+ /*
1007+ * Is it a plain scalar?
1008+ *
1009+ * A plain scalar may start with any non-blank characters except
1010+ *
1011+ * '-', '?', ':', ',', '[', ']', '{', '}',
1012+ * '#', '&', '*', '!', '|', '>', '\'', '\"',
1013+ * '%', '@', '`'.
1014+ *
1015+ * In the block context (and, for the '-' indicator, in the flow context
1016+ * too), it may also start with the characters
1017+ *
1018+ * '-', '?', ':'
1019+ *
1020+ * if it is followed by a non-space character.
1021+ *
1022+ * The last rule is more restrictive than the specification requires.
1023+ */
1024+
1025+ if (!(IS_BLANKZ(parser->buffer) || CHECK(parser->buffer, '-')
1026+ || CHECK(parser->buffer, '?') || CHECK(parser->buffer, ':')
1027+ || CHECK(parser->buffer, ',') || CHECK(parser->buffer, '[')
1028+ || CHECK(parser->buffer, ']') || CHECK(parser->buffer, '{')
1029+ || CHECK(parser->buffer, '}') || CHECK(parser->buffer, '#')
1030+ || CHECK(parser->buffer, '&') || CHECK(parser->buffer, '*')
1031+ || CHECK(parser->buffer, '!') || CHECK(parser->buffer, '|')
1032+ || CHECK(parser->buffer, '>') || CHECK(parser->buffer, '\'')
1033+ || CHECK(parser->buffer, '"') || CHECK(parser->buffer, '%')
1034+ || CHECK(parser->buffer, '@') || CHECK(parser->buffer, '`')) ||
1035+ (CHECK(parser->buffer, '-') && !IS_BLANK_AT(parser->buffer, 1)) ||
1036+ (!parser->flow_level &&
1037+ (CHECK(parser->buffer, '?') || CHECK(parser->buffer, ':'))
1038+ && !IS_BLANKZ_AT(parser->buffer, 1)))
1039+ return yaml_parser_fetch_plain_scalar(parser);
1040+
1041+ /*
1042+ * If we don't determine the token type so far, it is an error.
1043+ */
1044+
1045+ return yaml_parser_set_scanner_error(parser,
1046+ "while scanning for the next token", parser->mark,
1047+ "found character that cannot start any token");
1048+}
1049+
1050+/*
1051+ * Check the list of potential simple keys and remove the positions that
1052+ * cannot contain simple keys anymore.
1053+ */
1054+
1055+static int
1056+yaml_parser_stale_simple_keys(yaml_parser_t *parser)
1057+{
1058+ yaml_simple_key_t *simple_key;
1059+
1060+ /* Check for a potential simple key for each flow level. */
1061+
1062+ for (simple_key = parser->simple_keys.start;
1063+ simple_key != parser->simple_keys.top; simple_key ++)
1064+ {
1065+ /*
1066+ * The specification requires that a simple key
1067+ *
1068+ * - is limited to a single line,
1069+ * - is shorter than 1024 characters.
1070+ */
1071+
1072+ if (simple_key->possible
1073+ && (simple_key->mark.line < parser->mark.line
1074+ || simple_key->mark.index+1024 < parser->mark.index)) {
1075+
1076+ /* Check if the potential simple key to be removed is required. */
1077+
1078+ if (simple_key->required) {
1079+ return yaml_parser_set_scanner_error(parser,
1080+ "while scanning a simple key", simple_key->mark,
1081+ "could not find expected ':'");
1082+ }
1083+
1084+ simple_key->possible = 0;
1085+ }
1086+ }
1087+
1088+ return 1;
1089+}
1090+
1091+/*
1092+ * Check if a simple key may start at the current position and add it if
1093+ * needed.
1094+ */
1095+
1096+static int
1097+yaml_parser_save_simple_key(yaml_parser_t *parser)
1098+{
1099+ /*
1100+ * A simple key is required at the current position if the scanner is in
1101+ * the block context and the current column coincides with the indentation
1102+ * level.
1103+ */
1104+
1105+ int required = (!parser->flow_level
1106+ && parser->indent == (ptrdiff_t)parser->mark.column);
1107+
1108+ /*
1109+ * A simple key is required only when it is the first token in the current
1110+ * line. Therefore it is always allowed. But we add a check anyway.
1111+ */
1112+
1113+ assert(parser->simple_key_allowed || !required); /* Impossible. */
1114+
1115+ /*
1116+ * If the current position may start a simple key, save it.
1117+ */
1118+
1119+ if (parser->simple_key_allowed)
1120+ {
1121+ yaml_simple_key_t simple_key;
1122+ simple_key.possible = 1;
1123+ simple_key.required = required;
1124+ simple_key.token_number =
1125+ parser->tokens_parsed + (parser->tokens.tail - parser->tokens.head);
1126+ simple_key.mark = parser->mark;
1127+
1128+ if (!yaml_parser_remove_simple_key(parser)) return 0;
1129+
1130+ *(parser->simple_keys.top-1) = simple_key;
1131+ }
1132+
1133+ return 1;
1134+}
1135+
1136+/*
1137+ * Remove a potential simple key at the current flow level.
1138+ */
1139+
1140+static int
1141+yaml_parser_remove_simple_key(yaml_parser_t *parser)
1142+{
1143+ yaml_simple_key_t *simple_key = parser->simple_keys.top-1;
1144+
1145+ if (simple_key->possible)
1146+ {
1147+ /* If the key is required, it is an error. */
1148+
1149+ if (simple_key->required) {
1150+ return yaml_parser_set_scanner_error(parser,
1151+ "while scanning a simple key", simple_key->mark,
1152+ "could not find expected ':'");
1153+ }
1154+ }
1155+
1156+ /* Remove the key from the stack. */
1157+
1158+ simple_key->possible = 0;
1159+
1160+ return 1;
1161+}
1162+
1163+/*
1164+ * Increase the flow level and resize the simple key list if needed.
1165+ */
1166+
1167+static int
1168+yaml_parser_increase_flow_level(yaml_parser_t *parser)
1169+{
1170+ yaml_simple_key_t empty_simple_key = { 0, 0, 0, { 0, 0, 0 } };
1171+
1172+ /* Reset the simple key on the next level. */
1173+
1174+ if (!PUSH(parser, parser->simple_keys, empty_simple_key))
1175+ return 0;
1176+
1177+ /* Increase the flow level. */
1178+
1179+ if (parser->flow_level == INT_MAX) {
1180+ parser->error = YAML_MEMORY_ERROR;
1181+ return 0;
1182+ }
1183+
1184+ parser->flow_level++;
1185+
1186+ return 1;
1187+}
1188+
1189+/*
1190+ * Decrease the flow level.
1191+ */
1192+
1193+static int
1194+yaml_parser_decrease_flow_level(yaml_parser_t *parser)
1195+{
1196+ yaml_simple_key_t dummy_key; /* Used to eliminate a compiler warning. */
1197+
1198+ if (parser->flow_level) {
1199+ parser->flow_level --;
1200+ dummy_key = POP(parser, parser->simple_keys);
1201+ }
1202+
1203+ return 1;
1204+}
1205+
1206+/*
1207+ * Push the current indentation level to the stack and set the new level
1208+ * the current column is greater than the indentation level. In this case,
1209+ * append or insert the specified token into the token queue.
1210+ *
1211+ */
1212+
1213+static int
1214+yaml_parser_roll_indent(yaml_parser_t *parser, ptrdiff_t column,
1215+ ptrdiff_t number, yaml_token_type_t type, yaml_mark_t mark)
1216+{
1217+ yaml_token_t token;
1218+
1219+ /* In the flow context, do nothing. */
1220+
1221+ if (parser->flow_level)
1222+ return 1;
1223+
1224+ if (parser->indent < column)
1225+ {
1226+ /*
1227+ * Push the current indentation level to the stack and set the new
1228+ * indentation level.
1229+ */
1230+
1231+ if (!PUSH(parser, parser->indents, parser->indent))
1232+ return 0;
1233+
1234+ if (column > INT_MAX) {
1235+ parser->error = YAML_MEMORY_ERROR;
1236+ return 0;
1237+ }
1238+
1239+ parser->indent = column;
1240+
1241+ /* Create a token and insert it into the queue. */
1242+
1243+ TOKEN_INIT(token, type, mark, mark);
1244+
1245+ if (number == -1) {
1246+ if (!ENQUEUE(parser, parser->tokens, token))
1247+ return 0;
1248+ }
1249+ else {
1250+ if (!QUEUE_INSERT(parser,
1251+ parser->tokens, number - parser->tokens_parsed, token))
1252+ return 0;
1253+ }
1254+ }
1255+
1256+ return 1;
1257+}
1258+
1259+/*
1260+ * Pop indentation levels from the indents stack until the current level
1261+ * becomes less or equal to the column. For each intendation level, append
1262+ * the BLOCK-END token.
1263+ */
1264+
1265+
1266+static int
1267+yaml_parser_unroll_indent(yaml_parser_t *parser, ptrdiff_t column)
1268+{
1269+ yaml_token_t token;
1270+
1271+ /* In the flow context, do nothing. */
1272+
1273+ if (parser->flow_level)
1274+ return 1;
1275+
1276+ /* Loop through the intendation levels in the stack. */
1277+
1278+ while (parser->indent > column)
1279+ {
1280+ /* Create a token and append it to the queue. */
1281+
1282+ TOKEN_INIT(token, YAML_BLOCK_END_TOKEN, parser->mark, parser->mark);
1283+
1284+ if (!ENQUEUE(parser, parser->tokens, token))
1285+ return 0;
1286+
1287+ /* Pop the indentation level. */
1288+
1289+ parser->indent = POP(parser, parser->indents);
1290+ }
1291+
1292+ return 1;
1293+}
1294+
1295+/*
1296+ * Initialize the scanner and produce the STREAM-START token.
1297+ */
1298+
1299+static int
1300+yaml_parser_fetch_stream_start(yaml_parser_t *parser)
1301+{
1302+ yaml_simple_key_t simple_key = { 0, 0, 0, { 0, 0, 0 } };
1303+ yaml_token_t token;
1304+
1305+ /* Set the initial indentation. */
1306+
1307+ parser->indent = -1;
1308+
1309+ /* Initialize the simple key stack. */
1310+
1311+ if (!PUSH(parser, parser->simple_keys, simple_key))
1312+ return 0;
1313+
1314+ /* A simple key is allowed at the beginning of the stream. */
1315+
1316+ parser->simple_key_allowed = 1;
1317+
1318+ /* We have started. */
1319+
1320+ parser->stream_start_produced = 1;
1321+
1322+ /* Create the STREAM-START token and append it to the queue. */
1323+
1324+ STREAM_START_TOKEN_INIT(token, parser->encoding,
1325+ parser->mark, parser->mark);
1326+
1327+ if (!ENQUEUE(parser, parser->tokens, token))
1328+ return 0;
1329+
1330+ return 1;
1331+}
1332+
1333+/*
1334+ * Produce the STREAM-END token and shut down the scanner.
1335+ */
1336+
1337+static int
1338+yaml_parser_fetch_stream_end(yaml_parser_t *parser)
1339+{
1340+ yaml_token_t token;
1341+
1342+ /* Force new line. */
1343+
1344+ if (parser->mark.column != 0) {
1345+ parser->mark.column = 0;
1346+ parser->mark.line ++;
1347+ }
1348+
1349+ /* Reset the indentation level. */
1350+
1351+ if (!yaml_parser_unroll_indent(parser, -1))
1352+ return 0;
1353+
1354+ /* Reset simple keys. */
1355+
1356+ if (!yaml_parser_remove_simple_key(parser))
1357+ return 0;
1358+
1359+ parser->simple_key_allowed = 0;
1360+
1361+ /* Create the STREAM-END token and append it to the queue. */
1362+
1363+ STREAM_END_TOKEN_INIT(token, parser->mark, parser->mark);
1364+
1365+ if (!ENQUEUE(parser, parser->tokens, token))
1366+ return 0;
1367+
1368+ return 1;
1369+}
1370+
1371+/*
1372+ * Produce a VERSION-DIRECTIVE or TAG-DIRECTIVE token.
1373+ */
1374+
1375+static int
1376+yaml_parser_fetch_directive(yaml_parser_t *parser)
1377+{
1378+ yaml_token_t token;
1379+
1380+ /* Reset the indentation level. */
1381+
1382+ if (!yaml_parser_unroll_indent(parser, -1))
1383+ return 0;
1384+
1385+ /* Reset simple keys. */
1386+
1387+ if (!yaml_parser_remove_simple_key(parser))
1388+ return 0;
1389+
1390+ parser->simple_key_allowed = 0;
1391+
1392+ /* Create the YAML-DIRECTIVE or TAG-DIRECTIVE token. */
1393+
1394+ if (!yaml_parser_scan_directive(parser, &token))
1395+ return 0;
1396+
1397+ /* Append the token to the queue. */
1398+
1399+ if (!ENQUEUE(parser, parser->tokens, token)) {
1400+ yaml_token_delete(&token);
1401+ return 0;
1402+ }
1403+
1404+ return 1;
1405+}
1406+
1407+/*
1408+ * Produce the DOCUMENT-START or DOCUMENT-END token.
1409+ */
1410+
1411+static int
1412+yaml_parser_fetch_document_indicator(yaml_parser_t *parser,
1413+ yaml_token_type_t type)
1414+{
1415+ yaml_mark_t start_mark, end_mark;
1416+ yaml_token_t token;
1417+
1418+ /* Reset the indentation level. */
1419+
1420+ if (!yaml_parser_unroll_indent(parser, -1))
1421+ return 0;
1422+
1423+ /* Reset simple keys. */
1424+
1425+ if (!yaml_parser_remove_simple_key(parser))
1426+ return 0;
1427+
1428+ parser->simple_key_allowed = 0;
1429+
1430+ /* Consume the token. */
1431+
1432+ start_mark = parser->mark;
1433+
1434+ SKIP(parser);
1435+ SKIP(parser);
1436+ SKIP(parser);
1437+
1438+ end_mark = parser->mark;
1439+
1440+ /* Create the DOCUMENT-START or DOCUMENT-END token. */
1441+
1442+ TOKEN_INIT(token, type, start_mark, end_mark);
1443+
1444+ /* Append the token to the queue. */
1445+
1446+ if (!ENQUEUE(parser, parser->tokens, token))
1447+ return 0;
1448+
1449+ return 1;
1450+}
1451+
1452+/*
1453+ * Produce the FLOW-SEQUENCE-START or FLOW-MAPPING-START token.
1454+ */
1455+
1456+static int
1457+yaml_parser_fetch_flow_collection_start(yaml_parser_t *parser,
1458+ yaml_token_type_t type)
1459+{
1460+ yaml_mark_t start_mark, end_mark;
1461+ yaml_token_t token;
1462+
1463+ /* The indicators '[' and '{' may start a simple key. */
1464+
1465+ if (!yaml_parser_save_simple_key(parser))
1466+ return 0;
1467+
1468+ /* Increase the flow level. */
1469+
1470+ if (!yaml_parser_increase_flow_level(parser))
1471+ return 0;
1472+
1473+ /* A simple key may follow the indicators '[' and '{'. */
1474+
1475+ parser->simple_key_allowed = 1;
1476+
1477+ /* Consume the token. */
1478+
1479+ start_mark = parser->mark;
1480+ SKIP(parser);
1481+ end_mark = parser->mark;
1482+
1483+ /* Create the FLOW-SEQUENCE-START of FLOW-MAPPING-START token. */
1484+
1485+ TOKEN_INIT(token, type, start_mark, end_mark);
1486+
1487+ /* Append the token to the queue. */
1488+
1489+ if (!ENQUEUE(parser, parser->tokens, token))
1490+ return 0;
1491+
1492+ return 1;
1493+}
1494+
1495+/*
1496+ * Produce the FLOW-SEQUENCE-END or FLOW-MAPPING-END token.
1497+ */
1498+
1499+static int
1500+yaml_parser_fetch_flow_collection_end(yaml_parser_t *parser,
1501+ yaml_token_type_t type)
1502+{
1503+ yaml_mark_t start_mark, end_mark;
1504+ yaml_token_t token;
1505+
1506+ /* Reset any potential simple key on the current flow level. */
1507+
1508+ if (!yaml_parser_remove_simple_key(parser))
1509+ return 0;
1510+
1511+ /* Decrease the flow level. */
1512+
1513+ if (!yaml_parser_decrease_flow_level(parser))
1514+ return 0;
1515+
1516+ /* No simple keys after the indicators ']' and '}'. */
1517+
1518+ parser->simple_key_allowed = 0;
1519+
1520+ /* Consume the token. */
1521+
1522+ start_mark = parser->mark;
1523+ SKIP(parser);
1524+ end_mark = parser->mark;
1525+
1526+ /* Create the FLOW-SEQUENCE-END of FLOW-MAPPING-END token. */
1527+
1528+ TOKEN_INIT(token, type, start_mark, end_mark);
1529+
1530+ /* Append the token to the queue. */
1531+
1532+ if (!ENQUEUE(parser, parser->tokens, token))
1533+ return 0;
1534+
1535+ return 1;
1536+}
1537+
1538+/*
1539+ * Produce the FLOW-ENTRY token.
1540+ */
1541+
1542+static int
1543+yaml_parser_fetch_flow_entry(yaml_parser_t *parser)
1544+{
1545+ yaml_mark_t start_mark, end_mark;
1546+ yaml_token_t token;
1547+
1548+ /* Reset any potential simple keys on the current flow level. */
1549+
1550+ if (!yaml_parser_remove_simple_key(parser))
1551+ return 0;
1552+
1553+ /* Simple keys are allowed after ','. */
1554+
1555+ parser->simple_key_allowed = 1;
1556+
1557+ /* Consume the token. */
1558+
1559+ start_mark = parser->mark;
1560+ SKIP(parser);
1561+ end_mark = parser->mark;
1562+
1563+ /* Create the FLOW-ENTRY token and append it to the queue. */
1564+
1565+ TOKEN_INIT(token, YAML_FLOW_ENTRY_TOKEN, start_mark, end_mark);
1566+
1567+ if (!ENQUEUE(parser, parser->tokens, token))
1568+ return 0;
1569+
1570+ return 1;
1571+}
1572+
1573+/*
1574+ * Produce the BLOCK-ENTRY token.
1575+ */
1576+
1577+static int
1578+yaml_parser_fetch_block_entry(yaml_parser_t *parser)
1579+{
1580+ yaml_mark_t start_mark, end_mark;
1581+ yaml_token_t token;
1582+
1583+ /* Check if the scanner is in the block context. */
1584+
1585+ if (!parser->flow_level)
1586+ {
1587+ /* Check if we are allowed to start a new entry. */
1588+
1589+ if (!parser->simple_key_allowed) {
1590+ return yaml_parser_set_scanner_error(parser, NULL, parser->mark,
1591+ "block sequence entries are not allowed in this context");
1592+ }
1593+
1594+ /* Add the BLOCK-SEQUENCE-START token if needed. */
1595+
1596+ if (!yaml_parser_roll_indent(parser, parser->mark.column, -1,
1597+ YAML_BLOCK_SEQUENCE_START_TOKEN, parser->mark))
1598+ return 0;
1599+ }
1600+ else
1601+ {
1602+ /*
1603+ * It is an error for the '-' indicator to occur in the flow context,
1604+ * but we let the Parser detect and report about it because the Parser
1605+ * is able to point to the context.
1606+ */
1607+ }
1608+
1609+ /* Reset any potential simple keys on the current flow level. */
1610+
1611+ if (!yaml_parser_remove_simple_key(parser))
1612+ return 0;
1613+
1614+ /* Simple keys are allowed after '-'. */
1615+
1616+ parser->simple_key_allowed = 1;
1617+
1618+ /* Consume the token. */
1619+
1620+ start_mark = parser->mark;
1621+ SKIP(parser);
1622+ end_mark = parser->mark;
1623+
1624+ /* Create the BLOCK-ENTRY token and append it to the queue. */
1625+
1626+ TOKEN_INIT(token, YAML_BLOCK_ENTRY_TOKEN, start_mark, end_mark);
1627+
1628+ if (!ENQUEUE(parser, parser->tokens, token))
1629+ return 0;
1630+
1631+ return 1;
1632+}
1633+
1634+/*
1635+ * Produce the KEY token.
1636+ */
1637+
1638+static int
1639+yaml_parser_fetch_key(yaml_parser_t *parser)
1640+{
1641+ yaml_mark_t start_mark, end_mark;
1642+ yaml_token_t token;
1643+
1644+ /* In the block context, additional checks are required. */
1645+
1646+ if (!parser->flow_level)
1647+ {
1648+ /* Check if we are allowed to start a new key (not nessesary simple). */
1649+
1650+ if (!parser->simple_key_allowed) {
1651+ return yaml_parser_set_scanner_error(parser, NULL, parser->mark,
1652+ "mapping keys are not allowed in this context");
1653+ }
1654+
1655+ /* Add the BLOCK-MAPPING-START token if needed. */
1656+
1657+ if (!yaml_parser_roll_indent(parser, parser->mark.column, -1,
1658+ YAML_BLOCK_MAPPING_START_TOKEN, parser->mark))
1659+ return 0;
1660+ }
1661+
1662+ /* Reset any potential simple keys on the current flow level. */
1663+
1664+ if (!yaml_parser_remove_simple_key(parser))
1665+ return 0;
1666+
1667+ /* Simple keys are allowed after '?' in the block context. */
1668+
1669+ parser->simple_key_allowed = (!parser->flow_level);
1670+
1671+ /* Consume the token. */
1672+
1673+ start_mark = parser->mark;
1674+ SKIP(parser);
1675+ end_mark = parser->mark;
1676+
1677+ /* Create the KEY token and append it to the queue. */
1678+
1679+ TOKEN_INIT(token, YAML_KEY_TOKEN, start_mark, end_mark);
1680+
1681+ if (!ENQUEUE(parser, parser->tokens, token))
1682+ return 0;
1683+
1684+ return 1;
1685+}
1686+
1687+/*
1688+ * Produce the VALUE token.
1689+ */
1690+
1691+static int
1692+yaml_parser_fetch_value(yaml_parser_t *parser)
1693+{
1694+ yaml_mark_t start_mark, end_mark;
1695+ yaml_token_t token;
1696+ yaml_simple_key_t *simple_key = parser->simple_keys.top-1;
1697+
1698+ /* Have we found a simple key? */
1699+
1700+ if (simple_key->possible)
1701+ {
1702+
1703+ /* Create the KEY token and insert it into the queue. */
1704+
1705+ TOKEN_INIT(token, YAML_KEY_TOKEN, simple_key->mark, simple_key->mark);
1706+
1707+ if (!QUEUE_INSERT(parser, parser->tokens,
1708+ simple_key->token_number - parser->tokens_parsed, token))
1709+ return 0;
1710+
1711+ /* In the block context, we may need to add the BLOCK-MAPPING-START token. */
1712+
1713+ if (!yaml_parser_roll_indent(parser, simple_key->mark.column,
1714+ simple_key->token_number,
1715+ YAML_BLOCK_MAPPING_START_TOKEN, simple_key->mark))
1716+ return 0;
1717+
1718+ /* Remove the simple key. */
1719+
1720+ simple_key->possible = 0;
1721+
1722+ /* A simple key cannot follow another simple key. */
1723+
1724+ parser->simple_key_allowed = 0;
1725+ }
1726+ else
1727+ {
1728+ /* The ':' indicator follows a complex key. */
1729+
1730+ /* In the block context, extra checks are required. */
1731+
1732+ if (!parser->flow_level)
1733+ {
1734+ /* Check if we are allowed to start a complex value. */
1735+
1736+ if (!parser->simple_key_allowed) {
1737+ return yaml_parser_set_scanner_error(parser, NULL, parser->mark,
1738+ "mapping values are not allowed in this context");
1739+ }
1740+
1741+ /* Add the BLOCK-MAPPING-START token if needed. */
1742+
1743+ if (!yaml_parser_roll_indent(parser, parser->mark.column, -1,
1744+ YAML_BLOCK_MAPPING_START_TOKEN, parser->mark))
1745+ return 0;
1746+ }
1747+
1748+ /* Simple keys after ':' are allowed in the block context. */
1749+
1750+ parser->simple_key_allowed = (!parser->flow_level);
1751+ }
1752+
1753+ /* Consume the token. */
1754+
1755+ start_mark = parser->mark;
1756+ SKIP(parser);
1757+ end_mark = parser->mark;
1758+
1759+ /* Create the VALUE token and append it to the queue. */
1760+
1761+ TOKEN_INIT(token, YAML_VALUE_TOKEN, start_mark, end_mark);
1762+
1763+ if (!ENQUEUE(parser, parser->tokens, token))
1764+ return 0;
1765+
1766+ return 1;
1767+}
1768+
1769+/*
1770+ * Produce the ALIAS or ANCHOR token.
1771+ */
1772+
1773+static int
1774+yaml_parser_fetch_anchor(yaml_parser_t *parser, yaml_token_type_t type)
1775+{
1776+ yaml_token_t token;
1777+
1778+ /* An anchor or an alias could be a simple key. */
1779+
1780+ if (!yaml_parser_save_simple_key(parser))
1781+ return 0;
1782+
1783+ /* A simple key cannot follow an anchor or an alias. */
1784+
1785+ parser->simple_key_allowed = 0;
1786+
1787+ /* Create the ALIAS or ANCHOR token and append it to the queue. */
1788+
1789+ if (!yaml_parser_scan_anchor(parser, &token, type))
1790+ return 0;
1791+
1792+ if (!ENQUEUE(parser, parser->tokens, token)) {
1793+ yaml_token_delete(&token);
1794+ return 0;
1795+ }
1796+ return 1;
1797+}
1798+
1799+/*
1800+ * Produce the TAG token.
1801+ */
1802+
1803+static int
1804+yaml_parser_fetch_tag(yaml_parser_t *parser)
1805+{
1806+ yaml_token_t token;
1807+
1808+ /* A tag could be a simple key. */
1809+
1810+ if (!yaml_parser_save_simple_key(parser))
1811+ return 0;
1812+
1813+ /* A simple key cannot follow a tag. */
1814+
1815+ parser->simple_key_allowed = 0;
1816+
1817+ /* Create the TAG token and append it to the queue. */
1818+
1819+ if (!yaml_parser_scan_tag(parser, &token))
1820+ return 0;
1821+
1822+ if (!ENQUEUE(parser, parser->tokens, token)) {
1823+ yaml_token_delete(&token);
1824+ return 0;
1825+ }
1826+
1827+ return 1;
1828+}
1829+
1830+/*
1831+ * Produce the SCALAR(...,literal) or SCALAR(...,folded) tokens.
1832+ */
1833+
1834+static int
1835+yaml_parser_fetch_block_scalar(yaml_parser_t *parser, int literal)
1836+{
1837+ yaml_token_t token;
1838+
1839+ /* Remove any potential simple keys. */
1840+
1841+ if (!yaml_parser_remove_simple_key(parser))
1842+ return 0;
1843+
1844+ /* A simple key may follow a block scalar. */
1845+
1846+ parser->simple_key_allowed = 1;
1847+
1848+ /* Create the SCALAR token and append it to the queue. */
1849+
1850+ if (!yaml_parser_scan_block_scalar(parser, &token, literal))
1851+ return 0;
1852+
1853+ if (!ENQUEUE(parser, parser->tokens, token)) {
1854+ yaml_token_delete(&token);
1855+ return 0;
1856+ }
1857+
1858+ return 1;
1859+}
1860+
1861+/*
1862+ * Produce the SCALAR(...,single-quoted) or SCALAR(...,double-quoted) tokens.
1863+ */
1864+
1865+static int
1866+yaml_parser_fetch_flow_scalar(yaml_parser_t *parser, int single)
1867+{
1868+ yaml_token_t token;
1869+
1870+ /* A plain scalar could be a simple key. */
1871+
1872+ if (!yaml_parser_save_simple_key(parser))
1873+ return 0;
1874+
1875+ /* A simple key cannot follow a flow scalar. */
1876+
1877+ parser->simple_key_allowed = 0;
1878+
1879+ /* Create the SCALAR token and append it to the queue. */
1880+
1881+ if (!yaml_parser_scan_flow_scalar(parser, &token, single))
1882+ return 0;
1883+
1884+ if (!ENQUEUE(parser, parser->tokens, token)) {
1885+ yaml_token_delete(&token);
1886+ return 0;
1887+ }
1888+
1889+ return 1;
1890+}
1891+
1892+/*
1893+ * Produce the SCALAR(...,plain) token.
1894+ */
1895+
1896+static int
1897+yaml_parser_fetch_plain_scalar(yaml_parser_t *parser)
1898+{
1899+ yaml_token_t token;
1900+
1901+ /* A plain scalar could be a simple key. */
1902+
1903+ if (!yaml_parser_save_simple_key(parser))
1904+ return 0;
1905+
1906+ /* A simple key cannot follow a flow scalar. */
1907+
1908+ parser->simple_key_allowed = 0;
1909+
1910+ /* Create the SCALAR token and append it to the queue. */
1911+
1912+ if (!yaml_parser_scan_plain_scalar(parser, &token))
1913+ return 0;
1914+
1915+ if (!ENQUEUE(parser, parser->tokens, token)) {
1916+ yaml_token_delete(&token);
1917+ return 0;
1918+ }
1919+
1920+ return 1;
1921+}
1922+
1923+/*
1924+ * Eat whitespaces and comments until the next token is found.
1925+ */
1926+
1927+static int
1928+yaml_parser_scan_to_next_token(yaml_parser_t *parser)
1929+{
1930+ /* Until the next token is not found. */
1931+
1932+ while (1)
1933+ {
1934+ /* Allow the BOM mark to start a line. */
1935+
1936+ if (!CACHE(parser, 1)) return 0;
1937+
1938+ if (parser->mark.column == 0 && IS_BOM(parser->buffer))
1939+ SKIP(parser);
1940+
1941+ /*
1942+ * Eat whitespaces.
1943+ *
1944+ * Tabs are allowed:
1945+ *
1946+ * - in the flow context;
1947+ * - in the block context, but not at the beginning of the line or
1948+ * after '-', '?', or ':' (complex value).
1949+ */
1950+
1951+ if (!CACHE(parser, 1)) return 0;
1952+
1953+ while (CHECK(parser->buffer,' ') ||
1954+ ((parser->flow_level || !parser->simple_key_allowed) &&
1955+ CHECK(parser->buffer, '\t'))) {
1956+ SKIP(parser);
1957+ if (!CACHE(parser, 1)) return 0;
1958+ }
1959+
1960+ /* Eat a comment until a line break. */
1961+
1962+ if (CHECK(parser->buffer, '#')) {
1963+ while (!IS_BREAKZ(parser->buffer)) {
1964+ SKIP(parser);
1965+ if (!CACHE(parser, 1)) return 0;
1966+ }
1967+ }
1968+
1969+ /* If it is a line break, eat it. */
1970+
1971+ if (IS_BREAK(parser->buffer))
1972+ {
1973+ if (!CACHE(parser, 2)) return 0;
1974+ SKIP_LINE(parser);
1975+
1976+ /* In the block context, a new line may start a simple key. */
1977+
1978+ if (!parser->flow_level) {
1979+ parser->simple_key_allowed = 1;
1980+ }
1981+ }
1982+ else
1983+ {
1984+ /* We have found a token. */
1985+
1986+ break;
1987+ }
1988+ }
1989+
1990+ return 1;
1991+}
1992+
1993+/*
1994+ * Scan a YAML-DIRECTIVE or TAG-DIRECTIVE token.
1995+ *
1996+ * Scope:
1997+ * %YAML 1.1 # a comment \n
1998+ * ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1999+ * %TAG !yaml! tag:yaml.org,2002: \n
2000+ * ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2001+ */
2002+
2003+int
2004+yaml_parser_scan_directive(yaml_parser_t *parser, yaml_token_t *token)
2005+{
2006+ yaml_mark_t start_mark, end_mark;
2007+ yaml_char_t *name = NULL;
2008+ int major, minor;
2009+ yaml_char_t *handle = NULL, *prefix = NULL;
2010+
2011+ /* Eat '%'. */
2012+
2013+ start_mark = parser->mark;
2014+
2015+ SKIP(parser);
2016+
2017+ /* Scan the directive name. */
2018+
2019+ if (!yaml_parser_scan_directive_name(parser, start_mark, &name))
2020+ goto error;
2021+
2022+ /* Is it a YAML directive? */
2023+
2024+ if (strcmp((char *)name, "YAML") == 0)
2025+ {
2026+ /* Scan the VERSION directive value. */
2027+
2028+ if (!yaml_parser_scan_version_directive_value(parser, start_mark,
2029+ &major, &minor))
2030+ goto error;
2031+
2032+ end_mark = parser->mark;
2033+
2034+ /* Create a VERSION-DIRECTIVE token. */
2035+
2036+ VERSION_DIRECTIVE_TOKEN_INIT(*token, major, minor,
2037+ start_mark, end_mark);
2038+ }
2039+
2040+ /* Is it a TAG directive? */
2041+
2042+ else if (strcmp((char *)name, "TAG") == 0)
2043+ {
2044+ /* Scan the TAG directive value. */
2045+
2046+ if (!yaml_parser_scan_tag_directive_value(parser, start_mark,
2047+ &handle, &prefix))
2048+ goto error;
2049+
2050+ end_mark = parser->mark;
2051+
2052+ /* Create a TAG-DIRECTIVE token. */
2053+
2054+ TAG_DIRECTIVE_TOKEN_INIT(*token, handle, prefix,
2055+ start_mark, end_mark);
2056+ }
2057+
2058+ /* Unknown directive. */
2059+
2060+ else
2061+ {
2062+ yaml_parser_set_scanner_error(parser, "while scanning a directive",
2063+ start_mark, "found uknown directive name");
2064+ goto error;
2065+ }
2066+
2067+ /* Eat the rest of the line including any comments. */
2068+
2069+ if (!CACHE(parser, 1)) goto error;
2070+
2071+ while (IS_BLANK(parser->buffer)) {
2072+ SKIP(parser);
2073+ if (!CACHE(parser, 1)) goto error;
2074+ }
2075+
2076+ if (CHECK(parser->buffer, '#')) {
2077+ while (!IS_BREAKZ(parser->buffer)) {
2078+ SKIP(parser);
2079+ if (!CACHE(parser, 1)) goto error;
2080+ }
2081+ }
2082+
2083+ /* Check if we are at the end of the line. */
2084+
2085+ if (!IS_BREAKZ(parser->buffer)) {
2086+ yaml_parser_set_scanner_error(parser, "while scanning a directive",
2087+ start_mark, "did not find expected comment or line break");
2088+ goto error;
2089+ }
2090+
2091+ /* Eat a line break. */
2092+
2093+ if (IS_BREAK(parser->buffer)) {
2094+ if (!CACHE(parser, 2)) goto error;
2095+ SKIP_LINE(parser);
2096+ }
2097+
2098+ yaml_free(name);
2099+
2100+ return 1;
2101+
2102+error:
2103+ yaml_free(prefix);
2104+ yaml_free(handle);
2105+ yaml_free(name);
2106+ return 0;
2107+}
2108+
2109+/*
2110+ * Scan the directive name.
2111+ *
2112+ * Scope:
2113+ * %YAML 1.1 # a comment \n
2114+ * ^^^^
2115+ * %TAG !yaml! tag:yaml.org,2002: \n
2116+ * ^^^
2117+ */
2118+
2119+static int
2120+yaml_parser_scan_directive_name(yaml_parser_t *parser,
2121+ yaml_mark_t start_mark, yaml_char_t **name)
2122+{
2123+ yaml_string_t string = NULL_STRING;
2124+
2125+ if (!STRING_INIT(parser, string, INITIAL_STRING_SIZE)) goto error;
2126+
2127+ /* Consume the directive name. */
2128+
2129+ if (!CACHE(parser, 1)) goto error;
2130+
2131+ while (IS_ALPHA(parser->buffer))
2132+ {
2133+ if (!READ(parser, string)) goto error;
2134+ if (!CACHE(parser, 1)) goto error;
2135+ }
2136+
2137+ /* Check if the name is empty. */
2138+
2139+ if (string.start == string.pointer) {
2140+ yaml_parser_set_scanner_error(parser, "while scanning a directive",
2141+ start_mark, "could not find expected directive name");
2142+ goto error;
2143+ }
2144+
2145+ /* Check for an blank character after the name. */
2146+
2147+ if (!IS_BLANKZ(parser->buffer)) {
2148+ yaml_parser_set_scanner_error(parser, "while scanning a directive",
2149+ start_mark, "found unexpected non-alphabetical character");
2150+ goto error;
2151+ }
2152+
2153+ *name = string.start;
2154+
2155+ return 1;
2156+
2157+error:
2158+ STRING_DEL(parser, string);
2159+ return 0;
2160+}
2161+
2162+/*
2163+ * Scan the value of VERSION-DIRECTIVE.
2164+ *
2165+ * Scope:
2166+ * %YAML 1.1 # a comment \n
2167+ * ^^^^^^
2168+ */
2169+
2170+static int
2171+yaml_parser_scan_version_directive_value(yaml_parser_t *parser,
2172+ yaml_mark_t start_mark, int *major, int *minor)
2173+{
2174+ /* Eat whitespaces. */
2175+
2176+ if (!CACHE(parser, 1)) return 0;
2177+
2178+ while (IS_BLANK(parser->buffer)) {
2179+ SKIP(parser);
2180+ if (!CACHE(parser, 1)) return 0;
2181+ }
2182+
2183+ /* Consume the major version number. */
2184+
2185+ if (!yaml_parser_scan_version_directive_number(parser, start_mark, major))
2186+ return 0;
2187+
2188+ /* Eat '.'. */
2189+
2190+ if (!CHECK(parser->buffer, '.')) {
2191+ return yaml_parser_set_scanner_error(parser, "while scanning a %YAML directive",
2192+ start_mark, "did not find expected digit or '.' character");
2193+ }
2194+
2195+ SKIP(parser);
2196+
2197+ /* Consume the minor version number. */
2198+
2199+ if (!yaml_parser_scan_version_directive_number(parser, start_mark, minor))
2200+ return 0;
2201+
2202+ return 1;
2203+}
2204+
2205+#define MAX_NUMBER_LENGTH 9
2206+
2207+/*
2208+ * Scan the version number of VERSION-DIRECTIVE.
2209+ *
2210+ * Scope:
2211+ * %YAML 1.1 # a comment \n
2212+ * ^
2213+ * %YAML 1.1 # a comment \n
2214+ * ^
2215+ */
2216+
2217+static int
2218+yaml_parser_scan_version_directive_number(yaml_parser_t *parser,
2219+ yaml_mark_t start_mark, int *number)
2220+{
2221+ int value = 0;
2222+ size_t length = 0;
2223+
2224+ /* Repeat while the next character is digit. */
2225+
2226+ if (!CACHE(parser, 1)) return 0;
2227+
2228+ while (IS_DIGIT(parser->buffer))
2229+ {
2230+ /* Check if the number is too long. */
2231+
2232+ if (++length > MAX_NUMBER_LENGTH) {
2233+ return yaml_parser_set_scanner_error(parser, "while scanning a %YAML directive",
2234+ start_mark, "found extremely long version number");
2235+ }
2236+
2237+ value = value*10 + AS_DIGIT(parser->buffer);
2238+
2239+ SKIP(parser);
2240+
2241+ if (!CACHE(parser, 1)) return 0;
2242+ }
2243+
2244+ /* Check if the number was present. */
2245+
2246+ if (!length) {
2247+ return yaml_parser_set_scanner_error(parser, "while scanning a %YAML directive",
2248+ start_mark, "did not find expected version number");
2249+ }
2250+
2251+ *number = value;
2252+
2253+ return 1;
2254+}
2255+
2256+/*
2257+ * Scan the value of a TAG-DIRECTIVE token.
2258+ *
2259+ * Scope:
2260+ * %TAG !yaml! tag:yaml.org,2002: \n
2261+ * ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2262+ */
2263+
2264+static int
2265+yaml_parser_scan_tag_directive_value(yaml_parser_t *parser,
2266+ yaml_mark_t start_mark, yaml_char_t **handle, yaml_char_t **prefix)
2267+{
2268+ yaml_char_t *handle_value = NULL;
2269+ yaml_char_t *prefix_value = NULL;
2270+
2271+ /* Eat whitespaces. */
2272+
2273+ if (!CACHE(parser, 1)) goto error;
2274+
2275+ while (IS_BLANK(parser->buffer)) {
2276+ SKIP(parser);
2277+ if (!CACHE(parser, 1)) goto error;
2278+ }
2279+
2280+ /* Scan a handle. */
2281+
2282+ if (!yaml_parser_scan_tag_handle(parser, 1, start_mark, &handle_value))
2283+ goto error;
2284+
2285+ /* Expect a whitespace. */
2286+
2287+ if (!CACHE(parser, 1)) goto error;
2288+
2289+ if (!IS_BLANK(parser->buffer)) {
2290+ yaml_parser_set_scanner_error(parser, "while scanning a %TAG directive",
2291+ start_mark, "did not find expected whitespace");
2292+ goto error;
2293+ }
2294+
2295+ /* Eat whitespaces. */
2296+
2297+ while (IS_BLANK(parser->buffer)) {
2298+ SKIP(parser);
2299+ if (!CACHE(parser, 1)) goto error;
2300+ }
2301+
2302+ /* Scan a prefix. */
2303+
2304+ if (!yaml_parser_scan_tag_uri(parser, 1, NULL, start_mark, &prefix_value))
2305+ goto error;
2306+
2307+ /* Expect a whitespace or line break. */
2308+
2309+ if (!CACHE(parser, 1)) goto error;
2310+
2311+ if (!IS_BLANKZ(parser->buffer)) {
2312+ yaml_parser_set_scanner_error(parser, "while scanning a %TAG directive",
2313+ start_mark, "did not find expected whitespace or line break");
2314+ goto error;
2315+ }
2316+
2317+ *handle = handle_value;
2318+ *prefix = prefix_value;
2319+
2320+ return 1;
2321+
2322+error:
2323+ yaml_free(handle_value);
2324+ yaml_free(prefix_value);
2325+ return 0;
2326+}
2327+
2328+static int
2329+yaml_parser_scan_anchor(yaml_parser_t *parser, yaml_token_t *token,
2330+ yaml_token_type_t type)
2331+{
2332+ int length = 0;
2333+ yaml_mark_t start_mark, end_mark;
2334+ yaml_string_t string = NULL_STRING;
2335+
2336+ if (!STRING_INIT(parser, string, INITIAL_STRING_SIZE)) goto error;
2337+
2338+ /* Eat the indicator character. */
2339+
2340+ start_mark = parser->mark;
2341+
2342+ SKIP(parser);
2343+
2344+ /* Consume the value. */
2345+
2346+ if (!CACHE(parser, 1)) goto error;
2347+
2348+ while (IS_ALPHA(parser->buffer)) {
2349+ if (!READ(parser, string)) goto error;
2350+ if (!CACHE(parser, 1)) goto error;
2351+ length ++;
2352+ }
2353+
2354+ end_mark = parser->mark;
2355+
2356+ /*
2357+ * Check if length of the anchor is greater than 0 and it is followed by
2358+ * a whitespace character or one of the indicators:
2359+ *
2360+ * '?', ':', ',', ']', '}', '%', '@', '`'.
2361+ */
2362+
2363+ if (!length || !(IS_BLANKZ(parser->buffer) || CHECK(parser->buffer, '?')
2364+ || CHECK(parser->buffer, ':') || CHECK(parser->buffer, ',')
2365+ || CHECK(parser->buffer, ']') || CHECK(parser->buffer, '}')
2366+ || CHECK(parser->buffer, '%') || CHECK(parser->buffer, '@')
2367+ || CHECK(parser->buffer, '`'))) {
2368+ yaml_parser_set_scanner_error(parser, type == YAML_ANCHOR_TOKEN ?
2369+ "while scanning an anchor" : "while scanning an alias", start_mark,
2370+ "did not find expected alphabetic or numeric character");
2371+ goto error;
2372+ }
2373+
2374+ /* Create a token. */
2375+
2376+ if (type == YAML_ANCHOR_TOKEN) {
2377+ ANCHOR_TOKEN_INIT(*token, string.start, start_mark, end_mark);
2378+ }
2379+ else {
2380+ ALIAS_TOKEN_INIT(*token, string.start, start_mark, end_mark);
2381+ }
2382+
2383+ return 1;
2384+
2385+error:
2386+ STRING_DEL(parser, string);
2387+ return 0;
2388+}
2389+
2390+/*
2391+ * Scan a TAG token.
2392+ */
2393+
2394+static int
2395+yaml_parser_scan_tag(yaml_parser_t *parser, yaml_token_t *token)
2396+{
2397+ yaml_char_t *handle = NULL;
2398+ yaml_char_t *suffix = NULL;
2399+ yaml_mark_t start_mark, end_mark;
2400+
2401+ start_mark = parser->mark;
2402+
2403+ /* Check if the tag is in the canonical form. */
2404+
2405+ if (!CACHE(parser, 2)) goto error;
2406+
2407+ if (CHECK_AT(parser->buffer, '<', 1))
2408+ {
2409+ /* Set the handle to '' */
2410+
2411+ handle = yaml_malloc(1);
2412+ if (!handle) goto error;
2413+ handle[0] = '\0';
2414+
2415+ /* Eat '!<' */
2416+
2417+ SKIP(parser);
2418+ SKIP(parser);
2419+
2420+ /* Consume the tag value. */
2421+
2422+ if (!yaml_parser_scan_tag_uri(parser, 0, NULL, start_mark, &suffix))
2423+ goto error;
2424+
2425+ /* Check for '>' and eat it. */
2426+
2427+ if (!CHECK(parser->buffer, '>')) {
2428+ yaml_parser_set_scanner_error(parser, "while scanning a tag",
2429+ start_mark, "did not find the expected '>'");
2430+ goto error;
2431+ }
2432+
2433+ SKIP(parser);
2434+ }
2435+ else
2436+ {
2437+ /* The tag has either the '!suffix' or the '!handle!suffix' form. */
2438+
2439+ /* First, try to scan a handle. */
2440+
2441+ if (!yaml_parser_scan_tag_handle(parser, 0, start_mark, &handle))
2442+ goto error;
2443+
2444+ /* Check if it is, indeed, handle. */
2445+
2446+ if (handle[0] == '!' && handle[1] != '\0' && handle[strlen((char *)handle)-1] == '!')
2447+ {
2448+ /* Scan the suffix now. */
2449+
2450+ if (!yaml_parser_scan_tag_uri(parser, 0, NULL, start_mark, &suffix))
2451+ goto error;
2452+ }
2453+ else
2454+ {
2455+ /* It wasn't a handle after all. Scan the rest of the tag. */
2456+
2457+ if (!yaml_parser_scan_tag_uri(parser, 0, handle, start_mark, &suffix))
2458+ goto error;
2459+
2460+ /* Set the handle to '!'. */
2461+
2462+ yaml_free(handle);
2463+ handle = yaml_malloc(2);
2464+ if (!handle) goto error;
2465+ handle[0] = '!';
2466+ handle[1] = '\0';
2467+
2468+ /*
2469+ * A special case: the '!' tag. Set the handle to '' and the
2470+ * suffix to '!'.
2471+ */
2472+
2473+ if (suffix[0] == '\0') {
2474+ yaml_char_t *tmp = handle;
2475+ handle = suffix;
2476+ suffix = tmp;
2477+ }
2478+ }
2479+ }
2480+
2481+ /* Check the character which ends the tag. */
2482+
2483+ if (!CACHE(parser, 1)) goto error;
2484+
2485+ if (!IS_BLANKZ(parser->buffer)) {
2486+ yaml_parser_set_scanner_error(parser, "while scanning a tag",
2487+ start_mark, "did not find expected whitespace or line break");
2488+ goto error;
2489+ }
2490+
2491+ end_mark = parser->mark;
2492+
2493+ /* Create a token. */
2494+
2495+ TAG_TOKEN_INIT(*token, handle, suffix, start_mark, end_mark);
2496+
2497+ return 1;
2498+
2499+error:
2500+ yaml_free(handle);
2501+ yaml_free(suffix);
2502+ return 0;
2503+}
2504+
2505+/*
2506+ * Scan a tag handle.
2507+ */
2508+
2509+static int
2510+yaml_parser_scan_tag_handle(yaml_parser_t *parser, int directive,
2511+ yaml_mark_t start_mark, yaml_char_t **handle)
2512+{
2513+ yaml_string_t string = NULL_STRING;
2514+
2515+ if (!STRING_INIT(parser, string, INITIAL_STRING_SIZE)) goto error;
2516+
2517+ /* Check the initial '!' character. */
2518+
2519+ if (!CACHE(parser, 1)) goto error;
2520+
2521+ if (!CHECK(parser->buffer, '!')) {
2522+ yaml_parser_set_scanner_error(parser, directive ?
2523+ "while scanning a tag directive" : "while scanning a tag",
2524+ start_mark, "did not find expected '!'");
2525+ goto error;
2526+ }
2527+
2528+ /* Copy the '!' character. */
2529+
2530+ if (!READ(parser, string)) goto error;
2531+
2532+ /* Copy all subsequent alphabetical and numerical characters. */
2533+
2534+ if (!CACHE(parser, 1)) goto error;
2535+
2536+ while (IS_ALPHA(parser->buffer))
2537+ {
2538+ if (!READ(parser, string)) goto error;
2539+ if (!CACHE(parser, 1)) goto error;
2540+ }
2541+
2542+ /* Check if the trailing character is '!' and copy it. */
2543+
2544+ if (CHECK(parser->buffer, '!'))
2545+ {
2546+ if (!READ(parser, string)) goto error;
2547+ }
2548+ else
2549+ {
2550+ /*
2551+ * It's either the '!' tag or not really a tag handle. If it's a %TAG
2552+ * directive, it's an error. If it's a tag token, it must be a part of
2553+ * URI.
2554+ */
2555+
2556+ if (directive && !(string.start[0] == '!' && string.start[1] == '\0')) {
2557+ yaml_parser_set_scanner_error(parser, "while parsing a tag directive",
2558+ start_mark, "did not find expected '!'");
2559+ goto error;
2560+ }
2561+ }
2562+
2563+ *handle = string.start;
2564+
2565+ return 1;
2566+
2567+error:
2568+ STRING_DEL(parser, string);
2569+ return 0;
2570+}
2571+
2572+/*
2573+ * Scan a tag.
2574+ */
2575+
2576+static int
2577+yaml_parser_scan_tag_uri(yaml_parser_t *parser, int directive,
2578+ yaml_char_t *head, yaml_mark_t start_mark, yaml_char_t **uri)
2579+{
2580+ size_t length = head ? strlen((char *)head) : 0;
2581+ yaml_string_t string = NULL_STRING;
2582+
2583+ if (!STRING_INIT(parser, string, INITIAL_STRING_SIZE)) goto error;
2584+
2585+ /* Resize the string to include the head. */
2586+
2587+ while ((size_t)(string.end - string.start) <= length) {
2588+ if (!yaml_string_extend(&string.start, &string.pointer, &string.end)) {
2589+ parser->error = YAML_MEMORY_ERROR;
2590+ goto error;
2591+ }
2592+ }
2593+
2594+ /*
2595+ * Copy the head if needed.
2596+ *
2597+ * Note that we don't copy the leading '!' character.
2598+ */
2599+
2600+ if (length > 1) {
2601+ memcpy(string.start, head+1, length-1);
2602+ string.pointer += length-1;
2603+ }
2604+
2605+ /* Scan the tag. */
2606+
2607+ if (!CACHE(parser, 1)) goto error;
2608+
2609+ /*
2610+ * The set of characters that may appear in URI is as follows:
2611+ *
2612+ * '0'-'9', 'A'-'Z', 'a'-'z', '_', '-', ';', '/', '?', ':', '@', '&',
2613+ * '=', '+', '$', ',', '.', '!', '~', '*', '\'', '(', ')', '[', ']',
2614+ * '%'.
2615+ */
2616+
2617+ while (IS_ALPHA(parser->buffer) || CHECK(parser->buffer, ';')
2618+ || CHECK(parser->buffer, '/') || CHECK(parser->buffer, '?')
2619+ || CHECK(parser->buffer, ':') || CHECK(parser->buffer, '@')
2620+ || CHECK(parser->buffer, '&') || CHECK(parser->buffer, '=')
2621+ || CHECK(parser->buffer, '+') || CHECK(parser->buffer, '$')
2622+ || CHECK(parser->buffer, ',') || CHECK(parser->buffer, '.')
2623+ || CHECK(parser->buffer, '!') || CHECK(parser->buffer, '~')
2624+ || CHECK(parser->buffer, '*') || CHECK(parser->buffer, '\'')
2625+ || CHECK(parser->buffer, '(') || CHECK(parser->buffer, ')')
2626+ || CHECK(parser->buffer, '[') || CHECK(parser->buffer, ']')
2627+ || CHECK(parser->buffer, '%'))
2628+ {
2629+ /* Check if it is a URI-escape sequence. */
2630+
2631+ if (CHECK(parser->buffer, '%')) {
2632+ if (!yaml_parser_scan_uri_escapes(parser,
2633+ directive, start_mark, &string)) goto error;
2634+ }
2635+ else {
2636+ if (!READ(parser, string)) goto error;
2637+ }
2638+
2639+ length ++;
2640+ if (!CACHE(parser, 1)) goto error;
2641+ }
2642+
2643+ /* Check if the tag is non-empty. */
2644+
2645+ if (!length) {
2646+ if (!STRING_EXTEND(parser, string))
2647+ goto error;
2648+
2649+ yaml_parser_set_scanner_error(parser, directive ?
2650+ "while parsing a %TAG directive" : "while parsing a tag",
2651+ start_mark, "did not find expected tag URI");
2652+ goto error;
2653+ }
2654+
2655+ *uri = string.start;
2656+
2657+ return 1;
2658+
2659+error:
2660+ STRING_DEL(parser, string);
2661+ return 0;
2662+}
2663+
2664+/*
2665+ * Decode an URI-escape sequence corresponding to a single UTF-8 character.
2666+ */
2667+
2668+static int
2669+yaml_parser_scan_uri_escapes(yaml_parser_t *parser, int directive,
2670+ yaml_mark_t start_mark, yaml_string_t *string)
2671+{
2672+ int width = 0;
2673+
2674+ /* Decode the required number of characters. */
2675+
2676+ do {
2677+
2678+ unsigned char octet = 0;
2679+
2680+ /* Check for a URI-escaped octet. */
2681+
2682+ if (!CACHE(parser, 3)) return 0;
2683+
2684+ if (!(CHECK(parser->buffer, '%')
2685+ && IS_HEX_AT(parser->buffer, 1)
2686+ && IS_HEX_AT(parser->buffer, 2))) {
2687+ return yaml_parser_set_scanner_error(parser, directive ?
2688+ "while parsing a %TAG directive" : "while parsing a tag",
2689+ start_mark, "did not find URI escaped octet");
2690+ }
2691+
2692+ /* Get the octet. */
2693+
2694+ octet = (AS_HEX_AT(parser->buffer, 1) << 4) + AS_HEX_AT(parser->buffer, 2);
2695+
2696+ /* If it is the leading octet, determine the length of the UTF-8 sequence. */
2697+
2698+ if (!width)
2699+ {
2700+ width = (octet & 0x80) == 0x00 ? 1 :
2701+ (octet & 0xE0) == 0xC0 ? 2 :
2702+ (octet & 0xF0) == 0xE0 ? 3 :
2703+ (octet & 0xF8) == 0xF0 ? 4 : 0;
2704+ if (!width) {
2705+ return yaml_parser_set_scanner_error(parser, directive ?
2706+ "while parsing a %TAG directive" : "while parsing a tag",
2707+ start_mark, "found an incorrect leading UTF-8 octet");
2708+ }
2709+ }
2710+ else
2711+ {
2712+ /* Check if the trailing octet is correct. */
2713+
2714+ if ((octet & 0xC0) != 0x80) {
2715+ return yaml_parser_set_scanner_error(parser, directive ?
2716+ "while parsing a %TAG directive" : "while parsing a tag",
2717+ start_mark, "found an incorrect trailing UTF-8 octet");
2718+ }
2719+ }
2720+
2721+ /* Copy the octet and move the pointers. */
2722+
2723+ *(string->pointer++) = octet;
2724+ SKIP(parser);
2725+ SKIP(parser);
2726+ SKIP(parser);
2727+
2728+ } while (--width);
2729+
2730+ return 1;
2731+}
2732+
2733+/*
2734+ * Scan a block scalar.
2735+ */
2736+
2737+static int
2738+yaml_parser_scan_block_scalar(yaml_parser_t *parser, yaml_token_t *token,
2739+ int literal)
2740+{
2741+ yaml_mark_t start_mark;
2742+ yaml_mark_t end_mark;
2743+ yaml_string_t string = NULL_STRING;
2744+ yaml_string_t leading_break = NULL_STRING;
2745+ yaml_string_t trailing_breaks = NULL_STRING;
2746+ int chomping = 0;
2747+ int increment = 0;
2748+ int indent = 0;
2749+ int leading_blank = 0;
2750+ int trailing_blank = 0;
2751+
2752+ if (!STRING_INIT(parser, string, INITIAL_STRING_SIZE)) goto error;
2753+ if (!STRING_INIT(parser, leading_break, INITIAL_STRING_SIZE)) goto error;
2754+ if (!STRING_INIT(parser, trailing_breaks, INITIAL_STRING_SIZE)) goto error;
2755+
2756+ /* Eat the indicator '|' or '>'. */
2757+
2758+ start_mark = parser->mark;
2759+
2760+ SKIP(parser);
2761+
2762+ /* Scan the additional block scalar indicators. */
2763+
2764+ if (!CACHE(parser, 1)) goto error;
2765+
2766+ /* Check for a chomping indicator. */
2767+
2768+ if (CHECK(parser->buffer, '+') || CHECK(parser->buffer, '-'))
2769+ {
2770+ /* Set the chomping method and eat the indicator. */
2771+
2772+ chomping = CHECK(parser->buffer, '+') ? +1 : -1;
2773+
2774+ SKIP(parser);
2775+
2776+ /* Check for an indentation indicator. */
2777+
2778+ if (!CACHE(parser, 1)) goto error;
2779+
2780+ if (IS_DIGIT(parser->buffer))
2781+ {
2782+ /* Check that the intendation is greater than 0. */
2783+
2784+ if (CHECK(parser->buffer, '0')) {
2785+ yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
2786+ start_mark, "found an intendation indicator equal to 0");
2787+ goto error;
2788+ }
2789+
2790+ /* Get the intendation level and eat the indicator. */
2791+
2792+ increment = AS_DIGIT(parser->buffer);
2793+
2794+ SKIP(parser);
2795+ }
2796+ }
2797+
2798+ /* Do the same as above, but in the opposite order. */
2799+
2800+ else if (IS_DIGIT(parser->buffer))
2801+ {
2802+ if (CHECK(parser->buffer, '0')) {
2803+ yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
2804+ start_mark, "found an intendation indicator equal to 0");
2805+ goto error;
2806+ }
2807+
2808+ increment = AS_DIGIT(parser->buffer);
2809+
2810+ SKIP(parser);
2811+
2812+ if (!CACHE(parser, 1)) goto error;
2813+
2814+ if (CHECK(parser->buffer, '+') || CHECK(parser->buffer, '-')) {
2815+ chomping = CHECK(parser->buffer, '+') ? +1 : -1;
2816+
2817+ SKIP(parser);
2818+ }
2819+ }
2820+
2821+ /* Eat whitespaces and comments to the end of the line. */
2822+
2823+ if (!CACHE(parser, 1)) goto error;
2824+
2825+ while (IS_BLANK(parser->buffer)) {
2826+ SKIP(parser);
2827+ if (!CACHE(parser, 1)) goto error;
2828+ }
2829+
2830+ if (CHECK(parser->buffer, '#')) {
2831+ while (!IS_BREAKZ(parser->buffer)) {
2832+ SKIP(parser);
2833+ if (!CACHE(parser, 1)) goto error;
2834+ }
2835+ }
2836+
2837+ /* Check if we are at the end of the line. */
2838+
2839+ if (!IS_BREAKZ(parser->buffer)) {
2840+ yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
2841+ start_mark, "did not find expected comment or line break");
2842+ goto error;
2843+ }
2844+
2845+ /* Eat a line break. */
2846+
2847+ if (IS_BREAK(parser->buffer)) {
2848+ if (!CACHE(parser, 2)) goto error;
2849+ SKIP_LINE(parser);
2850+ }
2851+
2852+ end_mark = parser->mark;
2853+
2854+ /* Set the intendation level if it was specified. */
2855+
2856+ if (increment) {
2857+ indent = parser->indent >= 0 ? parser->indent+increment : increment;
2858+ }
2859+
2860+ /* Scan the leading line breaks and determine the indentation level if needed. */
2861+
2862+ if (!yaml_parser_scan_block_scalar_breaks(parser, &indent, &trailing_breaks,
2863+ start_mark, &end_mark)) goto error;
2864+
2865+ /* Scan the block scalar content. */
2866+
2867+ if (!CACHE(parser, 1)) goto error;
2868+
2869+ while ((int)parser->mark.column == indent && !IS_Z(parser->buffer))
2870+ {
2871+ /*
2872+ * We are at the beginning of a non-empty line.
2873+ */
2874+
2875+ /* Is it a trailing whitespace? */
2876+
2877+ trailing_blank = IS_BLANK(parser->buffer);
2878+
2879+ /* Check if we need to fold the leading line break. */
2880+
2881+ if (!literal && (*leading_break.start == '\n')
2882+ && !leading_blank && !trailing_blank)
2883+ {
2884+ /* Do we need to join the lines by space? */
2885+
2886+ if (*trailing_breaks.start == '\0') {
2887+ if (!STRING_EXTEND(parser, string)) goto error;
2888+ *(string.pointer ++) = ' ';
2889+ }
2890+
2891+ CLEAR(parser, leading_break);
2892+ }
2893+ else {
2894+ if (!JOIN(parser, string, leading_break)) goto error;
2895+ CLEAR(parser, leading_break);
2896+ }
2897+
2898+ /* Append the remaining line breaks. */
2899+
2900+ if (!JOIN(parser, string, trailing_breaks)) goto error;
2901+ CLEAR(parser, trailing_breaks);
2902+
2903+ /* Is it a leading whitespace? */
2904+
2905+ leading_blank = IS_BLANK(parser->buffer);
2906+
2907+ /* Consume the current line. */
2908+
2909+ while (!IS_BREAKZ(parser->buffer)) {
2910+ if (!READ(parser, string)) goto error;
2911+ if (!CACHE(parser, 1)) goto error;
2912+ }
2913+
2914+ /* Consume the line break. */
2915+
2916+ if (!CACHE(parser, 2)) goto error;
2917+
2918+ if (!READ_LINE(parser, leading_break)) goto error;
2919+
2920+ /* Eat the following intendation spaces and line breaks. */
2921+
2922+ if (!yaml_parser_scan_block_scalar_breaks(parser,
2923+ &indent, &trailing_breaks, start_mark, &end_mark)) goto error;
2924+ }
2925+
2926+ /* Chomp the tail. */
2927+
2928+ if (chomping != -1) {
2929+ if (!JOIN(parser, string, leading_break)) goto error;
2930+ }
2931+ if (chomping == 1) {
2932+ if (!JOIN(parser, string, trailing_breaks)) goto error;
2933+ }
2934+
2935+ /* Create a token. */
2936+
2937+ SCALAR_TOKEN_INIT(*token, string.start, string.pointer-string.start,
2938+ literal ? YAML_LITERAL_SCALAR_STYLE : YAML_FOLDED_SCALAR_STYLE,
2939+ start_mark, end_mark);
2940+
2941+ STRING_DEL(parser, leading_break);
2942+ STRING_DEL(parser, trailing_breaks);
2943+
2944+ return 1;
2945+
2946+error:
2947+ STRING_DEL(parser, string);
2948+ STRING_DEL(parser, leading_break);
2949+ STRING_DEL(parser, trailing_breaks);
2950+
2951+ return 0;
2952+}
2953+
2954+/*
2955+ * Scan intendation spaces and line breaks for a block scalar. Determine the
2956+ * intendation level if needed.
2957+ */
2958+
2959+static int
2960+yaml_parser_scan_block_scalar_breaks(yaml_parser_t *parser,
2961+ int *indent, yaml_string_t *breaks,
2962+ yaml_mark_t start_mark, yaml_mark_t *end_mark)
2963+{
2964+ int max_indent = 0;
2965+
2966+ *end_mark = parser->mark;
2967+
2968+ /* Eat the intendation spaces and line breaks. */
2969+
2970+ while (1)
2971+ {
2972+ /* Eat the intendation spaces. */
2973+
2974+ if (!CACHE(parser, 1)) return 0;
2975+
2976+ while ((!*indent || (int)parser->mark.column < *indent)
2977+ && IS_SPACE(parser->buffer)) {
2978+ SKIP(parser);
2979+ if (!CACHE(parser, 1)) return 0;
2980+ }
2981+
2982+ if ((int)parser->mark.column > max_indent)
2983+ max_indent = (int)parser->mark.column;
2984+
2985+ /* Check for a tab character messing the intendation. */
2986+
2987+ if ((!*indent || (int)parser->mark.column < *indent)
2988+ && IS_TAB(parser->buffer)) {
2989+ return yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
2990+ start_mark, "found a tab character where an intendation space is expected");
2991+ }
2992+
2993+ /* Have we found a non-empty line? */
2994+
2995+ if (!IS_BREAK(parser->buffer)) break;
2996+
2997+ /* Consume the line break. */
2998+
2999+ if (!CACHE(parser, 2)) return 0;
3000+ if (!READ_LINE(parser, *breaks)) return 0;
3001+ *end_mark = parser->mark;
3002+ }
3003+
3004+ /* Determine the indentation level if needed. */
3005+
3006+ if (!*indent) {
3007+ *indent = max_indent;
3008+ if (*indent < parser->indent + 1)
3009+ *indent = parser->indent + 1;
3010+ if (*indent < 1)
3011+ *indent = 1;
3012+ }
3013+
3014+ return 1;
3015+}
3016+
3017+/*
3018+ * Scan a quoted scalar.
3019+ */
3020+
3021+static int
3022+yaml_parser_scan_flow_scalar(yaml_parser_t *parser, yaml_token_t *token,
3023+ int single)
3024+{
3025+ yaml_mark_t start_mark;
3026+ yaml_mark_t end_mark;
3027+ yaml_string_t string = NULL_STRING;
3028+ yaml_string_t leading_break = NULL_STRING;
3029+ yaml_string_t trailing_breaks = NULL_STRING;
3030+ yaml_string_t whitespaces = NULL_STRING;
3031+ int leading_blanks;
3032+
3033+ if (!STRING_INIT(parser, string, INITIAL_STRING_SIZE)) goto error;
3034+ if (!STRING_INIT(parser, leading_break, INITIAL_STRING_SIZE)) goto error;
3035+ if (!STRING_INIT(parser, trailing_breaks, INITIAL_STRING_SIZE)) goto error;
3036+ if (!STRING_INIT(parser, whitespaces, INITIAL_STRING_SIZE)) goto error;
3037+
3038+ /* Eat the left quote. */
3039+
3040+ start_mark = parser->mark;
3041+
3042+ SKIP(parser);
3043+
3044+ /* Consume the content of the quoted scalar. */
3045+
3046+ while (1)
3047+ {
3048+ /* Check that there are no document indicators at the beginning of the line. */
3049+
3050+ if (!CACHE(parser, 4)) goto error;
3051+
3052+ if (parser->mark.column == 0 &&
3053+ ((CHECK_AT(parser->buffer, '-', 0) &&
3054+ CHECK_AT(parser->buffer, '-', 1) &&
3055+ CHECK_AT(parser->buffer, '-', 2)) ||
3056+ (CHECK_AT(parser->buffer, '.', 0) &&
3057+ CHECK_AT(parser->buffer, '.', 1) &&
3058+ CHECK_AT(parser->buffer, '.', 2))) &&
3059+ IS_BLANKZ_AT(parser->buffer, 3))
3060+ {
3061+ yaml_parser_set_scanner_error(parser, "while scanning a quoted scalar",
3062+ start_mark, "found unexpected document indicator");
3063+ goto error;
3064+ }
3065+
3066+ /* Check for EOF. */
3067+
3068+ if (IS_Z(parser->buffer)) {
3069+ yaml_parser_set_scanner_error(parser, "while scanning a quoted scalar",
3070+ start_mark, "found unexpected end of stream");
3071+ goto error;
3072+ }
3073+
3074+ /* Consume non-blank characters. */
3075+
3076+ if (!CACHE(parser, 2)) goto error;
3077+
3078+ leading_blanks = 0;
3079+
3080+ while (!IS_BLANKZ(parser->buffer))
3081+ {
3082+ /* Check for an escaped single quote. */
3083+
3084+ if (single && CHECK_AT(parser->buffer, '\'', 0)
3085+ && CHECK_AT(parser->buffer, '\'', 1))
3086+ {
3087+ if (!STRING_EXTEND(parser, string)) goto error;
3088+ *(string.pointer++) = '\'';
3089+ SKIP(parser);
3090+ SKIP(parser);
3091+ }
3092+
3093+ /* Check for the right quote. */
3094+
3095+ else if (CHECK(parser->buffer, single ? '\'' : '"'))
3096+ {
3097+ break;
3098+ }
3099+
3100+ /* Check for an escaped line break. */
3101+
3102+ else if (!single && CHECK(parser->buffer, '\\')
3103+ && IS_BREAK_AT(parser->buffer, 1))
3104+ {
3105+ if (!CACHE(parser, 3)) goto error;
3106+ SKIP(parser);
3107+ SKIP_LINE(parser);
3108+ leading_blanks = 1;
3109+ break;
3110+ }
3111+
3112+ /* Check for an escape sequence. */
3113+
3114+ else if (!single && CHECK(parser->buffer, '\\'))
3115+ {
3116+ size_t code_length = 0;
3117+
3118+ if (!STRING_EXTEND(parser, string)) goto error;
3119+
3120+ /* Check the escape character. */
3121+
3122+ switch (parser->buffer.pointer[1])
3123+ {
3124+ case '0':
3125+ *(string.pointer++) = '\0';
3126+ break;
3127+
3128+ case 'a':
3129+ *(string.pointer++) = '\x07';
3130+ break;
3131+
3132+ case 'b':
3133+ *(string.pointer++) = '\x08';
3134+ break;
3135+
3136+ case 't':
3137+ case '\t':
3138+ *(string.pointer++) = '\x09';
3139+ break;
3140+
3141+ case 'n':
3142+ *(string.pointer++) = '\x0A';
3143+ break;
3144+
3145+ case 'v':
3146+ *(string.pointer++) = '\x0B';
3147+ break;
3148+
3149+ case 'f':
3150+ *(string.pointer++) = '\x0C';
3151+ break;
3152+
3153+ case 'r':
3154+ *(string.pointer++) = '\x0D';
3155+ break;
3156+
3157+ case 'e':
3158+ *(string.pointer++) = '\x1B';
3159+ break;
3160+
3161+ case ' ':
3162+ *(string.pointer++) = '\x20';
3163+ break;
3164+
3165+ case '"':
3166+ *(string.pointer++) = '"';
3167+ break;
3168+
3169+ case '\'':
3170+ *(string.pointer++) = '\'';
3171+ break;
3172+
3173+ case '\\':
3174+ *(string.pointer++) = '\\';
3175+ break;
3176+
3177+ case 'N': /* NEL (#x85) */
3178+ *(string.pointer++) = '\xC2';
3179+ *(string.pointer++) = '\x85';
3180+ break;
3181+
3182+ case '_': /* #xA0 */
3183+ *(string.pointer++) = '\xC2';
3184+ *(string.pointer++) = '\xA0';
3185+ break;
3186+
3187+ case 'L': /* LS (#x2028) */
3188+ *(string.pointer++) = '\xE2';
3189+ *(string.pointer++) = '\x80';
3190+ *(string.pointer++) = '\xA8';
3191+ break;
3192+
3193+ case 'P': /* PS (#x2029) */
3194+ *(string.pointer++) = '\xE2';
3195+ *(string.pointer++) = '\x80';
3196+ *(string.pointer++) = '\xA9';
3197+ break;
3198+
3199+ case 'x':
3200+ code_length = 2;
3201+ break;
3202+
3203+ case 'u':
3204+ code_length = 4;
3205+ break;
3206+
3207+ case 'U':
3208+ code_length = 8;
3209+ break;
3210+
3211+ default:
3212+ yaml_parser_set_scanner_error(parser, "while parsing a quoted scalar",
3213+ start_mark, "found unknown escape character");
3214+ goto error;
3215+ }
3216+
3217+ SKIP(parser);
3218+ SKIP(parser);
3219+
3220+ /* Consume an arbitrary escape code. */
3221+
3222+ if (code_length)
3223+ {
3224+ unsigned int value = 0;
3225+ size_t k;
3226+
3227+ /* Scan the character value. */
3228+
3229+ if (!CACHE(parser, code_length)) goto error;
3230+
3231+ for (k = 0; k < code_length; k ++) {
3232+ if (!IS_HEX_AT(parser->buffer, k)) {
3233+ yaml_parser_set_scanner_error(parser, "while parsing a quoted scalar",
3234+ start_mark, "did not find expected hexdecimal number");
3235+ goto error;
3236+ }
3237+ value = (value << 4) + AS_HEX_AT(parser->buffer, k);
3238+ }
3239+
3240+ /* Check the value and write the character. */
3241+
3242+ if ((value >= 0xD800 && value <= 0xDFFF) || value > 0x10FFFF) {
3243+ yaml_parser_set_scanner_error(parser, "while parsing a quoted scalar",
3244+ start_mark, "found invalid Unicode character escape code");
3245+ goto error;
3246+ }
3247+
3248+ if (value <= 0x7F) {
3249+ *(string.pointer++) = value;
3250+ }
3251+ else if (value <= 0x7FF) {
3252+ *(string.pointer++) = 0xC0 + (value >> 6);
3253+ *(string.pointer++) = 0x80 + (value & 0x3F);
3254+ }
3255+ else if (value <= 0xFFFF) {
3256+ *(string.pointer++) = 0xE0 + (value >> 12);
3257+ *(string.pointer++) = 0x80 + ((value >> 6) & 0x3F);
3258+ *(string.pointer++) = 0x80 + (value & 0x3F);
3259+ }
3260+ else {
3261+ *(string.pointer++) = 0xF0 + (value >> 18);
3262+ *(string.pointer++) = 0x80 + ((value >> 12) & 0x3F);
3263+ *(string.pointer++) = 0x80 + ((value >> 6) & 0x3F);
3264+ *(string.pointer++) = 0x80 + (value & 0x3F);
3265+ }
3266+
3267+ /* Advance the pointer. */
3268+
3269+ for (k = 0; k < code_length; k ++) {
3270+ SKIP(parser);
3271+ }
3272+ }
3273+ }
3274+
3275+ else
3276+ {
3277+ /* It is a non-escaped non-blank character. */
3278+
3279+ if (!READ(parser, string)) goto error;
3280+ }
3281+
3282+ if (!CACHE(parser, 2)) goto error;
3283+ }
3284+
3285+ /* Check if we are at the end of the scalar. */
3286+
3287+ if (CHECK(parser->buffer, single ? '\'' : '"'))
3288+ break;
3289+
3290+ /* Consume blank characters. */
3291+
3292+ if (!CACHE(parser, 1)) goto error;
3293+
3294+ while (IS_BLANK(parser->buffer) || IS_BREAK(parser->buffer))
3295+ {
3296+ if (IS_BLANK(parser->buffer))
3297+ {
3298+ /* Consume a space or a tab character. */
3299+
3300+ if (!leading_blanks) {
3301+ if (!READ(parser, whitespaces)) goto error;
3302+ }
3303+ else {
3304+ SKIP(parser);
3305+ }
3306+ }
3307+ else
3308+ {
3309+ if (!CACHE(parser, 2)) goto error;
3310+
3311+ /* Check if it is a first line break. */
3312+
3313+ if (!leading_blanks)
3314+ {
3315+ CLEAR(parser, whitespaces);
3316+ if (!READ_LINE(parser, leading_break)) goto error;
3317+ leading_blanks = 1;
3318+ }
3319+ else
3320+ {
3321+ if (!READ_LINE(parser, trailing_breaks)) goto error;
3322+ }
3323+ }
3324+ if (!CACHE(parser, 1)) goto error;
3325+ }
3326+
3327+ /* Join the whitespaces or fold line breaks. */
3328+
3329+ if (leading_blanks)
3330+ {
3331+ /* Do we need to fold line breaks? */
3332+
3333+ if (leading_break.start[0] == '\n') {
3334+ if (trailing_breaks.start[0] == '\0') {
3335+ if (!STRING_EXTEND(parser, string)) goto error;
3336+ *(string.pointer++) = ' ';
3337+ }
3338+ else {
3339+ if (!JOIN(parser, string, trailing_breaks)) goto error;
3340+ CLEAR(parser, trailing_breaks);
3341+ }
3342+ CLEAR(parser, leading_break);
3343+ }
3344+ else {
3345+ if (!JOIN(parser, string, leading_break)) goto error;
3346+ if (!JOIN(parser, string, trailing_breaks)) goto error;
3347+ CLEAR(parser, leading_break);
3348+ CLEAR(parser, trailing_breaks);
3349+ }
3350+ }
3351+ else
3352+ {
3353+ if (!JOIN(parser, string, whitespaces)) goto error;
3354+ CLEAR(parser, whitespaces);
3355+ }
3356+ }
3357+
3358+ /* Eat the right quote. */
3359+
3360+ SKIP(parser);
3361+
3362+ end_mark = parser->mark;
3363+
3364+ /* Create a token. */
3365+
3366+ SCALAR_TOKEN_INIT(*token, string.start, string.pointer-string.start,
3367+ single ? YAML_SINGLE_QUOTED_SCALAR_STYLE : YAML_DOUBLE_QUOTED_SCALAR_STYLE,
3368+ start_mark, end_mark);
3369+
3370+ STRING_DEL(parser, leading_break);
3371+ STRING_DEL(parser, trailing_breaks);
3372+ STRING_DEL(parser, whitespaces);
3373+
3374+ return 1;
3375+
3376+error:
3377+ STRING_DEL(parser, string);
3378+ STRING_DEL(parser, leading_break);
3379+ STRING_DEL(parser, trailing_breaks);
3380+ STRING_DEL(parser, whitespaces);
3381+
3382+ return 0;
3383+}
3384+
3385+/*
3386+ * Scan a plain scalar.
3387+ */
3388+
3389+static int
3390+yaml_parser_scan_plain_scalar(yaml_parser_t *parser, yaml_token_t *token)
3391+{
3392+ yaml_mark_t start_mark;
3393+ yaml_mark_t end_mark;
3394+ yaml_string_t string = NULL_STRING;
3395+ yaml_string_t leading_break = NULL_STRING;
3396+ yaml_string_t trailing_breaks = NULL_STRING;
3397+ yaml_string_t whitespaces = NULL_STRING;
3398+ int leading_blanks = 0;
3399+ int indent = parser->indent+1;
3400+
3401+ if (!STRING_INIT(parser, string, INITIAL_STRING_SIZE)) goto error;
3402+ if (!STRING_INIT(parser, leading_break, INITIAL_STRING_SIZE)) goto error;
3403+ if (!STRING_INIT(parser, trailing_breaks, INITIAL_STRING_SIZE)) goto error;
3404+ if (!STRING_INIT(parser, whitespaces, INITIAL_STRING_SIZE)) goto error;
3405+
3406+ start_mark = end_mark = parser->mark;
3407+
3408+ /* Consume the content of the plain scalar. */
3409+
3410+ while (1)
3411+ {
3412+ /* Check for a document indicator. */
3413+
3414+ if (!CACHE(parser, 4)) goto error;
3415+
3416+ if (parser->mark.column == 0 &&
3417+ ((CHECK_AT(parser->buffer, '-', 0) &&
3418+ CHECK_AT(parser->buffer, '-', 1) &&
3419+ CHECK_AT(parser->buffer, '-', 2)) ||
3420+ (CHECK_AT(parser->buffer, '.', 0) &&
3421+ CHECK_AT(parser->buffer, '.', 1) &&
3422+ CHECK_AT(parser->buffer, '.', 2))) &&
3423+ IS_BLANKZ_AT(parser->buffer, 3)) break;
3424+
3425+ /* Check for a comment. */
3426+
3427+ if (CHECK(parser->buffer, '#'))
3428+ break;
3429+
3430+ /* Consume non-blank characters. */
3431+
3432+ while (!IS_BLANKZ(parser->buffer))
3433+ {
3434+ /* Check for 'x:x' in the flow context. TODO: Fix the test "spec-08-13". */
3435+
3436+ if (parser->flow_level
3437+ && CHECK(parser->buffer, ':')
3438+ && !IS_BLANKZ_AT(parser->buffer, 1)) {
3439+ yaml_parser_set_scanner_error(parser, "while scanning a plain scalar",
3440+ start_mark, "found unexpected ':'");
3441+ goto error;
3442+ }
3443+
3444+ /* Check for indicators that may end a plain scalar. */
3445+
3446+ if ((CHECK(parser->buffer, ':') && IS_BLANKZ_AT(parser->buffer, 1))
3447+ || (parser->flow_level &&
3448+ (CHECK(parser->buffer, ',') || CHECK(parser->buffer, ':')
3449+ || CHECK(parser->buffer, '?') || CHECK(parser->buffer, '[')
3450+ || CHECK(parser->buffer, ']') || CHECK(parser->buffer, '{')
3451+ || CHECK(parser->buffer, '}'))))
3452+ break;
3453+
3454+ /* Check if we need to join whitespaces and breaks. */
3455+
3456+ if (leading_blanks || whitespaces.start != whitespaces.pointer)
3457+ {
3458+ if (leading_blanks)
3459+ {
3460+ /* Do we need to fold line breaks? */
3461+
3462+ if (leading_break.start[0] == '\n') {
3463+ if (trailing_breaks.start[0] == '\0') {
3464+ if (!STRING_EXTEND(parser, string)) goto error;
3465+ *(string.pointer++) = ' ';
3466+ }
3467+ else {
3468+ if (!JOIN(parser, string, trailing_breaks)) goto error;
3469+ CLEAR(parser, trailing_breaks);
3470+ }
3471+ CLEAR(parser, leading_break);
3472+ }
3473+ else {
3474+ if (!JOIN(parser, string, leading_break)) goto error;
3475+ if (!JOIN(parser, string, trailing_breaks)) goto error;
3476+ CLEAR(parser, leading_break);
3477+ CLEAR(parser, trailing_breaks);
3478+ }
3479+
3480+ leading_blanks = 0;
3481+ }
3482+ else
3483+ {
3484+ if (!JOIN(parser, string, whitespaces)) goto error;
3485+ CLEAR(parser, whitespaces);
3486+ }
3487+ }
3488+
3489+ /* Copy the character. */
3490+
3491+ if (!READ(parser, string)) goto error;
3492+
3493+ end_mark = parser->mark;
3494+
3495+ if (!CACHE(parser, 2)) goto error;
3496+ }
3497+
3498+ /* Is it the end? */
3499+
3500+ if (!(IS_BLANK(parser->buffer) || IS_BREAK(parser->buffer)))
3501+ break;
3502+
3503+ /* Consume blank characters. */
3504+
3505+ if (!CACHE(parser, 1)) goto error;
3506+
3507+ while (IS_BLANK(parser->buffer) || IS_BREAK(parser->buffer))
3508+ {
3509+ if (IS_BLANK(parser->buffer))
3510+ {
3511+ /* Check for tab character that abuse intendation. */
3512+
3513+ if (leading_blanks && (int)parser->mark.column < indent
3514+ && IS_TAB(parser->buffer)) {
3515+ yaml_parser_set_scanner_error(parser, "while scanning a plain scalar",
3516+ start_mark, "found a tab character that violate intendation");
3517+ goto error;
3518+ }
3519+
3520+ /* Consume a space or a tab character. */
3521+
3522+ if (!leading_blanks) {
3523+ if (!READ(parser, whitespaces)) goto error;
3524+ }
3525+ else {
3526+ SKIP(parser);
3527+ }
3528+ }
3529+ else
3530+ {
3531+ if (!CACHE(parser, 2)) goto error;
3532+
3533+ /* Check if it is a first line break. */
3534+
3535+ if (!leading_blanks)
3536+ {
3537+ CLEAR(parser, whitespaces);
3538+ if (!READ_LINE(parser, leading_break)) goto error;
3539+ leading_blanks = 1;
3540+ }
3541+ else
3542+ {
3543+ if (!READ_LINE(parser, trailing_breaks)) goto error;
3544+ }
3545+ }
3546+ if (!CACHE(parser, 1)) goto error;
3547+ }
3548+
3549+ /* Check intendation level. */
3550+
3551+ if (!parser->flow_level && (int)parser->mark.column < indent)
3552+ break;
3553+ }
3554+
3555+ /* Create a token. */
3556+
3557+ SCALAR_TOKEN_INIT(*token, string.start, string.pointer-string.start,
3558+ YAML_PLAIN_SCALAR_STYLE, start_mark, end_mark);
3559+
3560+ /* Note that we change the 'simple_key_allowed' flag. */
3561+
3562+ if (leading_blanks) {
3563+ parser->simple_key_allowed = 1;
3564+ }
3565+
3566+ STRING_DEL(parser, leading_break);
3567+ STRING_DEL(parser, trailing_breaks);
3568+ STRING_DEL(parser, whitespaces);
3569+
3570+ return 1;
3571+
3572+error:
3573+ STRING_DEL(parser, string);
3574+ STRING_DEL(parser, leading_break);
3575+ STRING_DEL(parser, trailing_breaks);
3576+ STRING_DEL(parser, whitespaces);
3577+
3578+ return 0;
3579+}
3580+