| 1 | # SPDX-License-Identifier: MIT |
| 2 | |
| 3 | # The following YAML grammar is LL(1) and is parsed by a recursive descent |
| 4 | # parser. |
| 5 | # |
| 6 | # stream ::= STREAM-START implicit_document? explicit_document* STREAM-END |
| 7 | # implicit_document ::= block_node DOCUMENT-END* |
| 8 | # explicit_document ::= DIRECTIVE* DOCUMENT-START block_node? DOCUMENT-END* |
| 9 | # block_node_or_indentless_sequence ::= |
| 10 | # ALIAS |
| 11 | # | properties (block_content | indentless_block_sequence)? |
| 12 | # | block_content |
| 13 | # | indentless_block_sequence |
| 14 | # block_node ::= ALIAS |
| 15 | # | properties block_content? |
| 16 | # | block_content |
| 17 | # flow_node ::= ALIAS |
| 18 | # | properties flow_content? |
| 19 | # | flow_content |
| 20 | # properties ::= TAG ANCHOR? | ANCHOR TAG? |
| 21 | # block_content ::= block_collection | flow_collection | SCALAR |
| 22 | # flow_content ::= flow_collection | SCALAR |
| 23 | # block_collection ::= block_sequence | block_mapping |
| 24 | # flow_collection ::= flow_sequence | flow_mapping |
| 25 | # block_sequence ::= BLOCK-SEQUENCE-START (BLOCK-ENTRY block_node?)* BLOCK-END |
| 26 | # indentless_sequence ::= (BLOCK-ENTRY block_node?)+ |
| 27 | # block_mapping ::= BLOCK-MAPPING_START |
| 28 | # ((KEY block_node_or_indentless_sequence?)? |
| 29 | # (VALUE block_node_or_indentless_sequence?)?)* |
| 30 | # BLOCK-END |
| 31 | # flow_sequence ::= FLOW-SEQUENCE-START |
| 32 | # (flow_sequence_entry FLOW-ENTRY)* |
| 33 | # flow_sequence_entry? |
| 34 | # FLOW-SEQUENCE-END |
| 35 | # flow_sequence_entry ::= flow_node | KEY flow_node? (VALUE flow_node?)? |
| 36 | # flow_mapping ::= FLOW-MAPPING-START |
| 37 | # (flow_mapping_entry FLOW-ENTRY)* |
| 38 | # flow_mapping_entry? |
| 39 | # FLOW-MAPPING-END |
| 40 | # flow_mapping_entry ::= flow_node | KEY flow_node? (VALUE flow_node?)? |
| 41 | # |
| 42 | # FIRST sets: |
| 43 | # |
| 44 | # stream: { STREAM-START } |
| 45 | # explicit_document: { DIRECTIVE DOCUMENT-START } |
| 46 | # implicit_document: FIRST(block_node) |
| 47 | # block_node: { ALIAS TAG ANCHOR SCALAR BLOCK-SEQUENCE-START BLOCK-MAPPING-START FLOW-SEQUENCE-START FLOW-MAPPING-START } |
| 48 | # flow_node: { ALIAS ANCHOR TAG SCALAR FLOW-SEQUENCE-START FLOW-MAPPING-START } |
| 49 | # block_content: { BLOCK-SEQUENCE-START BLOCK-MAPPING-START FLOW-SEQUENCE-START FLOW-MAPPING-START SCALAR } |
| 50 | # flow_content: { FLOW-SEQUENCE-START FLOW-MAPPING-START SCALAR } |
| 51 | # block_collection: { BLOCK-SEQUENCE-START BLOCK-MAPPING-START } |
| 52 | # flow_collection: { FLOW-SEQUENCE-START FLOW-MAPPING-START } |
| 53 | # block_sequence: { BLOCK-SEQUENCE-START } |
| 54 | # block_mapping: { BLOCK-MAPPING-START } |
| 55 | # block_node_or_indentless_sequence: { ALIAS ANCHOR TAG SCALAR BLOCK-SEQUENCE-START BLOCK-MAPPING-START FLOW-SEQUENCE-START FLOW-MAPPING-START BLOCK-ENTRY } |
| 56 | # indentless_sequence: { ENTRY } |
| 57 | # flow_collection: { FLOW-SEQUENCE-START FLOW-MAPPING-START } |
| 58 | # flow_sequence: { FLOW-SEQUENCE-START } |
| 59 | # flow_mapping: { FLOW-MAPPING-START } |
| 60 | # flow_sequence_entry: { ALIAS ANCHOR TAG SCALAR FLOW-SEQUENCE-START FLOW-MAPPING-START KEY } |
| 61 | # flow_mapping_entry: { ALIAS ANCHOR TAG SCALAR FLOW-SEQUENCE-START FLOW-MAPPING-START KEY } |
| 62 | |
| 63 | __all__ = ['Parser', 'ParserError'] |
| 64 | |
| 65 | from .error import MarkedYAMLError |
| 66 | from .tokens import * |
| 67 | from .events import * |
| 68 | from .scanner import * |
| 69 | |
| 70 | class ParserError(MarkedYAMLError): |
| 71 | pass |
| 72 | |
| 73 | class Parser: |
| 74 | # Since writing a recursive-descendant parser is a straightforward task, we |
| 75 | # do not give many comments here. |
| 76 | |
| 77 | DEFAULT_TAGS = { |
| 78 | '!': '!', |
| 79 | '!!': 'tag:yaml.org,2002:', |
| 80 | } |
| 81 | |
| 82 | def __init__(self): |
| 83 | self.current_event = None |
| 84 | self.yaml_version = None |
| 85 | self.tag_handles = {} |
| 86 | self.states = [] |
| 87 | self.marks = [] |
| 88 | self.state = self.parse_stream_start |
| 89 | |
| 90 | def dispose(self): |
| 91 | # Reset the state attributes (to clear self-references) |
| 92 | self.states = [] |
| 93 | self.state = None |
| 94 | |
| 95 | def check_event(self, *choices): |
| 96 | # Check the type of the next event. |
| 97 | if self.current_event is None: |
| 98 | if self.state: |
| 99 | self.current_event = self.state() |
| 100 | if self.current_event is not None: |
| 101 | if not choices: |
| 102 | return True |
| 103 | for choice in choices: |
| 104 | if isinstance(self.current_event, choice): |
| 105 | return True |
| 106 | return False |
| 107 | |
| 108 | def peek_event(self): |
| 109 | # Get the next event. |
| 110 | if self.current_event is None: |
| 111 | if self.state: |
| 112 | self.current_event = self.state() |
| 113 | return self.current_event |
| 114 | |
| 115 | def get_event(self): |
| 116 | # Get the next event and proceed further. |
| 117 | if self.current_event is None: |
| 118 | if self.state: |
| 119 | self.current_event = self.state() |
| 120 | value = self.current_event |
| 121 | self.current_event = None |
| 122 | return value |
| 123 | |
| 124 | # stream ::= STREAM-START implicit_document? explicit_document* STREAM-END |
| 125 | # implicit_document ::= block_node DOCUMENT-END* |
| 126 | # explicit_document ::= DIRECTIVE* DOCUMENT-START block_node? DOCUMENT-END* |
| 127 | |
| 128 | def parse_stream_start(self): |
| 129 | |
| 130 | # Parse the stream start. |
| 131 | token = self.get_token() |
| 132 | event = StreamStartEvent(token.start_mark, token.end_mark, |
| 133 | encoding=token.encoding) |
| 134 | |
| 135 | # Prepare the next state. |
| 136 | self.state = self.parse_implicit_document_start |
| 137 | |
| 138 | return event |
| 139 | |
| 140 | def parse_implicit_document_start(self): |
| 141 | |
| 142 | # Parse an implicit document. |
| 143 | if not self.check_token(DirectiveToken, DocumentStartToken, |
| 144 | StreamEndToken): |
| 145 | self.tag_handles = self.DEFAULT_TAGS |
| 146 | token = self.peek_token() |
| 147 | start_mark = end_mark = token.start_mark |
| 148 | event = DocumentStartEvent(start_mark, end_mark, |
| 149 | explicit=False) |
| 150 | |
| 151 | # Prepare the next state. |
| 152 | self.states.append(self.parse_document_end) |
| 153 | self.state = self.parse_block_node |
| 154 | |
| 155 | return event |
| 156 | |
| 157 | else: |
| 158 | return self.parse_document_start() |
| 159 | |
| 160 | def parse_document_start(self): |
| 161 | |
| 162 | # Parse any extra document end indicators. |
| 163 | while self.check_token(DocumentEndToken): |
| 164 | self.get_token() |
| 165 | |
| 166 | # Parse an explicit document. |
| 167 | if not self.check_token(StreamEndToken): |
| 168 | token = self.peek_token() |
| 169 | start_mark = token.start_mark |
| 170 | version, tags = self.process_directives() |
| 171 | if not self.check_token(DocumentStartToken): |
| 172 | raise ParserError(None, None, |
| 173 | "expected '<document start>', but found %r" |
| 174 | % self.peek_token().id, |
| 175 | self.peek_token().start_mark) |
| 176 | token = self.get_token() |
| 177 | end_mark = token.end_mark |
| 178 | event = DocumentStartEvent(start_mark, end_mark, |
| 179 | explicit=True, version=version, tags=tags) |
| 180 | self.states.append(self.parse_document_end) |
| 181 | self.state = self.parse_document_content |
| 182 | else: |
| 183 | # Parse the end of the stream. |
| 184 | token = self.get_token() |
| 185 | event = StreamEndEvent(token.start_mark, token.end_mark) |
| 186 | assert not self.states |
| 187 | assert not self.marks |
| 188 | self.state = None |
| 189 | return event |
| 190 | |
| 191 | def parse_document_end(self): |
| 192 | |
| 193 | # Parse the document end. |
| 194 | token = self.peek_token() |
| 195 | start_mark = end_mark = token.start_mark |
| 196 | explicit = False |
| 197 | if self.check_token(DocumentEndToken): |
| 198 | token = self.get_token() |
| 199 | end_mark = token.end_mark |
| 200 | explicit = True |
| 201 | event = DocumentEndEvent(start_mark, end_mark, |
| 202 | explicit=explicit) |
| 203 | |
| 204 | # Prepare the next state. |
| 205 | self.state = self.parse_document_start |
| 206 | |
| 207 | return event |
| 208 | |
| 209 | def parse_document_content(self): |
| 210 | if self.check_token(DirectiveToken, |
| 211 | DocumentStartToken, DocumentEndToken, StreamEndToken): |
| 212 | event = self.process_empty_scalar(self.peek_token().start_mark) |
| 213 | self.state = self.states.pop() |
| 214 | return event |
| 215 | else: |
| 216 | return self.parse_block_node() |
| 217 | |
| 218 | def process_directives(self): |
| 219 | self.yaml_version = None |
| 220 | self.tag_handles = {} |
| 221 | while self.check_token(DirectiveToken): |
| 222 | token = self.get_token() |
| 223 | if token.name == 'YAML': |
| 224 | if self.yaml_version is not None: |
| 225 | raise ParserError(None, None, |
| 226 | "found duplicate YAML directive", token.start_mark) |
| 227 | major, minor = token.value |
| 228 | if major != 1: |
| 229 | raise ParserError(None, None, |
| 230 | "found incompatible YAML document (version 1.* is required)", |
| 231 | token.start_mark) |
| 232 | self.yaml_version = token.value |
| 233 | elif token.name == 'TAG': |
| 234 | handle, prefix = token.value |
| 235 | if handle in self.tag_handles: |
| 236 | raise ParserError(None, None, |
| 237 | "duplicate tag handle %r" % handle, |
| 238 | token.start_mark) |
| 239 | self.tag_handles[handle] = prefix |
| 240 | if self.tag_handles: |
| 241 | value = self.yaml_version, self.tag_handles.copy() |
| 242 | else: |
| 243 | value = self.yaml_version, None |
| 244 | for key in self.DEFAULT_TAGS: |
| 245 | if key not in self.tag_handles: |
| 246 | self.tag_handles[key] = self.DEFAULT_TAGS[key] |
| 247 | return value |
| 248 | |
| 249 | # block_node_or_indentless_sequence ::= ALIAS |
| 250 | # | properties (block_content | indentless_block_sequence)? |
| 251 | # | block_content |
| 252 | # | indentless_block_sequence |
| 253 | # block_node ::= ALIAS |
| 254 | # | properties block_content? |
| 255 | # | block_content |
| 256 | # flow_node ::= ALIAS |
| 257 | # | properties flow_content? |
| 258 | # | flow_content |
| 259 | # properties ::= TAG ANCHOR? | ANCHOR TAG? |
| 260 | # block_content ::= block_collection | flow_collection | SCALAR |
| 261 | # flow_content ::= flow_collection | SCALAR |
| 262 | # block_collection ::= block_sequence | block_mapping |
| 263 | # flow_collection ::= flow_sequence | flow_mapping |
| 264 | |
| 265 | def parse_block_node(self): |
| 266 | return self.parse_node(block=True) |
| 267 | |
| 268 | def parse_flow_node(self): |
| 269 | return self.parse_node() |
| 270 | |
| 271 | def parse_block_node_or_indentless_sequence(self): |
| 272 | return self.parse_node(block=True, indentless_sequence=True) |
| 273 | |
| 274 | def parse_node(self, block=False, indentless_sequence=False): |
| 275 | if self.check_token(AliasToken): |
| 276 | token = self.get_token() |
| 277 | event = AliasEvent(token.value, token.start_mark, token.end_mark) |
| 278 | self.state = self.states.pop() |
| 279 | else: |
| 280 | anchor = None |
| 281 | tag = None |
| 282 | start_mark = end_mark = tag_mark = None |
| 283 | if self.check_token(AnchorToken): |
| 284 | token = self.get_token() |
| 285 | start_mark = token.start_mark |
| 286 | end_mark = token.end_mark |
| 287 | anchor = token.value |
| 288 | if self.check_token(TagToken): |
| 289 | token = self.get_token() |
| 290 | tag_mark = token.start_mark |
| 291 | end_mark = token.end_mark |
| 292 | tag = token.value |
| 293 | elif self.check_token(TagToken): |
| 294 | token = self.get_token() |
| 295 | start_mark = tag_mark = token.start_mark |
| 296 | end_mark = token.end_mark |
| 297 | tag = token.value |
| 298 | if self.check_token(AnchorToken): |
| 299 | token = self.get_token() |
| 300 | end_mark = token.end_mark |
| 301 | anchor = token.value |
| 302 | if tag is not None: |
| 303 | handle, suffix = tag |
| 304 | if handle is not None: |
| 305 | if handle not in self.tag_handles: |
| 306 | raise ParserError("while parsing a node", start_mark, |
| 307 | "found undefined tag handle %r" % handle, |
| 308 | tag_mark) |
| 309 | tag = self.tag_handles[handle]+suffix |
| 310 | else: |
| 311 | tag = suffix |
| 312 | #if tag == '!': |
| 313 | # raise ParserError("while parsing a node", start_mark, |
| 314 | # "found non-specific tag '!'", tag_mark, |
| 315 | # "Please check 'http://pyyaml.org/wiki/YAMLNonSpecificTag' and share your opinion.") |
| 316 | if start_mark is None: |
| 317 | start_mark = end_mark = self.peek_token().start_mark |
| 318 | event = None |
| 319 | implicit = (tag is None or tag == '!') |
| 320 | if indentless_sequence and self.check_token(BlockEntryToken): |
| 321 | end_mark = self.peek_token().end_mark |
| 322 | event = SequenceStartEvent(anchor, tag, implicit, |
| 323 | start_mark, end_mark) |
| 324 | self.state = self.parse_indentless_sequence_entry |
| 325 | else: |
| 326 | if self.check_token(ScalarToken): |
| 327 | token = self.get_token() |
| 328 | end_mark = token.end_mark |
| 329 | if (token.plain and tag is None) or tag == '!': |
| 330 | implicit = (True, False) |
| 331 | elif tag is None: |
| 332 | implicit = (False, True) |
| 333 | else: |
| 334 | implicit = (False, False) |
| 335 | event = ScalarEvent(anchor, tag, implicit, token.value, |
| 336 | start_mark, end_mark, style=token.style) |
| 337 | self.state = self.states.pop() |
| 338 | elif self.check_token(FlowSequenceStartToken): |
| 339 | end_mark = self.peek_token().end_mark |
| 340 | event = SequenceStartEvent(anchor, tag, implicit, |
| 341 | start_mark, end_mark, flow_style=True) |
| 342 | self.state = self.parse_flow_sequence_first_entry |
| 343 | elif self.check_token(FlowMappingStartToken): |
| 344 | end_mark = self.peek_token().end_mark |
| 345 | event = MappingStartEvent(anchor, tag, implicit, |
| 346 | start_mark, end_mark, flow_style=True) |
| 347 | self.state = self.parse_flow_mapping_first_key |
| 348 | elif block and self.check_token(BlockSequenceStartToken): |
| 349 | end_mark = self.peek_token().start_mark |
| 350 | event = SequenceStartEvent(anchor, tag, implicit, |
| 351 | start_mark, end_mark, flow_style=False) |
| 352 | self.state = self.parse_block_sequence_first_entry |
| 353 | elif block and self.check_token(BlockMappingStartToken): |
| 354 | end_mark = self.peek_token().start_mark |
| 355 | event = MappingStartEvent(anchor, tag, implicit, |
| 356 | start_mark, end_mark, flow_style=False) |
| 357 | self.state = self.parse_block_mapping_first_key |
| 358 | elif anchor is not None or tag is not None: |
| 359 | # Empty scalars are allowed even if a tag or an anchor is |
| 360 | # specified. |
| 361 | event = ScalarEvent(anchor, tag, (implicit, False), '', |
| 362 | start_mark, end_mark) |
| 363 | self.state = self.states.pop() |
| 364 | else: |
| 365 | if block: |
| 366 | node = 'block' |
| 367 | else: |
| 368 | node = 'flow' |
| 369 | token = self.peek_token() |
| 370 | raise ParserError("while parsing a %s node" % node, start_mark, |
| 371 | "expected the node content, but found %r" % token.id, |
| 372 | token.start_mark) |
| 373 | return event |
| 374 | |
| 375 | # block_sequence ::= BLOCK-SEQUENCE-START (BLOCK-ENTRY block_node?)* BLOCK-END |
| 376 | |
| 377 | def parse_block_sequence_first_entry(self): |
| 378 | token = self.get_token() |
| 379 | self.marks.append(token.start_mark) |
| 380 | return self.parse_block_sequence_entry() |
| 381 | |
| 382 | def parse_block_sequence_entry(self): |
| 383 | if self.check_token(BlockEntryToken): |
| 384 | token = self.get_token() |
| 385 | if not self.check_token(BlockEntryToken, BlockEndToken): |
| 386 | self.states.append(self.parse_block_sequence_entry) |
| 387 | return self.parse_block_node() |
| 388 | else: |
| 389 | self.state = self.parse_block_sequence_entry |
| 390 | return self.process_empty_scalar(token.end_mark) |
| 391 | if not self.check_token(BlockEndToken): |
| 392 | token = self.peek_token() |
| 393 | raise ParserError("while parsing a block collection", self.marks[-1], |
| 394 | "expected <block end>, but found %r" % token.id, token.start_mark) |
| 395 | token = self.get_token() |
| 396 | event = SequenceEndEvent(token.start_mark, token.end_mark) |
| 397 | self.state = self.states.pop() |
| 398 | self.marks.pop() |
| 399 | return event |
| 400 | |
| 401 | # indentless_sequence ::= (BLOCK-ENTRY block_node?)+ |
| 402 | |
| 403 | def parse_indentless_sequence_entry(self): |
| 404 | if self.check_token(BlockEntryToken): |
| 405 | token = self.get_token() |
| 406 | if not self.check_token(BlockEntryToken, |
| 407 | KeyToken, ValueToken, BlockEndToken): |
| 408 | self.states.append(self.parse_indentless_sequence_entry) |
| 409 | return self.parse_block_node() |
| 410 | else: |
| 411 | self.state = self.parse_indentless_sequence_entry |
| 412 | return self.process_empty_scalar(token.end_mark) |
| 413 | token = self.peek_token() |
| 414 | event = SequenceEndEvent(token.start_mark, token.start_mark) |
| 415 | self.state = self.states.pop() |
| 416 | return event |
| 417 | |
| 418 | # block_mapping ::= BLOCK-MAPPING_START |
| 419 | # ((KEY block_node_or_indentless_sequence?)? |
| 420 | # (VALUE block_node_or_indentless_sequence?)?)* |
| 421 | # BLOCK-END |
| 422 | |
| 423 | def parse_block_mapping_first_key(self): |
| 424 | token = self.get_token() |
| 425 | self.marks.append(token.start_mark) |
| 426 | return self.parse_block_mapping_key() |
| 427 | |
| 428 | def parse_block_mapping_key(self): |
| 429 | if self.check_token(KeyToken): |
| 430 | token = self.get_token() |
| 431 | if not self.check_token(KeyToken, ValueToken, BlockEndToken): |
| 432 | self.states.append(self.parse_block_mapping_value) |
| 433 | return self.parse_block_node_or_indentless_sequence() |
| 434 | else: |
| 435 | self.state = self.parse_block_mapping_value |
| 436 | return self.process_empty_scalar(token.end_mark) |
| 437 | if not self.check_token(BlockEndToken): |
| 438 | token = self.peek_token() |
| 439 | raise ParserError("while parsing a block mapping", self.marks[-1], |
| 440 | "expected <block end>, but found %r" % token.id, token.start_mark) |
| 441 | token = self.get_token() |
| 442 | event = MappingEndEvent(token.start_mark, token.end_mark) |
| 443 | self.state = self.states.pop() |
| 444 | self.marks.pop() |
| 445 | return event |
| 446 | |
| 447 | def parse_block_mapping_value(self): |
| 448 | if self.check_token(ValueToken): |
| 449 | token = self.get_token() |
| 450 | if not self.check_token(KeyToken, ValueToken, BlockEndToken): |
| 451 | self.states.append(self.parse_block_mapping_key) |
| 452 | return self.parse_block_node_or_indentless_sequence() |
| 453 | else: |
| 454 | self.state = self.parse_block_mapping_key |
| 455 | return self.process_empty_scalar(token.end_mark) |
| 456 | else: |
| 457 | self.state = self.parse_block_mapping_key |
| 458 | token = self.peek_token() |
| 459 | return self.process_empty_scalar(token.start_mark) |
| 460 | |
| 461 | # flow_sequence ::= FLOW-SEQUENCE-START |
| 462 | # (flow_sequence_entry FLOW-ENTRY)* |
| 463 | # flow_sequence_entry? |
| 464 | # FLOW-SEQUENCE-END |
| 465 | # flow_sequence_entry ::= flow_node | KEY flow_node? (VALUE flow_node?)? |
| 466 | # |
| 467 | # Note that while production rules for both flow_sequence_entry and |
| 468 | # flow_mapping_entry are equal, their interpretations are different. |
| 469 | # For `flow_sequence_entry`, the part `KEY flow_node? (VALUE flow_node?)?` |
| 470 | # generate an inline mapping (set syntax). |
| 471 | |
| 472 | def parse_flow_sequence_first_entry(self): |
| 473 | token = self.get_token() |
| 474 | self.marks.append(token.start_mark) |
| 475 | return self.parse_flow_sequence_entry(first=True) |
| 476 | |
| 477 | def parse_flow_sequence_entry(self, first=False): |
| 478 | if not self.check_token(FlowSequenceEndToken): |
| 479 | if not first: |
| 480 | if self.check_token(FlowEntryToken): |
| 481 | self.get_token() |
| 482 | else: |
| 483 | token = self.peek_token() |
| 484 | raise ParserError("while parsing a flow sequence", self.marks[-1], |
| 485 | "expected ',' or ']', but got %r" % token.id, token.start_mark) |
| 486 | |
| 487 | if self.check_token(KeyToken): |
| 488 | token = self.peek_token() |
| 489 | event = MappingStartEvent(None, None, True, |
| 490 | token.start_mark, token.end_mark, |
| 491 | flow_style=True) |
| 492 | self.state = self.parse_flow_sequence_entry_mapping_key |
| 493 | return event |
| 494 | elif not self.check_token(FlowSequenceEndToken): |
| 495 | self.states.append(self.parse_flow_sequence_entry) |
| 496 | return self.parse_flow_node() |
| 497 | token = self.get_token() |
| 498 | event = SequenceEndEvent(token.start_mark, token.end_mark) |
| 499 | self.state = self.states.pop() |
| 500 | self.marks.pop() |
| 501 | return event |
| 502 | |
| 503 | def parse_flow_sequence_entry_mapping_key(self): |
| 504 | token = self.get_token() |
| 505 | if not self.check_token(ValueToken, |
| 506 | FlowEntryToken, FlowSequenceEndToken): |
| 507 | self.states.append(self.parse_flow_sequence_entry_mapping_value) |
| 508 | return self.parse_flow_node() |
| 509 | else: |
| 510 | self.state = self.parse_flow_sequence_entry_mapping_value |
| 511 | return self.process_empty_scalar(token.end_mark) |
| 512 | |
| 513 | def parse_flow_sequence_entry_mapping_value(self): |
| 514 | if self.check_token(ValueToken): |
| 515 | token = self.get_token() |
| 516 | if not self.check_token(FlowEntryToken, FlowSequenceEndToken): |
| 517 | self.states.append(self.parse_flow_sequence_entry_mapping_end) |
| 518 | return self.parse_flow_node() |
| 519 | else: |
| 520 | self.state = self.parse_flow_sequence_entry_mapping_end |
| 521 | return self.process_empty_scalar(token.end_mark) |
| 522 | else: |
| 523 | self.state = self.parse_flow_sequence_entry_mapping_end |
| 524 | token = self.peek_token() |
| 525 | return self.process_empty_scalar(token.start_mark) |
| 526 | |
| 527 | def parse_flow_sequence_entry_mapping_end(self): |
| 528 | self.state = self.parse_flow_sequence_entry |
| 529 | token = self.peek_token() |
| 530 | return MappingEndEvent(token.start_mark, token.start_mark) |
| 531 | |
| 532 | # flow_mapping ::= FLOW-MAPPING-START |
| 533 | # (flow_mapping_entry FLOW-ENTRY)* |
| 534 | # flow_mapping_entry? |
| 535 | # FLOW-MAPPING-END |
| 536 | # flow_mapping_entry ::= flow_node | KEY flow_node? (VALUE flow_node?)? |
| 537 | |
| 538 | def parse_flow_mapping_first_key(self): |
| 539 | token = self.get_token() |
| 540 | self.marks.append(token.start_mark) |
| 541 | return self.parse_flow_mapping_key(first=True) |
| 542 | |
| 543 | def parse_flow_mapping_key(self, first=False): |
| 544 | if not self.check_token(FlowMappingEndToken): |
| 545 | if not first: |
| 546 | if self.check_token(FlowEntryToken): |
| 547 | self.get_token() |
| 548 | else: |
| 549 | token = self.peek_token() |
| 550 | raise ParserError("while parsing a flow mapping", self.marks[-1], |
| 551 | "expected ',' or '}', but got %r" % token.id, token.start_mark) |
| 552 | if self.check_token(KeyToken): |
| 553 | token = self.get_token() |
| 554 | if not self.check_token(ValueToken, |
| 555 | FlowEntryToken, FlowMappingEndToken): |
| 556 | self.states.append(self.parse_flow_mapping_value) |
| 557 | return self.parse_flow_node() |
| 558 | else: |
| 559 | self.state = self.parse_flow_mapping_value |
| 560 | return self.process_empty_scalar(token.end_mark) |
| 561 | elif not self.check_token(FlowMappingEndToken): |
| 562 | self.states.append(self.parse_flow_mapping_empty_value) |
| 563 | return self.parse_flow_node() |
| 564 | token = self.get_token() |
| 565 | event = MappingEndEvent(token.start_mark, token.end_mark) |
| 566 | self.state = self.states.pop() |
| 567 | self.marks.pop() |
| 568 | return event |
| 569 | |
| 570 | def parse_flow_mapping_value(self): |
| 571 | if self.check_token(ValueToken): |
| 572 | token = self.get_token() |
| 573 | if not self.check_token(FlowEntryToken, FlowMappingEndToken): |
| 574 | self.states.append(self.parse_flow_mapping_key) |
| 575 | return self.parse_flow_node() |
| 576 | else: |
| 577 | self.state = self.parse_flow_mapping_key |
| 578 | return self.process_empty_scalar(token.end_mark) |
| 579 | else: |
| 580 | self.state = self.parse_flow_mapping_key |
| 581 | token = self.peek_token() |
| 582 | return self.process_empty_scalar(token.start_mark) |
| 583 | |
| 584 | def parse_flow_mapping_empty_value(self): |
| 585 | self.state = self.parse_flow_mapping_key |
| 586 | return self.process_empty_scalar(self.peek_token().start_mark) |
| 587 | |
| 588 | def process_empty_scalar(self, mark): |
| 589 | return ScalarEvent(None, None, (True, False), '', mark, mark) |
| 590 |