src/emitter.c

   1
   2 #include "yaml_private.h"
   3
   4 /*
   5  * Flush the buffer if needed.
   6  */
   7
   8 #define FLUSH(emitter)                                                          \
   9     ((emitter->buffer.pointer+5 < emitter->buffer.end)                          \
  10      || yaml_emitter_flush(emitter))
  11
  12 /*
  13  * Put a character to the output buffer.
  14  */
  15
  16 #define PUT(emitter,value)                                                      \
  17     (FLUSH(emitter)                                                             \
  18      && (*(emitter->buffer.pointer++) = (yaml_char_t)(value),                   \
  19          emitter->column ++,                                                    \
  20          1))
  21
  22 /*
  23  * Put a line break to the output buffer.
  24  */
  25
  26 #define PUT_BREAK(emitter)                                                      \
  27     (FLUSH(emitter)                                                             \
  28      && ((emitter->line_break == YAML_CR_BREAK ?                                \
  29              (*(emitter->buffer.pointer++) = (yaml_char_t) '\r') :              \
  30           emitter->line_break == YAML_LN_BREAK ?                                \
  31              (*(emitter->buffer.pointer++) = (yaml_char_t) '\n') :              \
  32           emitter->line_break == YAML_CRLN_BREAK ?                              \
  33              (*(emitter->buffer.pointer++) = (yaml_char_t) '\r',                \
  34               *(emitter->buffer.pointer++) = (yaml_char_t) '\n') : 0),          \
  35          emitter->column = 0,                                                   \
  36          emitter->line ++,                                                      \
  37          1))
  38
  39 /*
  40  * Copy a character from a string into buffer.
  41  */
  42
  43 #define WRITE(emitter,string)                                                   \
  44     (FLUSH(emitter)                                                             \
  45      && (COPY(emitter->buffer,string),                                          \
  46          emitter->column ++,                                                    \
  47          1))
  48
  49 /*
  50  * Copy a line break character from a string into buffer.
  51  */
  52
  53 #define WRITE_BREAK(emitter,string)                                             \
  54     (FLUSH(emitter)                                                             \
  55      && (CHECK(string,'\n') ?                                                   \
  56          (PUT_BREAK(emitter),                                                   \
  57           string.pointer ++,                                                    \
  58           1) :                                                                  \
  59          (COPY(emitter->buffer,string),                                         \
  60           emitter->column = 0,                                                  \
  61           emitter->line ++,                                                     \
  62           1)))
  63
  64 /*
  65  * API functions.
  66  */
  67
  68 YAML_DECLARE(int)
  69 yaml_emitter_emit(yaml_emitter_t *emitter, yaml_event_t *event);
  70
  71 /*
  72  * Utility functions.
  73  */
  74
  75 static int
  76 yaml_emitter_set_emitter_error(yaml_emitter_t *emitter, const char *problem);
  77
  78 static int
  79 yaml_emitter_need_more_events(yaml_emitter_t *emitter);
  80
  81 static int
  82 yaml_emitter_append_tag_directive(yaml_emitter_t *emitter,
  83         yaml_tag_directive_t value, int allow_duplicates);
  84
  85 static int
  86 yaml_emitter_increase_indent(yaml_emitter_t *emitter,
  87         int flow, int indentless);
  88
  89 /*
  90  * State functions.
  91  */
  92
  93 static int
  94 yaml_emitter_state_machine(yaml_emitter_t *emitter, yaml_event_t *event);
  95
  96 static int
  97 yaml_emitter_emit_stream_start(yaml_emitter_t *emitter,
  98         yaml_event_t *event);
  99
 100 static int
 101 yaml_emitter_emit_document_start(yaml_emitter_t *emitter,
 102         yaml_event_t *event, int first);
 103
 104 static int
 105 yaml_emitter_emit_document_content(yaml_emitter_t *emitter,
 106         yaml_event_t *event);
 107
 108 static int
 109 yaml_emitter_emit_document_end(yaml_emitter_t *emitter,
 110         yaml_event_t *event);
 111
 112 static int
 113 yaml_emitter_emit_flow_sequence_item(yaml_emitter_t *emitter,
 114         yaml_event_t *event, int first);
 115
 116 static int
 117 yaml_emitter_emit_flow_mapping_key(yaml_emitter_t *emitter,
 118         yaml_event_t *event, int first);
 119
 120 static int
 121 yaml_emitter_emit_flow_mapping_value(yaml_emitter_t *emitter,
 122         yaml_event_t *event, int simple);
 123
 124 static int
 125 yaml_emitter_emit_block_sequence_item(yaml_emitter_t *emitter,
 126         yaml_event_t *event, int first);
 127
 128 static int
 129 yaml_emitter_emit_block_mapping_key(yaml_emitter_t *emitter,
 130         yaml_event_t *event, int first);
 131
 132 static int
 133 yaml_emitter_emit_block_mapping_value(yaml_emitter_t *emitter,
 134         yaml_event_t *event, int simple);
 135
 136 static int
 137 yaml_emitter_emit_node(yaml_emitter_t *emitter, yaml_event_t *event,
 138         int root, int sequence, int mapping, int simple_key);
 139
 140 static int
 141 yaml_emitter_emit_alias(yaml_emitter_t *emitter, yaml_event_t *event);
 142
 143 static int
 144 yaml_emitter_emit_scalar(yaml_emitter_t *emitter, yaml_event_t *event);
 145
 146 static int
 147 yaml_emitter_emit_sequence_start(yaml_emitter_t *emitter, yaml_event_t *event);
 148
 149 static int
 150 yaml_emitter_emit_mapping_start(yaml_emitter_t *emitter, yaml_event_t *event);
 151
 152 /*
 153  * Checkers.
 154  */
 155
 156 static int
 157 yaml_emitter_check_empty_document(yaml_emitter_t *emitter);
 158
 159 static int
 160 yaml_emitter_check_empty_sequence(yaml_emitter_t *emitter);
 161
 162 static int
 163 yaml_emitter_check_empty_mapping(yaml_emitter_t *emitter);
 164
 165 static int
 166 yaml_emitter_check_simple_key(yaml_emitter_t *emitter);
 167
 168 static int
 169 yaml_emitter_select_scalar_style(yaml_emitter_t *emitter, yaml_event_t *event);
 170
 171 /*
 172  * Processors.
 173  */
 174
 175 static int
 176 yaml_emitter_process_anchor(yaml_emitter_t *emitter);
 177
 178 static int
 179 yaml_emitter_process_tag(yaml_emitter_t *emitter);
 180
 181 static int
 182 yaml_emitter_process_scalar(yaml_emitter_t *emitter);
 183
 184 /*
 185  * Analyzers.
 186  */
 187
 188 static int
 189 yaml_emitter_analyze_version_directive(yaml_emitter_t *emitter,
 190         yaml_version_directive_t version_directive);
 191
 192 static int
 193 yaml_emitter_analyze_tag_directive(yaml_emitter_t *emitter,
 194         yaml_tag_directive_t tag_directive);
 195
 196 static int
 197 yaml_emitter_analyze_anchor(yaml_emitter_t *emitter,
 198         yaml_char_t *anchor, int alias);
 199
 200 static int
 201 yaml_emitter_analyze_tag(yaml_emitter_t *emitter,
 202         yaml_char_t *tag);
 203
 204 static int
 205 yaml_emitter_analyze_scalar(yaml_emitter_t *emitter,
 206         yaml_char_t *value, size_t length);
 207
 208 static int
 209 yaml_emitter_analyze_event(yaml_emitter_t *emitter,
 210         yaml_event_t *event);
 211
 212 /*
 213  * Writers.
 214  */
 215
 216 static int
 217 yaml_emitter_write_bom(yaml_emitter_t *emitter);
 218
 219 static int
 220 yaml_emitter_write_indent(yaml_emitter_t *emitter);
 221
 222 static int
 223 yaml_emitter_write_indicator(yaml_emitter_t *emitter,
 224         char *indicator, int need_whitespace,
 225         int is_whitespace, int is_indention);
 226
 227 static int
 228 yaml_emitter_write_anchor(yaml_emitter_t *emitter,
 229         yaml_char_t *value, size_t length);
 230
 231 static int
 232 yaml_emitter_write_tag_handle(yaml_emitter_t *emitter,
 233         yaml_char_t *value, size_t length);
 234
 235 static int
 236 yaml_emitter_write_tag_content(yaml_emitter_t *emitter,
 237         yaml_char_t *value, size_t length, int need_whitespace);
 238
 239 static int
 240 yaml_emitter_write_plain_scalar(yaml_emitter_t *emitter,
 241         yaml_char_t *value, size_t length, int allow_breaks);
 242
 243 static int
 244 yaml_emitter_write_single_quoted_scalar(yaml_emitter_t *emitter,
 245         yaml_char_t *value, size_t length, int allow_breaks);
 246
 247 static int
 248 yaml_emitter_write_double_quoted_scalar(yaml_emitter_t *emitter,
 249         yaml_char_t *value, size_t length, int allow_breaks);
 250
 251 static int
 252 yaml_emitter_write_block_scalar_hints(yaml_emitter_t *emitter,
 253         yaml_string_t string);
 254
 255 static int
 256 yaml_emitter_write_literal_scalar(yaml_emitter_t *emitter,
 257         yaml_char_t *value, size_t length);
 258
 259 static int
 260 yaml_emitter_write_folded_scalar(yaml_emitter_t *emitter,
 261         yaml_char_t *value, size_t length);
 262
 263 /*
 264  * Set an emitter error and return 0.
 265  */
 266
 267 static int
 268 yaml_emitter_set_emitter_error(yaml_emitter_t *emitter, const char *problem)
 269 {
 270     emitter->error = YAML_EMITTER_ERROR;
 271     emitter->problem = problem;
 272
 273     return 0;
 274 }
 275
 276 /*
 277  * Emit an event.
 278  */
 279
 280 YAML_DECLARE(int)
 281 yaml_emitter_emit(yaml_emitter_t *emitter, yaml_event_t *event)
 282 {
 283     if (!ENQUEUE(emitter, emitter->events, *event)) {
 284         yaml_event_delete(event);
 285         return 0;
 286     }
 287
 288     while (!yaml_emitter_need_more_events(emitter)) {
 289         if (!yaml_emitter_analyze_event(emitter, emitter->events.head))
 290             return 0;
 291         if (!yaml_emitter_state_machine(emitter, emitter->events.head))
 292             return 0;
 293         yaml_event_delete(&DEQUEUE(emitter, emitter->events));
 294     }
 295
 296     return 1;
 297 }
 298
 299 /*
 300  * Check if we need to accumulate more events before emitting.
 301  *
 302  * We accumulate extra
 303  *  - 1 event for DOCUMENT-START
 304  *  - 2 events for SEQUENCE-START
 305  *  - 3 events for MAPPING-START
 306  */
 307
 308 static int
 309 yaml_emitter_need_more_events(yaml_emitter_t *emitter)
 310 {
 311     int level = 0;
 312     int accumulate = 0;
 313     yaml_event_t *event;
 314
 315     if (QUEUE_EMPTY(emitter, emitter->events))
 316         return 1;
 317
 318     switch (emitter->events.head->type) {
 319         case YAML_DOCUMENT_START_EVENT:
 320             accumulate = 1;
 321             break;
 322         case YAML_SEQUENCE_START_EVENT:
 323             accumulate = 2;
 324             break;
 325         case YAML_MAPPING_START_EVENT:
 326             accumulate = 3;
 327             break;
 328         default:
 329             return 0;
 330     }
 331
 332     if (emitter->events.tail - emitter->events.head > accumulate)
 333         return 0;
 334
 335     for (event = emitter->events.head; event != emitter->events.tail; event ++) {
 336         switch (event->type) {
 337             case YAML_STREAM_START_EVENT:
 338             case YAML_DOCUMENT_START_EVENT:
 339             case YAML_SEQUENCE_START_EVENT:
 340             case YAML_MAPPING_START_EVENT:
 341                 level += 1;
 342                 break;
 343             case YAML_STREAM_END_EVENT:
 344             case YAML_DOCUMENT_END_EVENT:
 345             case YAML_SEQUENCE_END_EVENT:
 346             case YAML_MAPPING_END_EVENT:
 347                 level -= 1;
 348                 break;
 349             default:
 350                 break;
 351         }
 352         if (!level)
 353             return 0;
 354     }
 355
 356     return 1;
 357 }
 358
 359 /*
 360  * Append a directive to the directives stack.
 361  */
 362
 363 static int
 364 yaml_emitter_append_tag_directive(yaml_emitter_t *emitter,
 365         yaml_tag_directive_t value, int allow_duplicates)
 366 {
 367     yaml_tag_directive_t *tag_directive;
 368     yaml_tag_directive_t copy = { NULL, NULL };
 369
 370     for (tag_directive = emitter->tag_directives.start;
 371             tag_directive != emitter->tag_directives.top; tag_directive ++) {
 372         if (strcmp((char *)value.handle, (char *)tag_directive->handle) == 0) {
 373             if (allow_duplicates)
 374                 return 1;
 375             return yaml_emitter_set_emitter_error(emitter,
 376                     "duplicate %TAG directive");
 377         }
 378     }
 379
 380     copy.handle = yaml_strdup(value.handle);
 381     copy.prefix = yaml_strdup(value.prefix);
 382     if (!copy.handle || !copy.prefix) {
 383         emitter->error = YAML_MEMORY_ERROR;
 384         goto error;
 385     }
 386
 387     if (!PUSH(emitter, emitter->tag_directives, copy))
 388         goto error;
 389
 390     return 1;
 391
 392 error:
 393     yaml_free(copy.handle);
 394     yaml_free(copy.prefix);
 395     return 0;
 396 }
 397
 398 /*
 399  * Increase the indentation level.
 400  */
 401
 402 static int
 403 yaml_emitter_increase_indent(yaml_emitter_t *emitter,
 404         int flow, int indentless)
 405 {
 406     if (!PUSH(emitter, emitter->indents, emitter->indent))
 407         return 0;
 408
 409     if (emitter->indent < 0) {
 410         emitter->indent = flow ? emitter->best_indent : 0;
 411     }
 412     else if (!indentless) {
 413         emitter->indent += emitter->best_indent;
 414     }
 415
 416     return 1;
 417 }
 418
 419 /*
 420  * State dispatcher.
 421  */
 422
 423 static int
 424 yaml_emitter_state_machine(yaml_emitter_t *emitter, yaml_event_t *event)
 425 {
 426     switch (emitter->state)
 427     {
 428         case YAML_EMIT_STREAM_START_STATE:
 429             return yaml_emitter_emit_stream_start(emitter, event);
 430
 431         case YAML_EMIT_FIRST_DOCUMENT_START_STATE:
 432             return yaml_emitter_emit_document_start(emitter, event, 1);
 433
 434         case YAML_EMIT_DOCUMENT_START_STATE:
 435             return yaml_emitter_emit_document_start(emitter, event, 0);
 436
 437         case YAML_EMIT_DOCUMENT_CONTENT_STATE:
 438             return yaml_emitter_emit_document_content(emitter, event);
 439
 440         case YAML_EMIT_DOCUMENT_END_STATE:
 441             return yaml_emitter_emit_document_end(emitter, event);
 442
 443         case YAML_EMIT_FLOW_SEQUENCE_FIRST_ITEM_STATE:
 444             return yaml_emitter_emit_flow_sequence_item(emitter, event, 1);
 445
 446         case YAML_EMIT_FLOW_SEQUENCE_ITEM_STATE:
 447             return yaml_emitter_emit_flow_sequence_item(emitter, event, 0);
 448
 449         case YAML_EMIT_FLOW_MAPPING_FIRST_KEY_STATE:
 450             return yaml_emitter_emit_flow_mapping_key(emitter, event, 1);
 451
 452         case YAML_EMIT_FLOW_MAPPING_KEY_STATE:
 453             return yaml_emitter_emit_flow_mapping_key(emitter, event, 0);
 454
 455         case YAML_EMIT_FLOW_MAPPING_SIMPLE_VALUE_STATE:
 456             return yaml_emitter_emit_flow_mapping_value(emitter, event, 1);
 457
 458         case YAML_EMIT_FLOW_MAPPING_VALUE_STATE:
 459             return yaml_emitter_emit_flow_mapping_value(emitter, event, 0);
 460
 461         case YAML_EMIT_BLOCK_SEQUENCE_FIRST_ITEM_STATE:
 462             return yaml_emitter_emit_block_sequence_item(emitter, event, 1);
 463
 464         case YAML_EMIT_BLOCK_SEQUENCE_ITEM_STATE:
 465             return yaml_emitter_emit_block_sequence_item(emitter, event, 0);
 466
 467         case YAML_EMIT_BLOCK_MAPPING_FIRST_KEY_STATE:
 468             return yaml_emitter_emit_block_mapping_key(emitter, event, 1);
 469
 470         case YAML_EMIT_BLOCK_MAPPING_KEY_STATE:
 471             return yaml_emitter_emit_block_mapping_key(emitter, event, 0);
 472
 473         case YAML_EMIT_BLOCK_MAPPING_SIMPLE_VALUE_STATE:
 474             return yaml_emitter_emit_block_mapping_value(emitter, event, 1);
 475
 476         case YAML_EMIT_BLOCK_MAPPING_VALUE_STATE:
 477             return yaml_emitter_emit_block_mapping_value(emitter, event, 0);
 478
 479         case YAML_EMIT_END_STATE:
 480             return yaml_emitter_set_emitter_error(emitter,
 481                     "expected nothing after STREAM-END");
 482
 483         default:
 484             assert(1);      /* Invalid state. */
 485     }
 486
 487     return 0;
 488 }
 489
 490 /*
 491  * Expect STREAM-START.
 492  */
 493
 494 static int
 495 yaml_emitter_emit_stream_start(yaml_emitter_t *emitter,
 496         yaml_event_t *event)
 497 {
 498     if (event->type == YAML_STREAM_START_EVENT)
 499     {
 500         if (!emitter->encoding) {
 501             emitter->encoding = event->data.stream_start.encoding;
 502         }
 503
 504         if (!emitter->encoding) {
 505             emitter->encoding = YAML_UTF8_ENCODING;
 506         }
 507
 508         if (emitter->best_indent < 2 || emitter->best_indent > 9) {
 509             emitter->best_indent  = 2;
 510         }
 511
 512         if (emitter->best_width >= 0
 513                 && emitter->best_width <= emitter->best_indent*2) {
 514             emitter->best_width = 80;
 515         }
 516
 517         if (emitter->best_width < 0) {
 518             emitter->best_width = INT_MAX;
 519         }
 520
 521         if (!emitter->line_break) {
 522             emitter->line_break = YAML_LN_BREAK;
 523         }
 524
 525         emitter->indent = -1;
 526
 527         emitter->line = 0;
 528         emitter->column = 0;
 529         emitter->whitespace = 1;
 530         emitter->indention = 1;
 531
 532         if (emitter->encoding != YAML_UTF8_ENCODING) {
 533             if (!yaml_emitter_write_bom(emitter))
 534                 return 0;
 535         }
 536
 537         emitter->state = YAML_EMIT_FIRST_DOCUMENT_START_STATE;
 538
 539         return 1;
 540     }
 541
 542     return yaml_emitter_set_emitter_error(emitter,
 543             "expected STREAM-START");
 544 }
 545
 546 /*
 547  * Expect DOCUMENT-START or STREAM-END.
 548  */
 549
 550 static int
 551 yaml_emitter_emit_document_start(yaml_emitter_t *emitter,
 552         yaml_event_t *event, int first)
 553 {
 554     if (event->type == YAML_DOCUMENT_START_EVENT)
 555     {
 556         yaml_tag_directive_t default_tag_directives[] = {
 557             {(yaml_char_t *)"!", (yaml_char_t *)"!"},
 558             {(yaml_char_t *)"!!", (yaml_char_t *)"tag:yaml.org,2002:"},
 559             {NULL, NULL}
 560         };
 561         yaml_tag_directive_t *tag_directive;
 562         int implicit;
 563
 564         if (event->data.document_start.version_directive) {
 565             if (!yaml_emitter_analyze_version_directive(emitter,
 566                         *event->data.document_start.version_directive))
 567                 return 0;
 568         }
 569
 570         for (tag_directive = event->data.document_start.tag_directives.start;
 571                 tag_directive != event->data.document_start.tag_directives.end;
 572                 tag_directive ++) {
 573             if (!yaml_emitter_analyze_tag_directive(emitter, *tag_directive))
 574                 return 0;
 575             if (!yaml_emitter_append_tag_directive(emitter, *tag_directive, 0))
 576                 return 0;
 577         }
 578
 579         for (tag_directive = default_tag_directives;
 580                 tag_directive->handle; tag_directive ++) {
 581             if (!yaml_emitter_append_tag_directive(emitter, *tag_directive, 1))
 582                 return 0;
 583         }
 584
 585         implicit = event->data.document_start.implicit;
 586         if (!first || emitter->canonical) {
 587             implicit = 0;
 588         }
 589
 590         if (event->data.document_start.version_directive) {
 591             implicit = 0;
 592             if (!yaml_emitter_write_indicator(emitter, "%YAML", 1, 0, 0))
 593                 return 0;
 594             if (!yaml_emitter_write_indicator(emitter, "1.1", 1, 0, 0))
 595                 return 0;
 596             if (!yaml_emitter_write_indent(emitter))
 597                 return 0;
 598         }
 599
 600         if (event->data.document_start.tag_directives.start
 601                 != event->data.document_start.tag_directives.end) {
 602             implicit = 0;
 603             for (tag_directive = event->data.document_start.tag_directives.start;
 604                     tag_directive != event->data.document_start.tag_directives.end;
 605                     tag_directive ++) {
 606                 if (!yaml_emitter_write_indicator(emitter, "%TAG", 1, 0, 0))
 607                     return 0;
 608                 if (!yaml_emitter_write_tag_handle(emitter, tag_directive->handle,
 609                             strlen((char *)tag_directive->handle)))
 610                     return 0;
 611                 if (!yaml_emitter_write_tag_content(emitter, tag_directive->prefix,
 612                             strlen((char *)tag_directive->prefix), 1))
 613                     return 0;
 614                 if (!yaml_emitter_write_indent(emitter))
 615                     return 0;
 616             }
 617         }
 618
 619         if (yaml_emitter_check_empty_document(emitter)) {
 620             implicit = 0;
 621         }
 622
 623         if (!implicit) {
 624             if (!yaml_emitter_write_indent(emitter))
 625                 return 0;
 626             if (!yaml_emitter_write_indicator(emitter, "---", 1, 0, 0))
 627                 return 0;
 628             if (emitter->canonical) {
 629                 if (!yaml_emitter_write_indent(emitter))
 630                     return 0;
 631             }
 632         }
 633
 634         emitter->state = YAML_EMIT_DOCUMENT_CONTENT_STATE;
 635
 636         return 1;
 637     }
 638
 639     else if (event->type == YAML_STREAM_END_EVENT)
 640     {
 641         if (!yaml_emitter_flush(emitter))
 642             return 0;
 643
 644         emitter->state = YAML_EMIT_END_STATE;
 645
 646         return 1;
 647     }
 648
 649     return yaml_emitter_set_emitter_error(emitter,
 650             "expected DOCUMENT-START or STREAM-END");
 651 }
 652
 653 /*
 654  * Expect the root node.
 655  */
 656
 657 static int
 658 yaml_emitter_emit_document_content(yaml_emitter_t *emitter,
 659         yaml_event_t *event)
 660 {
 661     if (!PUSH(emitter, emitter->states, YAML_EMIT_DOCUMENT_END_STATE))
 662         return 0;
 663
 664     return yaml_emitter_emit_node(emitter, event, 1, 0, 0, 0);
 665 }
 666
 667 /*
 668  * Expect DOCUMENT-END.
 669  */
 670
 671 static int
 672 yaml_emitter_emit_document_end(yaml_emitter_t *emitter,
 673         yaml_event_t *event)
 674 {
 675     if (event->type == YAML_DOCUMENT_END_EVENT)
 676     {
 677         if (!yaml_emitter_write_indent(emitter))
 678             return 0;
 679         if (!event->data.document_end.implicit) {
 680             if (!yaml_emitter_write_indicator(emitter, "...", 1, 0, 0))
 681                 return 0;
 682             if (!yaml_emitter_write_indent(emitter))
 683                 return 0;
 684         }
 685         if (!yaml_emitter_flush(emitter))
 686             return 0;
 687
 688         emitter->state = YAML_EMIT_DOCUMENT_START_STATE;
 689
 690         while (!STACK_EMPTY(emitter, emitter->tag_directives)) {
 691             yaml_tag_directive_t tag_directive = POP(emitter,
 692                     emitter->tag_directives);
 693             yaml_free(tag_directive.handle);
 694             yaml_free(tag_directive.prefix);
 695         }
 696
 697         return 1;
 698     }
 699
 700     return yaml_emitter_set_emitter_error(emitter,
 701             "expected DOCUMENT-END");
 702 }
 703
 704 /*
 705  *
 706  * Expect a flow item node.
 707  */
 708
 709 static int
 710 yaml_emitter_emit_flow_sequence_item(yaml_emitter_t *emitter,
 711         yaml_event_t *event, int first)
 712 {
 713     if (first)
 714     {
 715         if (!yaml_emitter_write_indicator(emitter, "[", 1, 1, 0))
 716             return 0;
 717         if (!yaml_emitter_increase_indent(emitter, 1, 0))
 718             return 0;
 719         emitter->flow_level ++;
 720     }
 721
 722     if (event->type == YAML_SEQUENCE_END_EVENT)
 723     {
 724         emitter->flow_level --;
 725         emitter->indent = POP(emitter, emitter->indents);
 726         if (emitter->canonical && !first) {
 727             if (!yaml_emitter_write_indicator(emitter, ",", 0, 0, 0))
 728                 return 0;
 729             if (!yaml_emitter_write_indent(emitter))
 730                 return 0;
 731         }
 732         if (!yaml_emitter_write_indicator(emitter, "]", 0, 0, 0))
 733             return 0;
 734         emitter->state = POP(emitter, emitter->states);
 735
 736         return 1;
 737     }
 738
 739     if (!first) {
 740         if (!yaml_emitter_write_indicator(emitter, ",", 0, 0, 0))
 741             return 0;
 742     }
 743
 744     if (emitter->canonical || emitter->column > emitter->best_width) {
 745         if (!yaml_emitter_write_indent(emitter))
 746             return 0;
 747     }
 748     if (!PUSH(emitter, emitter->states, YAML_EMIT_FLOW_SEQUENCE_ITEM_STATE))
 749         return 0;
 750
 751     return yaml_emitter_emit_node(emitter, event, 0, 1, 0, 0);
 752 }
 753
 754 /*
 755  * Expect a flow key node.
 756  */
 757
 758 static int
 759 yaml_emitter_emit_flow_mapping_key(yaml_emitter_t *emitter,
 760         yaml_event_t *event, int first)
 761 {
 762     if (first)
 763     {
 764         if (!yaml_emitter_write_indicator(emitter, "{", 1, 1, 0))
 765             return 0;
 766         if (!yaml_emitter_increase_indent(emitter, 1, 0))
 767             return 0;
 768         emitter->flow_level ++;
 769     }
 770
 771     if (event->type == YAML_MAPPING_END_EVENT)
 772     {
 773         emitter->flow_level --;
 774         emitter->indent = POP(emitter, emitter->indents);
 775         if (emitter->canonical && !first) {
 776             if (!yaml_emitter_write_indicator(emitter, ",", 0, 0, 0))
 777                 return 0;
 778             if (!yaml_emitter_write_indent(emitter))
 779                 return 0;
 780         }
 781         if (!yaml_emitter_write_indicator(emitter, "}", 0, 0, 0))
 782             return 0;
 783         emitter->state = POP(emitter, emitter->states);
 784
 785         return 1;
 786     }
 787
 788     if (!first) {
 789         if (!yaml_emitter_write_indicator(emitter, ",", 0, 0, 0))
 790             return 0;
 791     }
 792     if (emitter->canonical || emitter->column > emitter->best_width) {
 793         if (!yaml_emitter_write_indent(emitter))
 794             return 0;
 795     }
 796
 797     if (!emitter->canonical && yaml_emitter_check_simple_key(emitter))
 798     {
 799         if (!PUSH(emitter, emitter->states,
 800                     YAML_EMIT_FLOW_MAPPING_SIMPLE_VALUE_STATE))
 801             return 0;
 802
 803         return yaml_emitter_emit_node(emitter, event, 0, 0, 1, 1);
 804     }
 805     else
 806     {
 807         if (!yaml_emitter_write_indicator(emitter, "?", 1, 0, 0))
 808             return 0;
 809         if (!PUSH(emitter, emitter->states,
 810                     YAML_EMIT_FLOW_MAPPING_VALUE_STATE))
 811             return 0;
 812
 813         return yaml_emitter_emit_node(emitter, event, 0, 0, 1, 0);
 814     }
 815 }
 816
 817 /*
 818  * Expect a flow value node.
 819  */
 820
 821 static int
 822 yaml_emitter_emit_flow_mapping_value(yaml_emitter_t *emitter,
 823         yaml_event_t *event, int simple)
 824 {
 825     if (simple) {
 826         if (!yaml_emitter_write_indicator(emitter, ":", 0, 0, 0))
 827             return 0;
 828     }
 829     else {
 830         if (emitter->canonical || emitter->column > emitter->best_width) {
 831             if (!yaml_emitter_write_indent(emitter))
 832                 return 0;
 833         }
 834         if (!yaml_emitter_write_indicator(emitter, ":", 1, 0, 0))
 835             return 0;
 836     }
 837     if (!PUSH(emitter, emitter->states, YAML_EMIT_FLOW_MAPPING_KEY_STATE))
 838         return 0;
 839     return yaml_emitter_emit_node(emitter, event, 0, 0, 1, 0);
 840 }
 841
 842 /*
 843  * Expect a block item node.
 844  */
 845
 846 static int
 847 yaml_emitter_emit_block_sequence_item(yaml_emitter_t *emitter,
 848         yaml_event_t *event, int first)
 849 {
 850     if (first)
 851     {
 852         if (!yaml_emitter_increase_indent(emitter, 0,
 853                     (emitter->mapping_context && !emitter->indention)))
 854             return 0;
 855     }
 856
 857     if (event->type == YAML_SEQUENCE_END_EVENT)
 858     {
 859         emitter->indent = POP(emitter, emitter->indents);
 860         emitter->state = POP(emitter, emitter->states);
 861
 862         return 1;
 863     }
 864
 865     if (!yaml_emitter_write_indent(emitter))
 866         return 0;
 867     if (!yaml_emitter_write_indicator(emitter, "-", 1, 0, 1))
 868         return 0;
 869     if (!PUSH(emitter, emitter->states,
 870                 YAML_EMIT_BLOCK_SEQUENCE_ITEM_STATE))
 871         return 0;
 872
 873     return yaml_emitter_emit_node(emitter, event, 0, 1, 0, 0);
 874 }
 875
 876 /*
 877  * Expect a block key node.
 878  */
 879
 880 static int
 881 yaml_emitter_emit_block_mapping_key(yaml_emitter_t *emitter,
 882         yaml_event_t *event, int first)
 883 {
 884     if (first)
 885     {
 886         if (!yaml_emitter_increase_indent(emitter, 0, 0))
 887             return 0;
 888     }
 889
 890     if (event->type == YAML_MAPPING_END_EVENT)
 891     {
 892         emitter->indent = POP(emitter, emitter->indents);
 893         emitter->state = POP(emitter, emitter->states);
 894
 895         return 1;
 896     }
 897
 898     if (!yaml_emitter_write_indent(emitter))
 899         return 0;
 900
 901     if (yaml_emitter_check_simple_key(emitter))
 902     {
 903         if (!PUSH(emitter, emitter->states,
 904                     YAML_EMIT_BLOCK_MAPPING_SIMPLE_VALUE_STATE))
 905             return 0;
 906
 907         return yaml_emitter_emit_node(emitter, event, 0, 0, 1, 1);
 908     }
 909     else
 910     {
 911         if (!yaml_emitter_write_indicator(emitter, "?", 1, 0, 1))
 912             return 0;
 913         if (!PUSH(emitter, emitter->states,
 914                     YAML_EMIT_BLOCK_MAPPING_VALUE_STATE))
 915             return 0;
 916
 917         return yaml_emitter_emit_node(emitter, event, 0, 0, 1, 0);
 918     }
 919 }
 920
 921 /*
 922  * Expect a block value node.
 923  */
 924
 925 static int
 926 yaml_emitter_emit_block_mapping_value(yaml_emitter_t *emitter,
 927         yaml_event_t *event, int simple)
 928 {
 929     if (simple) {
 930         if (!yaml_emitter_write_indicator(emitter, ":", 0, 0, 0))
 931             return 0;
 932     }
 933     else {
 934         if (!yaml_emitter_write_indent(emitter))
 935             return 0;
 936         if (!yaml_emitter_write_indicator(emitter, ":", 1, 0, 1))
 937             return 0;
 938     }
 939     if (!PUSH(emitter, emitter->states,
 940                 YAML_EMIT_BLOCK_MAPPING_KEY_STATE))
 941         return 0;
 942
 943     return yaml_emitter_emit_node(emitter, event, 0, 0, 1, 0);
 944 }
 945
 946 /*
 947  * Expect a node.
 948  */
 949
 950 static int
 951 yaml_emitter_emit_node(yaml_emitter_t *emitter, yaml_event_t *event,
 952         int root, int sequence, int mapping, int simple_key)
 953 {
 954     emitter->root_context = root;
 955     emitter->sequence_context = sequence;
 956     emitter->mapping_context = mapping;
 957     emitter->simple_key_context = simple_key;
 958
 959     switch (event->type)
 960     {
 961         case YAML_ALIAS_EVENT:
 962             return yaml_emitter_emit_alias(emitter, event);
 963
 964         case YAML_SCALAR_EVENT:
 965             return yaml_emitter_emit_scalar(emitter, event);
 966
 967         case YAML_SEQUENCE_START_EVENT:
 968             return yaml_emitter_emit_sequence_start(emitter, event);
 969
 970         case YAML_MAPPING_START_EVENT:
 971             return yaml_emitter_emit_mapping_start(emitter, event);
 972
 973         default:
 974             return yaml_emitter_set_emitter_error(emitter,
 975                     "expected SCALAR, SEQUENCE-START, MAPPING-START, or ALIAS");
 976     }
 977
 978     return 0;
 979 }
 980
 981 /*
 982  * Expect ALIAS.
 983  */
 984
 985 static int
 986 yaml_emitter_emit_alias(yaml_emitter_t *emitter, yaml_event_t *event)
 987 {
 988     if (!yaml_emitter_process_anchor(emitter))
 989         return 0;
 990     emitter->state = POP(emitter, emitter->states);
 991
 992     return 1;
 993 }
 994
 995 /*
 996  * Expect SCALAR.
 997  */
 998
 999 static int
1000 yaml_emitter_emit_scalar(yaml_emitter_t *emitter, yaml_event_t *event)
1001 {
1002     if (!yaml_emitter_select_scalar_style(emitter, event))
1003         return 0;
1004     if (!yaml_emitter_process_anchor(emitter))
1005         return 0;
1006     if (!yaml_emitter_process_tag(emitter))
1007         return 0;
1008     if (!yaml_emitter_increase_indent(emitter, 1, 0))
1009         return 0;
1010     if (!yaml_emitter_process_scalar(emitter))
1011         return 0;
1012     emitter->indent = POP(emitter, emitter->indents);
1013     emitter->state = POP(emitter, emitter->states);
1014
1015     return 1;
1016 }
1017
1018 /*
1019  * Expect SEQUENCE-START.
1020  */
1021
1022 static int
1023 yaml_emitter_emit_sequence_start(yaml_emitter_t *emitter, yaml_event_t *event)
1024 {
1025     if (!yaml_emitter_process_anchor(emitter))
1026         return 0;
1027     if (!yaml_emitter_process_tag(emitter))
1028         return 0;
1029
1030     if (emitter->flow_level || emitter->canonical
1031             || event->data.sequence_start.style == YAML_FLOW_SEQUENCE_STYLE
1032             || yaml_emitter_check_empty_sequence(emitter)) {
1033         emitter->state = YAML_EMIT_FLOW_SEQUENCE_FIRST_ITEM_STATE;
1034     }
1035     else {
1036         emitter->state = YAML_EMIT_BLOCK_SEQUENCE_FIRST_ITEM_STATE;
1037     }
1038
1039     return 1;
1040 }
1041
1042 /*
1043  * Expect MAPPING-START.
1044  */
1045
1046 static int
1047 yaml_emitter_emit_mapping_start(yaml_emitter_t *emitter, yaml_event_t *event)
1048 {
1049     if (!yaml_emitter_process_anchor(emitter))
1050         return 0;
1051     if (!yaml_emitter_process_tag(emitter))
1052         return 0;
1053
1054     if (emitter->flow_level || emitter->canonical
1055             || event->data.mapping_start.style == YAML_FLOW_MAPPING_STYLE
1056             || yaml_emitter_check_empty_mapping(emitter)) {
1057         emitter->state = YAML_EMIT_FLOW_MAPPING_FIRST_KEY_STATE;
1058     }
1059     else {
1060         emitter->state = YAML_EMIT_BLOCK_MAPPING_FIRST_KEY_STATE;
1061     }
1062
1063     return 1;
1064 }
1065
1066 /*
1067  * Check if the document content is an empty scalar.
1068  */
1069
1070 static int
1071 yaml_emitter_check_empty_document(yaml_emitter_t *emitter)
1072 {
1073     return 0;
1074 }
1075
1076 /*
1077  * Check if the next events represent an empty sequence.
1078  */
1079
1080 static int
1081 yaml_emitter_check_empty_sequence(yaml_emitter_t *emitter)
1082 {
1083     if (emitter->events.tail - emitter->events.head < 2)
1084         return 0;
1085
1086     return (emitter->events.head[0].type == YAML_SEQUENCE_START_EVENT
1087             && emitter->events.head[1].type == YAML_SEQUENCE_END_EVENT);
1088 }
1089
1090 /*
1091  * Check if the next events represent an empty mapping.
1092  */
1093
1094 static int
1095 yaml_emitter_check_empty_mapping(yaml_emitter_t *emitter)
1096 {
1097     if (emitter->events.tail - emitter->events.head < 2)
1098         return 0;
1099
1100     return (emitter->events.head[0].type == YAML_MAPPING_START_EVENT
1101             && emitter->events.head[1].type == YAML_MAPPING_END_EVENT);
1102 }
1103
1104 /*
1105  * Check if the next node can be expressed as a simple key.
1106  */
1107
1108 static int
1109 yaml_emitter_check_simple_key(yaml_emitter_t *emitter)
1110 {
1111     yaml_event_t *event = emitter->events.head;
1112     size_t length = 0;
1113
1114     switch (event->type)
1115     {
1116         case YAML_ALIAS_EVENT:
1117             length += emitter->anchor_data.anchor_length;
1118             break;
1119
1120         case YAML_SCALAR_EVENT:
1121             if (emitter->scalar_data.multiline)
1122                 return 0;
1123             length += emitter->anchor_data.anchor_length
1124                 + emitter->tag_data.handle_length
1125                 + emitter->tag_data.suffix_length
1126                 + emitter->scalar_data.length;
1127             break;
1128
1129         case YAML_SEQUENCE_START_EVENT:
1130             if (!yaml_emitter_check_empty_sequence(emitter))
1131                 return 0;
1132             length += emitter->anchor_data.anchor_length
1133                 + emitter->tag_data.handle_length
1134                 + emitter->tag_data.suffix_length;
1135             break;
1136
1137         case YAML_MAPPING_START_EVENT:
1138             if (!yaml_emitter_check_empty_sequence(emitter))
1139                 return 0;
1140             length += emitter->anchor_data.anchor_length
1141                 + emitter->tag_data.handle_length
1142                 + emitter->tag_data.suffix_length;
1143             break;
1144
1145         default:
1146             return 0;
1147     }
1148
1149     if (length > 128)
1150         return 0;
1151
1152     return 1;
1153 }
1154
1155 /*
1156  * Determine an acceptable scalar style.
1157  */
1158
1159 static int
1160 yaml_emitter_select_scalar_style(yaml_emitter_t *emitter, yaml_event_t *event)
1161 {
1162     yaml_scalar_style_t style = event->data.scalar.style;
1163     int no_tag = (!emitter->tag_data.handle && !emitter->tag_data.suffix);
1164
1165     if (no_tag && !event->data.scalar.plain_implicit
1166             && !event->data.scalar.quoted_implicit) {
1167         return yaml_emitter_set_emitter_error(emitter,
1168                 "neither tag nor implicit flags are specified");
1169     }
1170
1171     if (style == YAML_ANY_SCALAR_STYLE)
1172         style = YAML_PLAIN_SCALAR_STYLE;
1173
1174     if (emitter->canonical)
1175         style = YAML_DOUBLE_QUOTED_SCALAR_STYLE;
1176
1177     if (emitter->simple_key_context && emitter->scalar_data.multiline)
1178         style = YAML_DOUBLE_QUOTED_SCALAR_STYLE;
1179
1180     if (style == YAML_PLAIN_SCALAR_STYLE)
1181     {
1182         if ((emitter->flow_level && !emitter->scalar_data.flow_plain_allowed)
1183                 || (!emitter->flow_level && !emitter->scalar_data.block_plain_allowed))
1184             style = YAML_SINGLE_QUOTED_SCALAR_STYLE;
1185         if (!emitter->scalar_data.length
1186                 && (emitter->flow_level || emitter->simple_key_context))
1187             style = YAML_SINGLE_QUOTED_SCALAR_STYLE;
1188         if (no_tag && !event->data.scalar.plain_implicit)
1189             style = YAML_SINGLE_QUOTED_SCALAR_STYLE;
1190     }
1191
1192     if (style == YAML_SINGLE_QUOTED_SCALAR_STYLE)
1193     {
1194         if (!emitter->scalar_data.single_quoted_allowed)
1195             style = YAML_DOUBLE_QUOTED_SCALAR_STYLE;
1196     }
1197
1198     if (style == YAML_LITERAL_SCALAR_STYLE || style == YAML_FOLDED_SCALAR_STYLE)
1199     {
1200         if (!emitter->scalar_data.block_allowed
1201                 || emitter->flow_level || emitter->simple_key_context)
1202             style = YAML_DOUBLE_QUOTED_SCALAR_STYLE;
1203     }
1204
1205     if (no_tag && !event->data.scalar.quoted_implicit
1206             && style != YAML_PLAIN_SCALAR_STYLE)
1207     {
1208         emitter->tag_data.handle = (yaml_char_t *)"!";
1209         emitter->tag_data.handle_length = 1;
1210     }
1211
1212     emitter->scalar_data.style = style;
1213
1214     return 1;
1215 }
1216
1217 /*
1218  * Write an achor.
1219  */
1220
1221 static int
1222 yaml_emitter_process_anchor(yaml_emitter_t *emitter)
1223 {
1224     if (!emitter->anchor_data.anchor)
1225         return 1;
1226
1227     if (!yaml_emitter_write_indicator(emitter,
1228                 (emitter->anchor_data.alias ? "*" : "&"), 1, 0, 0))
1229         return 0;
1230
1231     return yaml_emitter_write_anchor(emitter,
1232             emitter->anchor_data.anchor, emitter->anchor_data.anchor_length);
1233 }
1234
1235 /*
1236  * Write a tag.
1237  */
1238
1239 static int
1240 yaml_emitter_process_tag(yaml_emitter_t *emitter)
1241 {
1242     if (!emitter->tag_data.handle && !emitter->tag_data.suffix)
1243         return 1;
1244
1245     if (emitter->tag_data.handle)
1246     {
1247         if (!yaml_emitter_write_tag_handle(emitter, emitter->tag_data.handle,
1248                     emitter->tag_data.handle_length))
1249             return 0;
1250         if (emitter->tag_data.suffix) {
1251             if (!yaml_emitter_write_tag_content(emitter, emitter->tag_data.suffix,
1252                         emitter->tag_data.suffix_length, 0))
1253                 return 0;
1254         }
1255     }
1256     else
1257     {
1258         if (!yaml_emitter_write_indicator(emitter, "!<", 1, 0, 0))
1259             return 0;
1260         if (!yaml_emitter_write_tag_content(emitter, emitter->tag_data.suffix,
1261                     emitter->tag_data.suffix_length, 0))
1262             return 0;
1263         if (!yaml_emitter_write_indicator(emitter, ">", 0, 0, 0))
1264             return 0;
1265     }
1266
1267     return 1;
1268 }
1269
1270 /*
1271  * Write a scalar.
1272  */
1273
1274 static int
1275 yaml_emitter_process_scalar(yaml_emitter_t *emitter)
1276 {
1277     switch (emitter->scalar_data.style)
1278     {
1279         case YAML_PLAIN_SCALAR_STYLE:
1280             return yaml_emitter_write_plain_scalar(emitter,
1281                     emitter->scalar_data.value, emitter->scalar_data.length,
1282                     !emitter->simple_key_context);
1283
1284         case YAML_SINGLE_QUOTED_SCALAR_STYLE:
1285             return yaml_emitter_write_single_quoted_scalar(emitter,
1286                     emitter->scalar_data.value, emitter->scalar_data.length,
1287                     !emitter->simple_key_context);
1288
1289         case YAML_DOUBLE_QUOTED_SCALAR_STYLE:
1290             return yaml_emitter_write_double_quoted_scalar(emitter,
1291                     emitter->scalar_data.value, emitter->scalar_data.length,
1292                     !emitter->simple_key_context);
1293
1294         case YAML_LITERAL_SCALAR_STYLE:
1295             return yaml_emitter_write_literal_scalar(emitter,
1296                     emitter->scalar_data.value, emitter->scalar_data.length);
1297
1298         case YAML_FOLDED_SCALAR_STYLE:
1299             return yaml_emitter_write_folded_scalar(emitter,
1300                     emitter->scalar_data.value, emitter->scalar_data.length);
1301
1302         default:
1303             assert(1);      /* Impossible. */
1304     }
1305
1306     return 0;
1307 }
1308
1309 /*
1310  * Check if a %YAML directive is valid.
1311  */
1312
1313 static int
1314 yaml_emitter_analyze_version_directive(yaml_emitter_t *emitter,
1315         yaml_version_directive_t version_directive)
1316 {
1317     if (version_directive.major != 1 || version_directive.minor != 1) {
1318         return yaml_emitter_set_emitter_error(emitter,
1319                 "incompatible %YAML directive");
1320     }
1321
1322     return 1;
1323 }
1324
1325 /*
1326  * Check if a %TAG directive is valid.
1327  */
1328
1329 static int
1330 yaml_emitter_analyze_tag_directive(yaml_emitter_t *emitter,
1331         yaml_tag_directive_t tag_directive)
1332 {
1333     yaml_string_t handle = STRING(tag_directive.handle,
1334             strlen((char *)tag_directive.handle));
1335     yaml_string_t prefix = STRING(tag_directive.prefix,
1336             strlen((char *)tag_directive.prefix));
1337
1338     if (handle.start == handle.end) {
1339         return yaml_emitter_set_emitter_error(emitter,
1340                 "tag handle must not be empty");
1341     }
1342
1343     if (handle.start[0] != '!') {
1344         return yaml_emitter_set_emitter_error(emitter,
1345                 "tag handle must start with '!'");
1346     }
1347
1348     if (handle.end[-1] != '!') {
1349         return yaml_emitter_set_emitter_error(emitter,
1350                 "tag handle must end with '!'");
1351     }
1352
1353     handle.pointer ++;
1354
1355     while (handle.pointer < handle.end-1) {
1356         if (!IS_ALPHA(handle)) {
1357             return yaml_emitter_set_emitter_error(emitter,
1358                     "tag handle must contain alphanumerical characters only");
1359         }
1360         MOVE(handle);
1361     }
1362
1363     if (prefix.start == prefix.end) {
1364         return yaml_emitter_set_emitter_error(emitter,
1365                 "tag prefix must not be empty");
1366     }
1367
1368     return 1;
1369 }
1370
1371 /*
1372  * Check if an anchor is valid.
1373  */
1374
1375 static int
1376 yaml_emitter_analyze_anchor(yaml_emitter_t *emitter,
1377         yaml_char_t *anchor, int alias)
1378 {
1379     yaml_string_t string = STRING(anchor, strlen((char *)anchor));
1380
1381     if (string.start == string.end) {
1382         return yaml_emitter_set_emitter_error(emitter, alias ?
1383                 "alias value must not be empty" :
1384                 "anchor value must not be empty");
1385     }
1386
1387     while (string.pointer != string.end) {
1388         if (!IS_ALPHA(string)) {
1389             return yaml_emitter_set_emitter_error(emitter, alias ?
1390                     "alias value must contain alphanumerical characters only" :
1391                     "anchor value must contain alphanumerical characters only");
1392         }
1393         MOVE(string);
1394     }
1395
1396     emitter->anchor_data.anchor = string.start;
1397     emitter->anchor_data.anchor_length = string.end - string.start;
1398     emitter->anchor_data.alias = alias;
1399
1400     return 1;
1401 }
1402
1403 /*
1404  * Check if a tag is valid.
1405  */
1406
1407 static int
1408 yaml_emitter_analyze_tag(yaml_emitter_t *emitter,
1409         yaml_char_t *tag)
1410 {
1411     yaml_string_t string = STRING(tag, strlen((char *)tag));
1412     yaml_tag_directive_t *tag_directive;
1413
1414     if (string.start == string.end) {
1415         return yaml_emitter_set_emitter_error(emitter,
1416                 "tag value must not be empty");
1417     }
1418
1419     for (tag_directive = emitter->tag_directives.start;
1420             tag_directive != emitter->tag_directives.top; tag_directive ++) {
1421         size_t prefix_length = strlen((char *)tag_directive->prefix);
1422         if (prefix_length < (size_t)(string.end - string.start)
1423                 && strncmp((char *)tag_directive->prefix, (char *)string.start,
1424                     prefix_length) == 0)
1425         {
1426             emitter->tag_data.handle = tag_directive->handle;
1427             emitter->tag_data.handle_length =
1428                 strlen((char *)tag_directive->handle);
1429             emitter->tag_data.suffix = string.start + prefix_length;
1430             emitter->tag_data.suffix_length =
1431                 (string.end - string.start) - prefix_length;
1432             return 1;
1433         }
1434     }
1435
1436     emitter->tag_data.suffix = string.start;
1437     emitter->tag_data.suffix_length = string.end - string.start;
1438
1439     return 1;
1440 }
1441
1442 /*
1443  * Check if a scalar is valid.
1444  */
1445
1446 static int
1447 yaml_emitter_analyze_scalar(yaml_emitter_t *emitter,
1448         yaml_char_t *value, size_t length)
1449 {
1450     yaml_string_t string = STRING(value, length);
1451
1452     int block_indicators = 0;
1453     int flow_indicators = 0;
1454     int line_breaks = 0;
1455     int special_characters = 0;
1456
1457     int leading_space = 0;
1458     int leading_break = 0;
1459     int trailing_space = 0;
1460     int trailing_break = 0;
1461     int break_space = 0;
1462     int space_break = 0;
1463
1464     int preceeded_by_whitespace = 0;
1465     int followed_by_whitespace = 0;
1466     int previous_space = 0;
1467     int previous_break = 0;
1468
1469     emitter->scalar_data.value = value;
1470     emitter->scalar_data.length = length;
1471
1472     if (string.start == string.end)
1473     {
1474         emitter->scalar_data.multiline = 0;
1475         emitter->scalar_data.flow_plain_allowed = 0;
1476         emitter->scalar_data.block_plain_allowed = 1;
1477         emitter->scalar_data.single_quoted_allowed = 1;
1478         emitter->scalar_data.block_allowed = 0;
1479
1480         return 1;
1481     }
1482
1483     if ((CHECK_AT(string, '-', 0)
1484                 && CHECK_AT(string, '-', 1)
1485                 && CHECK_AT(string, '-', 2))
1486             || (CHECK_AT(string, '.', 0)
1487                 && CHECK_AT(string, '.', 1)
1488                 && CHECK_AT(string, '.', 2))) {
1489         block_indicators = 1;
1490         flow_indicators = 1;
1491     }
1492
1493     preceeded_by_whitespace = 1;
1494     followed_by_whitespace = IS_BLANKZ_AT(string, WIDTH(string));
1495
1496     while (string.pointer != string.end)
1497     {
1498         if (string.start == string.pointer)
1499         {
1500             if (CHECK(string, '#') || CHECK(string, ',')
1501                     || CHECK(string, '[') || CHECK(string, ']')
1502                     || CHECK(string, '{') || CHECK(string, '}')
1503                     || CHECK(string, '&') || CHECK(string, '*')
1504                     || CHECK(string, '!') || CHECK(string, '|')
1505                     || CHECK(string, '>') || CHECK(string, '\'')
1506                     || CHECK(string, '"') || CHECK(string, '%')
1507                     || CHECK(string, '@') || CHECK(string, '`')) {
1508                 flow_indicators = 1;
1509                 block_indicators = 1;
1510             }
1511
1512             if (CHECK(string, '?') || CHECK(string, ':')) {
1513                 flow_indicators = 1;
1514                 if (followed_by_whitespace) {
1515                     block_indicators = 1;
1516                 }
1517             }
1518
1519             if (CHECK(string, '-') && followed_by_whitespace) {
1520                 flow_indicators = 1;
1521                 block_indicators = 1;
1522             }
1523         }
1524         else
1525         {
1526             if (CHECK(string, ',') || CHECK(string, '?')
1527                     || CHECK(string, '[') || CHECK(string, ']')
1528                     || CHECK(string, '{') || CHECK(string, '}')) {
1529                 flow_indicators = 1;
1530             }
1531
1532             if (CHECK(string, ':')) {
1533                 flow_indicators = 1;
1534                 if (followed_by_whitespace) {
1535                     block_indicators = 1;
1536                 }
1537             }
1538
1539             if (CHECK(string, '#') && preceeded_by_whitespace) {
1540                 flow_indicators = 1;
1541                 block_indicators = 1;
1542             }
1543         }
1544
1545         if (!IS_PRINTABLE(string)
1546                 || (!IS_ASCII(string) && !emitter->unicode)) {
1547             special_characters = 1;
1548         }
1549
1550         if (IS_BREAK(string)) {
1551             line_breaks = 1;
1552         }
1553
1554         if (IS_SPACE(string))
1555         {
1556             if (string.start == string.pointer) {
1557                 leading_space = 1;
1558             }
1559             if (string.pointer+WIDTH(string) == string.end) {
1560                 trailing_space = 1;
1561             }
1562             if (previous_break) {
1563                 break_space = 1;
1564             }
1565             previous_space = 1;
1566             previous_break = 0;
1567         }
1568         else if (IS_BREAK(string))
1569         {
1570             if (string.start == string.pointer) {
1571                 leading_break = 1;
1572             }
1573             if (string.pointer+WIDTH(string) == string.end) {
1574                 trailing_break = 1;
1575             }
1576             if (previous_space) {
1577                 space_break = 1;
1578             }
1579             previous_space = 0;
1580             previous_break = 1;
1581         }
1582         else
1583         {
1584             previous_space = 0;
1585             previous_break = 0;
1586         }
1587
1588         preceeded_by_whitespace = IS_BLANKZ(string);
1589         MOVE(string);
1590         if (string.pointer != string.end) {
1591             followed_by_whitespace = IS_BLANKZ_AT(string, WIDTH(string));
1592         }
1593     }
1594
1595     emitter->scalar_data.multiline = line_breaks;
1596
1597     emitter->scalar_data.flow_plain_allowed = 1;
1598     emitter->scalar_data.block_plain_allowed = 1;
1599     emitter->scalar_data.single_quoted_allowed = 1;
1600     emitter->scalar_data.block_allowed = 1;
1601
1602     if (leading_space || leading_break || trailing_space || trailing_break) {
1603         emitter->scalar_data.flow_plain_allowed = 0;
1604         emitter->scalar_data.block_plain_allowed = 0;
1605     }
1606
1607     if (trailing_space) {
1608         emitter->scalar_data.block_allowed = 0;
1609     }
1610
1611     if (break_space) {
1612         emitter->scalar_data.flow_plain_allowed = 0;
1613         emitter->scalar_data.block_plain_allowed = 0;
1614         emitter->scalar_data.single_quoted_allowed = 0;
1615     }
1616
1617     if (space_break || special_characters) {
1618         emitter->scalar_data.flow_plain_allowed = 0;
1619         emitter->scalar_data.block_plain_allowed = 0;
1620         emitter->scalar_data.single_quoted_allowed = 0;
1621         emitter->scalar_data.block_allowed = 0;
1622     }
1623
1624     if (line_breaks) {
1625         emitter->scalar_data.flow_plain_allowed = 0;
1626         emitter->scalar_data.block_plain_allowed = 0;
1627     }
1628
1629     if (flow_indicators) {
1630         emitter->scalar_data.flow_plain_allowed = 0;
1631     }
1632
1633     if (block_indicators) {
1634         emitter->scalar_data.block_plain_allowed = 0;
1635     }
1636
1637     return 1;
1638 }
1639
1640 /*
1641  * Check if the event data is valid.
1642  */
1643
1644 static int
1645 yaml_emitter_analyze_event(yaml_emitter_t *emitter,
1646         yaml_event_t *event)
1647 {
1648     emitter->anchor_data.anchor = NULL;
1649     emitter->anchor_data.anchor_length = 0;
1650     emitter->tag_data.handle = NULL;
1651     emitter->tag_data.handle_length = 0;
1652     emitter->tag_data.suffix = NULL;
1653     emitter->tag_data.suffix_length = 0;
1654     emitter->scalar_data.value = NULL;
1655     emitter->scalar_data.length = 0;
1656
1657     switch (event->type)
1658     {
1659         case YAML_ALIAS_EVENT:
1660             if (!yaml_emitter_analyze_anchor(emitter,
1661                         event->data.alias.anchor, 1))
1662                 return 0;
1663             return 1;
1664
1665         case YAML_SCALAR_EVENT:
1666             if (event->data.scalar.anchor) {
1667                 if (!yaml_emitter_analyze_anchor(emitter,
1668                             event->data.scalar.anchor, 0))
1669                     return 0;
1670             }
1671             if (event->data.scalar.tag && (emitter->canonical ||
1672                         (!event->data.scalar.plain_implicit
1673                          && !event->data.scalar.quoted_implicit))) {
1674                 if (!yaml_emitter_analyze_tag(emitter, event->data.scalar.tag))
1675                     return 0;
1676             }
1677             if (!yaml_emitter_analyze_scalar(emitter,
1678                         event->data.scalar.value, event->data.scalar.length))
1679                 return 0;
1680             return 1;
1681
1682         case YAML_SEQUENCE_START_EVENT:
1683             if (event->data.sequence_start.anchor) {
1684                 if (!yaml_emitter_analyze_anchor(emitter,
1685                             event->data.sequence_start.anchor, 0))
1686                     return 0;
1687             }
1688             if (event->data.sequence_start.tag && (emitter->canonical ||
1689                         !event->data.sequence_start.implicit)) {
1690                 if (!yaml_emitter_analyze_tag(emitter,
1691                             event->data.sequence_start.tag))
1692                     return 0;
1693             }
1694             return 1;
1695
1696         case YAML_MAPPING_START_EVENT:
1697             if (event->data.mapping_start.anchor) {
1698                 if (!yaml_emitter_analyze_anchor(emitter,
1699                             event->data.mapping_start.anchor, 0))
1700                     return 0;
1701             }
1702             if (event->data.mapping_start.tag && (emitter->canonical ||
1703                         !event->data.mapping_start.implicit)) {
1704                 if (!yaml_emitter_analyze_tag(emitter,
1705                             event->data.mapping_start.tag))
1706                     return 0;
1707             }
1708             return 1;
1709
1710         default:
1711             return 1;
1712     }
1713 }
1714
1715 /*
1716  * Write the BOM character.
1717  */
1718
1719 static int
1720 yaml_emitter_write_bom(yaml_emitter_t *emitter)
1721 {
1722     if (!FLUSH(emitter)) return 0;
1723
1724     *(emitter->buffer.pointer++) = (yaml_char_t) '\xEF';
1725     *(emitter->buffer.pointer++) = (yaml_char_t) '\xBB';
1726     *(emitter->buffer.pointer++) = (yaml_char_t) '\xBF';
1727
1728     return 1;
1729 }
1730
1731 static int
1732 yaml_emitter_write_indent(yaml_emitter_t *emitter)
1733 {
1734     int indent = (emitter->indent >= 0) ? emitter->indent : 0;
1735
1736     if (!emitter->indention || emitter->column > indent
1737             || (emitter->column == indent && !emitter->whitespace)) {
1738         if (!PUT_BREAK(emitter)) return 0;
1739     }
1740
1741     while (emitter->column < indent) {
1742         if (!PUT(emitter, ' ')) return 0;
1743     }
1744
1745     emitter->whitespace = 1;
1746     emitter->indention = 1;
1747
1748     return 1;
1749 }
1750
1751 static int
1752 yaml_emitter_write_indicator(yaml_emitter_t *emitter,
1753         char *indicator, int need_whitespace,
1754         int is_whitespace, int is_indention)
1755 {
1756     yaml_string_t string = STRING((yaml_char_t *)indicator, strlen(indicator));
1757
1758     if (need_whitespace && !emitter->whitespace) {
1759         if (!PUT(emitter, ' ')) return 0;
1760     }
1761
1762     while (string.pointer != string.end) {
1763         if (!WRITE(emitter, string)) return 0;
1764     }
1765
1766     emitter->whitespace = is_whitespace;
1767     emitter->indention = (emitter->indention && is_indention);
1768
1769     return 1;
1770 }
1771
1772 static int
1773 yaml_emitter_write_anchor(yaml_emitter_t *emitter,
1774         yaml_char_t *value, size_t length)
1775 {
1776     yaml_string_t string = STRING(value, length);
1777
1778     while (string.pointer != string.end) {
1779         if (!WRITE(emitter, string)) return 0;
1780     }
1781
1782     emitter->whitespace = 0;
1783     emitter->indention = 0;
1784
1785     return 1;
1786 }
1787
1788 static int
1789 yaml_emitter_write_tag_handle(yaml_emitter_t *emitter,
1790         yaml_char_t *value, size_t length)
1791 {
1792     yaml_string_t string = STRING(value, length);
1793
1794     if (!emitter->whitespace) {
1795         if (!PUT(emitter, ' ')) return 0;
1796     }
1797
1798     while (string.pointer != string.end) {
1799         if (!WRITE(emitter, string)) return 0;
1800     }
1801
1802     emitter->whitespace = 0;
1803     emitter->indention = 0;
1804
1805     return 1;
1806 }
1807
1808 static int
1809 yaml_emitter_write_tag_content(yaml_emitter_t *emitter,
1810         yaml_char_t *value, size_t length,
1811         int need_whitespace)
1812 {
1813     yaml_string_t string = STRING(value, length);
1814
1815     if (need_whitespace && !emitter->whitespace) {
1816         if (!PUT(emitter, ' ')) return 0;
1817     }
1818
1819     while (string.pointer != string.end) {
1820         if (IS_ALPHA(string)
1821                 || CHECK(string, ';') || CHECK(string, '/')
1822                 || CHECK(string, '?') || CHECK(string, ':')
1823                 || CHECK(string, '@') || CHECK(string, '&')
1824                 || CHECK(string, '=') || CHECK(string, '+')
1825                 || CHECK(string, '$') || CHECK(string, ',')
1826                 || CHECK(string, '_') || CHECK(string, '.')
1827                 || CHECK(string, '~') || CHECK(string, '*')
1828                 || CHECK(string, '\'') || CHECK(string, '(')
1829                 || CHECK(string, ')') || CHECK(string, '[')
1830                 || CHECK(string, ']')) {
1831             if (!WRITE(emitter, string)) return 0;
1832         }
1833         else {
1834             int width = WIDTH(string);
1835             unsigned int value;
1836             while (width --) {
1837                 value = *(string.pointer++);
1838                 if (!PUT(emitter, '%')) return 0;
1839                 if (!PUT(emitter, (value >> 4)
1840                             + ((value >> 4) < 10 ? '0' : 'A' - 10)))
1841                     return 0;
1842                 if (!PUT(emitter, (value & 0x0F)
1843                             + ((value & 0x0F) < 10 ? '0' : 'A' - 10)))
1844                     return 0;
1845             }
1846         }
1847     }
1848
1849     emitter->whitespace = 0;
1850     emitter->indention = 0;
1851
1852     return 1;
1853 }
1854
1855 static int
1856 yaml_emitter_write_plain_scalar(yaml_emitter_t *emitter,
1857         yaml_char_t *value, size_t length, int allow_breaks)
1858 {
1859     yaml_string_t string = STRING(value, length);
1860     int spaces = 0;
1861     int breaks = 0;
1862
1863     if (!emitter->whitespace) {
1864         if (!PUT(emitter, ' ')) return 0;
1865     }
1866
1867     while (string.pointer != string.end)
1868     {
1869         if (IS_SPACE(string))
1870         {
1871             if (allow_breaks && !spaces
1872                     && emitter->column > emitter->best_width
1873                     && !IS_SPACE_AT(string, 1)) {
1874                 if (!yaml_emitter_write_indent(emitter)) return 0;
1875                 MOVE(string);
1876             }
1877             else {
1878                 if (!WRITE(emitter, string)) return 0;
1879             }
1880             spaces = 1;
1881         }
1882         else if (IS_BREAK(string))
1883         {
1884             if (!breaks && CHECK(string, '\n')) {
1885                 if (!PUT_BREAK(emitter)) return 0;
1886             }
1887             if (!WRITE_BREAK(emitter, string)) return 0;
1888             emitter->indention = 1;
1889             breaks = 1;
1890         }
1891         else
1892         {
1893             if (breaks) {
1894                 if (!yaml_emitter_write_indent(emitter)) return 0;
1895             }
1896             if (!WRITE(emitter, string)) return 0;
1897             emitter->indention = 0;
1898             spaces = 0;
1899             breaks = 0;
1900         }
1901     }
1902
1903     emitter->whitespace = 0;
1904     emitter->indention = 0;
1905
1906     return 1;
1907 }
1908
1909 static int
1910 yaml_emitter_write_single_quoted_scalar(yaml_emitter_t *emitter,
1911         yaml_char_t *value, size_t length, int allow_breaks)
1912 {
1913     yaml_string_t string = STRING(value, length);
1914     int spaces = 0;
1915     int breaks = 0;
1916
1917     if (!yaml_emitter_write_indicator(emitter, "'", 1, 0, 0))
1918         return 0;
1919
1920     while (string.pointer != string.end)
1921     {
1922         if (IS_SPACE(string))
1923         {
1924             if (allow_breaks && !spaces
1925                     && emitter->column > emitter->best_width
1926                     && string.pointer != string.start
1927                     && string.pointer != string.end - 1
1928                     && !IS_SPACE_AT(string, 1)) {
1929                 if (!yaml_emitter_write_indent(emitter)) return 0;
1930                 MOVE(string);
1931             }
1932             else {
1933                 if (!WRITE(emitter, string)) return 0;
1934             }
1935             spaces = 1;
1936         }
1937         else if (IS_BREAK(string))
1938         {
1939             if (!breaks && CHECK(string, '\n')) {
1940                 if (!PUT_BREAK(emitter)) return 0;
1941             }
1942             if (!WRITE_BREAK(emitter, string)) return 0;
1943             emitter->indention = 1;
1944             breaks = 1;
1945         }
1946         else
1947         {
1948             if (breaks) {
1949                 if (!yaml_emitter_write_indent(emitter)) return 0;
1950             }
1951             if (CHECK(string, '\'')) {
1952                 if (!PUT(emitter, '\'')) return 0;
1953             }
1954             if (!WRITE(emitter, string)) return 0;
1955             emitter->indention = 0;
1956             spaces = 0;
1957             breaks = 0;
1958         }
1959     }
1960
1961     if (!yaml_emitter_write_indicator(emitter, "'", 0, 0, 0))
1962         return 0;
1963
1964     emitter->whitespace = 0;
1965     emitter->indention = 0;
1966
1967     return 1;
1968 }
1969
1970 static int
1971 yaml_emitter_write_double_quoted_scalar(yaml_emitter_t *emitter,
1972         yaml_char_t *value, size_t length, int allow_breaks)
1973 {
1974     yaml_string_t string = STRING(value, length);
1975     int spaces = 0;
1976
1977     if (!yaml_emitter_write_indicator(emitter, "\"", 1, 0, 0))
1978         return 0;
1979
1980     while (string.pointer != string.end)
1981     {
1982         if (!IS_PRINTABLE(string) || (!emitter->unicode && !IS_ASCII(string))
1983                 || IS_BOM(string) || IS_BREAK(string)
1984                 || CHECK(string, '"') || CHECK(string, '\\'))
1985         {
1986             unsigned char octet;
1987             unsigned int width;
1988             unsigned int value;
1989             int k;
1990
1991             octet = string.pointer[0];
1992             width = (octet & 0x80) == 0x00 ? 1 :
1993                     (octet & 0xE0) == 0xC0 ? 2 :
1994                     (octet & 0xF0) == 0xE0 ? 3 :
1995                     (octet & 0xF8) == 0xF0 ? 4 : 0;
1996             value = (octet & 0x80) == 0x00 ? octet & 0x7F :
1997                     (octet & 0xE0) == 0xC0 ? octet & 0x1F :
1998                     (octet & 0xF0) == 0xE0 ? octet & 0x0F :
1999                     (octet & 0xF8) == 0xF0 ? octet & 0x07 : 0;
2000             for (k = 1; k < (int)width; k ++) {
2001                 octet = string.pointer[k];
2002                 value = (value << 6) + (octet & 0x3F);
2003             }
2004             string.pointer += width;
2005
2006             if (!PUT(emitter, '\\')) return 0;
2007
2008             switch (value)
2009             {
2010                 case 0x00:
2011                     if (!PUT(emitter, '0')) return 0;
2012                     break;
2013
2014                 case 0x07:
2015                     if (!PUT(emitter, 'a')) return 0;
2016                     break;
2017
2018                 case 0x08:
2019                     if (!PUT(emitter, 'b')) return 0;
2020                     break;
2021
2022                 case 0x09:
2023                     if (!PUT(emitter, 't')) return 0;
2024                     break;
2025
2026                 case 0x0A:
2027                     if (!PUT(emitter, 'n')) return 0;
2028                     break;
2029
2030                 case 0x0B:
2031                     if (!PUT(emitter, 'v')) return 0;
2032                     break;
2033
2034                 case 0x0C:
2035                     if (!PUT(emitter, 'f')) return 0;
2036                     break;
2037
2038                 case 0x0D:
2039                     if (!PUT(emitter, 'r')) return 0;
2040                     break;
2041
2042                 case 0x1B:
2043                     if (!PUT(emitter, 'e')) return 0;
2044                     break;
2045
2046                 case 0x22:
2047                     if (!PUT(emitter, '\"')) return 0;
2048                     break;
2049
2050                 case 0x5C:
2051                     if (!PUT(emitter, '\\')) return 0;
2052                     break;
2053
2054                 case 0x85:
2055                     if (!PUT(emitter, 'N')) return 0;
2056                     break;
2057
2058                 case 0xA0:
2059                     if (!PUT(emitter, '_')) return 0;
2060                     break;
2061
2062                 case 0x2028:
2063                     if (!PUT(emitter, 'L')) return 0;
2064                     break;
2065
2066                 case 0x2029:
2067                     if (!PUT(emitter, 'P')) return 0;
2068                     break;
2069
2070                 default:
2071                     if (value <= 0xFF) {
2072                         if (!PUT(emitter, 'x')) return 0;
2073                         width = 2;
2074                     }
2075                     else if (value <= 0xFFFF) {
2076                         if (!PUT(emitter, 'u')) return 0;
2077                         width = 4;
2078                     }
2079                     else {
2080                         if (!PUT(emitter, 'U')) return 0;
2081                         width = 8;
2082                     }
2083                     for (k = (width-1)*4; k >= 0; k -= 4) {
2084                         int digit = (value >> k) & 0x0F;
2085                         if (!PUT(emitter, digit + (digit < 10 ? '0' : 'A'-10)))
2086                             return 0;
2087                     }
2088             }
2089             spaces = 0;
2090         }
2091         else if (IS_SPACE(string))
2092         {
2093             if (allow_breaks && !spaces
2094                     && emitter->column > emitter->best_width
2095                     && string.pointer != string.start
2096                     && string.pointer != string.end - 1) {
2097                 if (!yaml_emitter_write_indent(emitter)) return 0;
2098                 if (IS_SPACE_AT(string, 1)) {
2099                     if (!PUT(emitter, '\\')) return 0;
2100                 }
2101                 MOVE(string);
2102             }
2103             else {
2104                 if (!WRITE(emitter, string)) return 0;
2105             }
2106             spaces = 1;
2107         }
2108         else
2109         {
2110             if (!WRITE(emitter, string)) return 0;
2111             spaces = 0;
2112         }
2113     }
2114
2115     if (!yaml_emitter_write_indicator(emitter, "\"", 0, 0, 0))
2116         return 0;
2117
2118     emitter->whitespace = 0;
2119     emitter->indention = 0;
2120
2121     return 1;
2122 }
2123
2124 static int
2125 yaml_emitter_write_block_scalar_hints(yaml_emitter_t *emitter,
2126         yaml_string_t string)
2127 {
2128     char indent_hint[2];
2129     char *chomp_hint = NULL;
2130
2131     if (IS_SPACE(string) || IS_BREAK(string))
2132     {
2133         indent_hint[0] = '0' + (char)emitter->best_indent;
2134         indent_hint[1] = '\0';
2135         if (!yaml_emitter_write_indicator(emitter, indent_hint, 0, 0, 0))
2136             return 0;
2137     }
2138
2139     string.pointer = string.end;
2140     if (string.start == string.pointer)
2141     {
2142         chomp_hint = "-";
2143     }
2144     else
2145     {
2146         do {
2147             string.pointer --;
2148         } while ((*string.pointer & 0xC0) == 0x80);
2149         if (!IS_BREAK(string))
2150         {
2151             chomp_hint = "-";
2152         }
2153         else if (string.start == string.pointer)
2154         {
2155             chomp_hint = "+";
2156         }
2157         else
2158         {
2159             do {
2160                 string.pointer --;
2161             } while ((*string.pointer & 0xC0) == 0x80);
2162             if (IS_BREAK(string))
2163             {
2164                 chomp_hint = "+";
2165             }
2166         }
2167     }
2168
2169     if (chomp_hint)
2170     {
2171         if (!yaml_emitter_write_indicator(emitter, chomp_hint, 0, 0, 0))
2172             return 0;
2173     }
2174
2175     return 1;
2176 }
2177
2178 static int
2179 yaml_emitter_write_literal_scalar(yaml_emitter_t *emitter,
2180         yaml_char_t *value, size_t length)
2181 {
2182     yaml_string_t string = STRING(value, length);
2183     int breaks = 1;
2184
2185     if (!yaml_emitter_write_indicator(emitter, "|", 1, 0, 0))
2186         return 0;
2187     if (!yaml_emitter_write_block_scalar_hints(emitter, string))
2188         return 0;
2189     if (!PUT_BREAK(emitter)) return 0;
2190     emitter->indention = 1;
2191     emitter->whitespace = 1;
2192
2193     while (string.pointer != string.end)
2194     {
2195         if (IS_BREAK(string))
2196         {
2197             if (!WRITE_BREAK(emitter, string)) return 0;
2198             emitter->indention = 1;
2199             breaks = 1;
2200         }
2201         else
2202         {
2203             if (breaks) {
2204                 if (!yaml_emitter_write_indent(emitter)) return 0;
2205             }
2206             if (!WRITE(emitter, string)) return 0;
2207             emitter->indention = 0;
2208             breaks = 0;
2209         }
2210     }
2211
2212     return 1;
2213 }
2214
2215 static int
2216 yaml_emitter_write_folded_scalar(yaml_emitter_t *emitter,
2217         yaml_char_t *value, size_t length)
2218 {
2219     yaml_string_t string = STRING(value, length);
2220     int breaks = 1;
2221     int leading_spaces = 1;
2222
2223     if (!yaml_emitter_write_indicator(emitter, ">", 1, 0, 0))
2224         return 0;
2225     if (!yaml_emitter_write_block_scalar_hints(emitter, string))
2226         return 0;
2227     if (!PUT_BREAK(emitter)) return 0;
2228     emitter->indention = 1;
2229     emitter->whitespace = 1;
2230
2231     while (string.pointer != string.end)
2232     {
2233         if (IS_BREAK(string))
2234         {
2235             if (!breaks && !leading_spaces && CHECK(string, '\n')) {
2236                 int k = 0;
2237                 while (IS_BREAK_AT(string, k)) {
2238                     k += WIDTH_AT(string, k);
2239                 }
2240                 if (!IS_BLANK_AT(string, k)) {
2241                     if (!PUT_BREAK(emitter)) return 0;
2242                 }
2243             }
2244             if (!WRITE_BREAK(emitter, string)) return 0;
2245             emitter->indention = 1;
2246             breaks = 1;
2247         }
2248         else
2249         {
2250             if (breaks) {
2251                 if (!yaml_emitter_write_indent(emitter)) return 0;
2252                 leading_spaces = IS_BLANK(string);
2253             }
2254             if (!breaks && IS_SPACE(string) && !IS_SPACE_AT(string, 1)
2255                     && emitter->column > emitter->best_width) {
2256                 if (!yaml_emitter_write_indent(emitter)) return 0;
2257                 MOVE(string);
2258             }
2259             else {
2260                 if (!WRITE(emitter, string)) return 0;
2261             }
2262             emitter->indention = 0;
2263             breaks = 0;
2264         }
2265     }
2266
2267     return 1;
2268 }
2269