1YAML::PP(3) User Contributed Perl Documentation YAML::PP(3)
2
3
4
6 YAML::PP - YAML 1.2 processor
7
9 WARNING: Most of the inner API is not stable yet.
10
11 Here are a few examples of the basic load and dump methods:
12
13 use YAML::PP;
14 my $ypp = YAML::PP->new;
15
16 my $yaml = <<'EOM';
17 --- # Document one is a mapping
18 name: Tina
19 age: 29
20 favourite language: Perl
21
22 --- # Document two is a sequence
23 - plain string
24 - 'in single quotes'
25 - "in double quotes we have escapes! like \t and \n"
26 - | # a literal block scalar
27 line1
28 line2
29 - > # a folded block scalar
30 this is all one
31 single line because the
32 linebreaks will be folded
33 EOM
34
35 my @documents = $ypp->load_string($yaml);
36 my @documents = $ypp->load_file($filename);
37
38 my $yaml = $ypp->dump_string($data1, $data2);
39 $ypp->dump_file($filename, $data1, $data2);
40
41 # The loader offers JSON::PP::Boolean, boolean.pm or
42 # perl 1/'' (currently default) for booleans
43 my $ypp = YAML::PP->new(boolean => 'JSON::PP');
44 my $ypp = YAML::PP->new(boolean => 'boolean');
45 my $ypp = YAML::PP->new(boolean => 'perl');
46
47 # Enable perl data types and objects
48 my $ypp = YAML::PP->new(schema => [qw/ + Perl /]);
49 my $yaml = $yp->dump_string($data_with_perl_objects);
50
51 # Legacy interface
52 use YAML::PP qw/ Load Dump LoadFile DumpFile /;
53 my @documents = Load($yaml);
54 my @documents = LoadFile($filename);
55 my @documents = LoadFile($filehandle);
56 my $yaml = = Dump(@documents);
57 DumpFile($filename, @documents);
58 DumpFile($filenhandle @documents);
59
60 Some utility scripts, mostly useful for debugging:
61
62 # Load YAML into a data structure and dump with Data::Dumper
63 yamlpp-load < file.yaml
64
65 # Load and Dump
66 yamlpp-load-dump < file.yaml
67
68 # Print the events from the parser in yaml-test-suite format
69 yamlpp-events < file.yaml
70
71 # Parse and emit events directly without loading
72 yamlpp-parse-emit < file.yaml
73
74 # Create ANSI colored YAML. Can also be useful for invalid YAML, showing
75 # you the exact location of the error
76 yamlpp-highlight < file.yaml
77
79 YAML::PP is a modular YAML processor.
80
81 It aims to support "YAML 1.2" and "YAML 1.1". See <https://yaml.org/>.
82 Some (rare) syntax elements are not yet supported and documented below.
83
84 YAML is a serialization language. The YAML input is called "YAML
85 Stream". A stream consists of one or more "Documents", separated by a
86 line with a document start marker "---". A document optionally ends
87 with the document end marker "...".
88
89 This allows one to process continuous streams additionally to a fixed
90 input file or string.
91
92 The YAML::PP frontend will currently load all documents, and return
93 only the first if called with scalar context.
94
95 The YAML backend is implemented in a modular way that allows one to add
96 custom handling of YAML tags, perl objects and data types. The inner
97 API is not yet stable. Suggestions welcome.
98
99 You can check out all current parse and load results from the yaml-
100 test-suite here:
101 <https://perlpunk.github.io/YAML-PP-p5/test-suite.html>
102
104 new
105 my $ypp = YAML::PP->new;
106 # load booleans via boolean.pm
107 my $ypp = YAML::PP->new( boolean => 'boolean' );
108 # load booleans via JSON::PP::true/false
109 my $ypp = YAML::PP->new( boolean => 'JSON::PP' );
110
111 # use YAML 1.2 Failsafe Schema
112 my $ypp = YAML::PP->new( schema => ['Failsafe'] );
113 # use YAML 1.2 JSON Schema
114 my $ypp = YAML::PP->new( schema => ['JSON'] );
115 # use YAML 1.2 Core Schema
116 my $ypp = YAML::PP->new( schema => ['Core'] );
117
118 # Die when detecting cyclic references
119 my $ypp = YAML::PP->new( cyclic_refs => 'fatal' );
120
121 my $ypp = YAML::PP->new(
122 boolean => 'JSON::PP',
123 schema => ['Core'],
124 cyclic_refs => 'fatal',
125 indent => 4,
126 header => 1,
127 footer => 1,
128 version_directive => 1,
129 );
130
131 Options:
132
133 boolean
134 Values: "perl" (currently default), "JSON::PP", "boolean",
135 "perl_experimental"
136
137 This option is for loading and dumping.
138
139 You can also specify more than one class, comma separated. This is
140 important for dumping.
141
142 Examples:
143
144 boolean => 'JSON::PP,boolean'
145 Booleans will be loaded as JSON::PP::Booleans, but when dumping, also
146 'boolean' objects will be recognized
147
148 boolean => 'JSON::PP,*'
149 Booleans will be loaded as JSON::PP::Booleans, but when dumping, all
150 currently supported boolean classes will be recognized
151
152 boolean => '*'
153 Booleans will be loaded as perl booleans, but when dumping, all
154 currently supported boolean classes will be recognized
155
156 If you have perl >= 5.36 then you might want to try out the
157 experimental boolean support, see builtin.
158
159 YAML::PP supports that by using the "perl_experimental" value for
160 the boolean option. Rules are the same as for the experimental
161 builtin class: It's not guaranteed to work in the future.
162
163 As soon as the builtin boolean support leaves experimental status,
164 I will update YAML::PP to support this via the default "perl"
165 value.
166
167 boolean => 'perl_experimental'
168 Booleans will be loaded as perl booleans, and they will be recognized
169 as such when dumping also
170
171 schema
172 Default: "['Core']"
173
174 This option is for loading and dumping.
175
176 Array reference. Here you can define what schema to use. Supported
177 standard Schemas are: "Failsafe", "JSON", "Core", "YAML1_1".
178
179 To get an overview how the different Schemas behave, see
180 <https://perlpunk.github.io/YAML-PP-p5/schemas.html>
181
182 Additionally you can add further schemas, for example "Merge".
183
184 cyclic_refs
185 Default: 'allow' but will be switched to fatal in the future for
186 safety!
187
188 This option is for loading only.
189
190 Defines what to do when a cyclic reference is detected when
191 loading.
192
193 # fatal - die
194 # warn - Just warn about them and replace with undef
195 # ignore - replace with undef
196 # allow - Default
197
198 duplicate_keys
199 Default: 0
200
201 Since version 0.027
202
203 This option is for loading.
204
205 The YAML Spec says duplicate mapping keys should be forbidden.
206
207 When set to true, duplicate keys in mappings are allowed (and will
208 overwrite the previous key).
209
210 When set to false, duplicate keys will result in an error when
211 loading.
212
213 This is especially useful when you have a longer mapping and don't
214 see the duplicate key in your editor:
215
216 ---
217 a: 1
218 b: 2
219 # .............
220 a: 23 # error
221
222 indent
223 Default: 2
224
225 This option is for dumping.
226
227 Use that many spaces for indenting
228
229 width
230 Since version 0.025
231
232 Default: 80
233
234 This option is for dumping.
235
236 Maximum columns when dumping.
237
238 This is only respected when dumping flow collections right now.
239
240 in the future it will be used also for wrapping long strings.
241
242 header
243 Default: 1
244
245 This option is for dumping.
246
247 Print document header "---"
248
249 footer
250 Default: 0
251
252 This option is for dumping.
253
254 Print document footer "..."
255
256 yaml_version
257 Since version 0.020
258
259 This option is for loading and dumping.
260
261 Default: 1.2
262
263 Note that in this case, a directive "%YAML 1.1" will basically be
264 ignored and everything loaded with the "1.2 Core" Schema.
265
266 If you want to support both YAML 1.1 and 1.2, you have to specify
267 that, and the schema ("Core" or "YAML1_1") will be chosen
268 automatically.
269
270 my $yp = YAML::PP->new(
271 yaml_version => ['1.2', '1.1'],
272 );
273
274 This is the same as
275
276 my $yp = YAML::PP->new(
277 schema => ['+'],
278 yaml_version => ['1.2', '1.1'],
279 );
280
281 because the "+" stands for the default schema per version.
282
283 When loading, and there is no %YAML directive, 1.2 will be
284 considered as default, and the "Core" schema will be used.
285
286 If there is a "%YAML 1.1" directive, the "YAML1_1" schema will be
287 used.
288
289 Of course, you can also make 1.1 the default:
290
291 my $yp = YAML::PP->new(
292 yaml_version => ['1.1', '1.2'],
293 );
294
295 You can also specify 1.1 only:
296
297 my $yp = YAML::PP->new(
298 yaml_version => ['1.1'],
299 );
300
301 In this case also documents with "%YAML 1.2" will be loaded with
302 the "YAML1_1" schema.
303
304 version_directive
305 Since version 0.020
306
307 This option is for dumping.
308
309 Default: 0
310
311 Print Version Directive "%YAML 1.2" (or "%YAML 1.1") on top of each
312 YAML document. It will use the first version specified in the
313 "yaml_version" option.
314
315 preserve
316 Since version 0.021
317
318 Default: false
319
320 This option is for loading and dumping.
321
322 Preserving scalar styles is still experimental.
323
324 use YAML::PP::Common qw/ :PRESERVE /;
325
326 # Preserve the order of hash keys
327 my $yp = YAML::PP->new( preserve => PRESERVE_ORDER );
328
329 # Preserve the quoting style of scalars
330 my $yp = YAML::PP->new( preserve => PRESERVE_SCALAR_STYLE );
331
332 # Preserve block/flow style (since 0.024)
333 my $yp = YAML::PP->new( preserve => PRESERVE_FLOW_STYLE );
334
335 # Preserve alias names (since 0.027)
336 my $yp = YAML::PP->new( preserve => PRESERVE_ALIAS );
337
338 # Combine, e.g. preserve order and scalar style
339 my $yp = YAML::PP->new( preserve => PRESERVE_ORDER | PRESERVE_SCALAR_STYLE );
340
341 Do NOT rely on the internal implementation of it.
342
343 If you load the following input:
344
345 ---
346 z: 1
347 a: 2
348 ---
349 - plain
350 - 'single'
351 - "double"
352 - |
353 literal
354 - >
355 folded
356 ---
357 block mapping: &alias
358 flow sequence: [a, b]
359 same mapping: *alias
360 flow mapping: {a: b}
361
362 with this code:
363
364 my $yp = YAML::PP->new(
365 preserve => PRESERVE_ORDER | PRESERVE_SCALAR_STYLE
366 | PRESERVE_FLOW_STYLE | PRESERVE_ALIAS
367 );
368 my ($hash, $styles, $flow) = $yp->load_file($file);
369 $yp->dump_file($hash, $styles, $flow);
370
371 Then dumping it will return the same output.
372
373 Note that YAML allows repeated definition of anchors. They cannot
374 be preserved with YAML::PP right now. Example:
375
376 ---
377 - &seq [a]
378 - *seq
379 - &seq [b]
380 - *seq
381
382 Because the data could be shuffled before dumping again, the anchor
383 definition could be broken. In this case repeated anchor names will
384 be discarded when loading and dumped with numeric anchors like
385 usual.
386
387 Implementation:
388
389 When loading, hashes will be tied to an internal class
390 ("YAML::PP::Preserve::Hash") that keeps the key order.
391
392 Scalars will be returned as objects of an internal class
393 ("YAML::PP::Preserve::Scalar") with overloading. If you assign to
394 such a scalar, the object will be replaced by a simple scalar.
395
396 # assignment, style gets lost
397 $styles->[1] .= ' append';
398
399 You can also pass 1 as a value. In this case all preserving options
400 will be enabled, also if there are new options added in the future.
401
402 There are also methods to create preserved nodes from scratch. See
403 the "preserved_(scalar|mapping|sequence)" "METHODS" below.
404
405 load_string
406 my $doc = $ypp->load_string("foo: bar");
407 my @docs = $ypp->load_string("foo: bar\n---\n- a");
408
409 Input should be Unicode characters.
410
411 So if you read from a file, you should decode it, for example with
412 "Encode::decode()".
413
414 Note that in scalar context, "load_string" and "load_file" return the
415 first document (like YAML::Syck), while YAML and YAML::XS return the
416 last.
417
418 load_file
419 my $doc = $ypp->load_file("file.yaml");
420 my @docs = $ypp->load_file("file.yaml");
421
422 Strings will be loaded as unicode characters.
423
424 dump_string
425 my $yaml = $ypp->dump_string($doc);
426 my $yaml = $ypp->dump_string($doc1, $doc2);
427 my $yaml = $ypp->dump_string(@docs);
428
429 Input strings should be Unicode characters.
430
431 Output will return Unicode characters.
432
433 So if you want to write that to a file (or pass to YAML::XS, for
434 example), you typically encode it via "Encode::encode()".
435
436 dump_file
437 $ypp->dump_file("file.yaml", $doc);
438 $ypp->dump_file("file.yaml", $doc1, $doc2);
439 $ypp->dump_file("file.yaml", @docs);
440
441 Input data should be Unicode characters.
442
443 dump
444 This will dump to a predefined writer. By default it will just use the
445 YAML::PP::Writer and output a string.
446
447 my $writer = MyWriter->new(\my $output);
448 my $yp = YAML::PP->new(
449 writer => $writer,
450 );
451 $yp->dump($data);
452
453 preserved_scalar
454 Since version 0.024
455
456 Experimental. Please report bugs or let me know this is useful and
457 works.
458
459 You can define a certain scalar style when dumping data. Figuring out
460 the best style is a hard task and practically impossible to get it
461 right for all cases. It's also a matter of taste.
462
463 use YAML::PP::Common qw/ PRESERVE_SCALAR_STYLE YAML_LITERAL_SCALAR_STYLE /;
464 my $yp = YAML::PP->new(
465 preserve => PRESERVE_SCALAR_STYLE,
466 );
467 # a single linebreak would normally be dumped with double quotes: "\n"
468 my $scalar = $yp->preserved_scalar("\n", style => YAML_LITERAL_SCALAR_STYLE );
469
470 my $data = { literal => $scalar };
471 my $dump = $yp->dump_string($data);
472 # output
473 ---
474 literal: |+
475
476 ...
477
478 preserved_mapping, preserved_sequence
479 Since version 0.024
480
481 Experimental. Please report bugs or let me know this is useful and
482 works.
483
484 With this you can define which nodes are dumped with the more compact
485 flow style instead of block style.
486
487 If you add "PRESERVE_ORDER" to the "preserve" option, it will also keep
488 the order of the keys in a hash.
489
490 use YAML::PP::Common qw/
491 PRESERVE_ORDER PRESERVE_FLOW_STYLE
492 YAML_FLOW_MAPPING_STYLE YAML_FLOW_SEQUENCE_STYLE
493 /;
494 my $yp = YAML::PP->new(
495 preserve => PRESERVE_FLOW_STYLE | PRESERVE_ORDER
496 );
497
498 my $hash = $yp->preserved_mapping({}, style => YAML_FLOW_MAPPING_STYLE);
499 # Add values after initialization to preserve order
500 %$hash = (z => 1, a => 2, y => 3, b => 4);
501
502 my $array = $yp->preserved_sequence([23, 24], style => YAML_FLOW_SEQUENCE_STYLE);
503
504 my $data = $yp->preserved_mapping({});
505 %$data = ( map => $hash, seq => $array );
506
507 my $dump = $yp->dump_string($data);
508 # output
509 ---
510 map: {z: 1, a: 2, y: 3, b: 4}
511 seq: [23, 24]
512
513 loader
514 Returns or sets the loader object, by default YAML::PP::Loader
515
516 dumper
517 Returns or sets the dumper object, by default YAML::PP::Dumper
518
519 schema
520 Returns or sets the schema object
521
522 default_schema
523 Creates and returns the default schema
524
526 The functions "Load", "LoadFile", "Dump" and "DumpFile" are provided as
527 a drop-in replacement for other existing YAML processors. No function
528 is exported by default.
529
530 Note that in scalar context, "Load" and "LoadFile" return the first
531 document (like YAML::Syck), while YAML and YAML::XS return the last.
532
533 Load
534 use YAML::PP qw/ Load /;
535 my $doc = Load($yaml);
536 my @docs = Load($yaml);
537
538 Works like "load_string".
539
540 LoadFile
541 use YAML::PP qw/ LoadFile /;
542 my $doc = LoadFile($file);
543 my @docs = LoadFile($file);
544 my @docs = LoadFile($filehandle);
545
546 Works like "load_file".
547
548 Dump
549 use YAML::PP qw/ Dump /;
550 my $yaml = Dump($doc);
551 my $yaml = Dump(@docs);
552
553 Works like "dump_string".
554
555 DumpFile
556 use YAML::PP qw/ DumpFile /;
557 DumpFile($file, $doc);
558 DumpFile($file, @docs);
559 DumpFile($filehandle, @docs);
560
561 Works like "dump_file".
562
564 You can alter the behaviour of YAML::PP by using the following schema
565 classes:
566
567 YAML::PP::Schema::Failsafe
568 One of the three YAML 1.2 official schemas
569
570 YAML::PP::Schema::JSON
571 One of the three YAML 1.2 official schemas.
572
573 YAML::PP::Schema::Core
574 One of the three YAML 1.2 official schemas. Default
575
576 YAML::PP::Schema::YAML1_1
577 Schema implementing the most common YAML 1.1 types
578
579 YAML::PP::Schema::Perl
580 Serializing Perl objects and types
581
582 YAML::PP::Schema::Binary
583 Serializing binary data
584
585 YAML::PP::Schema::Tie::IxHash
586 Deprecated. See option "preserve"
587
588 YAML::PP::Schema::Merge
589 YAML 1.1 merge keys for mappings
590
591 YAML::PP::Schema::Include
592 Include other YAML files via "!include" tags
593
594 To make the parsing process faster, you can plugin the libyaml parser
595 with YAML::PP::LibYAML.
596
598 The process of loading and dumping is split into the following steps:
599
600 Load:
601
602 YAML Stream Tokens Event List Data Structure
603 ---------> ---------> --------->
604 lex parse construct
605
606
607 Dump:
608
609 Data Structure Event List YAML Stream
610 ---------> --------->
611 represent emit
612
613 You can dump basic perl types like hashes, arrays, scalars (strings,
614 numbers). For dumping blessed objects and things like coderefs have a
615 look at YAML::PP::Perl/YAML::PP::Schema::Perl.
616
617 YAML::PP::Lexer
618 The Lexer is reading the YAML stream into tokens. This makes it
619 possible to generate syntax highlighted YAML output.
620
621 Note that the API to retrieve the tokens will change.
622
623 YAML::PP::Parser
624 The Parser retrieves the tokens from the Lexer. The main YAML
625 content is then parsed with the Grammar.
626
627 YAML::PP::Grammar
628 YAML::PP::Constructor
629 The Constructor creates a data structure from the Parser events.
630
631 YAML::PP::Loader
632 The Loader combines the constructor and parser.
633
634 YAML::PP::Dumper
635 The Dumper will delegate to the Representer
636
637 YAML::PP::Representer
638 The Representer will create Emitter events from the given data
639 structure.
640
641 YAML::PP::Emitter
642 The Emitter creates a YAML stream.
643
644 YAML::PP::Parser
645 Still TODO:
646
647 Implicit collection keys
648 ---
649 [ a, b, c ]: value
650
651 Implicit mapping in flow style sequences
652 This is supported since 0.029 (except some not relevant cases):
653
654 ---
655 [ a, b, c: d ]
656 # equals
657 [ a, b, { c: d } ]
658
659 Plain mapping keys ending with colons
660 ---
661 key ends with two colons::: value
662
663 Supported Characters
664 If you have valid YAML that's not parsed, or the other way round,
665 please create an issue.
666
667 Line and Column Numbers
668 You will see line and column numbers in the error message. The
669 column numbers might still be wrong in some cases.
670
671 Error Messages
672 The error messages need to be improved.
673
674 Unicode Surrogate Pairs
675 Currently loaded as single characters without validating
676
677 Possibly more
678
679 YAML::PP::Constructor
680 The Constructor now supports all three YAML 1.2 Schemas, Failsafe, JSON
681 and Core. Additionally you can choose the schema for YAML 1.1 as
682 "YAML1_1".
683
684 Too see what strings are resolved as booleans, numbers, null etc. look
685 at <https://perlpunk.github.io/YAML-PP-p5/schema-examples.html>.
686
687 You can choose the Schema like this:
688
689 my $ypp = YAML::PP->new(schema => ['JSON']); # default is 'Core'
690
691 The Tags "!!seq" and "!!map" are still ignored for now.
692
693 It supports:
694
695 Handling of Anchors/Aliases
696 Like in modules like YAML, the Constructor will use references for
697 mappings and sequences, but obviously not for scalars.
698
699 YAML::XS uses real aliases, which allows also aliasing scalars. I
700 might add an option for that since aliasing is now available in
701 pure perl.
702
703 Boolean Handling
704 You can choose between 'perl' (1/'', currently default), 'JSON::PP'
705 and 'boolean'.pm for handling boolean types. That allows you to
706 dump the data structure with one of the JSON modules without losing
707 information about booleans.
708
709 Numbers
710 Numbers are created as real numbers instead of strings, so that
711 they are dumped correctly by modules like JSON::PP or JSON::XS, for
712 example.
713
714 Complex Keys
715 Mapping Keys in YAML can be more than just scalars. Of course, you
716 can't load that into a native perl structure. The Constructor will
717 stringify those keys with Data::Dumper instead of just returning
718 something like "HASH(0x55dc1b5d0178)".
719
720 Example:
721
722 use YAML::PP;
723 use JSON::PP;
724 my $ypp = YAML::PP->new;
725 my $coder = JSON::PP->new->ascii->pretty->allow_nonref->canonical;
726 my $yaml = <<'EOM';
727 complex:
728 ?
729 ?
730 a: 1
731 c: 2
732 : 23
733 : 42
734 EOM
735 my $data = $yppl->load_string($yaml);
736 say $coder->encode($data);
737 __END__
738 {
739 "complex" : {
740 "{'{a => 1,c => 2}' => 23}" : 42
741 }
742 }
743
744 TODO:
745
746 Parse Tree
747 I would like to generate a complete parse tree, that allows you to
748 manipulate the data structure and also dump it, including all
749 whitespaces and comments. The spec says that this is throwaway
750 content, but I read that many people wish to be able to keep the
751 comments.
752
753 YAML::PP::Dumper, YAML::PP::Emitter
754 The Dumper should be able to dump strings correctly, adding quotes
755 whenever a plain scalar would look like a special string, like "true",
756 or when it contains or starts with characters that are not allowed.
757
758 Most strings will be dumped as plain scalars without quotes. If they
759 contain special characters or have a special meaning, they will be
760 dumped with single quotes. If they contain control characters,
761 including <"\n">, they will be dumped with double quotes.
762
763 It will recognize JSON::PP::Boolean and boolean.pm objects and dump
764 them correctly.
765
766 Numbers which also have a "PV" flag will be recognized as numbers and
767 not as strings:
768
769 my $int = 23;
770 say "int: $int"; # $int will now also have a PV flag
771
772 That means that if you accidentally use a string in numeric context, it
773 will also be recognized as a number:
774
775 my $string = "23";
776 my $something = $string + 0;
777 print $yp->dump_string($string);
778 # will be emitted as an integer without quotes!
779
780 The layout is like libyaml output:
781
782 key:
783 - a
784 - b
785 - c
786 ---
787 - key1: 1
788 key2: 2
789 key3: 3
790 ---
791 - - a1
792 - a2
793 - - b1
794 - b2
795
797 All the available parsers and loaders for Perl are behaving
798 differently, and more important, aren't conforming to the spec.
799 YAML::XS is doing pretty well, but "libyaml" only handles YAML 1.1 and
800 diverges a bit from the spec. The pure perl loaders lack support for a
801 number of features.
802
803 I was going over YAML.pm issues end of 2016, integrating old patches
804 from rt.cpan.org and creating some pull requests myself. I realized
805 that it would be difficult to patch YAML.pm to parse YAML 1.1 or even
806 1.2, and it would also break existing usages relying on the current
807 behaviour.
808
809 In 2016 Ingy döt Net initiated two really cool projects:
810
811 "YAML TEST SUITE"
812 "YAML EDITOR"
813
814 These projects are a big help for any developer. So I got the idea to
815 write my own parser and started on New Year's Day 2017. Without the
816 test suite and the editor I would have never started this.
817
818 I also started another YAML Test project which allows one to get a
819 quick overview of which frameworks support which YAML features:
820
821 "YAML TEST MATRIX"
822
823 YAML TEST SUITE
824 <https://github.com/yaml/yaml-test-suite>
825
826 It contains almost 400 test cases and expected parsing events and more.
827 There will be more tests coming. This test suite allows you to write
828 parsers without turning the examples from the Specification into tests
829 yourself. Also the examples aren't completely covering all cases - the
830 test suite aims to do that.
831
832 The suite contains .tml files, and in a separate 'data' release you
833 will find the content in separate files, if you can't or don't want to
834 use TestML.
835
836 Thanks also to Felix Krause, who is writing a YAML parser in Nim. He
837 turned all the spec examples into test cases.
838
839 YAML EDITOR
840 This is a tool to play around with several YAML parsers and loaders in
841 vim.
842
843 <https://github.com/yaml/yaml-editor>
844
845 The project contains the code to build the frameworks (16 as of this
846 writing) and put it into one big Docker image.
847
848 It also contains the yaml-editor itself, which will start a vim in the
849 docker container. It uses a lot of funky vimscript that makes playing
850 with it easy and useful. You can choose which frameworks you want to
851 test and see the output in a grid of vim windows.
852
853 Especially when writing a parser it is extremely helpful to have all
854 the test cases and be able to play around with your own examples to see
855 how they are handled.
856
857 YAML TEST MATRIX
858 I was curious to see how the different frameworks handle the test
859 cases, so, using the test suite and the docker image, I wrote some code
860 that runs the tests, manipulates the output to compare it with the
861 expected output, and created a matrix view.
862
863 <https://github.com/perlpunk/yaml-test-matrix>
864
865 You can find the latest build at <https://matrix.yaml.info>
866
868 Ingy döt Net
869 Ingy is one of the creators of YAML. In 2016 he started the YAML
870 Test Suite and the YAML Editor. He also made useful suggestions on
871 the class hierarchy of YAML::PP.
872
873 Felix "flyx" Krause
874 Felix answered countless questions about the YAML Specification.
875
877 YAML
878 YAML::XS
879 YAML::Syck
880 YAML::Tiny
881 YAML::PP::LibYAML
882 YAML::LibYAML::API
883 <https://www.yaml.info>
884
886 The Perl Foundation <https://www.perlfoundation.org/> sponsored this
887 project (and the YAML Test Suite) with a grant of 2500 USD in
888 2017-2018.
889
891 Copyright 2017-2022 by Tina Müller
892
893 This library is free software and may be distributed under the same
894 terms as perl itself.
895
896
897
898perl v5.36.0 2022-10-03 YAML::PP(3)