# YAML Test Matrix

--- &test-5U3A
  Title: Sequence on same Line as Mapping Key
  Tags: [ error, mapping, sequence ]

YAML

key: - a
     - b

Expected Events

+STR
+DOC
+MAP
=VAL :key

Expected JSON



cpp-rapidyaml-event

 invalid_incorrect
+STR
+DOC
+MAP
=VAL :key
+SEQ
=VAL :a
=VAL :b
-SEQ
-MAP
-DOC
-STR

hs-reference-yeast

 invalid_incorrect
Line  Col Char Byte Token|Content
   1    0    0    0 +DOC |
   1    0    0    0 +NODE|
   1    0    0    0 +MAP |
   1    0    0    0 +PAIR|
   1    0    0    0 +NODE|
   1    0    0    0 +VAL |
   1    0    0    0 =TEXT|key
   1    3    3    3 -VAL |
   1    3    3    3 -NODE|
   1    3    3    3 =SYNX|:
   1    4    4    4 +NODE|
   1    4    4    4 +VAL |
   1    4    4    4 -VAL |
   1    4    4    4 -NODE|
   1    4    4    4 =REST|.-.a
   1    8    8    8 =REST|\x0a
   2    0    9    9 =REST|.
   2    1   10   10 =REST|....-.b
   2    8   17   17 =REST|\x0a
   3    0   18   18 -PAIR|
   3    0   18   18 -MAP |
   3    0   18   18 -NODE|
   3    0   18   18 -DOC |

perl-syck-json

 invalid_incorrect
{
   "key" : [
      "a",
      "b"
   ]
}

perl-syck-perl

 invalid_incorrect
{
  'key' => [
             'a',
             'b'
           ]
}

c-libfyaml-event

 invalid_correct
stdin:1:6: error: block sequence on the same line as a mapping key
key: - a
     ^
+STR
+DOC
+MAP
=VAL :key

c-libfyaml-json

 invalid_correct
stdin:1:6: error: block sequence on the same line as a mapping key
key: - a
     ^

c-libyaml-event

 invalid_correct
Parse error: block sequence entries are not allowed in this context
+STR
+DOC
+MAP
=VAL :key

cpp-yamlcpp-event

 invalid_correct
Exception:
yaml-cpp: error at line 1, column 6: illegal block entry
+STR
+DOC
+MAP
=VAL :key

dotnet-yamldotnet-event

 invalid_correct
Unhandled exception. YamlDotNet.Core.SemanticErrorException: (Line: 1, Col: 6, Idx: 5) - (Line: 1, Col: 6, Idx: 5): Block sequence entries are not allowed in this context.
   at YamlDotNet.Core.Parser.ParseNode(Boolean isBlock, Boolean isIndentlessSequence)
   at YamlDotNet.Core.Parser.ParseBlockMappingValue()
   at YamlDotNet.Core.Parser.StateMachine()
   at YamlDotNet.Core.Parser.MoveNext()
   at YamlDotNet.RepresentationModel.LibYamlEventStream.WriteTo(TextWriter textWriter)
   at Program.Main(String[] commandLineArguments)
Aborted (core dumped)
+STR
+DOC
+MAP
=VAL :key

dotnet-yamldotnet-json

 invalid_correct
Unhandled exception. YamlDotNet.Core.SemanticErrorException: (Line: 1, Col: 6, Idx: 5) - (Line: 1, Col: 6, Idx: 5): Block sequence entries are not allowed in this context.
   at YamlDotNet.Core.Parser.ParseNode(Boolean isBlock, Boolean isIndentlessSequence)
   at YamlDotNet.Core.Parser.ParseBlockMappingValue()
   at YamlDotNet.Core.Parser.StateMachine()
   at YamlDotNet.Core.Parser.MoveNext()
   at YamlDotNet.Core.ParserExtensions.TryConsume[T](IParser parser, T& event)
   at YamlDotNet.Serialization.NodeDeserializers.ScalarNodeDeserializer.YamlDotNet.Serialization.INodeDeserializer.Deserialize(IParser parser, Type expectedType, Func`3 nestedObjectDeserializer, Object& value)
   at YamlDotNet.Serialization.ValueDeserializers.NodeValueDeserializer.DeserializeValue(IParser parser, Type expectedType, SerializerState state, IValueDeserializer nestedObjectDeserializer)
   at YamlDotNet.Serialization.ValueDeserializers.AliasValueDeserializer.DeserializeValue(IParser parser, Type expectedType, SerializerState state, IValueDeserializer nestedObjectDeserializer)
   at YamlDotNet.Serialization.ValueDeserializers.NodeValueDeserializer.<>c__DisplayClass3_0.<DeserializeValue>b__0(IParser r, Type t)
   at YamlDotNet.Serialization.NodeDeserializers.DictionaryNodeDeserializer.DeserializeHelper(Type tKey, Type tValue, IParser parser, Func`3 nestedObjectDeserializer, IDictionary result)
   at YamlDotNet.Serialization.NodeDeserializers.DictionaryNodeDeserializer.YamlDotNet.Serialization.INodeDeserializer.Deserialize(IParser parser, Type expectedType, Func`3 nestedObjectDeserializer, Object& value)
   at YamlDotNet.Serialization.ValueDeserializers.NodeValueDeserializer.DeserializeValue(IParser parser, Type expectedType, SerializerState state, IValueDeserializer nestedObjectDeserializer)
   at YamlDotNet.Serialization.ValueDeserializers.AliasValueDeserializer.DeserializeValue(IParser parser, Type expectedType, SerializerState state, IValueDeserializer nestedObjectDeserializer)
   at YamlDotNet.Serialization.Deserializer.Deserialize(IParser parser, Type type)
   at YamlDotNet.Serialization.Deserializer.Deserialize(TextReader input, Type type)
   at YamlDotNet.Serialization.Deserializer.Deserialize(TextReader input)
   at Program.Main(String[] commandLineArguments)
Aborted (core dumped)

go-yaml-json

 invalid_correct
yaml: block sequence entries are not allowed in this context

hs-hsyaml-event

 invalid_correct
Parsing error near byte offset Pos {posByteOffset = 4, posCharOffset = 4, posLine = 1, posColumn = 4} (Lexical error near " - a")
+STR
+DOC
+MAP
=VAL :key
=VAL :

hs-hsyaml-json

 invalid_correct
hsyaml-parser: user error (Lexical error near " - a")

js-jsyaml-json

 invalid_correct
/node/node_modules/js-yaml/lib/loader.js:187
  throw generateError(state, message);
  ^
YAMLException: bad indentation of a mapping entry (1:6)

 1 | key: - a
----------^
 2 |      - b
    at generateError (/node/node_modules/js-yaml/lib/loader.js:183:10)
    at throwError (/node/node_modules/js-yaml/lib/loader.js:187:9)
    at readBlockMapping (/node/node_modules/js-yaml/lib/loader.js:1182:7)
    at composeNode (/node/node_modules/js-yaml/lib/loader.js:1441:12)
    at readDocument (/node/node_modules/js-yaml/lib/loader.js:1625:3)
    at loadDocuments (/node/node_modules/js-yaml/lib/loader.js:1688:5)
    at Object.loadAll (/node/node_modules/js-yaml/lib/loader.js:1701:19)
    at Object.<anonymous> (/yaml/bin/js-jsyaml-json:7:13)
    at Module._compile (node:internal/modules/cjs/loader:1358:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1416:10) {
  reason: 'bad indentation of a mapping entry',
  mark: {
    name: null,
    buffer: 'key: - a\n     - b\n',
    position: 5,
    line: 0,
    column: 5,
    snippet: ' 1 | key: - a\n----------^\n 2 |      - b'
  }
}

Node.js v20.13.1

js-yaml-event

 invalid_correct
Implicit keys need to be on a single line at line 1, column 8:

key: - a
       ^
+STR
+DOC
+MAP
=VAL :key
+SEQ

js-yaml-json

 invalid_correct
/yaml/bin/js-yaml-json:9
    if (doc.errors.length !== 0) throw doc.errors[0]
                                 ^

YAMLParseError: Implicit keys need to be on a single line at line 1, column 8:

key: - a
       ^

    at Composer.onError (/node/node_modules/yaml/dist/compose/composer.js:69:34)
    at Object.resolveBlockMap (/node/node_modules/yaml/dist/compose/resolve-block-map.js:48:17)
    at resolveCollection (/node/node_modules/yaml/dist/compose/compose-collection.js:13:27)
    at Object.composeCollection (/node/node_modules/yaml/dist/compose/compose-collection.js:47:16)
    at Object.composeNode (/node/node_modules/yaml/dist/compose/compose-node.js:31:38)
    at Object.composeDoc (/node/node_modules/yaml/dist/compose/compose-doc.js:34:23)
    at Composer.next (/node/node_modules/yaml/dist/compose/composer.js:149:40)
    at next (<anonymous>)
    at Composer.compose (/node/node_modules/yaml/dist/compose/composer.js:131:25)
    at compose.next (<anonymous>) {
  code: 'MULTILINE_IMPLICIT_KEY',
  pos: [ 7, 17 ],
  linePos: [ { line: 1, col: 8 }, { line: 2, col: 9 } ]
}

Node.js v20.13.1

lua-lyaml-json

 invalid_correct
luajit: 1:1: block sequence entries are not allowed in this context
stack traceback:
	[C]: in function 'error'
	/usr/local/share/lua/5.1/lyaml/init.lua:306: in function 'error'
	/usr/local/share/lua/5.1/lyaml/init.lua:325: in function 'parse'
	/usr/local/share/lua/5.1/lyaml/init.lua:443: in function 'load_node'
	/usr/local/share/lua/5.1/lyaml/init.lua:378: in function 'load_node'
	/usr/local/share/lua/5.1/lyaml/init.lua:497: in function 'load'
	/yaml/bin/lua-lyaml-json:6: in main chunk
	[C]: at 0x559680600ed0

nim-nimyaml-event

 invalid_correct
/tmp/NimYAML-0.16.0/yaml/stream.nim(134) nimyaml_event
/tmp/NimYAML-0.16.0/yaml/stream.nim(106) next
Error: unhandled exception: Compact notation not allowed after implicit key [YamlStreamError]
+STR
+DOC
+MAP
=VAL :key

perl-pp-event

 invalid_correct
Line      : 1
Column    : 6
Expected  : ALIAS BLOCK_SCALAR DOC_END FLOWMAP_START FLOWSEQ_START PLAIN PLAIN_MULTI QUOTED QUOTED_MULTILINE
Got       : DASH
Where     : /perl5/lib/perl5/YAML/PP/Parser.pm line 392
YAML      : "- a\n"
  at /yaml/bin/perl-pp-event line 46.
+STR
+DOC
+MAP
=VAL :key

perl-pp-json

 invalid_correct
Line      : 1
Column    : 6
Expected  : ALIAS BLOCK_SCALAR DOC_END FLOWMAP_START FLOWSEQ_START PLAIN PLAIN_MULTI QUOTED QUOTED_MULTILINE
Got       : DASH
Where     : /perl5/lib/perl5/YAML/PP/Parser.pm line 392
YAML      : "- a\n"
  at /perl5/lib/perl5/YAML/PP/Loader.pm line 94.

perl-pp-perl

 invalid_correct
Line      : 1
Column    : 6
Expected  : ALIAS BLOCK_SCALAR DOC_END FLOWMAP_START FLOWSEQ_START PLAIN PLAIN_MULTI QUOTED QUOTED_MULTILINE
Got       : DASH
Where     : /perl5/lib/perl5/YAML/PP/Parser.pm line 392
YAML      : "- a\n"
  at /perl5/lib/perl5/YAML/PP/Loader.pm line 94.

perl-pplibyaml-json

 invalid_correct
YAML::PP::LibYAML Error: The problem:

    block sequence entries are not allowed in this context

was found at , line: 1, column: 6

perl-pplibyaml-perl

 invalid_correct
YAML::PP::LibYAML Error: The problem:

    block sequence entries are not allowed in this context

was found at , line: 1, column: 6

perl-refparser-event

 invalid_correct
Parser finished before end of input at /perl5/lib/perl5/YAML/Parser.pm line 4056, <> line 1.

perl-tiny-json

 invalid_correct
YAML::Tiny found illegal characters in plain scalar: '- a' at /yaml/bin/perl-tiny-json line 12.

perl-tiny-perl

 invalid_correct
YAML::Tiny found illegal characters in plain scalar: '- a' at /yaml/bin/perl-tiny-perl line 15.

perl-xs-json

 invalid_correct
YAML::XS::Load Error: The problem:

    block sequence entries are not allowed in this context

was found at document: 1, line: 1, column: 6

perl-xs-perl

 invalid_correct
YAML::XS::Load Error: The problem:

    block sequence entries are not allowed in this context

was found at document: 1, line: 1, column: 6

perl-yaml-json

 invalid_correct
YAML Error: Inconsistent indentation level
   Code: YAML_PARSE_ERR_INCONSISTENT_INDENTATION
   Line: 2
   Document: 1
 at /perl5/lib/perl5/YAML/Loader.pm line 804.

perl-yaml-perl

 invalid_correct
YAML Error: Inconsistent indentation level
   Code: YAML_PARSE_ERR_INCONSISTENT_INDENTATION
   Line: 2
   Document: 1
 at /perl5/lib/perl5/YAML/Loader.pm line 804.

py-pyyaml-event

 invalid_correct
Traceback (most recent call last):
  File "/yaml/bin/py-pyyaml-event", line 7, in <module>
    for event in yaml.parse(sys.stdin.read()):
  File "/python/lib/python3.12/site-packages/yaml/__init__.py", line 75, in parse
    while loader.check_event():
          ^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/parser.py", line 98, in check_event
    self.current_event = self.state()
                         ^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/parser.py", line 449, in parse_block_mapping_value
    if not self.check_token(KeyToken, ValueToken, BlockEndToken):
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 116, in check_token
    self.fetch_more_tokens()
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 215, in fetch_more_tokens
    return self.fetch_block_entry()
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 491, in fetch_block_entry
    raise ScannerError(None, None,
yaml.scanner.ScannerError: sequence entries are not allowed here
  in "<unicode string>", line 1, column 6:
    key: - a
         ^
+STR
+DOC
+MAP
=VAL :key

py-pyyaml-json

 invalid_correct
Traceback (most recent call last):
  File "/yaml/bin/py-pyyaml-json", line 19, in <module>
    for doc in yaml.load_all(sys.stdin.read(), Loader=yaml.FullLoader):
  File "/python/lib/python3.12/site-packages/yaml/__init__.py", line 130, in load_all
    yield loader.get_data()
          ^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/constructor.py", line 45, in get_data
    return self.construct_document(self.get_node())
                                   ^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/composer.py", line 27, in get_node
    return self.compose_document()
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/composer.py", line 55, in compose_document
    node = self.compose_node(None, None)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/composer.py", line 133, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/composer.py", line 64, in compose_node
    if self.check_event(AliasEvent):
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/parser.py", line 98, in check_event
    self.current_event = self.state()
                         ^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/parser.py", line 449, in parse_block_mapping_value
    if not self.check_token(KeyToken, ValueToken, BlockEndToken):
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 116, in check_token
    self.fetch_more_tokens()
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 215, in fetch_more_tokens
    return self.fetch_block_entry()
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 491, in fetch_block_entry
    raise ScannerError(None, None,
yaml.scanner.ScannerError: sequence entries are not allowed here
  in "<unicode string>", line 1, column 6:
    key: - a
         ^

py-pyyaml-py

 invalid_correct
Traceback (most recent call last):
  File "/yaml/bin/py-pyyaml-py", line 36, in <module>
    for doc in yaml.load_all(sys.stdin.read(), Loader=yaml.FullLoader):
  File "/python/lib/python3.12/site-packages/yaml/__init__.py", line 130, in load_all
    yield loader.get_data()
          ^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/constructor.py", line 45, in get_data
    return self.construct_document(self.get_node())
                                   ^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/composer.py", line 27, in get_node
    return self.compose_document()
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/composer.py", line 55, in compose_document
    node = self.compose_node(None, None)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/composer.py", line 133, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/composer.py", line 64, in compose_node
    if self.check_event(AliasEvent):
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/parser.py", line 98, in check_event
    self.current_event = self.state()
                         ^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/parser.py", line 449, in parse_block_mapping_value
    if not self.check_token(KeyToken, ValueToken, BlockEndToken):
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 116, in check_token
    self.fetch_more_tokens()
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 215, in fetch_more_tokens
    return self.fetch_block_entry()
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 491, in fetch_block_entry
    raise ScannerError(None, None,
yaml.scanner.ScannerError: sequence entries are not allowed here
  in "<unicode string>", line 1, column 6:
    key: - a
         ^

py-ruamel-event

 invalid_correct
Traceback (most recent call last):
  File "/yaml/bin/py-ruamel-event", line 9, in <module>
    for event in yaml.parse(sys.stdin.read()):
  File "/python/lib/python3.12/site-packages/ruamel/yaml/main.py", line 371, in parse
    while parser.check_event():
          ^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/parser.py", line 141, in check_event
    self.current_event = self.state()
                         ^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/parser.py", line 631, in parse_block_mapping_value
    if self.scanner.check_token(ValueToken):
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 170, in check_token
    self.fetch_more_tokens()
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 270, in fetch_more_tokens
    return self.fetch_block_entry()
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 543, in fetch_block_entry
    raise ScannerError(
ruamel.yaml.scanner.ScannerError: sequence entries are not allowed here
  in "<unicode string>", line 1, column 6:
    key: - a
         ^ (line: 1)
+STR
+DOC
+MAP
=VAL :key

py-ruamel-json

 invalid_correct
Traceback (most recent call last):
  File "/yaml/bin/py-ruamel-json", line 21, in <module>
    for doc in yaml.load_all(sys.stdin.read()):
  File "/python/lib/python3.12/site-packages/ruamel/yaml/main.py", line 476, in load_all
    yield constructor.get_data()
          ^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/constructor.py", line 110, in get_data
    return self.construct_document(self.composer.get_node())
                                   ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/composer.py", line 63, in get_node
    return self.compose_document()
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/composer.py", line 94, in compose_document
    node = self.compose_node(None, None)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/composer.py", line 130, in compose_node
    node = self.compose_mapping_node(anchor)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/composer.py", line 211, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/composer.py", line 106, in compose_node
    if self.parser.check_event(AliasEvent):
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/parser.py", line 141, in check_event
    self.current_event = self.state()
                         ^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/parser.py", line 631, in parse_block_mapping_value
    if self.scanner.check_token(ValueToken):
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 170, in check_token
    self.fetch_more_tokens()
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 270, in fetch_more_tokens
    return self.fetch_block_entry()
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 543, in fetch_block_entry
    raise ScannerError(
ruamel.yaml.scanner.ScannerError: sequence entries are not allowed here
  in "<unicode string>", line 1, column 6:
    key: - a
         ^ (line: 1)

py-ruamel-py

 invalid_correct
Traceback (most recent call last):
  File "/yaml/bin/py-ruamel-py", line 38, in <module>
    for doc in yaml.load_all(sys.stdin.read()):
  File "/python/lib/python3.12/site-packages/ruamel/yaml/main.py", line 476, in load_all
    yield constructor.get_data()
          ^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/constructor.py", line 110, in get_data
    return self.construct_document(self.composer.get_node())
                                   ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/composer.py", line 63, in get_node
    return self.compose_document()
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/composer.py", line 94, in compose_document
    node = self.compose_node(None, None)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/composer.py", line 130, in compose_node
    node = self.compose_mapping_node(anchor)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/composer.py", line 211, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/composer.py", line 106, in compose_node
    if self.parser.check_event(AliasEvent):
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/parser.py", line 141, in check_event
    self.current_event = self.state()
                         ^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/parser.py", line 631, in parse_block_mapping_value
    if self.scanner.check_token(ValueToken):
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 170, in check_token
    self.fetch_more_tokens()
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 270, in fetch_more_tokens
    return self.fetch_block_entry()
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 543, in fetch_block_entry
    raise ScannerError(
ruamel.yaml.scanner.ScannerError: sequence entries are not allowed here
  in "<unicode string>", line 1, column 6:
    key: - a
         ^ (line: 1)

ruby-psych-json

 invalid_correct
/ruby/gems/psych/lib/psych.rb:458:in `parse': (<unknown>): block sequence entries are not allowed in this context at line 1 column 6 (Psych::SyntaxError)
	from /ruby/gems/psych/lib/psych.rb:458:in `parse_stream'
	from /ruby/gems/psych/lib/psych.rb:632:in `load_stream'
	from /yaml/bin/ruby-psych-json:6:in `<main>'

rust-yamlrust-event

 invalid_correct
Error: ScanError { mark: Marker { index: 5, line: 1, col: 5 }, info: "block sequence entries are not allowed in this context" }
+STR
+DOC
+MAP
=VAL :key