SnakeYAML Engine 2.10 · org.snakeyaml.engine.v2.parser.ParserImpl

# The following YAML grammar is LL(1) and is parsed by a recursive descent parser.

stream            ::= STREAM-START implicit_document? explicit_document* STREAM-END
implicit_document ::= block_node DOCUMENT-END*
explicit_document ::= DIRECTIVE* DOCUMENT-START block_node? DOCUMENT-END*
block_node_or_indentless_sequence ::=
                      ALIAS
                      | properties (block_content | indentless_block_sequence)?
                      | block_content
                      | indentless_block_sequence
block_node        ::= ALIAS
                      | properties block_content?
                      | block_content
flow_node         ::= ALIAS
                      | properties flow_content?
                      | flow_content
properties        ::= TAG ANCHOR? | ANCHOR TAG?
block_content     ::= block_collection | flow_collection | SCALAR
flow_content      ::= flow_collection | SCALAR
block_collection  ::= block_sequence | block_mapping
flow_collection   ::= flow_sequence | flow_mapping
block_sequence    ::= BLOCK-SEQUENCE-START (BLOCK-ENTRY block_node?)* BLOCK-END
indentless_sequence   ::= (BLOCK-ENTRY block_node?)+
block_mapping     ::= BLOCK-MAPPING_START
                      ((KEY block_node_or_indentless_sequence?)?
                      (VALUE block_node_or_indentless_sequence?)?)*
                      BLOCK-END
flow_sequence     ::= FLOW-SEQUENCE-START
                      (flow_sequence_entry FLOW-ENTRY)*
                      flow_sequence_entry?
                      FLOW-SEQUENCE-END
flow_sequence_entry   ::= flow_node | KEY flow_node? (VALUE flow_node?)?
flow_mapping      ::= FLOW-MAPPING-START
                      (flow_mapping_entry FLOW-ENTRY)*
                      flow_mapping_entry?
                      FLOW-MAPPING-END
flow_mapping_entry    ::= flow_node | KEY flow_node? (VALUE flow_node?)?
#
FIRST sets:
#
stream: { STREAM-START }
explicit_document: { DIRECTIVE DOCUMENT-START }
implicit_document: FIRST(block_node)
block_node: { ALIAS TAG ANCHOR SCALAR BLOCK-SEQUENCE-START BLOCK-MAPPING-START FLOW-SEQUENCE-START FLOW-MAPPING-START }
flow_node: { ALIAS ANCHOR TAG SCALAR FLOW-SEQUENCE-START FLOW-MAPPING-START }
block_content: { BLOCK-SEQUENCE-START BLOCK-MAPPING-START FLOW-SEQUENCE-START FLOW-MAPPING-START SCALAR }
flow_content: { FLOW-SEQUENCE-START FLOW-MAPPING-START SCALAR }
block_collection: { BLOCK-SEQUENCE-START BLOCK-MAPPING-START }
flow_collection: { FLOW-SEQUENCE-START FLOW-MAPPING-START }
block_sequence: { BLOCK-SEQUENCE-START }
block_mapping: { BLOCK-MAPPING-START }
block_node_or_indentless_sequence: { ALIAS ANCHOR TAG SCALAR BLOCK-SEQUENCE-START BLOCK-MAPPING-START FLOW-SEQUENCE-START FLOW-MAPPING-START BLOCK-ENTRY }
indentless_sequence: { ENTRY }
flow_collection: { FLOW-SEQUENCE-START FLOW-MAPPING-START }
flow_sequence: { FLOW-SEQUENCE-START }
flow_mapping: { FLOW-MAPPING-START }
flow_sequence_entry: { ALIAS ANCHOR TAG SCALAR FLOW-SEQUENCE-START FLOW-MAPPING-START KEY }
flow_mapping_entry: { ALIAS ANCHOR TAG SCALAR FLOW-SEQUENCE-START FLOW-MAPPING-START KEY }

Since writing a recursive-descendant parser is a straightforward task, we do not give many comments here.

Modifier and Type	Class and Description
private class	ParserImpl.ParseBlockMappingFirstKey
private class	ParserImpl.ParseBlockMappingKey
private class	ParserImpl.ParseBlockMappingValue
private class	ParserImpl.ParseBlockMappingValueComment
private class	ParserImpl.ParseBlockMappingValueCommentList
private class	ParserImpl.ParseBlockNode block_node_or_indentless_sequence ::= ALIAS \| properties (block_content \| indentless_block_sequence)?
private class	ParserImpl.ParseBlockSequenceEntryKey
private class	ParserImpl.ParseBlockSequenceEntryValue
private class	ParserImpl.ParseBlockSequenceFirstEntry
private class	ParserImpl.ParseDocumentContent
private class	ParserImpl.ParseDocumentEnd
private class	ParserImpl.ParseDocumentStart
private class	ParserImpl.ParseFlowEndComment
private class	ParserImpl.ParseFlowMappingEmptyValue
private class	ParserImpl.ParseFlowMappingFirstKey flow_mapping ::= FLOW-MAPPING-START (flow_mapping_entry FLOW-ENTRY)* flow_mapping_entry?
private class	ParserImpl.ParseFlowMappingKey
private class	ParserImpl.ParseFlowMappingValue
private class	ParserImpl.ParseFlowSequenceEntry
private class	ParserImpl.ParseFlowSequenceEntryMappingEnd
private class	ParserImpl.ParseFlowSequenceEntryMappingKey
private class	ParserImpl.ParseFlowSequenceEntryMappingValue
private class	ParserImpl.ParseFlowSequenceFirstEntry flow_sequence ::= FLOW-SEQUENCE-START (flow_sequence_entry FLOW-ENTRY)* flow_sequence_entry?
private class	ParserImpl.ParseImplicitDocumentStart
private class	ParserImpl.ParseIndentlessSequenceEntryKey
private class	ParserImpl.ParseIndentlessSequenceEntryValue
private class	ParserImpl.ParseStreamStart

Field Summary

Modifier and Type	Field and Description
private Optional<Event>	currentEvent
private static final Map<String, String>	DEFAULT_TAGS
private Map<String, String>	directiveTags
private final ArrayStack<Optional<Mark>>	marksStack
protected final Scanner	scanner tokeniser
private final LoadSettings	settings
private Optional<Production>	state
private final ArrayStack<Production>	states

Constructor Summary

Access	Constructor and Description
public	ParserImpl(StreamReader - the input reader, LoadSettings - the configuration options settings) Deprecated use the other constructor with LoadSettings first
public	ParserImpl(LoadSettings - configuration options settings, StreamReader - the input reader) Create
public	ParserImpl(Scanner - input scanner, LoadSettings - configuration options settings) Deprecated use the other constructor with LoadSettings first
public	ParserImpl(LoadSettings - configuration options settings, Scanner - input scanner) Create

Method Summary

Modifier and Type	Method and Description
public boolean	checkEvent(Event.ID id) Implements org.snakeyaml.engine.v2.parser.Parser.checkEvent. Check the ID of the next event.
public boolean	Returns: true if there is another event hasNext() Implements java.util.Iterator.hasNext. Produce the event if not yet present.
private Optional<Mark>	markPop()
private void	markPush(Optional<Mark> mark)
public Event	next() Implements org.snakeyaml.engine.v2.parser.Parser.next. Consume the event (get the next event and removed it).
private Event	parseBlockNodeOrIndentlessSequence()
private Event	parseFlowNode()
private Event	parseNode(boolean block, boolean indentlessSequence)
public Event	peekEvent() Implements org.snakeyaml.engine.v2.parser.Parser.peekEvent. Get the next event (and keep it).
private VersionTagsTuple	processDirectives()
private Event	processEmptyScalar(Optional<Mark> mark) block_mapping ::= BLOCK-MAPPING_START ((KEY block_node_or_indentless_sequence?)?
private void	produce()
private CommentEvent	produceCommentEvent(CommentToken token)

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

public Class ParserImpl

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary