Add TLSConfig to nctalk (#1195)

Signed-off-by: Gary Kim <gary@garykim.dev>

1 files changed, 1229 insertions, 0 deletions

diff --git a/vendor/gopkg.in/yaml.v3/parserc.go b/vendor/gopkg.in/yaml.v3/parserc.go
new file mode 100644
index 00000000..aea9050b
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v3/parserc.go
@@ -0,0 +1,1229 @@
+//
+// Copyright (c) 2011-2019 Canonical Ltd
+// Copyright (c) 2006-2010 Kirill Simonov
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+// of the Software, and to permit persons to whom the Software is furnished to do
+// so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package yaml
+
+import (
+	"bytes"
+)
+
+// The parser implements the following grammar:
+//
+// 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?)?
+
+// Peek the next token in the token queue.
+func peek_token(parser *yaml_parser_t) *yaml_token_t {
+	if parser.token_available || yaml_parser_fetch_more_tokens(parser) {
+		token := &parser.tokens[parser.tokens_head]
+		yaml_parser_unfold_comments(parser, token)
+		return token
+	}
+	return nil
+}
+
+// yaml_parser_unfold_comments walks through the comments queue and joins all
+// comments behind the position of the provided token into the respective
+// top-level comment slices in the parser.
+func yaml_parser_unfold_comments(parser *yaml_parser_t, token *yaml_token_t) {
+	for parser.comments_head < len(parser.comments) && token.start_mark.index >= parser.comments[parser.comments_head].token_mark.index {
+		comment := &parser.comments[parser.comments_head]
+		if len(comment.head) > 0 {
+			if token.typ == yaml_BLOCK_END_TOKEN {
+				// No heads on ends, so keep comment.head for a follow up token.
+				break
+			}
+			if len(parser.head_comment) > 0 {
+				parser.head_comment = append(parser.head_comment, '\n')
+			}
+			parser.head_comment = append(parser.head_comment, comment.head...)
+		}
+		if len(comment.foot) > 0 {
+			if len(parser.foot_comment) > 0 {
+				parser.foot_comment = append(parser.foot_comment, '\n')
+			}
+			parser.foot_comment = append(parser.foot_comment, comment.foot...)
+		}
+		if len(comment.line) > 0 {
+			if len(parser.line_comment) > 0 {
+				parser.line_comment = append(parser.line_comment, '\n')
+			}
+			parser.line_comment = append(parser.line_comment, comment.line...)
+		}
+		*comment = yaml_comment_t{}
+		parser.comments_head++
+	}
+}
+
+// Remove the next token from the queue (must be called after peek_token).
+func skip_token(parser *yaml_parser_t) {
+	parser.token_available = false
+	parser.tokens_parsed++
+	parser.stream_end_produced = parser.tokens[parser.tokens_head].typ == yaml_STREAM_END_TOKEN
+	parser.tokens_head++
+}
+
+// Get the next event.
+func yaml_parser_parse(parser *yaml_parser_t, event *yaml_event_t) bool {
+	// Erase the event object.
+	*event = yaml_event_t{}
+
+	// No events after the end of the stream or error.
+	if parser.stream_end_produced || parser.error != yaml_NO_ERROR || parser.state == yaml_PARSE_END_STATE {
+		return true
+	}
+
+	// Generate the next event.
+	return yaml_parser_state_machine(parser, event)
+}
+
+// Set parser error.
+func yaml_parser_set_parser_error(parser *yaml_parser_t, problem string, problem_mark yaml_mark_t) bool {
+	parser.error = yaml_PARSER_ERROR
+	parser.problem = problem
+	parser.problem_mark = problem_mark
+	return false
+}
+
+func yaml_parser_set_parser_error_context(parser *yaml_parser_t, context string, context_mark yaml_mark_t, problem string, problem_mark yaml_mark_t) bool {
+	parser.error = yaml_PARSER_ERROR
+	parser.context = context
+	parser.context_mark = context_mark
+	parser.problem = problem
+	parser.problem_mark = problem_mark
+	return false
+}
+
+// State dispatcher.
+func yaml_parser_state_machine(parser *yaml_parser_t, event *yaml_event_t) bool {
+	//trace("yaml_parser_state_machine", "state:", parser.state.String())
+
+	switch parser.state {
+	case yaml_PARSE_STREAM_START_STATE:
+		return yaml_parser_parse_stream_start(parser, event)
+
+	case yaml_PARSE_IMPLICIT_DOCUMENT_START_STATE:
+		return yaml_parser_parse_document_start(parser, event, true)
+
+	case yaml_PARSE_DOCUMENT_START_STATE:
+		return yaml_parser_parse_document_start(parser, event, false)
+
+	case yaml_PARSE_DOCUMENT_CONTENT_STATE:
+		return yaml_parser_parse_document_content(parser, event)
+
+	case yaml_PARSE_DOCUMENT_END_STATE:
+		return yaml_parser_parse_document_end(parser, event)
+
+	case yaml_PARSE_BLOCK_NODE_STATE:
+		return yaml_parser_parse_node(parser, event, true, false)
+
+	case yaml_PARSE_BLOCK_NODE_OR_INDENTLESS_SEQUENCE_STATE:
+		return yaml_parser_parse_node(parser, event, true, true)
+
+	case yaml_PARSE_FLOW_NODE_STATE:
+		return yaml_parser_parse_node(parser, event, false, false)
+
+	case yaml_PARSE_BLOCK_SEQUENCE_FIRST_ENTRY_STATE:
+		return yaml_parser_parse_block_sequence_entry(parser, event, true)
+
+	case yaml_PARSE_BLOCK_SEQUENCE_ENTRY_STATE:
+		return yaml_parser_parse_block_sequence_entry(parser, event, false)
+
+	case yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE:
+		return yaml_parser_parse_indentless_sequence_entry(parser, event)
+
+	case yaml_PARSE_BLOCK_MAPPING_FIRST_KEY_STATE:
+		return yaml_parser_parse_block_mapping_key(parser, event, true)
+
+	case yaml_PARSE_BLOCK_MAPPING_KEY_STATE:
+		return yaml_parser_parse_block_mapping_key(parser, event, false)
+
+	case yaml_PARSE_BLOCK_MAPPING_VALUE_STATE:
+		return yaml_parser_parse_block_mapping_value(parser, event)
+
+	case yaml_PARSE_FLOW_SEQUENCE_FIRST_ENTRY_STATE:
+		return yaml_parser_parse_flow_sequence_entry(parser, event, true)
+
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_STATE:
+		return yaml_parser_parse_flow_sequence_entry(parser, event, false)
+
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_KEY_STATE:
+		return yaml_parser_parse_flow_sequence_entry_mapping_key(parser, event)
+
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_VALUE_STATE:
+		return yaml_parser_parse_flow_sequence_entry_mapping_value(parser, event)
+
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_END_STATE:
+		return yaml_parser_parse_flow_sequence_entry_mapping_end(parser, event)
+
+	case yaml_PARSE_FLOW_MAPPING_FIRST_KEY_STATE:
+		return yaml_parser_parse_flow_mapping_key(parser, event, true)
+
+	case yaml_PARSE_FLOW_MAPPING_KEY_STATE:
+		return yaml_parser_parse_flow_mapping_key(parser, event, false)
+
+	case yaml_PARSE_FLOW_MAPPING_VALUE_STATE:
+		return yaml_parser_parse_flow_mapping_value(parser, event, false)
+
+	case yaml_PARSE_FLOW_MAPPING_EMPTY_VALUE_STATE:
+		return yaml_parser_parse_flow_mapping_value(parser, event, true)
+
+	default:
+		panic("invalid parser state")
+	}
+}
+
+// Parse the production:
+// stream   ::= STREAM-START implicit_document? explicit_document* STREAM-END
+//              ************
+func yaml_parser_parse_stream_start(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if token.typ != yaml_STREAM_START_TOKEN {
+		return yaml_parser_set_parser_error(parser, "did not find expected <stream-start>", token.start_mark)
+	}
+	parser.state = yaml_PARSE_IMPLICIT_DOCUMENT_START_STATE
+	*event = yaml_event_t{
+		typ:        yaml_STREAM_START_EVENT,
+		start_mark: token.start_mark,
+		end_mark:   token.end_mark,
+		encoding:   token.encoding,
+	}
+	skip_token(parser)
+	return true
+}
+
+// Parse the productions:
+// implicit_document    ::= block_node DOCUMENT-END*
+//                          *
+// explicit_document    ::= DIRECTIVE* DOCUMENT-START block_node? DOCUMENT-END*
+//                          *************************
+func yaml_parser_parse_document_start(parser *yaml_parser_t, event *yaml_event_t, implicit bool) bool {
+
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	// Parse extra document end indicators.
+	if !implicit {
+		for token.typ == yaml_DOCUMENT_END_TOKEN {
+			skip_token(parser)
+			token = peek_token(parser)
+			if token == nil {
+				return false
+			}
+		}
+	}
+
+	if implicit && token.typ != yaml_VERSION_DIRECTIVE_TOKEN &&
+		token.typ != yaml_TAG_DIRECTIVE_TOKEN &&
+		token.typ != yaml_DOCUMENT_START_TOKEN &&
+		token.typ != yaml_STREAM_END_TOKEN {
+		// Parse an implicit document.
+		if !yaml_parser_process_directives(parser, nil, nil) {
+			return false
+		}
+		parser.states = append(parser.states, yaml_PARSE_DOCUMENT_END_STATE)
+		parser.state = yaml_PARSE_BLOCK_NODE_STATE
+
+		var head_comment []byte
+		if len(parser.head_comment) > 0 {
+			// [Go] Scan the header comment backwards, and if an empty line is found, break
+			//      the header so the part before the last empty line goes into the
+			//      document header, while the bottom of it goes into a follow up event.
+			for i := len(parser.head_comment) - 1; i > 0; i-- {
+				if parser.head_comment[i] == '\n' {
+					if i == len(parser.head_comment)-1 {
+						head_comment = parser.head_comment[:i]
+						parser.head_comment = parser.head_comment[i+1:]
+						break
+					} else if parser.head_comment[i-1] == '\n' {
+						head_comment = parser.head_comment[:i-1]
+						parser.head_comment = parser.head_comment[i+1:]
+						break
+					}
+				}
+			}
+		}
+
+		*event = yaml_event_t{
+			typ:        yaml_DOCUMENT_START_EVENT,
+			start_mark: token.start_mark,
+			end_mark:   token.end_mark,
+
+			head_comment: head_comment,
+		}
+
+	} else if token.typ != yaml_STREAM_END_TOKEN {
+		// Parse an explicit document.
+		var version_directive *yaml_version_directive_t
+		var tag_directives []yaml_tag_directive_t
+		start_mark := token.start_mark
+		if !yaml_parser_process_directives(parser, &version_directive, &tag_directives) {
+			return false
+		}
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_DOCUMENT_START_TOKEN {
+			yaml_parser_set_parser_error(parser,
+				"did not find expected <document start>", token.start_mark)
+			return false
+		}
+		parser.states = append(parser.states, yaml_PARSE_DOCUMENT_END_STATE)
+		parser.state = yaml_PARSE_DOCUMENT_CONTENT_STATE
+		end_mark := token.end_mark
+
+		*event = yaml_event_t{
+			typ:               yaml_DOCUMENT_START_EVENT,
+			start_mark:        start_mark,
+			end_mark:          end_mark,
+			version_directive: version_directive,
+			tag_directives:    tag_directives,
+			implicit:          false,
+		}
+		skip_token(parser)
+
+	} else {
+		// Parse the stream end.
+		parser.state = yaml_PARSE_END_STATE
+		*event = yaml_event_t{
+			typ:        yaml_STREAM_END_EVENT,
+			start_mark: token.start_mark,
+			end_mark:   token.end_mark,
+		}
+		skip_token(parser)
+	}
+
+	return true
+}
+
+// Parse the productions:
+// explicit_document    ::= DIRECTIVE* DOCUMENT-START block_node? DOCUMENT-END*
+//                                                    ***********
+//
+func yaml_parser_parse_document_content(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	if token.typ == yaml_VERSION_DIRECTIVE_TOKEN ||
+		token.typ == yaml_TAG_DIRECTIVE_TOKEN ||
+		token.typ == yaml_DOCUMENT_START_TOKEN ||
+		token.typ == yaml_DOCUMENT_END_TOKEN ||
+		token.typ == yaml_STREAM_END_TOKEN {
+		parser.state = parser.states[len(parser.states)-1]
+		parser.states = parser.states[:len(parser.states)-1]
+		return yaml_parser_process_empty_scalar(parser, event,
+			token.start_mark)
+	}
+	return yaml_parser_parse_node(parser, event, true, false)
+}
+
+// Parse the productions:
+// implicit_document    ::= block_node DOCUMENT-END*
+//                                     *************
+// explicit_document    ::= DIRECTIVE* DOCUMENT-START block_node? DOCUMENT-END*
+//
+func yaml_parser_parse_document_end(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	start_mark := token.start_mark
+	end_mark := token.start_mark
+
+	implicit := true
+	if token.typ == yaml_DOCUMENT_END_TOKEN {
+		end_mark = token.end_mark
+		skip_token(parser)
+		implicit = false
+	}
+
+	parser.tag_directives = parser.tag_directives[:0]
+
+	parser.state = yaml_PARSE_DOCUMENT_START_STATE
+	*event = yaml_event_t{
+		typ:        yaml_DOCUMENT_END_EVENT,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+		implicit:   implicit,
+	}
+	yaml_parser_set_event_comments(parser, event)
+	if len(event.head_comment) > 0 && len(event.foot_comment) == 0 {
+		event.foot_comment = event.head_comment
+		event.head_comment = nil
+	}
+	return true
+}
+
+func yaml_parser_set_event_comments(parser *yaml_parser_t, event *yaml_event_t) {
+	event.head_comment = parser.head_comment
+	event.line_comment = parser.line_comment
+	event.foot_comment = parser.foot_comment
+	parser.head_comment = nil
+	parser.line_comment = nil
+	parser.foot_comment = nil
+	parser.tail_comment = nil
+	parser.stem_comment = nil
+}
+
+// Parse the productions:
+// 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
+//                                            ******
+func yaml_parser_parse_node(parser *yaml_parser_t, event *yaml_event_t, block, indentless_sequence bool) bool {
+	//defer trace("yaml_parser_parse_node", "block:", block, "indentless_sequence:", indentless_sequence)()
+
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	if token.typ == yaml_ALIAS_TOKEN {
+		parser.state = parser.states[len(parser.states)-1]
+		parser.states = parser.states[:len(parser.states)-1]
+		*event = yaml_event_t{
+			typ:        yaml_ALIAS_EVENT,
+			start_mark: token.start_mark,
+			end_mark:   token.end_mark,
+			anchor:     token.value,
+		}
+		yaml_parser_set_event_comments(parser, event)
+		skip_token(parser)
+		return true
+	}
+
+	start_mark := token.start_mark
+	end_mark := token.start_mark
+
+	var tag_token bool
+	var tag_handle, tag_suffix, anchor []byte
+	var tag_mark yaml_mark_t
+	if token.typ == yaml_ANCHOR_TOKEN {
+		anchor = token.value
+		start_mark = token.start_mark
+		end_mark = token.end_mark
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ == yaml_TAG_TOKEN {
+			tag_token = true
+			tag_handle = token.value
+			tag_suffix = token.suffix
+			tag_mark = token.start_mark
+			end_mark = token.end_mark
+			skip_token(parser)
+			token = peek_token(parser)
+			if token == nil {
+				return false
+			}
+		}
+	} else if token.typ == yaml_TAG_TOKEN {
+		tag_token = true
+		tag_handle = token.value
+		tag_suffix = token.suffix
+		start_mark = token.start_mark
+		tag_mark = token.start_mark
+		end_mark = token.end_mark
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ == yaml_ANCHOR_TOKEN {
+			anchor = token.value
+			end_mark = token.end_mark
+			skip_token(parser)
+			token = peek_token(parser)
+			if token == nil {
+				return false
+			}
+		}
+	}
+
+	var tag []byte
+	if tag_token {
+		if len(tag_handle) == 0 {
+			tag = tag_suffix
+			tag_suffix = nil
+		} else {
+			for i := range parser.tag_directives {
+				if bytes.Equal(parser.tag_directives[i].handle, tag_handle) {
+					tag = append([]byte(nil), parser.tag_directives[i].prefix...)
+					tag = append(tag, tag_suffix...)
+					break
+				}
+			}
+			if len(tag) == 0 {
+				yaml_parser_set_parser_error_context(parser,
+					"while parsing a node", start_mark,
+					"found undefined tag handle", tag_mark)
+				return false
+			}
+		}
+	}
+
+	implicit := len(tag) == 0
+	if indentless_sequence && token.typ == yaml_BLOCK_ENTRY_TOKEN {
+		end_mark = token.end_mark
+		parser.state = yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE
+		*event = yaml_event_t{
+			typ:        yaml_SEQUENCE_START_EVENT,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			anchor:     anchor,
+			tag:        tag,
+			implicit:   implicit,
+			style:      yaml_style_t(yaml_BLOCK_SEQUENCE_STYLE),
+		}
+		return true
+	}
+	if token.typ == yaml_SCALAR_TOKEN {
+		var plain_implicit, quoted_implicit bool
+		end_mark = token.end_mark
+		if (len(tag) == 0 && token.style == yaml_PLAIN_SCALAR_STYLE) || (len(tag) == 1 && tag[0] == '!') {
+			plain_implicit = true
+		} else if len(tag) == 0 {
+			quoted_implicit = true
+		}
+		parser.state = parser.states[len(parser.states)-1]
+		parser.states = parser.states[:len(parser.states)-1]
+
+		*event = yaml_event_t{
+			typ:             yaml_SCALAR_EVENT,
+			start_mark:      start_mark,
+			end_mark:        end_mark,
+			anchor:          anchor,
+			tag:             tag,
+			value:           token.value,
+			implicit:        plain_implicit,
+			quoted_implicit: quoted_implicit,
+			style:           yaml_style_t(token.style),
+		}
+		yaml_parser_set_event_comments(parser, event)
+		skip_token(parser)
+		return true
+	}
+	if token.typ == yaml_FLOW_SEQUENCE_START_TOKEN {
+		// [Go] Some of the events below can be merged as they differ only on style.
+		end_mark = token.end_mark
+		parser.state = yaml_PARSE_FLOW_SEQUENCE_FIRST_ENTRY_STATE
+		*event = yaml_event_t{
+			typ:        yaml_SEQUENCE_START_EVENT,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			anchor:     anchor,
+			tag:        tag,
+			implicit:   implicit,
+			style:      yaml_style_t(yaml_FLOW_SEQUENCE_STYLE),
+		}
+		yaml_parser_set_event_comments(parser, event)
+		return true
+	}
+	if token.typ == yaml_FLOW_MAPPING_START_TOKEN {
+		end_mark = token.end_mark
+		parser.state = yaml_PARSE_FLOW_MAPPING_FIRST_KEY_STATE
+		*event = yaml_event_t{
+			typ:        yaml_MAPPING_START_EVENT,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			anchor:     anchor,
+			tag:        tag,
+			implicit:   implicit,
+			style:      yaml_style_t(yaml_FLOW_MAPPING_STYLE),
+		}
+		yaml_parser_set_event_comments(parser, event)
+		return true
+	}
+	if block && token.typ == yaml_BLOCK_SEQUENCE_START_TOKEN {
+		end_mark = token.end_mark
+		parser.state = yaml_PARSE_BLOCK_SEQUENCE_FIRST_ENTRY_STATE
+		*event = yaml_event_t{
+			typ:        yaml_SEQUENCE_START_EVENT,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			anchor:     anchor,
+			tag:        tag,
+			implicit:   implicit,
+			style:      yaml_style_t(yaml_BLOCK_SEQUENCE_STYLE),
+		}
+		if parser.stem_comment != nil {
+			event.head_comment = parser.stem_comment
+			parser.stem_comment = nil
+		}
+		return true
+	}
+	if block && token.typ == yaml_BLOCK_MAPPING_START_TOKEN {
+		end_mark = token.end_mark
+		parser.state = yaml_PARSE_BLOCK_MAPPING_FIRST_KEY_STATE
+		*event = yaml_event_t{
+			typ:        yaml_MAPPING_START_EVENT,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			anchor:     anchor,
+			tag:        tag,
+			implicit:   implicit,
+			style:      yaml_style_t(yaml_BLOCK_MAPPING_STYLE),
+		}
+		return true
+	}
+	if len(anchor) > 0 || len(tag) > 0 {
+		parser.state = parser.states[len(parser.states)-1]
+		parser.states = parser.states[:len(parser.states)-1]
+
+		*event = yaml_event_t{
+			typ:             yaml_SCALAR_EVENT,
+			start_mark:      start_mark,
+			end_mark:        end_mark,
+			anchor:          anchor,
+			tag:             tag,
+			implicit:        implicit,
+			quoted_implicit: false,
+			style:           yaml_style_t(yaml_PLAIN_SCALAR_STYLE),
+		}
+		return true
+	}
+
+	context := "while parsing a flow node"
+	if block {
+		context = "while parsing a block node"
+	}
+	yaml_parser_set_parser_error_context(parser, context, start_mark,
+		"did not find expected node content", token.start_mark)
+	return false
+}
+
+// Parse the productions:
+// block_sequence ::= BLOCK-SEQUENCE-START (BLOCK-ENTRY block_node?)* BLOCK-END
+//                    ********************  *********** *             *********
+//
+func yaml_parser_parse_block_sequence_entry(parser *yaml_parser_t, event *yaml_event_t, first bool) bool {
+	if first {
+		token := peek_token(parser)
+		parser.marks = append(parser.marks, token.start_mark)
+		skip_token(parser)
+	}
+
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	if token.typ == yaml_BLOCK_ENTRY_TOKEN {
+		mark := token.end_mark
+		prior_head := len(parser.head_comment)
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if prior_head > 0 && token.typ == yaml_BLOCK_SEQUENCE_START_TOKEN {
+			// [Go] It's a sequence under a sequence entry, so the former head comment
+			//      is for the list itself, not the first list item under it.
+			parser.stem_comment = parser.head_comment[:prior_head]
+			if len(parser.head_comment) == prior_head {
+				parser.head_comment = nil
+			} else {
+				// Copy suffix to prevent very strange bugs if someone ever appends
+				// further bytes to the prefix in the stem_comment slice above.
+				parser.head_comment = append([]byte(nil), parser.head_comment[prior_head+1:]...)
+			}
+
+		}
+		if token.typ != yaml_BLOCK_ENTRY_TOKEN && token.typ != yaml_BLOCK_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_BLOCK_SEQUENCE_ENTRY_STATE)
+			return yaml_parser_parse_node(parser, event, true, false)
+		} else {
+			parser.state = yaml_PARSE_BLOCK_SEQUENCE_ENTRY_STATE
+			return yaml_parser_process_empty_scalar(parser, event, mark)
+		}
+	}
+	if token.typ == yaml_BLOCK_END_TOKEN {
+		parser.state = parser.states[len(parser.states)-1]
+		parser.states = parser.states[:len(parser.states)-1]
+		parser.marks = parser.marks[:len(parser.marks)-1]
+
+		*event = yaml_event_t{
+			typ:        yaml_SEQUENCE_END_EVENT,
+			start_mark: token.start_mark,
+			end_mark:   token.end_mark,
+		}
+
+		skip_token(parser)
+		return true
+	}
+
+	context_mark := parser.marks[len(parser.marks)-1]
+	parser.marks = parser.marks[:len(parser.marks)-1]
+	return yaml_parser_set_parser_error_context(parser,
+		"while parsing a block collection", context_mark,
+		"did not find expected '-' indicator", token.start_mark)
+}
+
+// Parse the productions:
+// indentless_sequence  ::= (BLOCK-ENTRY block_node?)+
+//                           *********** *
+func yaml_parser_parse_indentless_sequence_entry(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	if token.typ == yaml_BLOCK_ENTRY_TOKEN {
+		mark := token.end_mark
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_BLOCK_ENTRY_TOKEN &&
+			token.typ != yaml_KEY_TOKEN &&
+			token.typ != yaml_VALUE_TOKEN &&
+			token.typ != yaml_BLOCK_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE)
+			return yaml_parser_parse_node(parser, event, true, false)
+		}
+		parser.state = yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE
+		return yaml_parser_process_empty_scalar(parser, event, mark)
+	}
+	parser.state = parser.states[len(parser.states)-1]
+	parser.states = parser.states[:len(parser.states)-1]
+
+	*event = yaml_event_t{
+		typ:        yaml_SEQUENCE_END_EVENT,
+		start_mark: token.start_mark,
+		end_mark:   token.start_mark, // [Go] Shouldn't this be token.end_mark?
+	}
+	return true
+}
+
+// Parse the productions:
+// block_mapping        ::= BLOCK-MAPPING_START
+//                          *******************
+//                          ((KEY block_node_or_indentless_sequence?)?
+//                            *** *
+//                          (VALUE block_node_or_indentless_sequence?)?)*
+//
+//                          BLOCK-END
+//                          *********
+//
+func yaml_parser_parse_block_mapping_key(parser *yaml_parser_t, event *yaml_event_t, first bool) bool {
+	if first {
+		token := peek_token(parser)
+		parser.marks = append(parser.marks, token.start_mark)
+		skip_token(parser)
+	}
+
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	// [Go] A tail comment was left from the prior mapping value processed. Emit an event
+	//      as it needs to be processed with that value and not the following key.
+	if len(parser.tail_comment) > 0 {
+		*event = yaml_event_t{
+			typ:          yaml_TAIL_COMMENT_EVENT,
+			start_mark:   token.start_mark,
+			end_mark:     token.end_mark,
+			foot_comment: parser.tail_comment,
+		}
+		parser.tail_comment = nil
+		return true
+	}
+
+	if token.typ == yaml_KEY_TOKEN {
+		mark := token.end_mark
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_KEY_TOKEN &&
+			token.typ != yaml_VALUE_TOKEN &&
+			token.typ != yaml_BLOCK_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_BLOCK_MAPPING_VALUE_STATE)
+			return yaml_parser_parse_node(parser, event, true, true)
+		} else {
+			parser.state = yaml_PARSE_BLOCK_MAPPING_VALUE_STATE
+			return yaml_parser_process_empty_scalar(parser, event, mark)
+		}
+	} else if token.typ == yaml_BLOCK_END_TOKEN {
+		parser.state = parser.states[len(parser.states)-1]
+		parser.states = parser.states[:len(parser.states)-1]
+		parser.marks = parser.marks[:len(parser.marks)-1]
+		*event = yaml_event_t{
+			typ:        yaml_MAPPING_END_EVENT,
+			start_mark: token.start_mark,
+			end_mark:   token.end_mark,
+		}
+		yaml_parser_set_event_comments(parser, event)
+		skip_token(parser)
+		return true
+	}
+
+	context_mark := parser.marks[len(parser.marks)-1]
+	parser.marks = parser.marks[:len(parser.marks)-1]
+	return yaml_parser_set_parser_error_context(parser,
+		"while parsing a block mapping", context_mark,
+		"did not find expected key", token.start_mark)
+}
+
+// Parse the productions:
+// block_mapping        ::= BLOCK-MAPPING_START
+//
+//                          ((KEY block_node_or_indentless_sequence?)?
+//
+//                          (VALUE block_node_or_indentless_sequence?)?)*
+//                           ***** *
+//                          BLOCK-END
+//
+//
+func yaml_parser_parse_block_mapping_value(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if token.typ == yaml_VALUE_TOKEN {
+		mark := token.end_mark
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_KEY_TOKEN &&
+			token.typ != yaml_VALUE_TOKEN &&
+			token.typ != yaml_BLOCK_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_BLOCK_MAPPING_KEY_STATE)
+			return yaml_parser_parse_node(parser, event, true, true)
+		}
+		parser.state = yaml_PARSE_BLOCK_MAPPING_KEY_STATE
+		return yaml_parser_process_empty_scalar(parser, event, mark)
+	}
+	parser.state = yaml_PARSE_BLOCK_MAPPING_KEY_STATE
+	return yaml_parser_process_empty_scalar(parser, event, token.start_mark)
+}
+
+// Parse the productions:
+// 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?)?
+//                          *
+//
+func yaml_parser_parse_flow_sequence_entry(parser *yaml_parser_t, event *yaml_event_t, first bool) bool {
+	if first {
+		token := peek_token(parser)
+		parser.marks = append(parser.marks, token.start_mark)
+		skip_token(parser)
+	}
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if token.typ != yaml_FLOW_SEQUENCE_END_TOKEN {
+		if !first {
+			if token.typ == yaml_FLOW_ENTRY_TOKEN {
+				skip_token(parser)
+				token = peek_token(parser)
+				if token == nil {
+					return false
+				}
+			} else {
+				context_mark := parser.marks[len(parser.marks)-1]
+				parser.marks = parser.marks[:len(parser.marks)-1]
+				return yaml_parser_set_parser_error_context(parser,
+					"while parsing a flow sequence", context_mark,
+					"did not find expected ',' or ']'", token.start_mark)
+			}
+		}
+
+		if token.typ == yaml_KEY_TOKEN {
+			parser.state = yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_KEY_STATE
+			*event = yaml_event_t{
+				typ:        yaml_MAPPING_START_EVENT,
+				start_mark: token.start_mark,
+				end_mark:   token.end_mark,
+				implicit:   true,
+				style:      yaml_style_t(yaml_FLOW_MAPPING_STYLE),
+			}
+			skip_token(parser)
+			return true
+		} else if token.typ != yaml_FLOW_SEQUENCE_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_FLOW_SEQUENCE_ENTRY_STATE)
+			return yaml_parser_parse_node(parser, event, false, false)
+		}
+	}
+
+	parser.state = parser.states[len(parser.states)-1]
+	parser.states = parser.states[:len(parser.states)-1]
+	parser.marks = parser.marks[:len(parser.marks)-1]
+
+	*event = yaml_event_t{
+		typ:        yaml_SEQUENCE_END_EVENT,
+		start_mark: token.start_mark,
+		end_mark:   token.end_mark,
+	}
+	yaml_parser_set_event_comments(parser, event)
+
+	skip_token(parser)
+	return true
+}
+
+//
+// Parse the productions:
+// flow_sequence_entry  ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+//                                      *** *
+//
+func yaml_parser_parse_flow_sequence_entry_mapping_key(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if token.typ != yaml_VALUE_TOKEN &&
+		token.typ != yaml_FLOW_ENTRY_TOKEN &&
+		token.typ != yaml_FLOW_SEQUENCE_END_TOKEN {
+		parser.states = append(parser.states, yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_VALUE_STATE)
+		return yaml_parser_parse_node(parser, event, false, false)
+	}
+	mark := token.end_mark
+	skip_token(parser)
+	parser.state = yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_VALUE_STATE
+	return yaml_parser_process_empty_scalar(parser, event, mark)
+}
+
+// Parse the productions:
+// flow_sequence_entry  ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+//                                                      ***** *
+//
+func yaml_parser_parse_flow_sequence_entry_mapping_value(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if token.typ == yaml_VALUE_TOKEN {
+		skip_token(parser)
+		token := peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_FLOW_ENTRY_TOKEN && token.typ != yaml_FLOW_SEQUENCE_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_END_STATE)
+			return yaml_parser_parse_node(parser, event, false, false)
+		}
+	}
+	parser.state = yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_END_STATE
+	return yaml_parser_process_empty_scalar(parser, event, token.start_mark)
+}
+
+// Parse the productions:
+// flow_sequence_entry  ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+//                                                                      *
+//
+func yaml_parser_parse_flow_sequence_entry_mapping_end(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	parser.state = yaml_PARSE_FLOW_SEQUENCE_ENTRY_STATE
+	*event = yaml_event_t{
+		typ:        yaml_MAPPING_END_EVENT,
+		start_mark: token.start_mark,
+		end_mark:   token.start_mark, // [Go] Shouldn't this be end_mark?
+	}
+	return true
+}
+
+// Parse the productions:
+// 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?)?
+//                          *           *** *
+//
+func yaml_parser_parse_flow_mapping_key(parser *yaml_parser_t, event *yaml_event_t, first bool) bool {
+	if first {
+		token := peek_token(parser)
+		parser.marks = append(parser.marks, token.start_mark)
+		skip_token(parser)
+	}
+
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	if token.typ != yaml_FLOW_MAPPING_END_TOKEN {
+		if !first {
+			if token.typ == yaml_FLOW_ENTRY_TOKEN {
+				skip_token(parser)
+				token = peek_token(parser)
+				if token == nil {
+					return false
+				}
+			} else {
+				context_mark := parser.marks[len(parser.marks)-1]
+				parser.marks = parser.marks[:len(parser.marks)-1]
+				return yaml_parser_set_parser_error_context(parser,
+					"while parsing a flow mapping", context_mark,
+					"did not find expected ',' or '}'", token.start_mark)
+			}
+		}
+
+		if token.typ == yaml_KEY_TOKEN {
+			skip_token(parser)
+			token = peek_token(parser)
+			if token == nil {
+				return false
+			}
+			if token.typ != yaml_VALUE_TOKEN &&
+				token.typ != yaml_FLOW_ENTRY_TOKEN &&
+				token.typ != yaml_FLOW_MAPPING_END_TOKEN {
+				parser.states = append(parser.states, yaml_PARSE_FLOW_MAPPING_VALUE_STATE)
+				return yaml_parser_parse_node(parser, event, false, false)
+			} else {
+				parser.state = yaml_PARSE_FLOW_MAPPING_VALUE_STATE
+				return yaml_parser_process_empty_scalar(parser, event, token.start_mark)
+			}
+		} else if token.typ != yaml_FLOW_MAPPING_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_FLOW_MAPPING_EMPTY_VALUE_STATE)
+			return yaml_parser_parse_node(parser, event, false, false)
+		}
+	}
+
+	parser.state = parser.states[len(parser.states)-1]
+	parser.states = parser.states[:len(parser.states)-1]
+	parser.marks = parser.marks[:len(parser.marks)-1]
+	*event = yaml_event_t{
+		typ:        yaml_MAPPING_END_EVENT,
+		start_mark: token.start_mark,
+		end_mark:   token.end_mark,
+	}
+	yaml_parser_set_event_comments(parser, event)
+	skip_token(parser)
+	return true
+}
+
+// Parse the productions:
+// flow_mapping_entry   ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+//                                   *                  ***** *
+//
+func yaml_parser_parse_flow_mapping_value(parser *yaml_parser_t, event *yaml_event_t, empty bool) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if empty {
+		parser.state = yaml_PARSE_FLOW_MAPPING_KEY_STATE
+		return yaml_parser_process_empty_scalar(parser, event, token.start_mark)
+	}
+	if token.typ == yaml_VALUE_TOKEN {
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_FLOW_ENTRY_TOKEN && token.typ != yaml_FLOW_MAPPING_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_FLOW_MAPPING_KEY_STATE)
+			return yaml_parser_parse_node(parser, event, false, false)
+		}
+	}
+	parser.state = yaml_PARSE_FLOW_MAPPING_KEY_STATE
+	return yaml_parser_process_empty_scalar(parser, event, token.start_mark)
+}
+
+// Generate an empty scalar event.
+func yaml_parser_process_empty_scalar(parser *yaml_parser_t, event *yaml_event_t, mark yaml_mark_t) bool {
+	*event = yaml_event_t{
+		typ:        yaml_SCALAR_EVENT,
+		start_mark: mark,
+		end_mark:   mark,
+		value:      nil, // Empty
+		implicit:   true,
+		style:      yaml_style_t(yaml_PLAIN_SCALAR_STYLE),
+	}
+	return true
+}
+
+var default_tag_directives = []yaml_tag_directive_t{
+	{[]byte("!"), []byte("!")},
+	{[]byte("!!"), []byte("tag:yaml.org,2002:")},
+}
+
+// Parse directives.
+func yaml_parser_process_directives(parser *yaml_parser_t,
+	version_directive_ref **yaml_version_directive_t,
+	tag_directives_ref *[]yaml_tag_directive_t) bool {
+
+	var version_directive *yaml_version_directive_t
+	var tag_directives []yaml_tag_directive_t
+
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	for token.typ == yaml_VERSION_DIRECTIVE_TOKEN || token.typ == yaml_TAG_DIRECTIVE_TOKEN {
+		if token.typ == yaml_VERSION_DIRECTIVE_TOKEN {
+			if version_directive != nil {
+				yaml_parser_set_parser_error(parser,
+					"found duplicate %YAML directive", token.start_mark)
+				return false
+			}
+			if token.major != 1 || token.minor != 1 {
+				yaml_parser_set_parser_error(parser,
+					"found incompatible YAML document", token.start_mark)
+				return false
+			}
+			version_directive = &yaml_version_directive_t{
+				major: token.major,
+				minor: token.minor,
+			}
+		} else if token.typ == yaml_TAG_DIRECTIVE_TOKEN {
+			value := yaml_tag_directive_t{
+				handle: token.value,
+				prefix: token.prefix,
+			}
+			if !yaml_parser_append_tag_directive(parser, value, false, token.start_mark) {
+				return false
+			}
+			tag_directives = append(tag_directives, value)
+		}
+
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+	}
+
+	for i := range default_tag_directives {
+		if !yaml_parser_append_tag_directive(parser, default_tag_directives[i], true, token.start_mark) {
+			return false
+		}
+	}
+
+	if version_directive_ref != nil {
+		*version_directive_ref = version_directive
+	}
+	if tag_directives_ref != nil {
+		*tag_directives_ref = tag_directives
+	}
+	return true
+}
+
+// Append a tag directive to the directives stack.
+func yaml_parser_append_tag_directive(parser *yaml_parser_t, value yaml_tag_directive_t, allow_duplicates bool, mark yaml_mark_t) bool {
+	for i := range parser.tag_directives {
+		if bytes.Equal(value.handle, parser.tag_directives[i].handle) {
+			if allow_duplicates {
+				return true
+			}
+			return yaml_parser_set_parser_error(parser, "found duplicate %TAG directive", mark)
+		}
+	}
+
+	// [Go] I suspect the copy is unnecessary. This was likely done
+	// because there was no way to track ownership of the data.
+	value_copy := yaml_tag_directive_t{
+		handle: make([]byte, len(value.handle)),
+		prefix: make([]byte, len(value.prefix)),
+	}
+	copy(value_copy.handle, value.handle)
+	copy(value_copy.prefix, value.prefix)
+	parser.tag_directives = append(parser.tag_directives, value_copy)
+	return true
+}