gtsocial-umbx

emitterc.go (55187B)

---

 //
 // 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"
 	"fmt"
 )
 
 // Flush the buffer if needed.
 func flush(emitter *yaml_emitter_t) bool {
 	if emitter.buffer_pos+5 >= len(emitter.buffer) {
 		return yaml_emitter_flush(emitter)
 	}
 	return true
 }
 
 // Put a character to the output buffer.
 func put(emitter *yaml_emitter_t, value byte) bool {
 	if emitter.buffer_pos+5 >= len(emitter.buffer) && !yaml_emitter_flush(emitter) {
 		return false
 	}
 	emitter.buffer[emitter.buffer_pos] = value
 	emitter.buffer_pos++
 	emitter.column++
 	return true
 }
 
 // Put a line break to the output buffer.
 func put_break(emitter *yaml_emitter_t) bool {
 	if emitter.buffer_pos+5 >= len(emitter.buffer) && !yaml_emitter_flush(emitter) {
 		return false
 	}
 	switch emitter.line_break {
 	case yaml_CR_BREAK:
 		emitter.buffer[emitter.buffer_pos] = '\r'
 		emitter.buffer_pos += 1
 	case yaml_LN_BREAK:
 		emitter.buffer[emitter.buffer_pos] = '\n'
 		emitter.buffer_pos += 1
 	case yaml_CRLN_BREAK:
 		emitter.buffer[emitter.buffer_pos+0] = '\r'
 		emitter.buffer[emitter.buffer_pos+1] = '\n'
 		emitter.buffer_pos += 2
 	default:
 		panic("unknown line break setting")
 	}
 	if emitter.column == 0 {
 		emitter.space_above = true
 	}
 	emitter.column = 0
 	emitter.line++
 	// [Go] Do this here and below and drop from everywhere else (see commented lines).
 	emitter.indention = true
 	return true
 }
 
 // Copy a character from a string into buffer.
 func write(emitter *yaml_emitter_t, s []byte, i *int) bool {
 	if emitter.buffer_pos+5 >= len(emitter.buffer) && !yaml_emitter_flush(emitter) {
 		return false
 	}
 	p := emitter.buffer_pos
 	w := width(s[*i])
 	switch w {
 	case 4:
 		emitter.buffer[p+3] = s[*i+3]
 		fallthrough
 	case 3:
 		emitter.buffer[p+2] = s[*i+2]
 		fallthrough
 	case 2:
 		emitter.buffer[p+1] = s[*i+1]
 		fallthrough
 	case 1:
 		emitter.buffer[p+0] = s[*i+0]
 	default:
 		panic("unknown character width")
 	}
 	emitter.column++
 	emitter.buffer_pos += w
 	*i += w
 	return true
 }
 
 // Write a whole string into buffer.
 func write_all(emitter *yaml_emitter_t, s []byte) bool {
 	for i := 0; i < len(s); {
 		if !write(emitter, s, &i) {
 			return false
 		}
 	}
 	return true
 }
 
 // Copy a line break character from a string into buffer.
 func write_break(emitter *yaml_emitter_t, s []byte, i *int) bool {
 	if s[*i] == '\n' {
 		if !put_break(emitter) {
 			return false
 		}
 		*i++
 	} else {
 		if !write(emitter, s, i) {
 			return false
 		}
 		if emitter.column == 0 {
 			emitter.space_above = true
 		}
 		emitter.column = 0
 		emitter.line++
 		// [Go] Do this here and above and drop from everywhere else (see commented lines).
 		emitter.indention = true
 	}
 	return true
 }
 
 // Set an emitter error and return false.
 func yaml_emitter_set_emitter_error(emitter *yaml_emitter_t, problem string) bool {
 	emitter.error = yaml_EMITTER_ERROR
 	emitter.problem = problem
 	return false
 }
 
 // Emit an event.
 func yaml_emitter_emit(emitter *yaml_emitter_t, event *yaml_event_t) bool {
 	emitter.events = append(emitter.events, *event)
 	for !yaml_emitter_need_more_events(emitter) {
 		event := &emitter.events[emitter.events_head]
 		if !yaml_emitter_analyze_event(emitter, event) {
 			return false
 		}
 		if !yaml_emitter_state_machine(emitter, event) {
 			return false
 		}
 		yaml_event_delete(event)
 		emitter.events_head++
 	}
 	return true
 }
 
 // Check if we need to accumulate more events before emitting.
 //
 // We accumulate extra
 //  - 1 event for DOCUMENT-START
 //  - 2 events for SEQUENCE-START
 //  - 3 events for MAPPING-START
 //
 func yaml_emitter_need_more_events(emitter *yaml_emitter_t) bool {
 	if emitter.events_head == len(emitter.events) {
 		return true
 	}
 	var accumulate int
 	switch emitter.events[emitter.events_head].typ {
 	case yaml_DOCUMENT_START_EVENT:
 		accumulate = 1
 		break
 	case yaml_SEQUENCE_START_EVENT:
 		accumulate = 2
 		break
 	case yaml_MAPPING_START_EVENT:
 		accumulate = 3
 		break
 	default:
 		return false
 	}
 	if len(emitter.events)-emitter.events_head > accumulate {
 		return false
 	}
 	var level int
 	for i := emitter.events_head; i < len(emitter.events); i++ {
 		switch emitter.events[i].typ {
 		case yaml_STREAM_START_EVENT, yaml_DOCUMENT_START_EVENT, yaml_SEQUENCE_START_EVENT, yaml_MAPPING_START_EVENT:
 			level++
 		case yaml_STREAM_END_EVENT, yaml_DOCUMENT_END_EVENT, yaml_SEQUENCE_END_EVENT, yaml_MAPPING_END_EVENT:
 			level--
 		}
 		if level == 0 {
 			return false
 		}
 	}
 	return true
 }
 
 // Append a directive to the directives stack.
 func yaml_emitter_append_tag_directive(emitter *yaml_emitter_t, value *yaml_tag_directive_t, allow_duplicates bool) bool {
 	for i := 0; i < len(emitter.tag_directives); i++ {
 		if bytes.Equal(value.handle, emitter.tag_directives[i].handle) {
 			if allow_duplicates {
 				return true
 			}
 			return yaml_emitter_set_emitter_error(emitter, "duplicate %TAG directive")
 		}
 	}
 
 	// [Go] Do we actually need to copy this given garbage collection
 	// and the lack of deallocating destructors?
 	tag_copy := yaml_tag_directive_t{
 		handle: make([]byte, len(value.handle)),
 		prefix: make([]byte, len(value.prefix)),
 	}
 	copy(tag_copy.handle, value.handle)
 	copy(tag_copy.prefix, value.prefix)
 	emitter.tag_directives = append(emitter.tag_directives, tag_copy)
 	return true
 }
 
 // Increase the indentation level.
 func yaml_emitter_increase_indent(emitter *yaml_emitter_t, flow, indentless bool) bool {
 	emitter.indents = append(emitter.indents, emitter.indent)
 	if emitter.indent < 0 {
 		if flow {
 			emitter.indent = emitter.best_indent
 		} else {
 			emitter.indent = 0
 		}
 	} else if !indentless {
 		// [Go] This was changed so that indentations are more regular.
 		if emitter.states[len(emitter.states)-1] == yaml_EMIT_BLOCK_SEQUENCE_ITEM_STATE {
 			// The first indent inside a sequence will just skip the "- " indicator.
 			emitter.indent += 2
 		} else {
 			// Everything else aligns to the chosen indentation.
 			emitter.indent = emitter.best_indent*((emitter.indent+emitter.best_indent)/emitter.best_indent)
 		}
 	}
 	return true
 }
 
 // State dispatcher.
 func yaml_emitter_state_machine(emitter *yaml_emitter_t, event *yaml_event_t) bool {
 	switch emitter.state {
 	default:
 	case yaml_EMIT_STREAM_START_STATE:
 		return yaml_emitter_emit_stream_start(emitter, event)
 
 	case yaml_EMIT_FIRST_DOCUMENT_START_STATE:
 		return yaml_emitter_emit_document_start(emitter, event, true)
 
 	case yaml_EMIT_DOCUMENT_START_STATE:
 		return yaml_emitter_emit_document_start(emitter, event, false)
 
 	case yaml_EMIT_DOCUMENT_CONTENT_STATE:
 		return yaml_emitter_emit_document_content(emitter, event)
 
 	case yaml_EMIT_DOCUMENT_END_STATE:
 		return yaml_emitter_emit_document_end(emitter, event)
 
 	case yaml_EMIT_FLOW_SEQUENCE_FIRST_ITEM_STATE:
 		return yaml_emitter_emit_flow_sequence_item(emitter, event, true, false)
 
 	case yaml_EMIT_FLOW_SEQUENCE_TRAIL_ITEM_STATE:
 		return yaml_emitter_emit_flow_sequence_item(emitter, event, false, true)
 
 	case yaml_EMIT_FLOW_SEQUENCE_ITEM_STATE:
 		return yaml_emitter_emit_flow_sequence_item(emitter, event, false, false)
 
 	case yaml_EMIT_FLOW_MAPPING_FIRST_KEY_STATE:
 		return yaml_emitter_emit_flow_mapping_key(emitter, event, true, false)
 
 	case yaml_EMIT_FLOW_MAPPING_TRAIL_KEY_STATE:
 		return yaml_emitter_emit_flow_mapping_key(emitter, event, false, true)
 
 	case yaml_EMIT_FLOW_MAPPING_KEY_STATE:
 		return yaml_emitter_emit_flow_mapping_key(emitter, event, false, false)
 
 	case yaml_EMIT_FLOW_MAPPING_SIMPLE_VALUE_STATE:
 		return yaml_emitter_emit_flow_mapping_value(emitter, event, true)
 
 	case yaml_EMIT_FLOW_MAPPING_VALUE_STATE:
 		return yaml_emitter_emit_flow_mapping_value(emitter, event, false)
 
 	case yaml_EMIT_BLOCK_SEQUENCE_FIRST_ITEM_STATE:
 		return yaml_emitter_emit_block_sequence_item(emitter, event, true)
 
 	case yaml_EMIT_BLOCK_SEQUENCE_ITEM_STATE:
 		return yaml_emitter_emit_block_sequence_item(emitter, event, false)
 
 	case yaml_EMIT_BLOCK_MAPPING_FIRST_KEY_STATE:
 		return yaml_emitter_emit_block_mapping_key(emitter, event, true)
 
 	case yaml_EMIT_BLOCK_MAPPING_KEY_STATE:
 		return yaml_emitter_emit_block_mapping_key(emitter, event, false)
 
 	case yaml_EMIT_BLOCK_MAPPING_SIMPLE_VALUE_STATE:
 		return yaml_emitter_emit_block_mapping_value(emitter, event, true)
 
 	case yaml_EMIT_BLOCK_MAPPING_VALUE_STATE:
 		return yaml_emitter_emit_block_mapping_value(emitter, event, false)
 
 	case yaml_EMIT_END_STATE:
 		return yaml_emitter_set_emitter_error(emitter, "expected nothing after STREAM-END")
 	}
 	panic("invalid emitter state")
 }
 
 // Expect STREAM-START.
 func yaml_emitter_emit_stream_start(emitter *yaml_emitter_t, event *yaml_event_t) bool {
 	if event.typ != yaml_STREAM_START_EVENT {
 		return yaml_emitter_set_emitter_error(emitter, "expected STREAM-START")
 	}
 	if emitter.encoding == yaml_ANY_ENCODING {
 		emitter.encoding = event.encoding
 		if emitter.encoding == yaml_ANY_ENCODING {
 			emitter.encoding = yaml_UTF8_ENCODING
 		}
 	}
 	if emitter.best_indent < 2 || emitter.best_indent > 9 {
 		emitter.best_indent = 2
 	}
 	if emitter.best_width >= 0 && emitter.best_width <= emitter.best_indent*2 {
 		emitter.best_width = 80
 	}
 	if emitter.best_width < 0 {
 		emitter.best_width = 1<<31 - 1
 	}
 	if emitter.line_break == yaml_ANY_BREAK {
 		emitter.line_break = yaml_LN_BREAK
 	}
 
 	emitter.indent = -1
 	emitter.line = 0
 	emitter.column = 0
 	emitter.whitespace = true
 	emitter.indention = true
 	emitter.space_above = true
 	emitter.foot_indent = -1
 
 	if emitter.encoding != yaml_UTF8_ENCODING {
 		if !yaml_emitter_write_bom(emitter) {
 			return false
 		}
 	}
 	emitter.state = yaml_EMIT_FIRST_DOCUMENT_START_STATE
 	return true
 }
 
 // Expect DOCUMENT-START or STREAM-END.
 func yaml_emitter_emit_document_start(emitter *yaml_emitter_t, event *yaml_event_t, first bool) bool {
 
 	if event.typ == yaml_DOCUMENT_START_EVENT {
 
 		if event.version_directive != nil {
 			if !yaml_emitter_analyze_version_directive(emitter, event.version_directive) {
 				return false
 			}
 		}
 
 		for i := 0; i < len(event.tag_directives); i++ {
 			tag_directive := &event.tag_directives[i]
 			if !yaml_emitter_analyze_tag_directive(emitter, tag_directive) {
 				return false
 			}
 			if !yaml_emitter_append_tag_directive(emitter, tag_directive, false) {
 				return false
 			}
 		}
 
 		for i := 0; i < len(default_tag_directives); i++ {
 			tag_directive := &default_tag_directives[i]
 			if !yaml_emitter_append_tag_directive(emitter, tag_directive, true) {
 				return false
 			}
 		}
 
 		implicit := event.implicit
 		if !first || emitter.canonical {
 			implicit = false
 		}
 
 		if emitter.open_ended && (event.version_directive != nil || len(event.tag_directives) > 0) {
 			if !yaml_emitter_write_indicator(emitter, []byte("..."), true, false, false) {
 				return false
 			}
 			if !yaml_emitter_write_indent(emitter) {
 				return false
 			}
 		}
 
 		if event.version_directive != nil {
 			implicit = false
 			if !yaml_emitter_write_indicator(emitter, []byte("%YAML"), true, false, false) {
 				return false
 			}
 			if !yaml_emitter_write_indicator(emitter, []byte("1.1"), true, false, false) {
 				return false
 			}
 			if !yaml_emitter_write_indent(emitter) {
 				return false
 			}
 		}
 
 		if len(event.tag_directives) > 0 {
 			implicit = false
 			for i := 0; i < len(event.tag_directives); i++ {
 				tag_directive := &event.tag_directives[i]
 				if !yaml_emitter_write_indicator(emitter, []byte("%TAG"), true, false, false) {
 					return false
 				}
 				if !yaml_emitter_write_tag_handle(emitter, tag_directive.handle) {
 					return false
 				}
 				if !yaml_emitter_write_tag_content(emitter, tag_directive.prefix, true) {
 					return false
 				}
 				if !yaml_emitter_write_indent(emitter) {
 					return false
 				}
 			}
 		}
 
 		if yaml_emitter_check_empty_document(emitter) {
 			implicit = false
 		}
 		if !implicit {
 			if !yaml_emitter_write_indent(emitter) {
 				return false
 			}
 			if !yaml_emitter_write_indicator(emitter, []byte("---"), true, false, false) {
 				return false
 			}
 			if emitter.canonical || true {
 				if !yaml_emitter_write_indent(emitter) {
 					return false
 				}
 			}
 		}
 
 		if len(emitter.head_comment) > 0 {
 			if !yaml_emitter_process_head_comment(emitter) {
 				return false
 			}
 			if !put_break(emitter) {
 				return false
 			}
 		}
 
 		emitter.state = yaml_EMIT_DOCUMENT_CONTENT_STATE
 		return true
 	}
 
 	if event.typ == yaml_STREAM_END_EVENT {
 		if emitter.open_ended {
 			if !yaml_emitter_write_indicator(emitter, []byte("..."), true, false, false) {
 				return false
 			}
 			if !yaml_emitter_write_indent(emitter) {
 				return false
 			}
 		}
 		if !yaml_emitter_flush(emitter) {
 			return false
 		}
 		emitter.state = yaml_EMIT_END_STATE
 		return true
 	}
 
 	return yaml_emitter_set_emitter_error(emitter, "expected DOCUMENT-START or STREAM-END")
 }
 
 // Expect the root node.
 func yaml_emitter_emit_document_content(emitter *yaml_emitter_t, event *yaml_event_t) bool {
 	emitter.states = append(emitter.states, yaml_EMIT_DOCUMENT_END_STATE)
 
 	if !yaml_emitter_process_head_comment(emitter) {
 		return false
 	}
 	if !yaml_emitter_emit_node(emitter, event, true, false, false, false) {
 		return false
 	}
 	if !yaml_emitter_process_line_comment(emitter) {
 		return false
 	}
 	if !yaml_emitter_process_foot_comment(emitter) {
 		return false
 	}
 	return true
 }
 
 // Expect DOCUMENT-END.
 func yaml_emitter_emit_document_end(emitter *yaml_emitter_t, event *yaml_event_t) bool {
 	if event.typ != yaml_DOCUMENT_END_EVENT {
 		return yaml_emitter_set_emitter_error(emitter, "expected DOCUMENT-END")
 	}
 	// [Go] Force document foot separation.
 	emitter.foot_indent = 0
 	if !yaml_emitter_process_foot_comment(emitter) {
 		return false
 	}
 	emitter.foot_indent = -1
 	if !yaml_emitter_write_indent(emitter) {
 		return false
 	}
 	if !event.implicit {
 		// [Go] Allocate the slice elsewhere.
 		if !yaml_emitter_write_indicator(emitter, []byte("..."), true, false, false) {
 			return false
 		}
 		if !yaml_emitter_write_indent(emitter) {
 			return false
 		}
 	}
 	if !yaml_emitter_flush(emitter) {
 		return false
 	}
 	emitter.state = yaml_EMIT_DOCUMENT_START_STATE
 	emitter.tag_directives = emitter.tag_directives[:0]
 	return true
 }
 
 // Expect a flow item node.
 func yaml_emitter_emit_flow_sequence_item(emitter *yaml_emitter_t, event *yaml_event_t, first, trail bool) bool {
 	if first {
 		if !yaml_emitter_write_indicator(emitter, []byte{'['}, true, true, false) {
 			return false
 		}
 		if !yaml_emitter_increase_indent(emitter, true, false) {
 			return false
 		}
 		emitter.flow_level++
 	}
 
 	if event.typ == yaml_SEQUENCE_END_EVENT {
 		if emitter.canonical && !first && !trail {
 			if !yaml_emitter_write_indicator(emitter, []byte{','}, false, false, false) {
 				return false
 			}
 		}
 		emitter.flow_level--
 		emitter.indent = emitter.indents[len(emitter.indents)-1]
 		emitter.indents = emitter.indents[:len(emitter.indents)-1]
 		if emitter.column == 0 || emitter.canonical && !first {
 			if !yaml_emitter_write_indent(emitter) {
 				return false
 			}
 		}
 		if !yaml_emitter_write_indicator(emitter, []byte{']'}, false, false, false) {
 			return false
 		}
 		if !yaml_emitter_process_line_comment(emitter) {
 			return false
 		}
 		if !yaml_emitter_process_foot_comment(emitter) {
 			return false
 		}
 		emitter.state = emitter.states[len(emitter.states)-1]
 		emitter.states = emitter.states[:len(emitter.states)-1]
 
 		return true
 	}
 
 	if !first && !trail {
 		if !yaml_emitter_write_indicator(emitter, []byte{','}, false, false, false) {
 			return false
 		}
 	}
 
 	if !yaml_emitter_process_head_comment(emitter) {
 		return false
 	}
 	if emitter.column == 0 {
 		if !yaml_emitter_write_indent(emitter) {
 			return false
 		}
 	}
 
 	if emitter.canonical || emitter.column > emitter.best_width {
 		if !yaml_emitter_write_indent(emitter) {
 			return false
 		}
 	}
 	if len(emitter.line_comment)+len(emitter.foot_comment)+len(emitter.tail_comment) > 0 {
 		emitter.states = append(emitter.states, yaml_EMIT_FLOW_SEQUENCE_TRAIL_ITEM_STATE)
 	} else {
 		emitter.states = append(emitter.states, yaml_EMIT_FLOW_SEQUENCE_ITEM_STATE)
 	}
 	if !yaml_emitter_emit_node(emitter, event, false, true, false, false) {
 		return false
 	}
 	if len(emitter.line_comment)+len(emitter.foot_comment)+len(emitter.tail_comment) > 0 {
 		if !yaml_emitter_write_indicator(emitter, []byte{','}, false, false, false) {
 			return false
 		}
 	}
 	if !yaml_emitter_process_line_comment(emitter) {
 		return false
 	}
 	if !yaml_emitter_process_foot_comment(emitter) {
 		return false
 	}
 	return true
 }
 
 // Expect a flow key node.
 func yaml_emitter_emit_flow_mapping_key(emitter *yaml_emitter_t, event *yaml_event_t, first, trail bool) bool {
 	if first {
 		if !yaml_emitter_write_indicator(emitter, []byte{'{'}, true, true, false) {
 			return false
 		}
 		if !yaml_emitter_increase_indent(emitter, true, false) {
 			return false
 		}
 		emitter.flow_level++
 	}
 
 	if event.typ == yaml_MAPPING_END_EVENT {
 		if (emitter.canonical || len(emitter.head_comment)+len(emitter.foot_comment)+len(emitter.tail_comment) > 0) && !first && !trail {
 			if !yaml_emitter_write_indicator(emitter, []byte{','}, false, false, false) {
 				return false
 			}
 		}
 		if !yaml_emitter_process_head_comment(emitter) {
 			return false
 		}
 		emitter.flow_level--
 		emitter.indent = emitter.indents[len(emitter.indents)-1]
 		emitter.indents = emitter.indents[:len(emitter.indents)-1]
 		if emitter.canonical && !first {
 			if !yaml_emitter_write_indent(emitter) {
 				return false
 			}
 		}
 		if !yaml_emitter_write_indicator(emitter, []byte{'}'}, false, false, false) {
 			return false
 		}
 		if !yaml_emitter_process_line_comment(emitter) {
 			return false
 		}
 		if !yaml_emitter_process_foot_comment(emitter) {
 			return false
 		}
 		emitter.state = emitter.states[len(emitter.states)-1]
 		emitter.states = emitter.states[:len(emitter.states)-1]
 		return true
 	}
 
 	if !first && !trail {
 		if !yaml_emitter_write_indicator(emitter, []byte{','}, false, false, false) {
 			return false
 		}
 	}
 
 	if !yaml_emitter_process_head_comment(emitter) {
 		return false
 	}
 
 	if emitter.column == 0 {
 		if !yaml_emitter_write_indent(emitter) {
 			return false
 		}
 	}
 
 	if emitter.canonical || emitter.column > emitter.best_width {
 		if !yaml_emitter_write_indent(emitter) {
 			return false
 		}
 	}
 
 	if !emitter.canonical && yaml_emitter_check_simple_key(emitter) {
 		emitter.states = append(emitter.states, yaml_EMIT_FLOW_MAPPING_SIMPLE_VALUE_STATE)
 		return yaml_emitter_emit_node(emitter, event, false, false, true, true)
 	}
 	if !yaml_emitter_write_indicator(emitter, []byte{'?'}, true, false, false) {
 		return false
 	}
 	emitter.states = append(emitter.states, yaml_EMIT_FLOW_MAPPING_VALUE_STATE)
 	return yaml_emitter_emit_node(emitter, event, false, false, true, false)
 }
 
 // Expect a flow value node.
 func yaml_emitter_emit_flow_mapping_value(emitter *yaml_emitter_t, event *yaml_event_t, simple bool) bool {
 	if simple {
 		if !yaml_emitter_write_indicator(emitter, []byte{':'}, false, false, false) {
 			return false
 		}
 	} else {
 		if emitter.canonical || emitter.column > emitter.best_width {
 			if !yaml_emitter_write_indent(emitter) {
 				return false
 			}
 		}
 		if !yaml_emitter_write_indicator(emitter, []byte{':'}, true, false, false) {
 			return false
 		}
 	}
 	if len(emitter.line_comment)+len(emitter.foot_comment)+len(emitter.tail_comment) > 0 {
 		emitter.states = append(emitter.states, yaml_EMIT_FLOW_MAPPING_TRAIL_KEY_STATE)
 	} else {
 		emitter.states = append(emitter.states, yaml_EMIT_FLOW_MAPPING_KEY_STATE)
 	}
 	if !yaml_emitter_emit_node(emitter, event, false, false, true, false) {
 		return false
 	}
 	if len(emitter.line_comment)+len(emitter.foot_comment)+len(emitter.tail_comment) > 0 {
 		if !yaml_emitter_write_indicator(emitter, []byte{','}, false, false, false) {
 			return false
 		}
 	}
 	if !yaml_emitter_process_line_comment(emitter) {
 		return false
 	}
 	if !yaml_emitter_process_foot_comment(emitter) {
 		return false
 	}
 	return true
 }
 
 // Expect a block item node.
 func yaml_emitter_emit_block_sequence_item(emitter *yaml_emitter_t, event *yaml_event_t, first bool) bool {
 	if first {
 		if !yaml_emitter_increase_indent(emitter, false, false) {
 			return false
 		}
 	}
 	if event.typ == yaml_SEQUENCE_END_EVENT {
 		emitter.indent = emitter.indents[len(emitter.indents)-1]
 		emitter.indents = emitter.indents[:len(emitter.indents)-1]
 		emitter.state = emitter.states[len(emitter.states)-1]
 		emitter.states = emitter.states[:len(emitter.states)-1]
 		return true
 	}
 	if !yaml_emitter_process_head_comment(emitter) {
 		return false
 	}
 	if !yaml_emitter_write_indent(emitter) {
 		return false
 	}
 	if !yaml_emitter_write_indicator(emitter, []byte{'-'}, true, false, true) {
 		return false
 	}
 	emitter.states = append(emitter.states, yaml_EMIT_BLOCK_SEQUENCE_ITEM_STATE)
 	if !yaml_emitter_emit_node(emitter, event, false, true, false, false) {
 		return false
 	}
 	if !yaml_emitter_process_line_comment(emitter) {
 		return false
 	}
 	if !yaml_emitter_process_foot_comment(emitter) {
 		return false
 	}
 	return true
 }
 
 // Expect a block key node.
 func yaml_emitter_emit_block_mapping_key(emitter *yaml_emitter_t, event *yaml_event_t, first bool) bool {
 	if first {
 		if !yaml_emitter_increase_indent(emitter, false, false) {
 			return false
 		}
 	}
 	if !yaml_emitter_process_head_comment(emitter) {
 		return false
 	}
 	if event.typ == yaml_MAPPING_END_EVENT {
 		emitter.indent = emitter.indents[len(emitter.indents)-1]
 		emitter.indents = emitter.indents[:len(emitter.indents)-1]
 		emitter.state = emitter.states[len(emitter.states)-1]
 		emitter.states = emitter.states[:len(emitter.states)-1]
 		return true
 	}
 	if !yaml_emitter_write_indent(emitter) {
 		return false
 	}
 	if len(emitter.line_comment) > 0 {
 		// [Go] A line comment was provided for the key. That's unusual as the
 		//      scanner associates line comments with the value. Either way,
 		//      save the line comment and render it appropriately later.
 		emitter.key_line_comment = emitter.line_comment
 		emitter.line_comment = nil
 	}
 	if yaml_emitter_check_simple_key(emitter) {
 		emitter.states = append(emitter.states, yaml_EMIT_BLOCK_MAPPING_SIMPLE_VALUE_STATE)
 		return yaml_emitter_emit_node(emitter, event, false, false, true, true)
 	}
 	if !yaml_emitter_write_indicator(emitter, []byte{'?'}, true, false, true) {
 		return false
 	}
 	emitter.states = append(emitter.states, yaml_EMIT_BLOCK_MAPPING_VALUE_STATE)
 	return yaml_emitter_emit_node(emitter, event, false, false, true, false)
 }
 
 // Expect a block value node.
 func yaml_emitter_emit_block_mapping_value(emitter *yaml_emitter_t, event *yaml_event_t, simple bool) bool {
 	if simple {
 		if !yaml_emitter_write_indicator(emitter, []byte{':'}, false, false, false) {
 			return false
 		}
 	} else {
 		if !yaml_emitter_write_indent(emitter) {
 			return false
 		}
 		if !yaml_emitter_write_indicator(emitter, []byte{':'}, true, false, true) {
 			return false
 		}
 	}
 	if len(emitter.key_line_comment) > 0 {
 		// [Go] Line comments are generally associated with the value, but when there's
 		//      no value on the same line as a mapping key they end up attached to the
 		//      key itself.
 		if event.typ == yaml_SCALAR_EVENT {
 			if len(emitter.line_comment) == 0 {
 				// A scalar is coming and it has no line comments by itself yet,
 				// so just let it handle the line comment as usual. If it has a
 				// line comment, we can't have both so the one from the key is lost.
 				emitter.line_comment = emitter.key_line_comment
 				emitter.key_line_comment = nil
 			}
 		} else if event.sequence_style() != yaml_FLOW_SEQUENCE_STYLE && (event.typ == yaml_MAPPING_START_EVENT || event.typ == yaml_SEQUENCE_START_EVENT) {
 			// An indented block follows, so write the comment right now.
 			emitter.line_comment, emitter.key_line_comment = emitter.key_line_comment, emitter.line_comment
 			if !yaml_emitter_process_line_comment(emitter) {
 				return false
 			}
 			emitter.line_comment, emitter.key_line_comment = emitter.key_line_comment, emitter.line_comment
 		}
 	}
 	emitter.states = append(emitter.states, yaml_EMIT_BLOCK_MAPPING_KEY_STATE)
 	if !yaml_emitter_emit_node(emitter, event, false, false, true, false) {
 		return false
 	}
 	if !yaml_emitter_process_line_comment(emitter) {
 		return false
 	}
 	if !yaml_emitter_process_foot_comment(emitter) {
 		return false
 	}
 	return true
 }
 
 func yaml_emitter_silent_nil_event(emitter *yaml_emitter_t, event *yaml_event_t) bool {
 	return event.typ == yaml_SCALAR_EVENT && event.implicit && !emitter.canonical && len(emitter.scalar_data.value) == 0
 }
 
 // Expect a node.
 func yaml_emitter_emit_node(emitter *yaml_emitter_t, event *yaml_event_t,
 	root bool, sequence bool, mapping bool, simple_key bool) bool {
 
 	emitter.root_context = root
 	emitter.sequence_context = sequence
 	emitter.mapping_context = mapping
 	emitter.simple_key_context = simple_key
 
 	switch event.typ {
 	case yaml_ALIAS_EVENT:
 		return yaml_emitter_emit_alias(emitter, event)
 	case yaml_SCALAR_EVENT:
 		return yaml_emitter_emit_scalar(emitter, event)
 	case yaml_SEQUENCE_START_EVENT:
 		return yaml_emitter_emit_sequence_start(emitter, event)
 	case yaml_MAPPING_START_EVENT:
 		return yaml_emitter_emit_mapping_start(emitter, event)
 	default:
 		return yaml_emitter_set_emitter_error(emitter,
 			fmt.Sprintf("expected SCALAR, SEQUENCE-START, MAPPING-START, or ALIAS, but got %v", event.typ))
 	}
 }
 
 // Expect ALIAS.
 func yaml_emitter_emit_alias(emitter *yaml_emitter_t, event *yaml_event_t) bool {
 	if !yaml_emitter_process_anchor(emitter) {
 		return false
 	}
 	emitter.state = emitter.states[len(emitter.states)-1]
 	emitter.states = emitter.states[:len(emitter.states)-1]
 	return true
 }
 
 // Expect SCALAR.
 func yaml_emitter_emit_scalar(emitter *yaml_emitter_t, event *yaml_event_t) bool {
 	if !yaml_emitter_select_scalar_style(emitter, event) {
 		return false
 	}
 	if !yaml_emitter_process_anchor(emitter) {
 		return false
 	}
 	if !yaml_emitter_process_tag(emitter) {
 		return false
 	}
 	if !yaml_emitter_increase_indent(emitter, true, false) {
 		return false
 	}
 	if !yaml_emitter_process_scalar(emitter) {
 		return false
 	}
 	emitter.indent = emitter.indents[len(emitter.indents)-1]
 	emitter.indents = emitter.indents[:len(emitter.indents)-1]
 	emitter.state = emitter.states[len(emitter.states)-1]
 	emitter.states = emitter.states[:len(emitter.states)-1]
 	return true
 }
 
 // Expect SEQUENCE-START.
 func yaml_emitter_emit_sequence_start(emitter *yaml_emitter_t, event *yaml_event_t) bool {
 	if !yaml_emitter_process_anchor(emitter) {
 		return false
 	}
 	if !yaml_emitter_process_tag(emitter) {
 		return false
 	}
 	if emitter.flow_level > 0 || emitter.canonical || event.sequence_style() == yaml_FLOW_SEQUENCE_STYLE ||
 		yaml_emitter_check_empty_sequence(emitter) {
 		emitter.state = yaml_EMIT_FLOW_SEQUENCE_FIRST_ITEM_STATE
 	} else {
 		emitter.state = yaml_EMIT_BLOCK_SEQUENCE_FIRST_ITEM_STATE
 	}
 	return true
 }
 
 // Expect MAPPING-START.
 func yaml_emitter_emit_mapping_start(emitter *yaml_emitter_t, event *yaml_event_t) bool {
 	if !yaml_emitter_process_anchor(emitter) {
 		return false
 	}
 	if !yaml_emitter_process_tag(emitter) {
 		return false
 	}
 	if emitter.flow_level > 0 || emitter.canonical || event.mapping_style() == yaml_FLOW_MAPPING_STYLE ||
 		yaml_emitter_check_empty_mapping(emitter) {
 		emitter.state = yaml_EMIT_FLOW_MAPPING_FIRST_KEY_STATE
 	} else {
 		emitter.state = yaml_EMIT_BLOCK_MAPPING_FIRST_KEY_STATE
 	}
 	return true
 }
 
 // Check if the document content is an empty scalar.
 func yaml_emitter_check_empty_document(emitter *yaml_emitter_t) bool {
 	return false // [Go] Huh?
 }
 
 // Check if the next events represent an empty sequence.
 func yaml_emitter_check_empty_sequence(emitter *yaml_emitter_t) bool {
 	if len(emitter.events)-emitter.events_head < 2 {
 		return false
 	}
 	return emitter.events[emitter.events_head].typ == yaml_SEQUENCE_START_EVENT &&
 		emitter.events[emitter.events_head+1].typ == yaml_SEQUENCE_END_EVENT
 }
 
 // Check if the next events represent an empty mapping.
 func yaml_emitter_check_empty_mapping(emitter *yaml_emitter_t) bool {
 	if len(emitter.events)-emitter.events_head < 2 {
 		return false
 	}
 	return emitter.events[emitter.events_head].typ == yaml_MAPPING_START_EVENT &&
 		emitter.events[emitter.events_head+1].typ == yaml_MAPPING_END_EVENT
 }
 
 // Check if the next node can be expressed as a simple key.
 func yaml_emitter_check_simple_key(emitter *yaml_emitter_t) bool {
 	length := 0
 	switch emitter.events[emitter.events_head].typ {
 	case yaml_ALIAS_EVENT:
 		length += len(emitter.anchor_data.anchor)
 	case yaml_SCALAR_EVENT:
 		if emitter.scalar_data.multiline {
 			return false
 		}
 		length += len(emitter.anchor_data.anchor) +
 			len(emitter.tag_data.handle) +
 			len(emitter.tag_data.suffix) +
 			len(emitter.scalar_data.value)
 	case yaml_SEQUENCE_START_EVENT:
 		if !yaml_emitter_check_empty_sequence(emitter) {
 			return false
 		}
 		length += len(emitter.anchor_data.anchor) +
 			len(emitter.tag_data.handle) +
 			len(emitter.tag_data.suffix)
 	case yaml_MAPPING_START_EVENT:
 		if !yaml_emitter_check_empty_mapping(emitter) {
 			return false
 		}
 		length += len(emitter.anchor_data.anchor) +
 			len(emitter.tag_data.handle) +
 			len(emitter.tag_data.suffix)
 	default:
 		return false
 	}
 	return length <= 128
 }
 
 // Determine an acceptable scalar style.
 func yaml_emitter_select_scalar_style(emitter *yaml_emitter_t, event *yaml_event_t) bool {
 
 	no_tag := len(emitter.tag_data.handle) == 0 && len(emitter.tag_data.suffix) == 0
 	if no_tag && !event.implicit && !event.quoted_implicit {
 		return yaml_emitter_set_emitter_error(emitter, "neither tag nor implicit flags are specified")
 	}
 
 	style := event.scalar_style()
 	if style == yaml_ANY_SCALAR_STYLE {
 		style = yaml_PLAIN_SCALAR_STYLE
 	}
 	if emitter.canonical {
 		style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
 	}
 	if emitter.simple_key_context && emitter.scalar_data.multiline {
 		style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
 	}
 
 	if style == yaml_PLAIN_SCALAR_STYLE {
 		if emitter.flow_level > 0 && !emitter.scalar_data.flow_plain_allowed ||
 			emitter.flow_level == 0 && !emitter.scalar_data.block_plain_allowed {
 			style = yaml_SINGLE_QUOTED_SCALAR_STYLE
 		}
 		if len(emitter.scalar_data.value) == 0 && (emitter.flow_level > 0 || emitter.simple_key_context) {
 			style = yaml_SINGLE_QUOTED_SCALAR_STYLE
 		}
 		if no_tag && !event.implicit {
 			style = yaml_SINGLE_QUOTED_SCALAR_STYLE
 		}
 	}
 	if style == yaml_SINGLE_QUOTED_SCALAR_STYLE {
 		if !emitter.scalar_data.single_quoted_allowed {
 			style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
 		}
 	}
 	if style == yaml_LITERAL_SCALAR_STYLE || style == yaml_FOLDED_SCALAR_STYLE {
 		if !emitter.scalar_data.block_allowed || emitter.flow_level > 0 || emitter.simple_key_context {
 			style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
 		}
 	}
 
 	if no_tag && !event.quoted_implicit && style != yaml_PLAIN_SCALAR_STYLE {
 		emitter.tag_data.handle = []byte{'!'}
 	}
 	emitter.scalar_data.style = style
 	return true
 }
 
 // Write an anchor.
 func yaml_emitter_process_anchor(emitter *yaml_emitter_t) bool {
 	if emitter.anchor_data.anchor == nil {
 		return true
 	}
 	c := []byte{'&'}
 	if emitter.anchor_data.alias {
 		c[0] = '*'
 	}
 	if !yaml_emitter_write_indicator(emitter, c, true, false, false) {
 		return false
 	}
 	return yaml_emitter_write_anchor(emitter, emitter.anchor_data.anchor)
 }
 
 // Write a tag.
 func yaml_emitter_process_tag(emitter *yaml_emitter_t) bool {
 	if len(emitter.tag_data.handle) == 0 && len(emitter.tag_data.suffix) == 0 {
 		return true
 	}
 	if len(emitter.tag_data.handle) > 0 {
 		if !yaml_emitter_write_tag_handle(emitter, emitter.tag_data.handle) {
 			return false
 		}
 		if len(emitter.tag_data.suffix) > 0 {
 			if !yaml_emitter_write_tag_content(emitter, emitter.tag_data.suffix, false) {
 				return false
 			}
 		}
 	} else {
 		// [Go] Allocate these slices elsewhere.
 		if !yaml_emitter_write_indicator(emitter, []byte("!<"), true, false, false) {
 			return false
 		}
 		if !yaml_emitter_write_tag_content(emitter, emitter.tag_data.suffix, false) {
 			return false
 		}
 		if !yaml_emitter_write_indicator(emitter, []byte{'>'}, false, false, false) {
 			return false
 		}
 	}
 	return true
 }
 
 // Write a scalar.
 func yaml_emitter_process_scalar(emitter *yaml_emitter_t) bool {
 	switch emitter.scalar_data.style {
 	case yaml_PLAIN_SCALAR_STYLE:
 		return yaml_emitter_write_plain_scalar(emitter, emitter.scalar_data.value, !emitter.simple_key_context)
 
 	case yaml_SINGLE_QUOTED_SCALAR_STYLE:
 		return yaml_emitter_write_single_quoted_scalar(emitter, emitter.scalar_data.value, !emitter.simple_key_context)
 
 	case yaml_DOUBLE_QUOTED_SCALAR_STYLE:
 		return yaml_emitter_write_double_quoted_scalar(emitter, emitter.scalar_data.value, !emitter.simple_key_context)
 
 	case yaml_LITERAL_SCALAR_STYLE:
 		return yaml_emitter_write_literal_scalar(emitter, emitter.scalar_data.value)
 
 	case yaml_FOLDED_SCALAR_STYLE:
 		return yaml_emitter_write_folded_scalar(emitter, emitter.scalar_data.value)
 	}
 	panic("unknown scalar style")
 }
 
 // Write a head comment.
 func yaml_emitter_process_head_comment(emitter *yaml_emitter_t) bool {
 	if len(emitter.tail_comment) > 0 {
 		if !yaml_emitter_write_indent(emitter) {
 			return false
 		}
 		if !yaml_emitter_write_comment(emitter, emitter.tail_comment) {
 			return false
 		}
 		emitter.tail_comment = emitter.tail_comment[:0]
 		emitter.foot_indent = emitter.indent
 		if emitter.foot_indent < 0 {
 			emitter.foot_indent = 0
 		}
 	}
 
 	if len(emitter.head_comment) == 0 {
 		return true
 	}
 	if !yaml_emitter_write_indent(emitter) {
 		return false
 	}
 	if !yaml_emitter_write_comment(emitter, emitter.head_comment) {
 		return false
 	}
 	emitter.head_comment = emitter.head_comment[:0]
 	return true
 }
 
 // Write an line comment.
 func yaml_emitter_process_line_comment(emitter *yaml_emitter_t) bool {
 	if len(emitter.line_comment) == 0 {
 		return true
 	}
 	if !emitter.whitespace {
 		if !put(emitter, ' ') {
 			return false
 		}
 	}
 	if !yaml_emitter_write_comment(emitter, emitter.line_comment) {
 		return false
 	}
 	emitter.line_comment = emitter.line_comment[:0]
 	return true
 }
 
 // Write a foot comment.
 func yaml_emitter_process_foot_comment(emitter *yaml_emitter_t) bool {
 	if len(emitter.foot_comment) == 0 {
 		return true
 	}
 	if !yaml_emitter_write_indent(emitter) {
 		return false
 	}
 	if !yaml_emitter_write_comment(emitter, emitter.foot_comment) {
 		return false
 	}
 	emitter.foot_comment = emitter.foot_comment[:0]
 	emitter.foot_indent = emitter.indent
 	if emitter.foot_indent < 0 {
 		emitter.foot_indent = 0
 	}
 	return true
 }
 
 // Check if a %YAML directive is valid.
 func yaml_emitter_analyze_version_directive(emitter *yaml_emitter_t, version_directive *yaml_version_directive_t) bool {
 	if version_directive.major != 1 || version_directive.minor != 1 {
 		return yaml_emitter_set_emitter_error(emitter, "incompatible %YAML directive")
 	}
 	return true
 }
 
 // Check if a %TAG directive is valid.
 func yaml_emitter_analyze_tag_directive(emitter *yaml_emitter_t, tag_directive *yaml_tag_directive_t) bool {
 	handle := tag_directive.handle
 	prefix := tag_directive.prefix
 	if len(handle) == 0 {
 		return yaml_emitter_set_emitter_error(emitter, "tag handle must not be empty")
 	}
 	if handle[0] != '!' {
 		return yaml_emitter_set_emitter_error(emitter, "tag handle must start with '!'")
 	}
 	if handle[len(handle)-1] != '!' {
 		return yaml_emitter_set_emitter_error(emitter, "tag handle must end with '!'")
 	}
 	for i := 1; i < len(handle)-1; i += width(handle[i]) {
 		if !is_alpha(handle, i) {
 			return yaml_emitter_set_emitter_error(emitter, "tag handle must contain alphanumerical characters only")
 		}
 	}
 	if len(prefix) == 0 {
 		return yaml_emitter_set_emitter_error(emitter, "tag prefix must not be empty")
 	}
 	return true
 }
 
 // Check if an anchor is valid.
 func yaml_emitter_analyze_anchor(emitter *yaml_emitter_t, anchor []byte, alias bool) bool {
 	if len(anchor) == 0 {
 		problem := "anchor value must not be empty"
 		if alias {
 			problem = "alias value must not be empty"
 		}
 		return yaml_emitter_set_emitter_error(emitter, problem)
 	}
 	for i := 0; i < len(anchor); i += width(anchor[i]) {
 		if !is_alpha(anchor, i) {
 			problem := "anchor value must contain alphanumerical characters only"
 			if alias {
 				problem = "alias value must contain alphanumerical characters only"
 			}
 			return yaml_emitter_set_emitter_error(emitter, problem)
 		}
 	}
 	emitter.anchor_data.anchor = anchor
 	emitter.anchor_data.alias = alias
 	return true
 }
 
 // Check if a tag is valid.
 func yaml_emitter_analyze_tag(emitter *yaml_emitter_t, tag []byte) bool {
 	if len(tag) == 0 {
 		return yaml_emitter_set_emitter_error(emitter, "tag value must not be empty")
 	}
 	for i := 0; i < len(emitter.tag_directives); i++ {
 		tag_directive := &emitter.tag_directives[i]
 		if bytes.HasPrefix(tag, tag_directive.prefix) {
 			emitter.tag_data.handle = tag_directive.handle
 			emitter.tag_data.suffix = tag[len(tag_directive.prefix):]
 			return true
 		}
 	}
 	emitter.tag_data.suffix = tag
 	return true
 }
 
 // Check if a scalar is valid.
 func yaml_emitter_analyze_scalar(emitter *yaml_emitter_t, value []byte) bool {
 	var (
 		block_indicators   = false
 		flow_indicators    = false
 		line_breaks        = false
 		special_characters = false
 		tab_characters     = false
 
 		leading_space  = false
 		leading_break  = false
 		trailing_space = false
 		trailing_break = false
 		break_space    = false
 		space_break    = false
 
 		preceded_by_whitespace = false
 		followed_by_whitespace = false
 		previous_space         = false
 		previous_break         = false
 	)
 
 	emitter.scalar_data.value = value
 
 	if len(value) == 0 {
 		emitter.scalar_data.multiline = false
 		emitter.scalar_data.flow_plain_allowed = false
 		emitter.scalar_data.block_plain_allowed = true
 		emitter.scalar_data.single_quoted_allowed = true
 		emitter.scalar_data.block_allowed = false
 		return true
 	}
 
 	if len(value) >= 3 && ((value[0] == '-' && value[1] == '-' && value[2] == '-') || (value[0] == '.' && value[1] == '.' && value[2] == '.')) {
 		block_indicators = true
 		flow_indicators = true
 	}
 
 	preceded_by_whitespace = true
 	for i, w := 0, 0; i < len(value); i += w {
 		w = width(value[i])
 		followed_by_whitespace = i+w >= len(value) || is_blank(value, i+w)
 
 		if i == 0 {
 			switch value[i] {
 			case '#', ',', '[', ']', '{', '}', '&', '*', '!', '|', '>', '\'', '"', '%', '@', '`':
 				flow_indicators = true
 				block_indicators = true
 			case '?', ':':
 				flow_indicators = true
 				if followed_by_whitespace {
 					block_indicators = true
 				}
 			case '-':
 				if followed_by_whitespace {
 					flow_indicators = true
 					block_indicators = true
 				}
 			}
 		} else {
 			switch value[i] {
 			case ',', '?', '[', ']', '{', '}':
 				flow_indicators = true
 			case ':':
 				flow_indicators = true
 				if followed_by_whitespace {
 					block_indicators = true
 				}
 			case '#':
 				if preceded_by_whitespace {
 					flow_indicators = true
 					block_indicators = true
 				}
 			}
 		}
 
 		if value[i] == '\t' {
 			tab_characters = true
 		} else if !is_printable(value, i) || !is_ascii(value, i) && !emitter.unicode {
 			special_characters = true
 		}
 		if is_space(value, i) {
 			if i == 0 {
 				leading_space = true
 			}
 			if i+width(value[i]) == len(value) {
 				trailing_space = true
 			}
 			if previous_break {
 				break_space = true
 			}
 			previous_space = true
 			previous_break = false
 		} else if is_break(value, i) {
 			line_breaks = true
 			if i == 0 {
 				leading_break = true
 			}
 			if i+width(value[i]) == len(value) {
 				trailing_break = true
 			}
 			if previous_space {
 				space_break = true
 			}
 			previous_space = false
 			previous_break = true
 		} else {
 			previous_space = false
 			previous_break = false
 		}
 
 		// [Go]: Why 'z'? Couldn't be the end of the string as that's the loop condition.
 		preceded_by_whitespace = is_blankz(value, i)
 	}
 
 	emitter.scalar_data.multiline = line_breaks
 	emitter.scalar_data.flow_plain_allowed = true
 	emitter.scalar_data.block_plain_allowed = true
 	emitter.scalar_data.single_quoted_allowed = true
 	emitter.scalar_data.block_allowed = true
 
 	if leading_space || leading_break || trailing_space || trailing_break {
 		emitter.scalar_data.flow_plain_allowed = false
 		emitter.scalar_data.block_plain_allowed = false
 	}
 	if trailing_space {
 		emitter.scalar_data.block_allowed = false
 	}
 	if break_space {
 		emitter.scalar_data.flow_plain_allowed = false
 		emitter.scalar_data.block_plain_allowed = false
 		emitter.scalar_data.single_quoted_allowed = false
 	}
 	if space_break || tab_characters || special_characters {
 		emitter.scalar_data.flow_plain_allowed = false
 		emitter.scalar_data.block_plain_allowed = false
 		emitter.scalar_data.single_quoted_allowed = false
 	}
 	if space_break || special_characters {
 		emitter.scalar_data.block_allowed = false
 	}
 	if line_breaks {
 		emitter.scalar_data.flow_plain_allowed = false
 		emitter.scalar_data.block_plain_allowed = false
 	}
 	if flow_indicators {
 		emitter.scalar_data.flow_plain_allowed = false
 	}
 	if block_indicators {
 		emitter.scalar_data.block_plain_allowed = false
 	}
 	return true
 }
 
 // Check if the event data is valid.
 func yaml_emitter_analyze_event(emitter *yaml_emitter_t, event *yaml_event_t) bool {
 
 	emitter.anchor_data.anchor = nil
 	emitter.tag_data.handle = nil
 	emitter.tag_data.suffix = nil
 	emitter.scalar_data.value = nil
 
 	if len(event.head_comment) > 0 {
 		emitter.head_comment = event.head_comment
 	}
 	if len(event.line_comment) > 0 {
 		emitter.line_comment = event.line_comment
 	}
 	if len(event.foot_comment) > 0 {
 		emitter.foot_comment = event.foot_comment
 	}
 	if len(event.tail_comment) > 0 {
 		emitter.tail_comment = event.tail_comment
 	}
 
 	switch event.typ {
 	case yaml_ALIAS_EVENT:
 		if !yaml_emitter_analyze_anchor(emitter, event.anchor, true) {
 			return false
 		}
 
 	case yaml_SCALAR_EVENT:
 		if len(event.anchor) > 0 {
 			if !yaml_emitter_analyze_anchor(emitter, event.anchor, false) {
 				return false
 			}
 		}
 		if len(event.tag) > 0 && (emitter.canonical || (!event.implicit && !event.quoted_implicit)) {
 			if !yaml_emitter_analyze_tag(emitter, event.tag) {
 				return false
 			}
 		}
 		if !yaml_emitter_analyze_scalar(emitter, event.value) {
 			return false
 		}
 
 	case yaml_SEQUENCE_START_EVENT:
 		if len(event.anchor) > 0 {
 			if !yaml_emitter_analyze_anchor(emitter, event.anchor, false) {
 				return false
 			}
 		}
 		if len(event.tag) > 0 && (emitter.canonical || !event.implicit) {
 			if !yaml_emitter_analyze_tag(emitter, event.tag) {
 				return false
 			}
 		}
 
 	case yaml_MAPPING_START_EVENT:
 		if len(event.anchor) > 0 {
 			if !yaml_emitter_analyze_anchor(emitter, event.anchor, false) {
 				return false
 			}
 		}
 		if len(event.tag) > 0 && (emitter.canonical || !event.implicit) {
 			if !yaml_emitter_analyze_tag(emitter, event.tag) {
 				return false
 			}
 		}
 	}
 	return true
 }
 
 // Write the BOM character.
 func yaml_emitter_write_bom(emitter *yaml_emitter_t) bool {
 	if !flush(emitter) {
 		return false
 	}
 	pos := emitter.buffer_pos
 	emitter.buffer[pos+0] = '\xEF'
 	emitter.buffer[pos+1] = '\xBB'
 	emitter.buffer[pos+2] = '\xBF'
 	emitter.buffer_pos += 3
 	return true
 }
 
 func yaml_emitter_write_indent(emitter *yaml_emitter_t) bool {
 	indent := emitter.indent
 	if indent < 0 {
 		indent = 0
 	}
 	if !emitter.indention || emitter.column > indent || (emitter.column == indent && !emitter.whitespace) {
 		if !put_break(emitter) {
 			return false
 		}
 	}
 	if emitter.foot_indent == indent {
 		if !put_break(emitter) {
 			return false
 		}
 	}
 	for emitter.column < indent {
 		if !put(emitter, ' ') {
 			return false
 		}
 	}
 	emitter.whitespace = true
 	//emitter.indention = true
 	emitter.space_above = false
 	emitter.foot_indent = -1
 	return true
 }
 
 func yaml_emitter_write_indicator(emitter *yaml_emitter_t, indicator []byte, need_whitespace, is_whitespace, is_indention bool) bool {
 	if need_whitespace && !emitter.whitespace {
 		if !put(emitter, ' ') {
 			return false
 		}
 	}
 	if !write_all(emitter, indicator) {
 		return false
 	}
 	emitter.whitespace = is_whitespace
 	emitter.indention = (emitter.indention && is_indention)
 	emitter.open_ended = false
 	return true
 }
 
 func yaml_emitter_write_anchor(emitter *yaml_emitter_t, value []byte) bool {
 	if !write_all(emitter, value) {
 		return false
 	}
 	emitter.whitespace = false
 	emitter.indention = false
 	return true
 }
 
 func yaml_emitter_write_tag_handle(emitter *yaml_emitter_t, value []byte) bool {
 	if !emitter.whitespace {
 		if !put(emitter, ' ') {
 			return false
 		}
 	}
 	if !write_all(emitter, value) {
 		return false
 	}
 	emitter.whitespace = false
 	emitter.indention = false
 	return true
 }
 
 func yaml_emitter_write_tag_content(emitter *yaml_emitter_t, value []byte, need_whitespace bool) bool {
 	if need_whitespace && !emitter.whitespace {
 		if !put(emitter, ' ') {
 			return false
 		}
 	}
 	for i := 0; i < len(value); {
 		var must_write bool
 		switch value[i] {
 		case ';', '/', '?', ':', '@', '&', '=', '+', '$', ',', '_', '.', '~', '*', '\'', '(', ')', '[', ']':
 			must_write = true
 		default:
 			must_write = is_alpha(value, i)
 		}
 		if must_write {
 			if !write(emitter, value, &i) {
 				return false
 			}
 		} else {
 			w := width(value[i])
 			for k := 0; k < w; k++ {
 				octet := value[i]
 				i++
 				if !put(emitter, '%') {
 					return false
 				}
 
 				c := octet >> 4
 				if c < 10 {
 					c += '0'
 				} else {
 					c += 'A' - 10
 				}
 				if !put(emitter, c) {
 					return false
 				}
 
 				c = octet & 0x0f
 				if c < 10 {
 					c += '0'
 				} else {
 					c += 'A' - 10
 				}
 				if !put(emitter, c) {
 					return false
 				}
 			}
 		}
 	}
 	emitter.whitespace = false
 	emitter.indention = false
 	return true
 }
 
 func yaml_emitter_write_plain_scalar(emitter *yaml_emitter_t, value []byte, allow_breaks bool) bool {
 	if len(value) > 0 && !emitter.whitespace {
 		if !put(emitter, ' ') {
 			return false
 		}
 	}
 
 	spaces := false
 	breaks := false
 	for i := 0; i < len(value); {
 		if is_space(value, i) {
 			if allow_breaks && !spaces && emitter.column > emitter.best_width && !is_space(value, i+1) {
 				if !yaml_emitter_write_indent(emitter) {
 					return false
 				}
 				i += width(value[i])
 			} else {
 				if !write(emitter, value, &i) {
 					return false
 				}
 			}
 			spaces = true
 		} else if is_break(value, i) {
 			if !breaks && value[i] == '\n' {
 				if !put_break(emitter) {
 					return false
 				}
 			}
 			if !write_break(emitter, value, &i) {
 				return false
 			}
 			//emitter.indention = true
 			breaks = true
 		} else {
 			if breaks {
 				if !yaml_emitter_write_indent(emitter) {
 					return false
 				}
 			}
 			if !write(emitter, value, &i) {
 				return false
 			}
 			emitter.indention = false
 			spaces = false
 			breaks = false
 		}
 	}
 
 	if len(value) > 0 {
 		emitter.whitespace = false
 	}
 	emitter.indention = false
 	if emitter.root_context {
 		emitter.open_ended = true
 	}
 
 	return true
 }
 
 func yaml_emitter_write_single_quoted_scalar(emitter *yaml_emitter_t, value []byte, allow_breaks bool) bool {
 
 	if !yaml_emitter_write_indicator(emitter, []byte{'\''}, true, false, false) {
 		return false
 	}
 
 	spaces := false
 	breaks := false
 	for i := 0; i < len(value); {
 		if is_space(value, i) {
 			if allow_breaks && !spaces && emitter.column > emitter.best_width && i > 0 && i < len(value)-1 && !is_space(value, i+1) {
 				if !yaml_emitter_write_indent(emitter) {
 					return false
 				}
 				i += width(value[i])
 			} else {
 				if !write(emitter, value, &i) {
 					return false
 				}
 			}
 			spaces = true
 		} else if is_break(value, i) {
 			if !breaks && value[i] == '\n' {
 				if !put_break(emitter) {
 					return false
 				}
 			}
 			if !write_break(emitter, value, &i) {
 				return false
 			}
 			//emitter.indention = true
 			breaks = true
 		} else {
 			if breaks {
 				if !yaml_emitter_write_indent(emitter) {
 					return false
 				}
 			}
 			if value[i] == '\'' {
 				if !put(emitter, '\'') {
 					return false
 				}
 			}
 			if !write(emitter, value, &i) {
 				return false
 			}
 			emitter.indention = false
 			spaces = false
 			breaks = false
 		}
 	}
 	if !yaml_emitter_write_indicator(emitter, []byte{'\''}, false, false, false) {
 		return false
 	}
 	emitter.whitespace = false
 	emitter.indention = false
 	return true
 }
 
 func yaml_emitter_write_double_quoted_scalar(emitter *yaml_emitter_t, value []byte, allow_breaks bool) bool {
 	spaces := false
 	if !yaml_emitter_write_indicator(emitter, []byte{'"'}, true, false, false) {
 		return false
 	}
 
 	for i := 0; i < len(value); {
 		if !is_printable(value, i) || (!emitter.unicode && !is_ascii(value, i)) ||
 			is_bom(value, i) || is_break(value, i) ||
 			value[i] == '"' || value[i] == '\\' {
 
 			octet := value[i]
 
 			var w int
 			var v rune
 			switch {
 			case octet&0x80 == 0x00:
 				w, v = 1, rune(octet&0x7F)
 			case octet&0xE0 == 0xC0:
 				w, v = 2, rune(octet&0x1F)
 			case octet&0xF0 == 0xE0:
 				w, v = 3, rune(octet&0x0F)
 			case octet&0xF8 == 0xF0:
 				w, v = 4, rune(octet&0x07)
 			}
 			for k := 1; k < w; k++ {
 				octet = value[i+k]
 				v = (v << 6) + (rune(octet) & 0x3F)
 			}
 			i += w
 
 			if !put(emitter, '\\') {
 				return false
 			}
 
 			var ok bool
 			switch v {
 			case 0x00:
 				ok = put(emitter, '0')
 			case 0x07:
 				ok = put(emitter, 'a')
 			case 0x08:
 				ok = put(emitter, 'b')
 			case 0x09:
 				ok = put(emitter, 't')
 			case 0x0A:
 				ok = put(emitter, 'n')
 			case 0x0b:
 				ok = put(emitter, 'v')
 			case 0x0c:
 				ok = put(emitter, 'f')
 			case 0x0d:
 				ok = put(emitter, 'r')
 			case 0x1b:
 				ok = put(emitter, 'e')
 			case 0x22:
 				ok = put(emitter, '"')
 			case 0x5c:
 				ok = put(emitter, '\\')
 			case 0x85:
 				ok = put(emitter, 'N')
 			case 0xA0:
 				ok = put(emitter, '_')
 			case 0x2028:
 				ok = put(emitter, 'L')
 			case 0x2029:
 				ok = put(emitter, 'P')
 			default:
 				if v <= 0xFF {
 					ok = put(emitter, 'x')
 					w = 2
 				} else if v <= 0xFFFF {
 					ok = put(emitter, 'u')
 					w = 4
 				} else {
 					ok = put(emitter, 'U')
 					w = 8
 				}
 				for k := (w - 1) * 4; ok && k >= 0; k -= 4 {
 					digit := byte((v >> uint(k)) & 0x0F)
 					if digit < 10 {
 						ok = put(emitter, digit+'0')
 					} else {
 						ok = put(emitter, digit+'A'-10)
 					}
 				}
 			}
 			if !ok {
 				return false
 			}
 			spaces = false
 		} else if is_space(value, i) {
 			if allow_breaks && !spaces && emitter.column > emitter.best_width && i > 0 && i < len(value)-1 {
 				if !yaml_emitter_write_indent(emitter) {
 					return false
 				}
 				if is_space(value, i+1) {
 					if !put(emitter, '\\') {
 						return false
 					}
 				}
 				i += width(value[i])
 			} else if !write(emitter, value, &i) {
 				return false
 			}
 			spaces = true
 		} else {
 			if !write(emitter, value, &i) {
 				return false
 			}
 			spaces = false
 		}
 	}
 	if !yaml_emitter_write_indicator(emitter, []byte{'"'}, false, false, false) {
 		return false
 	}
 	emitter.whitespace = false
 	emitter.indention = false
 	return true
 }
 
 func yaml_emitter_write_block_scalar_hints(emitter *yaml_emitter_t, value []byte) bool {
 	if is_space(value, 0) || is_break(value, 0) {
 		indent_hint := []byte{'0' + byte(emitter.best_indent)}
 		if !yaml_emitter_write_indicator(emitter, indent_hint, false, false, false) {
 			return false
 		}
 	}
 
 	emitter.open_ended = false
 
 	var chomp_hint [1]byte
 	if len(value) == 0 {
 		chomp_hint[0] = '-'
 	} else {
 		i := len(value) - 1
 		for value[i]&0xC0 == 0x80 {
 			i--
 		}
 		if !is_break(value, i) {
 			chomp_hint[0] = '-'
 		} else if i == 0 {
 			chomp_hint[0] = '+'
 			emitter.open_ended = true
 		} else {
 			i--
 			for value[i]&0xC0 == 0x80 {
 				i--
 			}
 			if is_break(value, i) {
 				chomp_hint[0] = '+'
 				emitter.open_ended = true
 			}
 		}
 	}
 	if chomp_hint[0] != 0 {
 		if !yaml_emitter_write_indicator(emitter, chomp_hint[:], false, false, false) {
 			return false
 		}
 	}
 	return true
 }
 
 func yaml_emitter_write_literal_scalar(emitter *yaml_emitter_t, value []byte) bool {
 	if !yaml_emitter_write_indicator(emitter, []byte{'|'}, true, false, false) {
 		return false
 	}
 	if !yaml_emitter_write_block_scalar_hints(emitter, value) {
 		return false
 	}
 	if !yaml_emitter_process_line_comment(emitter) {
 		return false
 	}
 	//emitter.indention = true
 	emitter.whitespace = true
 	breaks := true
 	for i := 0; i < len(value); {
 		if is_break(value, i) {
 			if !write_break(emitter, value, &i) {
 				return false
 			}
 			//emitter.indention = true
 			breaks = true
 		} else {
 			if breaks {
 				if !yaml_emitter_write_indent(emitter) {
 					return false
 				}
 			}
 			if !write(emitter, value, &i) {
 				return false
 			}
 			emitter.indention = false
 			breaks = false
 		}
 	}
 
 	return true
 }
 
 func yaml_emitter_write_folded_scalar(emitter *yaml_emitter_t, value []byte) bool {
 	if !yaml_emitter_write_indicator(emitter, []byte{'>'}, true, false, false) {
 		return false
 	}
 	if !yaml_emitter_write_block_scalar_hints(emitter, value) {
 		return false
 	}
 	if !yaml_emitter_process_line_comment(emitter) {
 		return false
 	}
 
 	//emitter.indention = true
 	emitter.whitespace = true
 
 	breaks := true
 	leading_spaces := true
 	for i := 0; i < len(value); {
 		if is_break(value, i) {
 			if !breaks && !leading_spaces && value[i] == '\n' {
 				k := 0
 				for is_break(value, k) {
 					k += width(value[k])
 				}
 				if !is_blankz(value, k) {
 					if !put_break(emitter) {
 						return false
 					}
 				}
 			}
 			if !write_break(emitter, value, &i) {
 				return false
 			}
 			//emitter.indention = true
 			breaks = true
 		} else {
 			if breaks {
 				if !yaml_emitter_write_indent(emitter) {
 					return false
 				}
 				leading_spaces = is_blank(value, i)
 			}
 			if !breaks && is_space(value, i) && !is_space(value, i+1) && emitter.column > emitter.best_width {
 				if !yaml_emitter_write_indent(emitter) {
 					return false
 				}
 				i += width(value[i])
 			} else {
 				if !write(emitter, value, &i) {
 					return false
 				}
 			}
 			emitter.indention = false
 			breaks = false
 		}
 	}
 	return true
 }
 
 func yaml_emitter_write_comment(emitter *yaml_emitter_t, comment []byte) bool {
 	breaks := false
 	pound := false
 	for i := 0; i < len(comment); {
 		if is_break(comment, i) {
 			if !write_break(emitter, comment, &i) {
 				return false
 			}
 			//emitter.indention = true
 			breaks = true
 			pound = false
 		} else {
 			if breaks && !yaml_emitter_write_indent(emitter) {
 				return false
 			}
 			if !pound {
 				if comment[i] != '#' && (!put(emitter, '#') || !put(emitter, ' ')) {
 					return false
 				}
 				pound = true
 			}
 			if !write(emitter, comment, &i) {
 				return false
 			}
 			emitter.indention = false
 			breaks = false
 		}
 	}
 	if !breaks && !put_break(emitter) {
 		return false
 	}
 
 	emitter.whitespace = true
 	//emitter.indention = true
 	return true
 }