source: code/trunk/vendor/gopkg.in/yaml.v3/yamlh.go@ 75

//
// 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 (
        "fmt"
        "io"
)

// The version directive data.
type yaml_version_directive_t struct {
        major int8 // The major version number.
        minor int8 // The minor version number.
}

// The tag directive data.
type yaml_tag_directive_t struct {
        handle []byte // The tag handle.
        prefix []byte // The tag prefix.
}

type yaml_encoding_t int

// The stream encoding.
const (
        // Let the parser choose the encoding.
        yaml_ANY_ENCODING yaml_encoding_t = iota

        yaml_UTF8_ENCODING    // The default UTF-8 encoding.
        yaml_UTF16LE_ENCODING // The UTF-16-LE encoding with BOM.
        yaml_UTF16BE_ENCODING // The UTF-16-BE encoding with BOM.
)

type yaml_break_t int

// Line break types.
const (
        // Let the parser choose the break type.
        yaml_ANY_BREAK yaml_break_t = iota

        yaml_CR_BREAK   // Use CR for line breaks (Mac style).
        yaml_LN_BREAK   // Use LN for line breaks (Unix style).
        yaml_CRLN_BREAK // Use CR LN for line breaks (DOS style).
)

type yaml_error_type_t int

// Many bad things could happen with the parser and emitter.
const (
        // No error is produced.
        yaml_NO_ERROR yaml_error_type_t = iota

        yaml_MEMORY_ERROR   // Cannot allocate or reallocate a block of memory.
        yaml_READER_ERROR   // Cannot read or decode the input stream.
        yaml_SCANNER_ERROR  // Cannot scan the input stream.
        yaml_PARSER_ERROR   // Cannot parse the input stream.
        yaml_COMPOSER_ERROR // Cannot compose a YAML document.
        yaml_WRITER_ERROR   // Cannot write to the output stream.
        yaml_EMITTER_ERROR  // Cannot emit a YAML stream.
)

// The pointer position.
type yaml_mark_t struct {
        index  int // The position index.
        line   int // The position line.
        column int // The position column.
}

// Node Styles

type yaml_style_t int8

type yaml_scalar_style_t yaml_style_t

// Scalar styles.
const (
        // Let the emitter choose the style.
        yaml_ANY_SCALAR_STYLE yaml_scalar_style_t = 0

        yaml_PLAIN_SCALAR_STYLE         yaml_scalar_style_t = 1 << iota // The plain scalar style.
        yaml_SINGLE_QUOTED_SCALAR_STYLE                                 // The single-quoted scalar style.
        yaml_DOUBLE_QUOTED_SCALAR_STYLE                                 // The double-quoted scalar style.
        yaml_LITERAL_SCALAR_STYLE                                       // The literal scalar style.
        yaml_FOLDED_SCALAR_STYLE                                        // The folded scalar style.
)

type yaml_sequence_style_t yaml_style_t

// Sequence styles.
const (
        // Let the emitter choose the style.
        yaml_ANY_SEQUENCE_STYLE yaml_sequence_style_t = iota

        yaml_BLOCK_SEQUENCE_STYLE // The block sequence style.
        yaml_FLOW_SEQUENCE_STYLE  // The flow sequence style.
)

type yaml_mapping_style_t yaml_style_t

// Mapping styles.
const (
        // Let the emitter choose the style.
        yaml_ANY_MAPPING_STYLE yaml_mapping_style_t = iota

        yaml_BLOCK_MAPPING_STYLE // The block mapping style.
        yaml_FLOW_MAPPING_STYLE  // The flow mapping style.
)

// Tokens

type yaml_token_type_t int

// Token types.
const (
        // An empty token.
        yaml_NO_TOKEN yaml_token_type_t = iota

        yaml_STREAM_START_TOKEN // A STREAM-START token.
        yaml_STREAM_END_TOKEN   // A STREAM-END token.

        yaml_VERSION_DIRECTIVE_TOKEN // A VERSION-DIRECTIVE token.
        yaml_TAG_DIRECTIVE_TOKEN     // A TAG-DIRECTIVE token.
        yaml_DOCUMENT_START_TOKEN    // A DOCUMENT-START token.
        yaml_DOCUMENT_END_TOKEN      // A DOCUMENT-END token.

        yaml_BLOCK_SEQUENCE_START_TOKEN // A BLOCK-SEQUENCE-START token.
        yaml_BLOCK_MAPPING_START_TOKEN  // A BLOCK-SEQUENCE-END token.
        yaml_BLOCK_END_TOKEN            // A BLOCK-END token.

        yaml_FLOW_SEQUENCE_START_TOKEN // A FLOW-SEQUENCE-START token.
        yaml_FLOW_SEQUENCE_END_TOKEN   // A FLOW-SEQUENCE-END token.
        yaml_FLOW_MAPPING_START_TOKEN  // A FLOW-MAPPING-START token.
        yaml_FLOW_MAPPING_END_TOKEN    // A FLOW-MAPPING-END token.

        yaml_BLOCK_ENTRY_TOKEN // A BLOCK-ENTRY token.
        yaml_FLOW_ENTRY_TOKEN  // A FLOW-ENTRY token.
        yaml_KEY_TOKEN         // A KEY token.
        yaml_VALUE_TOKEN       // A VALUE token.

        yaml_ALIAS_TOKEN  // An ALIAS token.
        yaml_ANCHOR_TOKEN // An ANCHOR token.
        yaml_TAG_TOKEN    // A TAG token.
        yaml_SCALAR_TOKEN // A SCALAR token.
)

func (tt yaml_token_type_t) String() string {
        switch tt {
        case yaml_NO_TOKEN:
                return "yaml_NO_TOKEN"
        case yaml_STREAM_START_TOKEN:
                return "yaml_STREAM_START_TOKEN"
        case yaml_STREAM_END_TOKEN:
                return "yaml_STREAM_END_TOKEN"
        case yaml_VERSION_DIRECTIVE_TOKEN:
                return "yaml_VERSION_DIRECTIVE_TOKEN"
        case yaml_TAG_DIRECTIVE_TOKEN:
                return "yaml_TAG_DIRECTIVE_TOKEN"
        case yaml_DOCUMENT_START_TOKEN:
                return "yaml_DOCUMENT_START_TOKEN"
        case yaml_DOCUMENT_END_TOKEN:
                return "yaml_DOCUMENT_END_TOKEN"
        case yaml_BLOCK_SEQUENCE_START_TOKEN:
                return "yaml_BLOCK_SEQUENCE_START_TOKEN"
        case yaml_BLOCK_MAPPING_START_TOKEN:
                return "yaml_BLOCK_MAPPING_START_TOKEN"
        case yaml_BLOCK_END_TOKEN:
                return "yaml_BLOCK_END_TOKEN"
        case yaml_FLOW_SEQUENCE_START_TOKEN:
                return "yaml_FLOW_SEQUENCE_START_TOKEN"
        case yaml_FLOW_SEQUENCE_END_TOKEN:
                return "yaml_FLOW_SEQUENCE_END_TOKEN"
        case yaml_FLOW_MAPPING_START_TOKEN:
                return "yaml_FLOW_MAPPING_START_TOKEN"
        case yaml_FLOW_MAPPING_END_TOKEN:
                return "yaml_FLOW_MAPPING_END_TOKEN"
        case yaml_BLOCK_ENTRY_TOKEN:
                return "yaml_BLOCK_ENTRY_TOKEN"
        case yaml_FLOW_ENTRY_TOKEN:
                return "yaml_FLOW_ENTRY_TOKEN"
        case yaml_KEY_TOKEN:
                return "yaml_KEY_TOKEN"
        case yaml_VALUE_TOKEN:
                return "yaml_VALUE_TOKEN"
        case yaml_ALIAS_TOKEN:
                return "yaml_ALIAS_TOKEN"
        case yaml_ANCHOR_TOKEN:
                return "yaml_ANCHOR_TOKEN"
        case yaml_TAG_TOKEN:
                return "yaml_TAG_TOKEN"
        case yaml_SCALAR_TOKEN:
                return "yaml_SCALAR_TOKEN"
        }
        return "<unknown token>"
}

// The token structure.
type yaml_token_t struct {
        // The token type.
        typ yaml_token_type_t

        // The start/end of the token.
        start_mark, end_mark yaml_mark_t

        // The stream encoding (for yaml_STREAM_START_TOKEN).
        encoding yaml_encoding_t

        // The alias/anchor/scalar value or tag/tag directive handle
        // (for yaml_ALIAS_TOKEN, yaml_ANCHOR_TOKEN, yaml_SCALAR_TOKEN, yaml_TAG_TOKEN, yaml_TAG_DIRECTIVE_TOKEN).
        value []byte

        // The tag suffix (for yaml_TAG_TOKEN).
        suffix []byte

        // The tag directive prefix (for yaml_TAG_DIRECTIVE_TOKEN).
        prefix []byte

        // The scalar style (for yaml_SCALAR_TOKEN).
        style yaml_scalar_style_t

        // The version directive major/minor (for yaml_VERSION_DIRECTIVE_TOKEN).
        major, minor int8
}

// Events

type yaml_event_type_t int8

// Event types.
const (
        // An empty event.
        yaml_NO_EVENT yaml_event_type_t = iota

        yaml_STREAM_START_EVENT   // A STREAM-START event.
        yaml_STREAM_END_EVENT     // A STREAM-END event.
        yaml_DOCUMENT_START_EVENT // A DOCUMENT-START event.
        yaml_DOCUMENT_END_EVENT   // A DOCUMENT-END event.
        yaml_ALIAS_EVENT          // An ALIAS event.
        yaml_SCALAR_EVENT         // A SCALAR event.
        yaml_SEQUENCE_START_EVENT // A SEQUENCE-START event.
        yaml_SEQUENCE_END_EVENT   // A SEQUENCE-END event.
        yaml_MAPPING_START_EVENT  // A MAPPING-START event.
        yaml_MAPPING_END_EVENT    // A MAPPING-END event.
        yaml_TAIL_COMMENT_EVENT
)

var eventStrings = []string{
        yaml_NO_EVENT:             "none",
        yaml_STREAM_START_EVENT:   "stream start",
        yaml_STREAM_END_EVENT:     "stream end",
        yaml_DOCUMENT_START_EVENT: "document start",
        yaml_DOCUMENT_END_EVENT:   "document end",
        yaml_ALIAS_EVENT:          "alias",
        yaml_SCALAR_EVENT:         "scalar",
        yaml_SEQUENCE_START_EVENT: "sequence start",
        yaml_SEQUENCE_END_EVENT:   "sequence end",
        yaml_MAPPING_START_EVENT:  "mapping start",
        yaml_MAPPING_END_EVENT:    "mapping end",
        yaml_TAIL_COMMENT_EVENT:   "tail comment",
}

func (e yaml_event_type_t) String() string {
        if e < 0 || int(e) >= len(eventStrings) {
                return fmt.Sprintf("unknown event %d", e)
        }
        return eventStrings[e]
}

// The event structure.
type yaml_event_t struct {

        // The event type.
        typ yaml_event_type_t

        // The start and end of the event.
        start_mark, end_mark yaml_mark_t

        // The document encoding (for yaml_STREAM_START_EVENT).
        encoding yaml_encoding_t

        // The version directive (for yaml_DOCUMENT_START_EVENT).
        version_directive *yaml_version_directive_t

        // The list of tag directives (for yaml_DOCUMENT_START_EVENT).
        tag_directives []yaml_tag_directive_t

        // The comments
        head_comment []byte
        line_comment []byte
        foot_comment []byte
        tail_comment []byte

        // The anchor (for yaml_SCALAR_EVENT, yaml_SEQUENCE_START_EVENT, yaml_MAPPING_START_EVENT, yaml_ALIAS_EVENT).
        anchor []byte

        // The tag (for yaml_SCALAR_EVENT, yaml_SEQUENCE_START_EVENT, yaml_MAPPING_START_EVENT).
        tag []byte

        // The scalar value (for yaml_SCALAR_EVENT).
        value []byte

        // Is the document start/end indicator implicit, or the tag optional?
        // (for yaml_DOCUMENT_START_EVENT, yaml_DOCUMENT_END_EVENT, yaml_SEQUENCE_START_EVENT, yaml_MAPPING_START_EVENT, yaml_SCALAR_EVENT).
        implicit bool

        // Is the tag optional for any non-plain style? (for yaml_SCALAR_EVENT).
        quoted_implicit bool

        // The style (for yaml_SCALAR_EVENT, yaml_SEQUENCE_START_EVENT, yaml_MAPPING_START_EVENT).
        style yaml_style_t
}

func (e *yaml_event_t) scalar_style() yaml_scalar_style_t     { return yaml_scalar_style_t(e.style) }
func (e *yaml_event_t) sequence_style() yaml_sequence_style_t { return yaml_sequence_style_t(e.style) }
func (e *yaml_event_t) mapping_style() yaml_mapping_style_t   { return yaml_mapping_style_t(e.style) }

// Nodes

const (
        yaml_NULL_TAG      = "tag:yaml.org,2002:null"      // The tag !!null with the only possible value: null.
        yaml_BOOL_TAG      = "tag:yaml.org,2002:bool"      // The tag !!bool with the values: true and false.
        yaml_STR_TAG       = "tag:yaml.org,2002:str"       // The tag !!str for string values.
        yaml_INT_TAG       = "tag:yaml.org,2002:int"       // The tag !!int for integer values.
        yaml_FLOAT_TAG     = "tag:yaml.org,2002:float"     // The tag !!float for float values.
        yaml_TIMESTAMP_TAG = "tag:yaml.org,2002:timestamp" // The tag !!timestamp for date and time values.

        yaml_SEQ_TAG = "tag:yaml.org,2002:seq" // The tag !!seq is used to denote sequences.
        yaml_MAP_TAG = "tag:yaml.org,2002:map" // The tag !!map is used to denote mapping.

        // Not in original libyaml.
        yaml_BINARY_TAG = "tag:yaml.org,2002:binary"
        yaml_MERGE_TAG  = "tag:yaml.org,2002:merge"

        yaml_DEFAULT_SCALAR_TAG   = yaml_STR_TAG // The default scalar tag is !!str.
        yaml_DEFAULT_SEQUENCE_TAG = yaml_SEQ_TAG // The default sequence tag is !!seq.
        yaml_DEFAULT_MAPPING_TAG  = yaml_MAP_TAG // The default mapping tag is !!map.
)

type yaml_node_type_t int

// Node types.
const (
        // An empty node.
        yaml_NO_NODE yaml_node_type_t = iota

        yaml_SCALAR_NODE   // A scalar node.
        yaml_SEQUENCE_NODE // A sequence node.
        yaml_MAPPING_NODE  // A mapping node.
)

// An element of a sequence node.
type yaml_node_item_t int

// An element of a mapping node.
type yaml_node_pair_t struct {
        key   int // The key of the element.
        value int // The value of the element.
}

// The node structure.
type yaml_node_t struct {
        typ yaml_node_type_t // The node type.
        tag []byte           // The node tag.

        // The node data.

        // The scalar parameters (for yaml_SCALAR_NODE).
        scalar struct {
                value  []byte              // The scalar value.
                length int                 // The length of the scalar value.
                style  yaml_scalar_style_t // The scalar style.
        }

        // The sequence parameters (for YAML_SEQUENCE_NODE).
        sequence struct {
                items_data []yaml_node_item_t    // The stack of sequence items.
                style      yaml_sequence_style_t // The sequence style.
        }

        // The mapping parameters (for yaml_MAPPING_NODE).
        mapping struct {
                pairs_data  []yaml_node_pair_t   // The stack of mapping pairs (key, value).
                pairs_start *yaml_node_pair_t    // The beginning of the stack.
                pairs_end   *yaml_node_pair_t    // The end of the stack.
                pairs_top   *yaml_node_pair_t    // The top of the stack.
                style       yaml_mapping_style_t // The mapping style.
        }

        start_mark yaml_mark_t // The beginning of the node.
        end_mark   yaml_mark_t // The end of the node.

}

// The document structure.
type yaml_document_t struct {

        // The document nodes.
        nodes []yaml_node_t

        // The version directive.
        version_directive *yaml_version_directive_t

        // The list of tag directives.
        tag_directives_data  []yaml_tag_directive_t
        tag_directives_start int // The beginning of the tag directives list.
        tag_directives_end   int // The end of the tag directives list.

        start_implicit int // Is the document start indicator implicit?
        end_implicit   int // Is the document end indicator implicit?

        // The start/end of the document.
        start_mark, end_mark yaml_mark_t
}

// The prototype of a read handler.
//
// The read handler is called when the parser needs to read more bytes from the
// source. The handler should write not more than size bytes to the buffer.
// The number of written bytes should be set to the size_read variable.
//
// [in,out]   data        A pointer to an application data specified by
//                        yaml_parser_set_input().
// [out]      buffer      The buffer to write the data from the source.
// [in]       size        The size of the buffer.
// [out]      size_read   The actual number of bytes read from the source.
//
// On success, the handler should return 1.  If the handler failed,
// the returned value should be 0. On EOF, the handler should set the
// size_read to 0 and return 1.
type yaml_read_handler_t func(parser *yaml_parser_t, buffer []byte) (n int, err error)

// This structure holds information about a potential simple key.
type yaml_simple_key_t struct {
        possible     bool        // Is a simple key possible?
        required     bool        // Is a simple key required?
        token_number int         // The number of the token.
        mark         yaml_mark_t // The position mark.
}

// The states of the parser.
type yaml_parser_state_t int

const (
        yaml_PARSE_STREAM_START_STATE yaml_parser_state_t = iota

        yaml_PARSE_IMPLICIT_DOCUMENT_START_STATE           // Expect the beginning of an implicit document.
        yaml_PARSE_DOCUMENT_START_STATE                    // Expect DOCUMENT-START.
        yaml_PARSE_DOCUMENT_CONTENT_STATE                  // Expect the content of a document.
        yaml_PARSE_DOCUMENT_END_STATE                      // Expect DOCUMENT-END.
        yaml_PARSE_BLOCK_NODE_STATE                        // Expect a block node.
        yaml_PARSE_BLOCK_NODE_OR_INDENTLESS_SEQUENCE_STATE // Expect a block node or indentless sequence.
        yaml_PARSE_FLOW_NODE_STATE                         // Expect a flow node.
        yaml_PARSE_BLOCK_SEQUENCE_FIRST_ENTRY_STATE        // Expect the first entry of a block sequence.
        yaml_PARSE_BLOCK_SEQUENCE_ENTRY_STATE              // Expect an entry of a block sequence.
        yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE         // Expect an entry of an indentless sequence.
        yaml_PARSE_BLOCK_MAPPING_FIRST_KEY_STATE           // Expect the first key of a block mapping.
        yaml_PARSE_BLOCK_MAPPING_KEY_STATE                 // Expect a block mapping key.
        yaml_PARSE_BLOCK_MAPPING_VALUE_STATE               // Expect a block mapping value.
        yaml_PARSE_FLOW_SEQUENCE_FIRST_ENTRY_STATE         // Expect the first entry of a flow sequence.
        yaml_PARSE_FLOW_SEQUENCE_ENTRY_STATE               // Expect an entry of a flow sequence.
        yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_KEY_STATE   // Expect a key of an ordered mapping.
        yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_VALUE_STATE // Expect a value of an ordered mapping.
        yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_END_STATE   // Expect the and of an ordered mapping entry.
        yaml_PARSE_FLOW_MAPPING_FIRST_KEY_STATE            // Expect the first key of a flow mapping.
        yaml_PARSE_FLOW_MAPPING_KEY_STATE                  // Expect a key of a flow mapping.
        yaml_PARSE_FLOW_MAPPING_VALUE_STATE                // Expect a value of a flow mapping.
        yaml_PARSE_FLOW_MAPPING_EMPTY_VALUE_STATE          // Expect an empty value of a flow mapping.
        yaml_PARSE_END_STATE                               // Expect nothing.
)

func (ps yaml_parser_state_t) String() string {
        switch ps {
        case yaml_PARSE_STREAM_START_STATE:
                return "yaml_PARSE_STREAM_START_STATE"
        case yaml_PARSE_IMPLICIT_DOCUMENT_START_STATE:
                return "yaml_PARSE_IMPLICIT_DOCUMENT_START_STATE"
        case yaml_PARSE_DOCUMENT_START_STATE:
                return "yaml_PARSE_DOCUMENT_START_STATE"
        case yaml_PARSE_DOCUMENT_CONTENT_STATE:
                return "yaml_PARSE_DOCUMENT_CONTENT_STATE"
        case yaml_PARSE_DOCUMENT_END_STATE:
                return "yaml_PARSE_DOCUMENT_END_STATE"
        case yaml_PARSE_BLOCK_NODE_STATE:
                return "yaml_PARSE_BLOCK_NODE_STATE"
        case yaml_PARSE_BLOCK_NODE_OR_INDENTLESS_SEQUENCE_STATE:
                return "yaml_PARSE_BLOCK_NODE_OR_INDENTLESS_SEQUENCE_STATE"
        case yaml_PARSE_FLOW_NODE_STATE:
                return "yaml_PARSE_FLOW_NODE_STATE"
        case yaml_PARSE_BLOCK_SEQUENCE_FIRST_ENTRY_STATE:
                return "yaml_PARSE_BLOCK_SEQUENCE_FIRST_ENTRY_STATE"
        case yaml_PARSE_BLOCK_SEQUENCE_ENTRY_STATE:
                return "yaml_PARSE_BLOCK_SEQUENCE_ENTRY_STATE"
        case yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE:
                return "yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE"
        case yaml_PARSE_BLOCK_MAPPING_FIRST_KEY_STATE:
                return "yaml_PARSE_BLOCK_MAPPING_FIRST_KEY_STATE"
        case yaml_PARSE_BLOCK_MAPPING_KEY_STATE:
                return "yaml_PARSE_BLOCK_MAPPING_KEY_STATE"
        case yaml_PARSE_BLOCK_MAPPING_VALUE_STATE:
                return "yaml_PARSE_BLOCK_MAPPING_VALUE_STATE"
        case yaml_PARSE_FLOW_SEQUENCE_FIRST_ENTRY_STATE:
                return "yaml_PARSE_FLOW_SEQUENCE_FIRST_ENTRY_STATE"
        case yaml_PARSE_FLOW_SEQUENCE_ENTRY_STATE:
                return "yaml_PARSE_FLOW_SEQUENCE_ENTRY_STATE"
        case yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_KEY_STATE:
                return "yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_KEY_STATE"
        case yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_VALUE_STATE:
                return "yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_VALUE_STATE"
        case yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_END_STATE:
                return "yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_END_STATE"
        case yaml_PARSE_FLOW_MAPPING_FIRST_KEY_STATE:
                return "yaml_PARSE_FLOW_MAPPING_FIRST_KEY_STATE"
        case yaml_PARSE_FLOW_MAPPING_KEY_STATE:
                return "yaml_PARSE_FLOW_MAPPING_KEY_STATE"
        case yaml_PARSE_FLOW_MAPPING_VALUE_STATE:
                return "yaml_PARSE_FLOW_MAPPING_VALUE_STATE"
        case yaml_PARSE_FLOW_MAPPING_EMPTY_VALUE_STATE:
                return "yaml_PARSE_FLOW_MAPPING_EMPTY_VALUE_STATE"
        case yaml_PARSE_END_STATE:
                return "yaml_PARSE_END_STATE"
        }
        return "<unknown parser state>"
}

// This structure holds aliases data.
type yaml_alias_data_t struct {
        anchor []byte      // The anchor.
        index  int         // The node id.
        mark   yaml_mark_t // The anchor mark.
}

// The parser structure.
//
// All members are internal. Manage the structure using the
// yaml_parser_ family of functions.
type yaml_parser_t struct {

        // Error handling

        error yaml_error_type_t // Error type.

        problem string // Error description.

        // The byte about which the problem occurred.
        problem_offset int
        problem_value  int
        problem_mark   yaml_mark_t

        // The error context.
        context      string
        context_mark yaml_mark_t

        // Reader stuff

        read_handler yaml_read_handler_t // Read handler.

        input_reader io.Reader // File input data.
        input        []byte    // String input data.
        input_pos    int

        eof bool // EOF flag

        buffer     []byte // The working buffer.
        buffer_pos int    // The current position of the buffer.

        unread int // The number of unread characters in the buffer.

        newlines int // The number of line breaks since last non-break/non-blank character

        raw_buffer     []byte // The raw buffer.
        raw_buffer_pos int    // The current position of the buffer.

        encoding yaml_encoding_t // The input encoding.

        offset int         // The offset of the current position (in bytes).
        mark   yaml_mark_t // The mark of the current position.

        // Comments

        head_comment []byte // The current head comments
        line_comment []byte // The current line comments
        foot_comment []byte // The current foot comments
        tail_comment []byte // Foot comment that happens at the end of a block.
        stem_comment []byte // Comment in item preceding a nested structure (list inside list item, etc)

        comments      []yaml_comment_t // The folded comments for all parsed tokens
        comments_head int

        // Scanner stuff

        stream_start_produced bool // Have we started to scan the input stream?
        stream_end_produced   bool // Have we reached the end of the input stream?

        flow_level int // The number of unclosed '[' and '{' indicators.

        tokens          []yaml_token_t // The tokens queue.
        tokens_head     int            // The head of the tokens queue.
        tokens_parsed   int            // The number of tokens fetched from the queue.
        token_available bool           // Does the tokens queue contain a token ready for dequeueing.

        indent  int   // The current indentation level.
        indents []int // The indentation levels stack.

        simple_key_allowed bool                // May a simple key occur at the current position?
        simple_keys        []yaml_simple_key_t // The stack of simple keys.
        simple_keys_by_tok map[int]int         // possible simple_key indexes indexed by token_number

        // Parser stuff

        state          yaml_parser_state_t    // The current parser state.
        states         []yaml_parser_state_t  // The parser states stack.
        marks          []yaml_mark_t          // The stack of marks.
        tag_directives []yaml_tag_directive_t // The list of TAG directives.

        // Dumper stuff

        aliases []yaml_alias_data_t // The alias data.

        document *yaml_document_t // The currently parsed document.
}

type yaml_comment_t struct {

        scan_mark  yaml_mark_t // Position where scanning for comments started
        token_mark yaml_mark_t // Position after which tokens will be associated with this comment
        start_mark yaml_mark_t // Position of '#' comment mark
        end_mark   yaml_mark_t // Position where comment terminated

        head []byte
        line []byte
        foot []byte
}

// Emitter Definitions

// The prototype of a write handler.
//
// The write handler is called when the emitter needs to flush the accumulated
// characters to the output.  The handler should write @a size bytes of the
// @a buffer to the output.
//
// @param[in,out]   data        A pointer to an application data specified by
//                              yaml_emitter_set_output().
// @param[in]       buffer      The buffer with bytes to be written.
// @param[in]       size        The size of the buffer.
//
// @returns On success, the handler should return @c 1.  If the handler failed,
// the returned value should be @c 0.
//
type yaml_write_handler_t func(emitter *yaml_emitter_t, buffer []byte) error

type yaml_emitter_state_t int

// The emitter states.
const (
        // Expect STREAM-START.
        yaml_EMIT_STREAM_START_STATE yaml_emitter_state_t = iota

        yaml_EMIT_FIRST_DOCUMENT_START_STATE       // Expect the first DOCUMENT-START or STREAM-END.
        yaml_EMIT_DOCUMENT_START_STATE             // Expect DOCUMENT-START or STREAM-END.
        yaml_EMIT_DOCUMENT_CONTENT_STATE           // Expect the content of a document.
        yaml_EMIT_DOCUMENT_END_STATE               // Expect DOCUMENT-END.
        yaml_EMIT_FLOW_SEQUENCE_FIRST_ITEM_STATE   // Expect the first item of a flow sequence.
        yaml_EMIT_FLOW_SEQUENCE_TRAIL_ITEM_STATE   // Expect the next item of a flow sequence, with the comma already written out
        yaml_EMIT_FLOW_SEQUENCE_ITEM_STATE         // Expect an item of a flow sequence.
        yaml_EMIT_FLOW_MAPPING_FIRST_KEY_STATE     // Expect the first key of a flow mapping.
        yaml_EMIT_FLOW_MAPPING_TRAIL_KEY_STATE     // Expect the next key of a flow mapping, with the comma already written out
        yaml_EMIT_FLOW_MAPPING_KEY_STATE           // Expect a key of a flow mapping.
        yaml_EMIT_FLOW_MAPPING_SIMPLE_VALUE_STATE  // Expect a value for a simple key of a flow mapping.
        yaml_EMIT_FLOW_MAPPING_VALUE_STATE         // Expect a value of a flow mapping.
        yaml_EMIT_BLOCK_SEQUENCE_FIRST_ITEM_STATE  // Expect the first item of a block sequence.
        yaml_EMIT_BLOCK_SEQUENCE_ITEM_STATE        // Expect an item of a block sequence.
        yaml_EMIT_BLOCK_MAPPING_FIRST_KEY_STATE    // Expect the first key of a block mapping.
        yaml_EMIT_BLOCK_MAPPING_KEY_STATE          // Expect the key of a block mapping.
        yaml_EMIT_BLOCK_MAPPING_SIMPLE_VALUE_STATE // Expect a value for a simple key of a block mapping.
        yaml_EMIT_BLOCK_MAPPING_VALUE_STATE        // Expect a value of a block mapping.
        yaml_EMIT_END_STATE                        // Expect nothing.
)

// The emitter structure.
//
// All members are internal.  Manage the structure using the @c yaml_emitter_
// family of functions.
type yaml_emitter_t struct {

        // Error handling

        error   yaml_error_type_t // Error type.
        problem string            // Error description.

        // Writer stuff

        write_handler yaml_write_handler_t // Write handler.

        output_buffer *[]byte   // String output data.
        output_writer io.Writer // File output data.

        buffer     []byte // The working buffer.
        buffer_pos int    // The current position of the buffer.

        raw_buffer     []byte // The raw buffer.
        raw_buffer_pos int    // The current position of the buffer.

        encoding yaml_encoding_t // The stream encoding.

        // Emitter stuff

        canonical   bool         // If the output is in the canonical style?
        best_indent int          // The number of indentation spaces.
        best_width  int          // The preferred width of the output lines.
        unicode     bool         // Allow unescaped non-ASCII characters?
        line_break  yaml_break_t // The preferred line break.

        state  yaml_emitter_state_t   // The current emitter state.
        states []yaml_emitter_state_t // The stack of states.

        events      []yaml_event_t // The event queue.
        events_head int            // The head of the event queue.

        indents []int // The stack of indentation levels.

        tag_directives []yaml_tag_directive_t // The list of tag directives.

        indent int // The current indentation level.

        flow_level int // The current flow level.

        root_context       bool // Is it the document root context?
        sequence_context   bool // Is it a sequence context?
        mapping_context    bool // Is it a mapping context?
        simple_key_context bool // Is it a simple mapping key context?

        line       int  // The current line.
        column     int  // The current column.
        whitespace bool // If the last character was a whitespace?
        indention  bool // If the last character was an indentation character (' ', '-', '?', ':')?
        open_ended bool // If an explicit document end is required?

        space_above bool // Is there's an empty line above?
        foot_indent int  // The indent used to write the foot comment above, or -1 if none.

        // Anchor analysis.
        anchor_data struct {
                anchor []byte // The anchor value.
                alias  bool   // Is it an alias?
        }

        // Tag analysis.
        tag_data struct {
                handle []byte // The tag handle.
                suffix []byte // The tag suffix.
        }

        // Scalar analysis.
        scalar_data struct {
                value                 []byte              // The scalar value.
                multiline             bool                // Does the scalar contain line breaks?
                flow_plain_allowed    bool                // Can the scalar be expessed in the flow plain style?
                block_plain_allowed   bool                // Can the scalar be expressed in the block plain style?
                single_quoted_allowed bool                // Can the scalar be expressed in the single quoted style?
                block_allowed         bool                // Can the scalar be expressed in the literal or folded styles?
                style                 yaml_scalar_style_t // The output style.
        }

        // Comments
        head_comment []byte
        line_comment []byte
        foot_comment []byte
        tail_comment []byte

        key_line_comment []byte

        // Dumper stuff

        opened bool // If the stream was already opened?
        closed bool // If the stream was already closed?

        // The information associated with the document nodes.
        anchors *struct {
                references int  // The number of references.
                anchor     int  // The anchor id.
                serialized bool // If the node has been emitted?
        }

        last_anchor_id int // The last assigned anchor id.

        document *yaml_document_t // The currently emitted document.
}