--- /dev/null
+package yaml
+
+import (
+ "bytes"
+ "fmt"
+)
+
+// Introduction
+// ************
+//
+// The following notes assume that you are familiar with the YAML specification
+// (http://yaml.org/spec/1.2/spec.html). We mostly follow it, although in
+// some cases we are less restrictive that it requires.
+//
+// The process of transforming a YAML stream into a sequence of events is
+// divided on two steps: Scanning and Parsing.
+//
+// The Scanner transforms the input stream into a sequence of tokens, while the
+// parser transform the sequence of tokens produced by the Scanner into a
+// sequence of parsing events.
+//
+// The Scanner is rather clever and complicated. The Parser, on the contrary,
+// is a straightforward implementation of a recursive-descendant parser (or,
+// LL(1) parser, as it is usually called).
+//
+// Actually there are two issues of Scanning that might be called "clever", the
+// rest is quite straightforward. The issues are "block collection start" and
+// "simple keys". Both issues are explained below in details.
+//
+// Here the Scanning step is explained and implemented. We start with the list
+// of all the tokens produced by the Scanner together with short descriptions.
+//
+// Now, tokens:
+//
+// STREAM-START(encoding) # The stream start.
+// STREAM-END # The stream end.
+// VERSION-DIRECTIVE(major,minor) # The '%YAML' directive.
+// TAG-DIRECTIVE(handle,prefix) # The '%TAG' directive.
+// DOCUMENT-START # '---'
+// DOCUMENT-END # '...'
+// BLOCK-SEQUENCE-START # Indentation increase denoting a block
+// BLOCK-MAPPING-START # sequence or a block mapping.
+// BLOCK-END # Indentation decrease.
+// FLOW-SEQUENCE-START # '['
+// FLOW-SEQUENCE-END # ']'
+// BLOCK-SEQUENCE-START # '{'
+// BLOCK-SEQUENCE-END # '}'
+// BLOCK-ENTRY # '-'
+// FLOW-ENTRY # ','
+// KEY # '?' or nothing (simple keys).
+// VALUE # ':'
+// ALIAS(anchor) # '*anchor'
+// ANCHOR(anchor) # '&anchor'
+// TAG(handle,suffix) # '!handle!suffix'
+// SCALAR(value,style) # A scalar.
+//
+// The following two tokens are "virtual" tokens denoting the beginning and the
+// end of the stream:
+//
+// STREAM-START(encoding)
+// STREAM-END
+//
+// We pass the information about the input stream encoding with the
+// STREAM-START token.
+//
+// The next two tokens are responsible for tags:
+//
+// VERSION-DIRECTIVE(major,minor)
+// TAG-DIRECTIVE(handle,prefix)
+//
+// Example:
+//
+// %YAML 1.1
+// %TAG ! !foo
+// %TAG !yaml! tag:yaml.org,2002:
+// ---
+//
+// The correspoding sequence of tokens:
+//
+// STREAM-START(utf-8)
+// VERSION-DIRECTIVE(1,1)
+// TAG-DIRECTIVE("!","!foo")
+// TAG-DIRECTIVE("!yaml","tag:yaml.org,2002:")
+// DOCUMENT-START
+// STREAM-END
+//
+// Note that the VERSION-DIRECTIVE and TAG-DIRECTIVE tokens occupy a whole
+// line.
+//
+// The document start and end indicators are represented by:
+//
+// DOCUMENT-START
+// DOCUMENT-END
+//
+// Note that if a YAML stream contains an implicit document (without '---'
+// and '...' indicators), no DOCUMENT-START and DOCUMENT-END tokens will be
+// produced.
+//
+// In the following examples, we present whole documents together with the
+// produced tokens.
+//
+// 1. An implicit document:
+//
+// 'a scalar'
+//
+// Tokens:
+//
+// STREAM-START(utf-8)
+// SCALAR("a scalar",single-quoted)
+// STREAM-END
+//
+// 2. An explicit document:
+//
+// ---
+// 'a scalar'
+// ...
+//
+// Tokens:
+//
+// STREAM-START(utf-8)
+// DOCUMENT-START
+// SCALAR("a scalar",single-quoted)
+// DOCUMENT-END
+// STREAM-END
+//
+// 3. Several documents in a stream:
+//
+// 'a scalar'
+// ---
+// 'another scalar'
+// ---
+// 'yet another scalar'
+//
+// Tokens:
+//
+// STREAM-START(utf-8)
+// SCALAR("a scalar",single-quoted)
+// DOCUMENT-START
+// SCALAR("another scalar",single-quoted)
+// DOCUMENT-START
+// SCALAR("yet another scalar",single-quoted)
+// STREAM-END
+//
+// We have already introduced the SCALAR token above. The following tokens are
+// used to describe aliases, anchors, tag, and scalars:
+//
+// ALIAS(anchor)
+// ANCHOR(anchor)
+// TAG(handle,suffix)
+// SCALAR(value,style)
+//
+// The following series of examples illustrate the usage of these tokens:
+//
+// 1. A recursive sequence:
+//
+// &A [ *A ]
+//
+// Tokens:
+//
+// STREAM-START(utf-8)
+// ANCHOR("A")
+// FLOW-SEQUENCE-START
+// ALIAS("A")
+// FLOW-SEQUENCE-END
+// STREAM-END
+//
+// 2. A tagged scalar:
+//
+// !!float "3.14" # A good approximation.
+//
+// Tokens:
+//
+// STREAM-START(utf-8)
+// TAG("!!","float")
+// SCALAR("3.14",double-quoted)
+// STREAM-END
+//
+// 3. Various scalar styles:
+//
+// --- # Implicit empty plain scalars do not produce tokens.
+// --- a plain scalar
+// --- 'a single-quoted scalar'
+// --- "a double-quoted scalar"
+// --- |-
+// a literal scalar
+// --- >-
+// a folded
+// scalar
+//
+// Tokens:
+//
+// STREAM-START(utf-8)
+// DOCUMENT-START
+// DOCUMENT-START
+// SCALAR("a plain scalar",plain)
+// DOCUMENT-START
+// SCALAR("a single-quoted scalar",single-quoted)
+// DOCUMENT-START
+// SCALAR("a double-quoted scalar",double-quoted)
+// DOCUMENT-START
+// SCALAR("a literal scalar",literal)
+// DOCUMENT-START
+// SCALAR("a folded scalar",folded)
+// STREAM-END
+//
+// Now it's time to review collection-related tokens. We will start with
+// flow collections:
+//
+// FLOW-SEQUENCE-START
+// FLOW-SEQUENCE-END
+// FLOW-MAPPING-START
+// FLOW-MAPPING-END
+// FLOW-ENTRY
+// KEY
+// VALUE
+//
+// The tokens FLOW-SEQUENCE-START, FLOW-SEQUENCE-END, FLOW-MAPPING-START, and
+// FLOW-MAPPING-END represent the indicators '[', ']', '{', and '}'
+// correspondingly. FLOW-ENTRY represent the ',' indicator. Finally the
+// indicators '?' and ':', which are used for denoting mapping keys and values,
+// are represented by the KEY and VALUE tokens.
+//
+// The following examples show flow collections:
+//
+// 1. A flow sequence:
+//
+// [item 1, item 2, item 3]
+//
+// Tokens:
+//
+// STREAM-START(utf-8)
+// FLOW-SEQUENCE-START
+// SCALAR("item 1",plain)
+// FLOW-ENTRY
+// SCALAR("item 2",plain)
+// FLOW-ENTRY
+// SCALAR("item 3",plain)
+// FLOW-SEQUENCE-END
+// STREAM-END
+//
+// 2. A flow mapping:
+//
+// {
+// a simple key: a value, # Note that the KEY token is produced.
+// ? a complex key: another value,
+// }
+//
+// Tokens:
+//
+// STREAM-START(utf-8)
+// FLOW-MAPPING-START
+// KEY
+// SCALAR("a simple key",plain)
+// VALUE
+// SCALAR("a value",plain)
+// FLOW-ENTRY
+// KEY
+// SCALAR("a complex key",plain)
+// VALUE
+// SCALAR("another value",plain)
+// FLOW-ENTRY
+// FLOW-MAPPING-END
+// STREAM-END
+//
+// A simple key is a key which is not denoted by the '?' indicator. Note that
+// the Scanner still produce the KEY token whenever it encounters a simple key.
+//
+// For scanning block collections, the following tokens are used (note that we
+// repeat KEY and VALUE here):
+//
+// BLOCK-SEQUENCE-START
+// BLOCK-MAPPING-START
+// BLOCK-END
+// BLOCK-ENTRY
+// KEY
+// VALUE
+//
+// The tokens BLOCK-SEQUENCE-START and BLOCK-MAPPING-START denote indentation
+// increase that precedes a block collection (cf. the INDENT token in Python).
+// The token BLOCK-END denote indentation decrease that ends a block collection
+// (cf. the DEDENT token in Python). However YAML has some syntax pecularities
+// that makes detections of these tokens more complex.
+//
+// The tokens BLOCK-ENTRY, KEY, and VALUE are used to represent the indicators
+// '-', '?', and ':' correspondingly.
+//
+// The following examples show how the tokens BLOCK-SEQUENCE-START,
+// BLOCK-MAPPING-START, and BLOCK-END are emitted by the Scanner:
+//
+// 1. Block sequences:
+//
+// - item 1
+// - item 2
+// -
+// - item 3.1
+// - item 3.2
+// -
+// key 1: value 1
+// key 2: value 2
+//
+// Tokens:
+//
+// STREAM-START(utf-8)
+// BLOCK-SEQUENCE-START
+// BLOCK-ENTRY
+// SCALAR("item 1",plain)
+// BLOCK-ENTRY
+// SCALAR("item 2",plain)
+// BLOCK-ENTRY
+// BLOCK-SEQUENCE-START
+// BLOCK-ENTRY
+// SCALAR("item 3.1",plain)
+// BLOCK-ENTRY
+// SCALAR("item 3.2",plain)
+// BLOCK-END
+// BLOCK-ENTRY
+// BLOCK-MAPPING-START
+// KEY
+// SCALAR("key 1",plain)
+// VALUE
+// SCALAR("value 1",plain)
+// KEY
+// SCALAR("key 2",plain)
+// VALUE
+// SCALAR("value 2",plain)
+// BLOCK-END
+// BLOCK-END
+// STREAM-END
+//
+// 2. Block mappings:
+//
+// a simple key: a value # The KEY token is produced here.
+// ? a complex key
+// : another value
+// a mapping:
+// key 1: value 1
+// key 2: value 2
+// a sequence:
+// - item 1
+// - item 2
+//
+// Tokens:
+//
+// STREAM-START(utf-8)
+// BLOCK-MAPPING-START
+// KEY
+// SCALAR("a simple key",plain)
+// VALUE
+// SCALAR("a value",plain)
+// KEY
+// SCALAR("a complex key",plain)
+// VALUE
+// SCALAR("another value",plain)
+// KEY
+// SCALAR("a mapping",plain)
+// BLOCK-MAPPING-START
+// KEY
+// SCALAR("key 1",plain)
+// VALUE
+// SCALAR("value 1",plain)
+// KEY
+// SCALAR("key 2",plain)
+// VALUE
+// SCALAR("value 2",plain)
+// BLOCK-END
+// KEY
+// SCALAR("a sequence",plain)
+// VALUE
+// BLOCK-SEQUENCE-START
+// BLOCK-ENTRY
+// SCALAR("item 1",plain)
+// BLOCK-ENTRY
+// SCALAR("item 2",plain)
+// BLOCK-END
+// BLOCK-END
+// STREAM-END
+//
+// YAML does not always require to start a new block collection from a new
+// line. If the current line contains only '-', '?', and ':' indicators, a new
+// block collection may start at the current line. The following examples
+// illustrate this case:
+//
+// 1. Collections in a sequence:
+//
+// - - item 1
+// - item 2
+// - key 1: value 1
+// key 2: value 2
+// - ? complex key
+// : complex value
+//
+// Tokens:
+//
+// STREAM-START(utf-8)
+// BLOCK-SEQUENCE-START
+// BLOCK-ENTRY
+// BLOCK-SEQUENCE-START
+// BLOCK-ENTRY
+// SCALAR("item 1",plain)
+// BLOCK-ENTRY
+// SCALAR("item 2",plain)
+// BLOCK-END
+// BLOCK-ENTRY
+// BLOCK-MAPPING-START
+// KEY
+// SCALAR("key 1",plain)
+// VALUE
+// SCALAR("value 1",plain)
+// KEY
+// SCALAR("key 2",plain)
+// VALUE
+// SCALAR("value 2",plain)
+// BLOCK-END
+// BLOCK-ENTRY
+// BLOCK-MAPPING-START
+// KEY
+// SCALAR("complex key")
+// VALUE
+// SCALAR("complex value")
+// BLOCK-END
+// BLOCK-END
+// STREAM-END
+//
+// 2. Collections in a mapping:
+//
+// ? a sequence
+// : - item 1
+// - item 2
+// ? a mapping
+// : key 1: value 1
+// key 2: value 2
+//
+// Tokens:
+//
+// STREAM-START(utf-8)
+// BLOCK-MAPPING-START
+// KEY
+// SCALAR("a sequence",plain)
+// VALUE
+// BLOCK-SEQUENCE-START
+// BLOCK-ENTRY
+// SCALAR("item 1",plain)
+// BLOCK-ENTRY
+// SCALAR("item 2",plain)
+// BLOCK-END
+// KEY
+// SCALAR("a mapping",plain)
+// VALUE
+// BLOCK-MAPPING-START
+// KEY
+// SCALAR("key 1",plain)
+// VALUE
+// SCALAR("value 1",plain)
+// KEY
+// SCALAR("key 2",plain)
+// VALUE
+// SCALAR("value 2",plain)
+// BLOCK-END
+// BLOCK-END
+// STREAM-END
+//
+// YAML also permits non-indented sequences if they are included into a block
+// mapping. In this case, the token BLOCK-SEQUENCE-START is not produced:
+//
+// key:
+// - item 1 # BLOCK-SEQUENCE-START is NOT produced here.
+// - item 2
+//
+// Tokens:
+//
+// STREAM-START(utf-8)
+// BLOCK-MAPPING-START
+// KEY
+// SCALAR("key",plain)
+// VALUE
+// BLOCK-ENTRY
+// SCALAR("item 1",plain)
+// BLOCK-ENTRY
+// SCALAR("item 2",plain)
+// BLOCK-END
+//
+
+// Ensure that the buffer contains the required number of characters.
+// Return true on success, false on failure (reader error or memory error).
+func cache(parser *yaml_parser_t, length int) bool {
+ // [Go] This was inlined: !cache(A, B) -> unread < B && !update(A, B)
+ return parser.unread >= length || yaml_parser_update_buffer(parser, length)
+}
+
+// Advance the buffer pointer.
+func skip(parser *yaml_parser_t) {
+ parser.mark.index++
+ parser.mark.column++
+ parser.unread--
+ parser.buffer_pos += width(parser.buffer[parser.buffer_pos])
+}
+
+func skip_line(parser *yaml_parser_t) {
+ if is_crlf(parser.buffer, parser.buffer_pos) {
+ parser.mark.index += 2
+ parser.mark.column = 0
+ parser.mark.line++
+ parser.unread -= 2
+ parser.buffer_pos += 2
+ } else if is_break(parser.buffer, parser.buffer_pos) {
+ parser.mark.index++
+ parser.mark.column = 0
+ parser.mark.line++
+ parser.unread--
+ parser.buffer_pos += width(parser.buffer[parser.buffer_pos])
+ }
+}
+
+// Copy a character to a string buffer and advance pointers.
+func read(parser *yaml_parser_t, s []byte) []byte {
+ w := width(parser.buffer[parser.buffer_pos])
+ if w == 0 {
+ panic("invalid character sequence")
+ }
+ if len(s) == 0 {
+ s = make([]byte, 0, 32)
+ }
+ if w == 1 && len(s)+w <= cap(s) {
+ s = s[:len(s)+1]
+ s[len(s)-1] = parser.buffer[parser.buffer_pos]
+ parser.buffer_pos++
+ } else {
+ s = append(s, parser.buffer[parser.buffer_pos:parser.buffer_pos+w]...)
+ parser.buffer_pos += w
+ }
+ parser.mark.index++
+ parser.mark.column++
+ parser.unread--
+ return s
+}
+
+// Copy a line break character to a string buffer and advance pointers.
+func read_line(parser *yaml_parser_t, s []byte) []byte {
+ buf := parser.buffer
+ pos := parser.buffer_pos
+ switch {
+ case buf[pos] == '\r' && buf[pos+1] == '\n':
+ // CR LF . LF
+ s = append(s, '\n')
+ parser.buffer_pos += 2
+ parser.mark.index++
+ parser.unread--
+ case buf[pos] == '\r' || buf[pos] == '\n':
+ // CR|LF . LF
+ s = append(s, '\n')
+ parser.buffer_pos += 1
+ case buf[pos] == '\xC2' && buf[pos+1] == '\x85':
+ // NEL . LF
+ s = append(s, '\n')
+ parser.buffer_pos += 2
+ case buf[pos] == '\xE2' && buf[pos+1] == '\x80' && (buf[pos+2] == '\xA8' || buf[pos+2] == '\xA9'):
+ // LS|PS . LS|PS
+ s = append(s, buf[parser.buffer_pos:pos+3]...)
+ parser.buffer_pos += 3
+ default:
+ return s
+ }
+ parser.mark.index++
+ parser.mark.column = 0
+ parser.mark.line++
+ parser.unread--
+ return s
+}
+
+// Get the next token.
+func yaml_parser_scan(parser *yaml_parser_t, token *yaml_token_t) bool {
+ // Erase the token object.
+ *token = yaml_token_t{} // [Go] Is this necessary?
+
+ // No tokens after STREAM-END or error.
+ if parser.stream_end_produced || parser.error != yaml_NO_ERROR {
+ return true
+ }
+
+ // Ensure that the tokens queue contains enough tokens.
+ if !parser.token_available {
+ if !yaml_parser_fetch_more_tokens(parser) {
+ return false
+ }
+ }
+
+ // Fetch the next token from the queue.
+ *token = parser.tokens[parser.tokens_head]
+ parser.tokens_head++
+ parser.tokens_parsed++
+ parser.token_available = false
+
+ if token.typ == yaml_STREAM_END_TOKEN {
+ parser.stream_end_produced = true
+ }
+ return true
+}
+
+// Set the scanner error and return false.
+func yaml_parser_set_scanner_error(parser *yaml_parser_t, context string, context_mark yaml_mark_t, problem string) bool {
+ parser.error = yaml_SCANNER_ERROR
+ parser.context = context
+ parser.context_mark = context_mark
+ parser.problem = problem
+ parser.problem_mark = parser.mark
+ return false
+}
+
+func yaml_parser_set_scanner_tag_error(parser *yaml_parser_t, directive bool, context_mark yaml_mark_t, problem string) bool {
+ context := "while parsing a tag"
+ if directive {
+ context = "while parsing a %TAG directive"
+ }
+ return yaml_parser_set_scanner_error(parser, context, context_mark, problem)
+}
+
+func trace(args ...interface{}) func() {
+ pargs := append([]interface{}{"+++"}, args...)
+ fmt.Println(pargs...)
+ pargs = append([]interface{}{"---"}, args...)
+ return func() { fmt.Println(pargs...) }
+}
+
+// Ensure that the tokens queue contains at least one token which can be
+// returned to the Parser.
+func yaml_parser_fetch_more_tokens(parser *yaml_parser_t) bool {
+ // While we need more tokens to fetch, do it.
+ for {
+ // Check if we really need to fetch more tokens.
+ need_more_tokens := false
+
+ if parser.tokens_head == len(parser.tokens) {
+ // Queue is empty.
+ need_more_tokens = true
+ } else {
+ // Check if any potential simple key may occupy the head position.
+ if !yaml_parser_stale_simple_keys(parser) {
+ return false
+ }
+
+ for i := range parser.simple_keys {
+ simple_key := &parser.simple_keys[i]
+ if simple_key.possible && simple_key.token_number == parser.tokens_parsed {
+ need_more_tokens = true
+ break
+ }
+ }
+ }
+
+ // We are finished.
+ if !need_more_tokens {
+ break
+ }
+ // Fetch the next token.
+ if !yaml_parser_fetch_next_token(parser) {
+ return false
+ }
+ }
+
+ parser.token_available = true
+ return true
+}
+
+// The dispatcher for token fetchers.
+func yaml_parser_fetch_next_token(parser *yaml_parser_t) bool {
+ // Ensure that the buffer is initialized.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+
+ // Check if we just started scanning. Fetch STREAM-START then.
+ if !parser.stream_start_produced {
+ return yaml_parser_fetch_stream_start(parser)
+ }
+
+ // Eat whitespaces and comments until we reach the next token.
+ if !yaml_parser_scan_to_next_token(parser) {
+ return false
+ }
+
+ // Remove obsolete potential simple keys.
+ if !yaml_parser_stale_simple_keys(parser) {
+ return false
+ }
+
+ // Check the indentation level against the current column.
+ if !yaml_parser_unroll_indent(parser, parser.mark.column) {
+ return false
+ }
+
+ // Ensure that the buffer contains at least 4 characters. 4 is the length
+ // of the longest indicators ('--- ' and '... ').
+ if parser.unread < 4 && !yaml_parser_update_buffer(parser, 4) {
+ return false
+ }
+
+ // Is it the end of the stream?
+ if is_z(parser.buffer, parser.buffer_pos) {
+ return yaml_parser_fetch_stream_end(parser)
+ }
+
+ // Is it a directive?
+ if parser.mark.column == 0 && parser.buffer[parser.buffer_pos] == '%' {
+ return yaml_parser_fetch_directive(parser)
+ }
+
+ buf := parser.buffer
+ pos := parser.buffer_pos
+
+ // Is it the document start indicator?
+ if parser.mark.column == 0 && buf[pos] == '-' && buf[pos+1] == '-' && buf[pos+2] == '-' && is_blankz(buf, pos+3) {
+ return yaml_parser_fetch_document_indicator(parser, yaml_DOCUMENT_START_TOKEN)
+ }
+
+ // Is it the document end indicator?
+ if parser.mark.column == 0 && buf[pos] == '.' && buf[pos+1] == '.' && buf[pos+2] == '.' && is_blankz(buf, pos+3) {
+ return yaml_parser_fetch_document_indicator(parser, yaml_DOCUMENT_END_TOKEN)
+ }
+
+ // Is it the flow sequence start indicator?
+ if buf[pos] == '[' {
+ return yaml_parser_fetch_flow_collection_start(parser, yaml_FLOW_SEQUENCE_START_TOKEN)
+ }
+
+ // Is it the flow mapping start indicator?
+ if parser.buffer[parser.buffer_pos] == '{' {
+ return yaml_parser_fetch_flow_collection_start(parser, yaml_FLOW_MAPPING_START_TOKEN)
+ }
+
+ // Is it the flow sequence end indicator?
+ if parser.buffer[parser.buffer_pos] == ']' {
+ return yaml_parser_fetch_flow_collection_end(parser,
+ yaml_FLOW_SEQUENCE_END_TOKEN)
+ }
+
+ // Is it the flow mapping end indicator?
+ if parser.buffer[parser.buffer_pos] == '}' {
+ return yaml_parser_fetch_flow_collection_end(parser,
+ yaml_FLOW_MAPPING_END_TOKEN)
+ }
+
+ // Is it the flow entry indicator?
+ if parser.buffer[parser.buffer_pos] == ',' {
+ return yaml_parser_fetch_flow_entry(parser)
+ }
+
+ // Is it the block entry indicator?
+ if parser.buffer[parser.buffer_pos] == '-' && is_blankz(parser.buffer, parser.buffer_pos+1) {
+ return yaml_parser_fetch_block_entry(parser)
+ }
+
+ // Is it the key indicator?
+ if parser.buffer[parser.buffer_pos] == '?' && (parser.flow_level > 0 || is_blankz(parser.buffer, parser.buffer_pos+1)) {
+ return yaml_parser_fetch_key(parser)
+ }
+
+ // Is it the value indicator?
+ if parser.buffer[parser.buffer_pos] == ':' && (parser.flow_level > 0 || is_blankz(parser.buffer, parser.buffer_pos+1)) {
+ return yaml_parser_fetch_value(parser)
+ }
+
+ // Is it an alias?
+ if parser.buffer[parser.buffer_pos] == '*' {
+ return yaml_parser_fetch_anchor(parser, yaml_ALIAS_TOKEN)
+ }
+
+ // Is it an anchor?
+ if parser.buffer[parser.buffer_pos] == '&' {
+ return yaml_parser_fetch_anchor(parser, yaml_ANCHOR_TOKEN)
+ }
+
+ // Is it a tag?
+ if parser.buffer[parser.buffer_pos] == '!' {
+ return yaml_parser_fetch_tag(parser)
+ }
+
+ // Is it a literal scalar?
+ if parser.buffer[parser.buffer_pos] == '|' && parser.flow_level == 0 {
+ return yaml_parser_fetch_block_scalar(parser, true)
+ }
+
+ // Is it a folded scalar?
+ if parser.buffer[parser.buffer_pos] == '>' && parser.flow_level == 0 {
+ return yaml_parser_fetch_block_scalar(parser, false)
+ }
+
+ // Is it a single-quoted scalar?
+ if parser.buffer[parser.buffer_pos] == '\'' {
+ return yaml_parser_fetch_flow_scalar(parser, true)
+ }
+
+ // Is it a double-quoted scalar?
+ if parser.buffer[parser.buffer_pos] == '"' {
+ return yaml_parser_fetch_flow_scalar(parser, false)
+ }
+
+ // Is it a plain scalar?
+ //
+ // A plain scalar may start with any non-blank characters except
+ //
+ // '-', '?', ':', ',', '[', ']', '{', '}',
+ // '#', '&', '*', '!', '|', '>', '\'', '\"',
+ // '%', '@', '`'.
+ //
+ // In the block context (and, for the '-' indicator, in the flow context
+ // too), it may also start with the characters
+ //
+ // '-', '?', ':'
+ //
+ // if it is followed by a non-space character.
+ //
+ // The last rule is more restrictive than the specification requires.
+ // [Go] Make this logic more reasonable.
+ //switch parser.buffer[parser.buffer_pos] {
+ //case '-', '?', ':', ',', '?', '-', ',', ':', ']', '[', '}', '{', '&', '#', '!', '*', '>', '|', '"', '\'', '@', '%', '-', '`':
+ //}
+ if !(is_blankz(parser.buffer, parser.buffer_pos) || parser.buffer[parser.buffer_pos] == '-' ||
+ parser.buffer[parser.buffer_pos] == '?' || parser.buffer[parser.buffer_pos] == ':' ||
+ parser.buffer[parser.buffer_pos] == ',' || parser.buffer[parser.buffer_pos] == '[' ||
+ parser.buffer[parser.buffer_pos] == ']' || parser.buffer[parser.buffer_pos] == '{' ||
+ parser.buffer[parser.buffer_pos] == '}' || parser.buffer[parser.buffer_pos] == '#' ||
+ parser.buffer[parser.buffer_pos] == '&' || parser.buffer[parser.buffer_pos] == '*' ||
+ parser.buffer[parser.buffer_pos] == '!' || parser.buffer[parser.buffer_pos] == '|' ||
+ parser.buffer[parser.buffer_pos] == '>' || parser.buffer[parser.buffer_pos] == '\'' ||
+ parser.buffer[parser.buffer_pos] == '"' || parser.buffer[parser.buffer_pos] == '%' ||
+ parser.buffer[parser.buffer_pos] == '@' || parser.buffer[parser.buffer_pos] == '`') ||
+ (parser.buffer[parser.buffer_pos] == '-' && !is_blank(parser.buffer, parser.buffer_pos+1)) ||
+ (parser.flow_level == 0 &&
+ (parser.buffer[parser.buffer_pos] == '?' || parser.buffer[parser.buffer_pos] == ':') &&
+ !is_blankz(parser.buffer, parser.buffer_pos+1)) {
+ return yaml_parser_fetch_plain_scalar(parser)
+ }
+
+ // If we don't determine the token type so far, it is an error.
+ return yaml_parser_set_scanner_error(parser,
+ "while scanning for the next token", parser.mark,
+ "found character that cannot start any token")
+}
+
+// Check the list of potential simple keys and remove the positions that
+// cannot contain simple keys anymore.
+func yaml_parser_stale_simple_keys(parser *yaml_parser_t) bool {
+ // Check for a potential simple key for each flow level.
+ for i := range parser.simple_keys {
+ simple_key := &parser.simple_keys[i]
+
+ // The specification requires that a simple key
+ //
+ // - is limited to a single line,
+ // - is shorter than 1024 characters.
+ if simple_key.possible && (simple_key.mark.line < parser.mark.line || simple_key.mark.index+1024 < parser.mark.index) {
+
+ // Check if the potential simple key to be removed is required.
+ if simple_key.required {
+ return yaml_parser_set_scanner_error(parser,
+ "while scanning a simple key", simple_key.mark,
+ "could not find expected ':'")
+ }
+ simple_key.possible = false
+ }
+ }
+ return true
+}
+
+// Check if a simple key may start at the current position and add it if
+// needed.
+func yaml_parser_save_simple_key(parser *yaml_parser_t) bool {
+ // A simple key is required at the current position if the scanner is in
+ // the block context and the current column coincides with the indentation
+ // level.
+
+ required := parser.flow_level == 0 && parser.indent == parser.mark.column
+
+ // A simple key is required only when it is the first token in the current
+ // line. Therefore it is always allowed. But we add a check anyway.
+ if required && !parser.simple_key_allowed {
+ panic("should not happen")
+ }
+
+ //
+ // If the current position may start a simple key, save it.
+ //
+ if parser.simple_key_allowed {
+ simple_key := yaml_simple_key_t{
+ possible: true,
+ required: required,
+ token_number: parser.tokens_parsed + (len(parser.tokens) - parser.tokens_head),
+ }
+ simple_key.mark = parser.mark
+
+ if !yaml_parser_remove_simple_key(parser) {
+ return false
+ }
+ parser.simple_keys[len(parser.simple_keys)-1] = simple_key
+ }
+ return true
+}
+
+// Remove a potential simple key at the current flow level.
+func yaml_parser_remove_simple_key(parser *yaml_parser_t) bool {
+ i := len(parser.simple_keys) - 1
+ if parser.simple_keys[i].possible {
+ // If the key is required, it is an error.
+ if parser.simple_keys[i].required {
+ return yaml_parser_set_scanner_error(parser,
+ "while scanning a simple key", parser.simple_keys[i].mark,
+ "could not find expected ':'")
+ }
+ }
+ // Remove the key from the stack.
+ parser.simple_keys[i].possible = false
+ return true
+}
+
+// Increase the flow level and resize the simple key list if needed.
+func yaml_parser_increase_flow_level(parser *yaml_parser_t) bool {
+ // Reset the simple key on the next level.
+ parser.simple_keys = append(parser.simple_keys, yaml_simple_key_t{})
+
+ // Increase the flow level.
+ parser.flow_level++
+ return true
+}
+
+// Decrease the flow level.
+func yaml_parser_decrease_flow_level(parser *yaml_parser_t) bool {
+ if parser.flow_level > 0 {
+ parser.flow_level--
+ parser.simple_keys = parser.simple_keys[:len(parser.simple_keys)-1]
+ }
+ return true
+}
+
+// Push the current indentation level to the stack and set the new level
+// the current column is greater than the indentation level. In this case,
+// append or insert the specified token into the token queue.
+func yaml_parser_roll_indent(parser *yaml_parser_t, column, number int, typ yaml_token_type_t, mark yaml_mark_t) bool {
+ // In the flow context, do nothing.
+ if parser.flow_level > 0 {
+ return true
+ }
+
+ if parser.indent < column {
+ // Push the current indentation level to the stack and set the new
+ // indentation level.
+ parser.indents = append(parser.indents, parser.indent)
+ parser.indent = column
+
+ // Create a token and insert it into the queue.
+ token := yaml_token_t{
+ typ: typ,
+ start_mark: mark,
+ end_mark: mark,
+ }
+ if number > -1 {
+ number -= parser.tokens_parsed
+ }
+ yaml_insert_token(parser, number, &token)
+ }
+ return true
+}
+
+// Pop indentation levels from the indents stack until the current level
+// becomes less or equal to the column. For each indentation level, append
+// the BLOCK-END token.
+func yaml_parser_unroll_indent(parser *yaml_parser_t, column int) bool {
+ // In the flow context, do nothing.
+ if parser.flow_level > 0 {
+ return true
+ }
+
+ // Loop through the indentation levels in the stack.
+ for parser.indent > column {
+ // Create a token and append it to the queue.
+ token := yaml_token_t{
+ typ: yaml_BLOCK_END_TOKEN,
+ start_mark: parser.mark,
+ end_mark: parser.mark,
+ }
+ yaml_insert_token(parser, -1, &token)
+
+ // Pop the indentation level.
+ parser.indent = parser.indents[len(parser.indents)-1]
+ parser.indents = parser.indents[:len(parser.indents)-1]
+ }
+ return true
+}
+
+// Initialize the scanner and produce the STREAM-START token.
+func yaml_parser_fetch_stream_start(parser *yaml_parser_t) bool {
+
+ // Set the initial indentation.
+ parser.indent = -1
+
+ // Initialize the simple key stack.
+ parser.simple_keys = append(parser.simple_keys, yaml_simple_key_t{})
+
+ // A simple key is allowed at the beginning of the stream.
+ parser.simple_key_allowed = true
+
+ // We have started.
+ parser.stream_start_produced = true
+
+ // Create the STREAM-START token and append it to the queue.
+ token := yaml_token_t{
+ typ: yaml_STREAM_START_TOKEN,
+ start_mark: parser.mark,
+ end_mark: parser.mark,
+ encoding: parser.encoding,
+ }
+ yaml_insert_token(parser, -1, &token)
+ return true
+}
+
+// Produce the STREAM-END token and shut down the scanner.
+func yaml_parser_fetch_stream_end(parser *yaml_parser_t) bool {
+
+ // Force new line.
+ if parser.mark.column != 0 {
+ parser.mark.column = 0
+ parser.mark.line++
+ }
+
+ // Reset the indentation level.
+ if !yaml_parser_unroll_indent(parser, -1) {
+ return false
+ }
+
+ // Reset simple keys.
+ if !yaml_parser_remove_simple_key(parser) {
+ return false
+ }
+
+ parser.simple_key_allowed = false
+
+ // Create the STREAM-END token and append it to the queue.
+ token := yaml_token_t{
+ typ: yaml_STREAM_END_TOKEN,
+ start_mark: parser.mark,
+ end_mark: parser.mark,
+ }
+ yaml_insert_token(parser, -1, &token)
+ return true
+}
+
+// Produce a VERSION-DIRECTIVE or TAG-DIRECTIVE token.
+func yaml_parser_fetch_directive(parser *yaml_parser_t) bool {
+ // Reset the indentation level.
+ if !yaml_parser_unroll_indent(parser, -1) {
+ return false
+ }
+
+ // Reset simple keys.
+ if !yaml_parser_remove_simple_key(parser) {
+ return false
+ }
+
+ parser.simple_key_allowed = false
+
+ // Create the YAML-DIRECTIVE or TAG-DIRECTIVE token.
+ token := yaml_token_t{}
+ if !yaml_parser_scan_directive(parser, &token) {
+ return false
+ }
+ // Append the token to the queue.
+ yaml_insert_token(parser, -1, &token)
+ return true
+}
+
+// Produce the DOCUMENT-START or DOCUMENT-END token.
+func yaml_parser_fetch_document_indicator(parser *yaml_parser_t, typ yaml_token_type_t) bool {
+ // Reset the indentation level.
+ if !yaml_parser_unroll_indent(parser, -1) {
+ return false
+ }
+
+ // Reset simple keys.
+ if !yaml_parser_remove_simple_key(parser) {
+ return false
+ }
+
+ parser.simple_key_allowed = false
+
+ // Consume the token.
+ start_mark := parser.mark
+
+ skip(parser)
+ skip(parser)
+ skip(parser)
+
+ end_mark := parser.mark
+
+ // Create the DOCUMENT-START or DOCUMENT-END token.
+ token := yaml_token_t{
+ typ: typ,
+ start_mark: start_mark,
+ end_mark: end_mark,
+ }
+ // Append the token to the queue.
+ yaml_insert_token(parser, -1, &token)
+ return true
+}
+
+// Produce the FLOW-SEQUENCE-START or FLOW-MAPPING-START token.
+func yaml_parser_fetch_flow_collection_start(parser *yaml_parser_t, typ yaml_token_type_t) bool {
+ // The indicators '[' and '{' may start a simple key.
+ if !yaml_parser_save_simple_key(parser) {
+ return false
+ }
+
+ // Increase the flow level.
+ if !yaml_parser_increase_flow_level(parser) {
+ return false
+ }
+
+ // A simple key may follow the indicators '[' and '{'.
+ parser.simple_key_allowed = true
+
+ // Consume the token.
+ start_mark := parser.mark
+ skip(parser)
+ end_mark := parser.mark
+
+ // Create the FLOW-SEQUENCE-START of FLOW-MAPPING-START token.
+ token := yaml_token_t{
+ typ: typ,
+ start_mark: start_mark,
+ end_mark: end_mark,
+ }
+ // Append the token to the queue.
+ yaml_insert_token(parser, -1, &token)
+ return true
+}
+
+// Produce the FLOW-SEQUENCE-END or FLOW-MAPPING-END token.
+func yaml_parser_fetch_flow_collection_end(parser *yaml_parser_t, typ yaml_token_type_t) bool {
+ // Reset any potential simple key on the current flow level.
+ if !yaml_parser_remove_simple_key(parser) {
+ return false
+ }
+
+ // Decrease the flow level.
+ if !yaml_parser_decrease_flow_level(parser) {
+ return false
+ }
+
+ // No simple keys after the indicators ']' and '}'.
+ parser.simple_key_allowed = false
+
+ // Consume the token.
+
+ start_mark := parser.mark
+ skip(parser)
+ end_mark := parser.mark
+
+ // Create the FLOW-SEQUENCE-END of FLOW-MAPPING-END token.
+ token := yaml_token_t{
+ typ: typ,
+ start_mark: start_mark,
+ end_mark: end_mark,
+ }
+ // Append the token to the queue.
+ yaml_insert_token(parser, -1, &token)
+ return true
+}
+
+// Produce the FLOW-ENTRY token.
+func yaml_parser_fetch_flow_entry(parser *yaml_parser_t) bool {
+ // Reset any potential simple keys on the current flow level.
+ if !yaml_parser_remove_simple_key(parser) {
+ return false
+ }
+
+ // Simple keys are allowed after ','.
+ parser.simple_key_allowed = true
+
+ // Consume the token.
+ start_mark := parser.mark
+ skip(parser)
+ end_mark := parser.mark
+
+ // Create the FLOW-ENTRY token and append it to the queue.
+ token := yaml_token_t{
+ typ: yaml_FLOW_ENTRY_TOKEN,
+ start_mark: start_mark,
+ end_mark: end_mark,
+ }
+ yaml_insert_token(parser, -1, &token)
+ return true
+}
+
+// Produce the BLOCK-ENTRY token.
+func yaml_parser_fetch_block_entry(parser *yaml_parser_t) bool {
+ // Check if the scanner is in the block context.
+ if parser.flow_level == 0 {
+ // Check if we are allowed to start a new entry.
+ if !parser.simple_key_allowed {
+ return yaml_parser_set_scanner_error(parser, "", parser.mark,
+ "block sequence entries are not allowed in this context")
+ }
+ // Add the BLOCK-SEQUENCE-START token if needed.
+ if !yaml_parser_roll_indent(parser, parser.mark.column, -1, yaml_BLOCK_SEQUENCE_START_TOKEN, parser.mark) {
+ return false
+ }
+ } else {
+ // It is an error for the '-' indicator to occur in the flow context,
+ // but we let the Parser detect and report about it because the Parser
+ // is able to point to the context.
+ }
+
+ // Reset any potential simple keys on the current flow level.
+ if !yaml_parser_remove_simple_key(parser) {
+ return false
+ }
+
+ // Simple keys are allowed after '-'.
+ parser.simple_key_allowed = true
+
+ // Consume the token.
+ start_mark := parser.mark
+ skip(parser)
+ end_mark := parser.mark
+
+ // Create the BLOCK-ENTRY token and append it to the queue.
+ token := yaml_token_t{
+ typ: yaml_BLOCK_ENTRY_TOKEN,
+ start_mark: start_mark,
+ end_mark: end_mark,
+ }
+ yaml_insert_token(parser, -1, &token)
+ return true
+}
+
+// Produce the KEY token.
+func yaml_parser_fetch_key(parser *yaml_parser_t) bool {
+
+ // In the block context, additional checks are required.
+ if parser.flow_level == 0 {
+ // Check if we are allowed to start a new key (not nessesary simple).
+ if !parser.simple_key_allowed {
+ return yaml_parser_set_scanner_error(parser, "", parser.mark,
+ "mapping keys are not allowed in this context")
+ }
+ // Add the BLOCK-MAPPING-START token if needed.
+ if !yaml_parser_roll_indent(parser, parser.mark.column, -1, yaml_BLOCK_MAPPING_START_TOKEN, parser.mark) {
+ return false
+ }
+ }
+
+ // Reset any potential simple keys on the current flow level.
+ if !yaml_parser_remove_simple_key(parser) {
+ return false
+ }
+
+ // Simple keys are allowed after '?' in the block context.
+ parser.simple_key_allowed = parser.flow_level == 0
+
+ // Consume the token.
+ start_mark := parser.mark
+ skip(parser)
+ end_mark := parser.mark
+
+ // Create the KEY token and append it to the queue.
+ token := yaml_token_t{
+ typ: yaml_KEY_TOKEN,
+ start_mark: start_mark,
+ end_mark: end_mark,
+ }
+ yaml_insert_token(parser, -1, &token)
+ return true
+}
+
+// Produce the VALUE token.
+func yaml_parser_fetch_value(parser *yaml_parser_t) bool {
+
+ simple_key := &parser.simple_keys[len(parser.simple_keys)-1]
+
+ // Have we found a simple key?
+ if simple_key.possible {
+ // Create the KEY token and insert it into the queue.
+ token := yaml_token_t{
+ typ: yaml_KEY_TOKEN,
+ start_mark: simple_key.mark,
+ end_mark: simple_key.mark,
+ }
+ yaml_insert_token(parser, simple_key.token_number-parser.tokens_parsed, &token)
+
+ // In the block context, we may need to add the BLOCK-MAPPING-START token.
+ if !yaml_parser_roll_indent(parser, simple_key.mark.column,
+ simple_key.token_number,
+ yaml_BLOCK_MAPPING_START_TOKEN, simple_key.mark) {
+ return false
+ }
+
+ // Remove the simple key.
+ simple_key.possible = false
+
+ // A simple key cannot follow another simple key.
+ parser.simple_key_allowed = false
+
+ } else {
+ // The ':' indicator follows a complex key.
+
+ // In the block context, extra checks are required.
+ if parser.flow_level == 0 {
+
+ // Check if we are allowed to start a complex value.
+ if !parser.simple_key_allowed {
+ return yaml_parser_set_scanner_error(parser, "", parser.mark,
+ "mapping values are not allowed in this context")
+ }
+
+ // Add the BLOCK-MAPPING-START token if needed.
+ if !yaml_parser_roll_indent(parser, parser.mark.column, -1, yaml_BLOCK_MAPPING_START_TOKEN, parser.mark) {
+ return false
+ }
+ }
+
+ // Simple keys after ':' are allowed in the block context.
+ parser.simple_key_allowed = parser.flow_level == 0
+ }
+
+ // Consume the token.
+ start_mark := parser.mark
+ skip(parser)
+ end_mark := parser.mark
+
+ // Create the VALUE token and append it to the queue.
+ token := yaml_token_t{
+ typ: yaml_VALUE_TOKEN,
+ start_mark: start_mark,
+ end_mark: end_mark,
+ }
+ yaml_insert_token(parser, -1, &token)
+ return true
+}
+
+// Produce the ALIAS or ANCHOR token.
+func yaml_parser_fetch_anchor(parser *yaml_parser_t, typ yaml_token_type_t) bool {
+ // An anchor or an alias could be a simple key.
+ if !yaml_parser_save_simple_key(parser) {
+ return false
+ }
+
+ // A simple key cannot follow an anchor or an alias.
+ parser.simple_key_allowed = false
+
+ // Create the ALIAS or ANCHOR token and append it to the queue.
+ var token yaml_token_t
+ if !yaml_parser_scan_anchor(parser, &token, typ) {
+ return false
+ }
+ yaml_insert_token(parser, -1, &token)
+ return true
+}
+
+// Produce the TAG token.
+func yaml_parser_fetch_tag(parser *yaml_parser_t) bool {
+ // A tag could be a simple key.
+ if !yaml_parser_save_simple_key(parser) {
+ return false
+ }
+
+ // A simple key cannot follow a tag.
+ parser.simple_key_allowed = false
+
+ // Create the TAG token and append it to the queue.
+ var token yaml_token_t
+ if !yaml_parser_scan_tag(parser, &token) {
+ return false
+ }
+ yaml_insert_token(parser, -1, &token)
+ return true
+}
+
+// Produce the SCALAR(...,literal) or SCALAR(...,folded) tokens.
+func yaml_parser_fetch_block_scalar(parser *yaml_parser_t, literal bool) bool {
+ // Remove any potential simple keys.
+ if !yaml_parser_remove_simple_key(parser) {
+ return false
+ }
+
+ // A simple key may follow a block scalar.
+ parser.simple_key_allowed = true
+
+ // Create the SCALAR token and append it to the queue.
+ var token yaml_token_t
+ if !yaml_parser_scan_block_scalar(parser, &token, literal) {
+ return false
+ }
+ yaml_insert_token(parser, -1, &token)
+ return true
+}
+
+// Produce the SCALAR(...,single-quoted) or SCALAR(...,double-quoted) tokens.
+func yaml_parser_fetch_flow_scalar(parser *yaml_parser_t, single bool) bool {
+ // A plain scalar could be a simple key.
+ if !yaml_parser_save_simple_key(parser) {
+ return false
+ }
+
+ // A simple key cannot follow a flow scalar.
+ parser.simple_key_allowed = false
+
+ // Create the SCALAR token and append it to the queue.
+ var token yaml_token_t
+ if !yaml_parser_scan_flow_scalar(parser, &token, single) {
+ return false
+ }
+ yaml_insert_token(parser, -1, &token)
+ return true
+}
+
+// Produce the SCALAR(...,plain) token.
+func yaml_parser_fetch_plain_scalar(parser *yaml_parser_t) bool {
+ // A plain scalar could be a simple key.
+ if !yaml_parser_save_simple_key(parser) {
+ return false
+ }
+
+ // A simple key cannot follow a flow scalar.
+ parser.simple_key_allowed = false
+
+ // Create the SCALAR token and append it to the queue.
+ var token yaml_token_t
+ if !yaml_parser_scan_plain_scalar(parser, &token) {
+ return false
+ }
+ yaml_insert_token(parser, -1, &token)
+ return true
+}
+
+// Eat whitespaces and comments until the next token is found.
+func yaml_parser_scan_to_next_token(parser *yaml_parser_t) bool {
+
+ // Until the next token is not found.
+ for {
+ // Allow the BOM mark to start a line.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ if parser.mark.column == 0 && is_bom(parser.buffer, parser.buffer_pos) {
+ skip(parser)
+ }
+
+ // Eat whitespaces.
+ // Tabs are allowed:
+ // - in the flow context
+ // - in the block context, but not at the beginning of the line or
+ // after '-', '?', or ':' (complex value).
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+
+ for parser.buffer[parser.buffer_pos] == ' ' || ((parser.flow_level > 0 || !parser.simple_key_allowed) && parser.buffer[parser.buffer_pos] == '\t') {
+ skip(parser)
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ }
+
+ // Eat a comment until a line break.
+ if parser.buffer[parser.buffer_pos] == '#' {
+ for !is_breakz(parser.buffer, parser.buffer_pos) {
+ skip(parser)
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ }
+ }
+
+ // If it is a line break, eat it.
+ if is_break(parser.buffer, parser.buffer_pos) {
+ if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+ return false
+ }
+ skip_line(parser)
+
+ // In the block context, a new line may start a simple key.
+ if parser.flow_level == 0 {
+ parser.simple_key_allowed = true
+ }
+ } else {
+ break // We have found a token.
+ }
+ }
+
+ return true
+}
+
+// Scan a YAML-DIRECTIVE or TAG-DIRECTIVE token.
+//
+// Scope:
+// %YAML 1.1 # a comment \n
+// ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+// %TAG !yaml! tag:yaml.org,2002: \n
+// ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+//
+func yaml_parser_scan_directive(parser *yaml_parser_t, token *yaml_token_t) bool {
+ // Eat '%'.
+ start_mark := parser.mark
+ skip(parser)
+
+ // Scan the directive name.
+ var name []byte
+ if !yaml_parser_scan_directive_name(parser, start_mark, &name) {
+ return false
+ }
+
+ // Is it a YAML directive?
+ if bytes.Equal(name, []byte("YAML")) {
+ // Scan the VERSION directive value.
+ var major, minor int8
+ if !yaml_parser_scan_version_directive_value(parser, start_mark, &major, &minor) {
+ return false
+ }
+ end_mark := parser.mark
+
+ // Create a VERSION-DIRECTIVE token.
+ *token = yaml_token_t{
+ typ: yaml_VERSION_DIRECTIVE_TOKEN,
+ start_mark: start_mark,
+ end_mark: end_mark,
+ major: major,
+ minor: minor,
+ }
+
+ // Is it a TAG directive?
+ } else if bytes.Equal(name, []byte("TAG")) {
+ // Scan the TAG directive value.
+ var handle, prefix []byte
+ if !yaml_parser_scan_tag_directive_value(parser, start_mark, &handle, &prefix) {
+ return false
+ }
+ end_mark := parser.mark
+
+ // Create a TAG-DIRECTIVE token.
+ *token = yaml_token_t{
+ typ: yaml_TAG_DIRECTIVE_TOKEN,
+ start_mark: start_mark,
+ end_mark: end_mark,
+ value: handle,
+ prefix: prefix,
+ }
+
+ // Unknown directive.
+ } else {
+ yaml_parser_set_scanner_error(parser, "while scanning a directive",
+ start_mark, "found unknown directive name")
+ return false
+ }
+
+ // Eat the rest of the line including any comments.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+
+ for is_blank(parser.buffer, parser.buffer_pos) {
+ skip(parser)
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ }
+
+ if parser.buffer[parser.buffer_pos] == '#' {
+ for !is_breakz(parser.buffer, parser.buffer_pos) {
+ skip(parser)
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ }
+ }
+
+ // Check if we are at the end of the line.
+ if !is_breakz(parser.buffer, parser.buffer_pos) {
+ yaml_parser_set_scanner_error(parser, "while scanning a directive",
+ start_mark, "did not find expected comment or line break")
+ return false
+ }
+
+ // Eat a line break.
+ if is_break(parser.buffer, parser.buffer_pos) {
+ if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+ return false
+ }
+ skip_line(parser)
+ }
+
+ return true
+}
+
+// Scan the directive name.
+//
+// Scope:
+// %YAML 1.1 # a comment \n
+// ^^^^
+// %TAG !yaml! tag:yaml.org,2002: \n
+// ^^^
+//
+func yaml_parser_scan_directive_name(parser *yaml_parser_t, start_mark yaml_mark_t, name *[]byte) bool {
+ // Consume the directive name.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+
+ var s []byte
+ for is_alpha(parser.buffer, parser.buffer_pos) {
+ s = read(parser, s)
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ }
+
+ // Check if the name is empty.
+ if len(s) == 0 {
+ yaml_parser_set_scanner_error(parser, "while scanning a directive",
+ start_mark, "could not find expected directive name")
+ return false
+ }
+
+ // Check for an blank character after the name.
+ if !is_blankz(parser.buffer, parser.buffer_pos) {
+ yaml_parser_set_scanner_error(parser, "while scanning a directive",
+ start_mark, "found unexpected non-alphabetical character")
+ return false
+ }
+ *name = s
+ return true
+}
+
+// Scan the value of VERSION-DIRECTIVE.
+//
+// Scope:
+// %YAML 1.1 # a comment \n
+// ^^^^^^
+func yaml_parser_scan_version_directive_value(parser *yaml_parser_t, start_mark yaml_mark_t, major, minor *int8) bool {
+ // Eat whitespaces.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ for is_blank(parser.buffer, parser.buffer_pos) {
+ skip(parser)
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ }
+
+ // Consume the major version number.
+ if !yaml_parser_scan_version_directive_number(parser, start_mark, major) {
+ return false
+ }
+
+ // Eat '.'.
+ if parser.buffer[parser.buffer_pos] != '.' {
+ return yaml_parser_set_scanner_error(parser, "while scanning a %YAML directive",
+ start_mark, "did not find expected digit or '.' character")
+ }
+
+ skip(parser)
+
+ // Consume the minor version number.
+ if !yaml_parser_scan_version_directive_number(parser, start_mark, minor) {
+ return false
+ }
+ return true
+}
+
+const max_number_length = 2
+
+// Scan the version number of VERSION-DIRECTIVE.
+//
+// Scope:
+// %YAML 1.1 # a comment \n
+// ^
+// %YAML 1.1 # a comment \n
+// ^
+func yaml_parser_scan_version_directive_number(parser *yaml_parser_t, start_mark yaml_mark_t, number *int8) bool {
+
+ // Repeat while the next character is digit.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ var value, length int8
+ for is_digit(parser.buffer, parser.buffer_pos) {
+ // Check if the number is too long.
+ length++
+ if length > max_number_length {
+ return yaml_parser_set_scanner_error(parser, "while scanning a %YAML directive",
+ start_mark, "found extremely long version number")
+ }
+ value = value*10 + int8(as_digit(parser.buffer, parser.buffer_pos))
+ skip(parser)
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ }
+
+ // Check if the number was present.
+ if length == 0 {
+ return yaml_parser_set_scanner_error(parser, "while scanning a %YAML directive",
+ start_mark, "did not find expected version number")
+ }
+ *number = value
+ return true
+}
+
+// Scan the value of a TAG-DIRECTIVE token.
+//
+// Scope:
+// %TAG !yaml! tag:yaml.org,2002: \n
+// ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+//
+func yaml_parser_scan_tag_directive_value(parser *yaml_parser_t, start_mark yaml_mark_t, handle, prefix *[]byte) bool {
+ var handle_value, prefix_value []byte
+
+ // Eat whitespaces.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+
+ for is_blank(parser.buffer, parser.buffer_pos) {
+ skip(parser)
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ }
+
+ // Scan a handle.
+ if !yaml_parser_scan_tag_handle(parser, true, start_mark, &handle_value) {
+ return false
+ }
+
+ // Expect a whitespace.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ if !is_blank(parser.buffer, parser.buffer_pos) {
+ yaml_parser_set_scanner_error(parser, "while scanning a %TAG directive",
+ start_mark, "did not find expected whitespace")
+ return false
+ }
+
+ // Eat whitespaces.
+ for is_blank(parser.buffer, parser.buffer_pos) {
+ skip(parser)
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ }
+
+ // Scan a prefix.
+ if !yaml_parser_scan_tag_uri(parser, true, nil, start_mark, &prefix_value) {
+ return false
+ }
+
+ // Expect a whitespace or line break.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ if !is_blankz(parser.buffer, parser.buffer_pos) {
+ yaml_parser_set_scanner_error(parser, "while scanning a %TAG directive",
+ start_mark, "did not find expected whitespace or line break")
+ return false
+ }
+
+ *handle = handle_value
+ *prefix = prefix_value
+ return true
+}
+
+func yaml_parser_scan_anchor(parser *yaml_parser_t, token *yaml_token_t, typ yaml_token_type_t) bool {
+ var s []byte
+
+ // Eat the indicator character.
+ start_mark := parser.mark
+ skip(parser)
+
+ // Consume the value.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+
+ for is_alpha(parser.buffer, parser.buffer_pos) {
+ s = read(parser, s)
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ }
+
+ end_mark := parser.mark
+
+ /*
+ * Check if length of the anchor is greater than 0 and it is followed by
+ * a whitespace character or one of the indicators:
+ *
+ * '?', ':', ',', ']', '}', '%', '@', '`'.
+ */
+
+ if len(s) == 0 ||
+ !(is_blankz(parser.buffer, parser.buffer_pos) || parser.buffer[parser.buffer_pos] == '?' ||
+ parser.buffer[parser.buffer_pos] == ':' || parser.buffer[parser.buffer_pos] == ',' ||
+ parser.buffer[parser.buffer_pos] == ']' || parser.buffer[parser.buffer_pos] == '}' ||
+ parser.buffer[parser.buffer_pos] == '%' || parser.buffer[parser.buffer_pos] == '@' ||
+ parser.buffer[parser.buffer_pos] == '`') {
+ context := "while scanning an alias"
+ if typ == yaml_ANCHOR_TOKEN {
+ context = "while scanning an anchor"
+ }
+ yaml_parser_set_scanner_error(parser, context, start_mark,
+ "did not find expected alphabetic or numeric character")
+ return false
+ }
+
+ // Create a token.
+ *token = yaml_token_t{
+ typ: typ,
+ start_mark: start_mark,
+ end_mark: end_mark,
+ value: s,
+ }
+
+ return true
+}
+
+/*
+ * Scan a TAG token.
+ */
+
+func yaml_parser_scan_tag(parser *yaml_parser_t, token *yaml_token_t) bool {
+ var handle, suffix []byte
+
+ start_mark := parser.mark
+
+ // Check if the tag is in the canonical form.
+ if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+ return false
+ }
+
+ if parser.buffer[parser.buffer_pos+1] == '<' {
+ // Keep the handle as ''
+
+ // Eat '!<'
+ skip(parser)
+ skip(parser)
+
+ // Consume the tag value.
+ if !yaml_parser_scan_tag_uri(parser, false, nil, start_mark, &suffix) {
+ return false
+ }
+
+ // Check for '>' and eat it.
+ if parser.buffer[parser.buffer_pos] != '>' {
+ yaml_parser_set_scanner_error(parser, "while scanning a tag",
+ start_mark, "did not find the expected '>'")
+ return false
+ }
+
+ skip(parser)
+ } else {
+ // The tag has either the '!suffix' or the '!handle!suffix' form.
+
+ // First, try to scan a handle.
+ if !yaml_parser_scan_tag_handle(parser, false, start_mark, &handle) {
+ return false
+ }
+
+ // Check if it is, indeed, handle.
+ if handle[0] == '!' && len(handle) > 1 && handle[len(handle)-1] == '!' {
+ // Scan the suffix now.
+ if !yaml_parser_scan_tag_uri(parser, false, nil, start_mark, &suffix) {
+ return false
+ }
+ } else {
+ // It wasn't a handle after all. Scan the rest of the tag.
+ if !yaml_parser_scan_tag_uri(parser, false, handle, start_mark, &suffix) {
+ return false
+ }
+
+ // Set the handle to '!'.
+ handle = []byte{'!'}
+
+ // A special case: the '!' tag. Set the handle to '' and the
+ // suffix to '!'.
+ if len(suffix) == 0 {
+ handle, suffix = suffix, handle
+ }
+ }
+ }
+
+ // Check the character which ends the tag.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ if !is_blankz(parser.buffer, parser.buffer_pos) {
+ yaml_parser_set_scanner_error(parser, "while scanning a tag",
+ start_mark, "did not find expected whitespace or line break")
+ return false
+ }
+
+ end_mark := parser.mark
+
+ // Create a token.
+ *token = yaml_token_t{
+ typ: yaml_TAG_TOKEN,
+ start_mark: start_mark,
+ end_mark: end_mark,
+ value: handle,
+ suffix: suffix,
+ }
+ return true
+}
+
+// Scan a tag handle.
+func yaml_parser_scan_tag_handle(parser *yaml_parser_t, directive bool, start_mark yaml_mark_t, handle *[]byte) bool {
+ // Check the initial '!' character.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ if parser.buffer[parser.buffer_pos] != '!' {
+ yaml_parser_set_scanner_tag_error(parser, directive,
+ start_mark, "did not find expected '!'")
+ return false
+ }
+
+ var s []byte
+
+ // Copy the '!' character.
+ s = read(parser, s)
+
+ // Copy all subsequent alphabetical and numerical characters.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ for is_alpha(parser.buffer, parser.buffer_pos) {
+ s = read(parser, s)
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ }
+
+ // Check if the trailing character is '!' and copy it.
+ if parser.buffer[parser.buffer_pos] == '!' {
+ s = read(parser, s)
+ } else {
+ // It's either the '!' tag or not really a tag handle. If it's a %TAG
+ // directive, it's an error. If it's a tag token, it must be a part of URI.
+ if directive && string(s) != "!" {
+ yaml_parser_set_scanner_tag_error(parser, directive,
+ start_mark, "did not find expected '!'")
+ return false
+ }
+ }
+
+ *handle = s
+ return true
+}
+
+// Scan a tag.
+func yaml_parser_scan_tag_uri(parser *yaml_parser_t, directive bool, head []byte, start_mark yaml_mark_t, uri *[]byte) bool {
+ //size_t length = head ? strlen((char *)head) : 0
+ var s []byte
+ hasTag := len(head) > 0
+
+ // Copy the head if needed.
+ //
+ // Note that we don't copy the leading '!' character.
+ if len(head) > 1 {
+ s = append(s, head[1:]...)
+ }
+
+ // Scan the tag.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+
+ // The set of characters that may appear in URI is as follows:
+ //
+ // '0'-'9', 'A'-'Z', 'a'-'z', '_', '-', ';', '/', '?', ':', '@', '&',
+ // '=', '+', '$', ',', '.', '!', '~', '*', '\'', '(', ')', '[', ']',
+ // '%'.
+ // [Go] Convert this into more reasonable logic.
+ for is_alpha(parser.buffer, parser.buffer_pos) || parser.buffer[parser.buffer_pos] == ';' ||
+ parser.buffer[parser.buffer_pos] == '/' || parser.buffer[parser.buffer_pos] == '?' ||
+ parser.buffer[parser.buffer_pos] == ':' || parser.buffer[parser.buffer_pos] == '@' ||
+ parser.buffer[parser.buffer_pos] == '&' || parser.buffer[parser.buffer_pos] == '=' ||
+ parser.buffer[parser.buffer_pos] == '+' || parser.buffer[parser.buffer_pos] == '$' ||
+ parser.buffer[parser.buffer_pos] == ',' || parser.buffer[parser.buffer_pos] == '.' ||
+ parser.buffer[parser.buffer_pos] == '!' || parser.buffer[parser.buffer_pos] == '~' ||
+ parser.buffer[parser.buffer_pos] == '*' || parser.buffer[parser.buffer_pos] == '\'' ||
+ parser.buffer[parser.buffer_pos] == '(' || parser.buffer[parser.buffer_pos] == ')' ||
+ parser.buffer[parser.buffer_pos] == '[' || parser.buffer[parser.buffer_pos] == ']' ||
+ parser.buffer[parser.buffer_pos] == '%' {
+ // Check if it is a URI-escape sequence.
+ if parser.buffer[parser.buffer_pos] == '%' {
+ if !yaml_parser_scan_uri_escapes(parser, directive, start_mark, &s) {
+ return false
+ }
+ } else {
+ s = read(parser, s)
+ }
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ hasTag = true
+ }
+
+ if !hasTag {
+ yaml_parser_set_scanner_tag_error(parser, directive,
+ start_mark, "did not find expected tag URI")
+ return false
+ }
+ *uri = s
+ return true
+}
+
+// Decode an URI-escape sequence corresponding to a single UTF-8 character.
+func yaml_parser_scan_uri_escapes(parser *yaml_parser_t, directive bool, start_mark yaml_mark_t, s *[]byte) bool {
+
+ // Decode the required number of characters.
+ w := 1024
+ for w > 0 {
+ // Check for a URI-escaped octet.
+ if parser.unread < 3 && !yaml_parser_update_buffer(parser, 3) {
+ return false
+ }
+
+ if !(parser.buffer[parser.buffer_pos] == '%' &&
+ is_hex(parser.buffer, parser.buffer_pos+1) &&
+ is_hex(parser.buffer, parser.buffer_pos+2)) {
+ return yaml_parser_set_scanner_tag_error(parser, directive,
+ start_mark, "did not find URI escaped octet")
+ }
+
+ // Get the octet.
+ octet := byte((as_hex(parser.buffer, parser.buffer_pos+1) << 4) + as_hex(parser.buffer, parser.buffer_pos+2))
+
+ // If it is the leading octet, determine the length of the UTF-8 sequence.
+ if w == 1024 {
+ w = width(octet)
+ if w == 0 {
+ return yaml_parser_set_scanner_tag_error(parser, directive,
+ start_mark, "found an incorrect leading UTF-8 octet")
+ }
+ } else {
+ // Check if the trailing octet is correct.
+ if octet&0xC0 != 0x80 {
+ return yaml_parser_set_scanner_tag_error(parser, directive,
+ start_mark, "found an incorrect trailing UTF-8 octet")
+ }
+ }
+
+ // Copy the octet and move the pointers.
+ *s = append(*s, octet)
+ skip(parser)
+ skip(parser)
+ skip(parser)
+ w--
+ }
+ return true
+}
+
+// Scan a block scalar.
+func yaml_parser_scan_block_scalar(parser *yaml_parser_t, token *yaml_token_t, literal bool) bool {
+ // Eat the indicator '|' or '>'.
+ start_mark := parser.mark
+ skip(parser)
+
+ // Scan the additional block scalar indicators.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+
+ // Check for a chomping indicator.
+ var chomping, increment int
+ if parser.buffer[parser.buffer_pos] == '+' || parser.buffer[parser.buffer_pos] == '-' {
+ // Set the chomping method and eat the indicator.
+ if parser.buffer[parser.buffer_pos] == '+' {
+ chomping = +1
+ } else {
+ chomping = -1
+ }
+ skip(parser)
+
+ // Check for an indentation indicator.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ if is_digit(parser.buffer, parser.buffer_pos) {
+ // Check that the indentation is greater than 0.
+ if parser.buffer[parser.buffer_pos] == '0' {
+ yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
+ start_mark, "found an indentation indicator equal to 0")
+ return false
+ }
+
+ // Get the indentation level and eat the indicator.
+ increment = as_digit(parser.buffer, parser.buffer_pos)
+ skip(parser)
+ }
+
+ } else if is_digit(parser.buffer, parser.buffer_pos) {
+ // Do the same as above, but in the opposite order.
+
+ if parser.buffer[parser.buffer_pos] == '0' {
+ yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
+ start_mark, "found an indentation indicator equal to 0")
+ return false
+ }
+ increment = as_digit(parser.buffer, parser.buffer_pos)
+ skip(parser)
+
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ if parser.buffer[parser.buffer_pos] == '+' || parser.buffer[parser.buffer_pos] == '-' {
+ if parser.buffer[parser.buffer_pos] == '+' {
+ chomping = +1
+ } else {
+ chomping = -1
+ }
+ skip(parser)
+ }
+ }
+
+ // Eat whitespaces and comments to the end of the line.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ for is_blank(parser.buffer, parser.buffer_pos) {
+ skip(parser)
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ }
+ if parser.buffer[parser.buffer_pos] == '#' {
+ for !is_breakz(parser.buffer, parser.buffer_pos) {
+ skip(parser)
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ }
+ }
+
+ // Check if we are at the end of the line.
+ if !is_breakz(parser.buffer, parser.buffer_pos) {
+ yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
+ start_mark, "did not find expected comment or line break")
+ return false
+ }
+
+ // Eat a line break.
+ if is_break(parser.buffer, parser.buffer_pos) {
+ if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+ return false
+ }
+ skip_line(parser)
+ }
+
+ end_mark := parser.mark
+
+ // Set the indentation level if it was specified.
+ var indent int
+ if increment > 0 {
+ if parser.indent >= 0 {
+ indent = parser.indent + increment
+ } else {
+ indent = increment
+ }
+ }
+
+ // Scan the leading line breaks and determine the indentation level if needed.
+ var s, leading_break, trailing_breaks []byte
+ if !yaml_parser_scan_block_scalar_breaks(parser, &indent, &trailing_breaks, start_mark, &end_mark) {
+ return false
+ }
+
+ // Scan the block scalar content.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ var leading_blank, trailing_blank bool
+ for parser.mark.column == indent && !is_z(parser.buffer, parser.buffer_pos) {
+ // We are at the beginning of a non-empty line.
+
+ // Is it a trailing whitespace?
+ trailing_blank = is_blank(parser.buffer, parser.buffer_pos)
+
+ // Check if we need to fold the leading line break.
+ if !literal && !leading_blank && !trailing_blank && len(leading_break) > 0 && leading_break[0] == '\n' {
+ // Do we need to join the lines by space?
+ if len(trailing_breaks) == 0 {
+ s = append(s, ' ')
+ }
+ } else {
+ s = append(s, leading_break...)
+ }
+ leading_break = leading_break[:0]
+
+ // Append the remaining line breaks.
+ s = append(s, trailing_breaks...)
+ trailing_breaks = trailing_breaks[:0]
+
+ // Is it a leading whitespace?
+ leading_blank = is_blank(parser.buffer, parser.buffer_pos)
+
+ // Consume the current line.
+ for !is_breakz(parser.buffer, parser.buffer_pos) {
+ s = read(parser, s)
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ }
+
+ // Consume the line break.
+ if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+ return false
+ }
+
+ leading_break = read_line(parser, leading_break)
+
+ // Eat the following indentation spaces and line breaks.
+ if !yaml_parser_scan_block_scalar_breaks(parser, &indent, &trailing_breaks, start_mark, &end_mark) {
+ return false
+ }
+ }
+
+ // Chomp the tail.
+ if chomping != -1 {
+ s = append(s, leading_break...)
+ }
+ if chomping == 1 {
+ s = append(s, trailing_breaks...)
+ }
+
+ // Create a token.
+ *token = yaml_token_t{
+ typ: yaml_SCALAR_TOKEN,
+ start_mark: start_mark,
+ end_mark: end_mark,
+ value: s,
+ style: yaml_LITERAL_SCALAR_STYLE,
+ }
+ if !literal {
+ token.style = yaml_FOLDED_SCALAR_STYLE
+ }
+ return true
+}
+
+// Scan indentation spaces and line breaks for a block scalar. Determine the
+// indentation level if needed.
+func yaml_parser_scan_block_scalar_breaks(parser *yaml_parser_t, indent *int, breaks *[]byte, start_mark yaml_mark_t, end_mark *yaml_mark_t) bool {
+ *end_mark = parser.mark
+
+ // Eat the indentation spaces and line breaks.
+ max_indent := 0
+ for {
+ // Eat the indentation spaces.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ for (*indent == 0 || parser.mark.column < *indent) && is_space(parser.buffer, parser.buffer_pos) {
+ skip(parser)
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ }
+ if parser.mark.column > max_indent {
+ max_indent = parser.mark.column
+ }
+
+ // Check for a tab character messing the indentation.
+ if (*indent == 0 || parser.mark.column < *indent) && is_tab(parser.buffer, parser.buffer_pos) {
+ return yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
+ start_mark, "found a tab character where an indentation space is expected")
+ }
+
+ // Have we found a non-empty line?
+ if !is_break(parser.buffer, parser.buffer_pos) {
+ break
+ }
+
+ // Consume the line break.
+ if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+ return false
+ }
+ // [Go] Should really be returning breaks instead.
+ *breaks = read_line(parser, *breaks)
+ *end_mark = parser.mark
+ }
+
+ // Determine the indentation level if needed.
+ if *indent == 0 {
+ *indent = max_indent
+ if *indent < parser.indent+1 {
+ *indent = parser.indent + 1
+ }
+ if *indent < 1 {
+ *indent = 1
+ }
+ }
+ return true
+}
+
+// Scan a quoted scalar.
+func yaml_parser_scan_flow_scalar(parser *yaml_parser_t, token *yaml_token_t, single bool) bool {
+ // Eat the left quote.
+ start_mark := parser.mark
+ skip(parser)
+
+ // Consume the content of the quoted scalar.
+ var s, leading_break, trailing_breaks, whitespaces []byte
+ for {
+ // Check that there are no document indicators at the beginning of the line.
+ if parser.unread < 4 && !yaml_parser_update_buffer(parser, 4) {
+ return false
+ }
+
+ if parser.mark.column == 0 &&
+ ((parser.buffer[parser.buffer_pos+0] == '-' &&
+ parser.buffer[parser.buffer_pos+1] == '-' &&
+ parser.buffer[parser.buffer_pos+2] == '-') ||
+ (parser.buffer[parser.buffer_pos+0] == '.' &&
+ parser.buffer[parser.buffer_pos+1] == '.' &&
+ parser.buffer[parser.buffer_pos+2] == '.')) &&
+ is_blankz(parser.buffer, parser.buffer_pos+3) {
+ yaml_parser_set_scanner_error(parser, "while scanning a quoted scalar",
+ start_mark, "found unexpected document indicator")
+ return false
+ }
+
+ // Check for EOF.
+ if is_z(parser.buffer, parser.buffer_pos) {
+ yaml_parser_set_scanner_error(parser, "while scanning a quoted scalar",
+ start_mark, "found unexpected end of stream")
+ return false
+ }
+
+ // Consume non-blank characters.
+ leading_blanks := false
+ for !is_blankz(parser.buffer, parser.buffer_pos) {
+ if single && parser.buffer[parser.buffer_pos] == '\'' && parser.buffer[parser.buffer_pos+1] == '\'' {
+ // Is is an escaped single quote.
+ s = append(s, '\'')
+ skip(parser)
+ skip(parser)
+
+ } else if single && parser.buffer[parser.buffer_pos] == '\'' {
+ // It is a right single quote.
+ break
+ } else if !single && parser.buffer[parser.buffer_pos] == '"' {
+ // It is a right double quote.
+ break
+
+ } else if !single && parser.buffer[parser.buffer_pos] == '\\' && is_break(parser.buffer, parser.buffer_pos+1) {
+ // It is an escaped line break.
+ if parser.unread < 3 && !yaml_parser_update_buffer(parser, 3) {
+ return false
+ }
+ skip(parser)
+ skip_line(parser)
+ leading_blanks = true
+ break
+
+ } else if !single && parser.buffer[parser.buffer_pos] == '\\' {
+ // It is an escape sequence.
+ code_length := 0
+
+ // Check the escape character.
+ switch parser.buffer[parser.buffer_pos+1] {
+ case '0':
+ s = append(s, 0)
+ case 'a':
+ s = append(s, '\x07')
+ case 'b':
+ s = append(s, '\x08')
+ case 't', '\t':
+ s = append(s, '\x09')
+ case 'n':
+ s = append(s, '\x0A')
+ case 'v':
+ s = append(s, '\x0B')
+ case 'f':
+ s = append(s, '\x0C')
+ case 'r':
+ s = append(s, '\x0D')
+ case 'e':
+ s = append(s, '\x1B')
+ case ' ':
+ s = append(s, '\x20')
+ case '"':
+ s = append(s, '"')
+ case '\'':
+ s = append(s, '\'')
+ case '\\':
+ s = append(s, '\\')
+ case 'N': // NEL (#x85)
+ s = append(s, '\xC2')
+ s = append(s, '\x85')
+ case '_': // #xA0
+ s = append(s, '\xC2')
+ s = append(s, '\xA0')
+ case 'L': // LS (#x2028)
+ s = append(s, '\xE2')
+ s = append(s, '\x80')
+ s = append(s, '\xA8')
+ case 'P': // PS (#x2029)
+ s = append(s, '\xE2')
+ s = append(s, '\x80')
+ s = append(s, '\xA9')
+ case 'x':
+ code_length = 2
+ case 'u':
+ code_length = 4
+ case 'U':
+ code_length = 8
+ default:
+ yaml_parser_set_scanner_error(parser, "while parsing a quoted scalar",
+ start_mark, "found unknown escape character")
+ return false
+ }
+
+ skip(parser)
+ skip(parser)
+
+ // Consume an arbitrary escape code.
+ if code_length > 0 {
+ var value int
+
+ // Scan the character value.
+ if parser.unread < code_length && !yaml_parser_update_buffer(parser, code_length) {
+ return false
+ }
+ for k := 0; k < code_length; k++ {
+ if !is_hex(parser.buffer, parser.buffer_pos+k) {
+ yaml_parser_set_scanner_error(parser, "while parsing a quoted scalar",
+ start_mark, "did not find expected hexdecimal number")
+ return false
+ }
+ value = (value << 4) + as_hex(parser.buffer, parser.buffer_pos+k)
+ }
+
+ // Check the value and write the character.
+ if (value >= 0xD800 && value <= 0xDFFF) || value > 0x10FFFF {
+ yaml_parser_set_scanner_error(parser, "while parsing a quoted scalar",
+ start_mark, "found invalid Unicode character escape code")
+ return false
+ }
+ if value <= 0x7F {
+ s = append(s, byte(value))
+ } else if value <= 0x7FF {
+ s = append(s, byte(0xC0+(value>>6)))
+ s = append(s, byte(0x80+(value&0x3F)))
+ } else if value <= 0xFFFF {
+ s = append(s, byte(0xE0+(value>>12)))
+ s = append(s, byte(0x80+((value>>6)&0x3F)))
+ s = append(s, byte(0x80+(value&0x3F)))
+ } else {
+ s = append(s, byte(0xF0+(value>>18)))
+ s = append(s, byte(0x80+((value>>12)&0x3F)))
+ s = append(s, byte(0x80+((value>>6)&0x3F)))
+ s = append(s, byte(0x80+(value&0x3F)))
+ }
+
+ // Advance the pointer.
+ for k := 0; k < code_length; k++ {
+ skip(parser)
+ }
+ }
+ } else {
+ // It is a non-escaped non-blank character.
+ s = read(parser, s)
+ }
+ if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+ return false
+ }
+ }
+
+ // Check if we are at the end of the scalar.
+ if single {
+ if parser.buffer[parser.buffer_pos] == '\'' {
+ break
+ }
+ } else {
+ if parser.buffer[parser.buffer_pos] == '"' {
+ break
+ }
+ }
+
+ // Consume blank characters.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+
+ for is_blank(parser.buffer, parser.buffer_pos) || is_break(parser.buffer, parser.buffer_pos) {
+ if is_blank(parser.buffer, parser.buffer_pos) {
+ // Consume a space or a tab character.
+ if !leading_blanks {
+ whitespaces = read(parser, whitespaces)
+ } else {
+ skip(parser)
+ }
+ } else {
+ if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+ return false
+ }
+
+ // Check if it is a first line break.
+ if !leading_blanks {
+ whitespaces = whitespaces[:0]
+ leading_break = read_line(parser, leading_break)
+ leading_blanks = true
+ } else {
+ trailing_breaks = read_line(parser, trailing_breaks)
+ }
+ }
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ }
+
+ // Join the whitespaces or fold line breaks.
+ if leading_blanks {
+ // Do we need to fold line breaks?
+ if len(leading_break) > 0 && leading_break[0] == '\n' {
+ if len(trailing_breaks) == 0 {
+ s = append(s, ' ')
+ } else {
+ s = append(s, trailing_breaks...)
+ }
+ } else {
+ s = append(s, leading_break...)
+ s = append(s, trailing_breaks...)
+ }
+ trailing_breaks = trailing_breaks[:0]
+ leading_break = leading_break[:0]
+ } else {
+ s = append(s, whitespaces...)
+ whitespaces = whitespaces[:0]
+ }
+ }
+
+ // Eat the right quote.
+ skip(parser)
+ end_mark := parser.mark
+
+ // Create a token.
+ *token = yaml_token_t{
+ typ: yaml_SCALAR_TOKEN,
+ start_mark: start_mark,
+ end_mark: end_mark,
+ value: s,
+ style: yaml_SINGLE_QUOTED_SCALAR_STYLE,
+ }
+ if !single {
+ token.style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+ }
+ return true
+}
+
+// Scan a plain scalar.
+func yaml_parser_scan_plain_scalar(parser *yaml_parser_t, token *yaml_token_t) bool {
+
+ var s, leading_break, trailing_breaks, whitespaces []byte
+ var leading_blanks bool
+ var indent = parser.indent + 1
+
+ start_mark := parser.mark
+ end_mark := parser.mark
+
+ // Consume the content of the plain scalar.
+ for {
+ // Check for a document indicator.
+ if parser.unread < 4 && !yaml_parser_update_buffer(parser, 4) {
+ return false
+ }
+ if parser.mark.column == 0 &&
+ ((parser.buffer[parser.buffer_pos+0] == '-' &&
+ parser.buffer[parser.buffer_pos+1] == '-' &&
+ parser.buffer[parser.buffer_pos+2] == '-') ||
+ (parser.buffer[parser.buffer_pos+0] == '.' &&
+ parser.buffer[parser.buffer_pos+1] == '.' &&
+ parser.buffer[parser.buffer_pos+2] == '.')) &&
+ is_blankz(parser.buffer, parser.buffer_pos+3) {
+ break
+ }
+
+ // Check for a comment.
+ if parser.buffer[parser.buffer_pos] == '#' {
+ break
+ }
+
+ // Consume non-blank characters.
+ for !is_blankz(parser.buffer, parser.buffer_pos) {
+
+ // Check for 'x:x' in the flow context. TODO: Fix the test "spec-08-13".
+ if parser.flow_level > 0 &&
+ parser.buffer[parser.buffer_pos] == ':' &&
+ !is_blankz(parser.buffer, parser.buffer_pos+1) {
+ yaml_parser_set_scanner_error(parser, "while scanning a plain scalar",
+ start_mark, "found unexpected ':'")
+ return false
+ }
+
+ // Check for indicators that may end a plain scalar.
+ if (parser.buffer[parser.buffer_pos] == ':' && is_blankz(parser.buffer, parser.buffer_pos+1)) ||
+ (parser.flow_level > 0 &&
+ (parser.buffer[parser.buffer_pos] == ',' || parser.buffer[parser.buffer_pos] == ':' ||
+ parser.buffer[parser.buffer_pos] == '?' || parser.buffer[parser.buffer_pos] == '[' ||
+ parser.buffer[parser.buffer_pos] == ']' || parser.buffer[parser.buffer_pos] == '{' ||
+ parser.buffer[parser.buffer_pos] == '}')) {
+ break
+ }
+
+ // Check if we need to join whitespaces and breaks.
+ if leading_blanks || len(whitespaces) > 0 {
+ if leading_blanks {
+ // Do we need to fold line breaks?
+ if leading_break[0] == '\n' {
+ if len(trailing_breaks) == 0 {
+ s = append(s, ' ')
+ } else {
+ s = append(s, trailing_breaks...)
+ }
+ } else {
+ s = append(s, leading_break...)
+ s = append(s, trailing_breaks...)
+ }
+ trailing_breaks = trailing_breaks[:0]
+ leading_break = leading_break[:0]
+ leading_blanks = false
+ } else {
+ s = append(s, whitespaces...)
+ whitespaces = whitespaces[:0]
+ }
+ }
+
+ // Copy the character.
+ s = read(parser, s)
+
+ end_mark = parser.mark
+ if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+ return false
+ }
+ }
+
+ // Is it the end?
+ if !(is_blank(parser.buffer, parser.buffer_pos) || is_break(parser.buffer, parser.buffer_pos)) {
+ break
+ }
+
+ // Consume blank characters.
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+
+ for is_blank(parser.buffer, parser.buffer_pos) || is_break(parser.buffer, parser.buffer_pos) {
+ if is_blank(parser.buffer, parser.buffer_pos) {
+
+ // Check for tab character that abuse indentation.
+ if leading_blanks && parser.mark.column < indent && is_tab(parser.buffer, parser.buffer_pos) {
+ yaml_parser_set_scanner_error(parser, "while scanning a plain scalar",
+ start_mark, "found a tab character that violate indentation")
+ return false
+ }
+
+ // Consume a space or a tab character.
+ if !leading_blanks {
+ whitespaces = read(parser, whitespaces)
+ } else {
+ skip(parser)
+ }
+ } else {
+ if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+ return false
+ }
+
+ // Check if it is a first line break.
+ if !leading_blanks {
+ whitespaces = whitespaces[:0]
+ leading_break = read_line(parser, leading_break)
+ leading_blanks = true
+ } else {
+ trailing_breaks = read_line(parser, trailing_breaks)
+ }
+ }
+ if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+ return false
+ }
+ }
+
+ // Check indentation level.
+ if parser.flow_level == 0 && parser.mark.column < indent {
+ break
+ }
+ }
+
+ // Create a token.
+ *token = yaml_token_t{
+ typ: yaml_SCALAR_TOKEN,
+ start_mark: start_mark,
+ end_mark: end_mark,
+ value: s,
+ style: yaml_PLAIN_SCALAR_STYLE,
+ }
+
+ // Note that we change the 'simple_key_allowed' flag.
+ if leading_blanks {
+ parser.simple_key_allowed = true
+ }
+ return true
+}
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