l0bsterssg

loader.js (44356B)

---

 'use strict';
 
 /*eslint-disable max-len,no-use-before-define*/
 
 var common              = require('./common');
 var YAMLException       = require('./exception');
 var Mark                = require('./mark');
 var DEFAULT_SAFE_SCHEMA = require('./schema/default_safe');
 var DEFAULT_FULL_SCHEMA = require('./schema/default_full');
 
 
 var _hasOwnProperty = Object.prototype.hasOwnProperty;
 
 
 var CONTEXT_FLOW_IN   = 1;
 var CONTEXT_FLOW_OUT  = 2;
 var CONTEXT_BLOCK_IN  = 3;
 var CONTEXT_BLOCK_OUT = 4;
 
 
 var CHOMPING_CLIP  = 1;
 var CHOMPING_STRIP = 2;
 var CHOMPING_KEEP  = 3;
 
 
 var PATTERN_NON_PRINTABLE         = /[\x00-\x08\x0B\x0C\x0E-\x1F\x7F-\x84\x86-\x9F\uFFFE\uFFFF]|[\uD800-\uDBFF](?![\uDC00-\uDFFF])|(?:[^\uD800-\uDBFF]|^)[\uDC00-\uDFFF]/;
 var PATTERN_NON_ASCII_LINE_BREAKS = /[\x85\u2028\u2029]/;
 var PATTERN_FLOW_INDICATORS       = /[,\[\]\{\}]/;
 var PATTERN_TAG_HANDLE            = /^(?:!|!!|![a-z\-]+!)$/i;
 var PATTERN_TAG_URI               = /^(?:!|[^,\[\]\{\}])(?:%[0-9a-f]{2}|[0-9a-z\-#;\/\?:@&=\+\$,_\.!~\*'\(\)\[\]])*$/i;
 
 
 function _class(obj) { return Object.prototype.toString.call(obj); }
 
 function is_EOL(c) {
   return (c === 0x0A/* LF */) || (c === 0x0D/* CR */);
 }
 
 function is_WHITE_SPACE(c) {
   return (c === 0x09/* Tab */) || (c === 0x20/* Space */);
 }
 
 function is_WS_OR_EOL(c) {
   return (c === 0x09/* Tab */) ||
          (c === 0x20/* Space */) ||
          (c === 0x0A/* LF */) ||
          (c === 0x0D/* CR */);
 }
 
 function is_FLOW_INDICATOR(c) {
   return c === 0x2C/* , */ ||
          c === 0x5B/* [ */ ||
          c === 0x5D/* ] */ ||
          c === 0x7B/* { */ ||
          c === 0x7D/* } */;
 }
 
 function fromHexCode(c) {
   var lc;
 
   if ((0x30/* 0 */ <= c) && (c <= 0x39/* 9 */)) {
     return c - 0x30;
   }
 
   /*eslint-disable no-bitwise*/
   lc = c | 0x20;
 
   if ((0x61/* a */ <= lc) && (lc <= 0x66/* f */)) {
     return lc - 0x61 + 10;
   }
 
   return -1;
 }
 
 function escapedHexLen(c) {
   if (c === 0x78/* x */) { return 2; }
   if (c === 0x75/* u */) { return 4; }
   if (c === 0x55/* U */) { return 8; }
   return 0;
 }
 
 function fromDecimalCode(c) {
   if ((0x30/* 0 */ <= c) && (c <= 0x39/* 9 */)) {
     return c - 0x30;
   }
 
   return -1;
 }
 
 function simpleEscapeSequence(c) {
   /* eslint-disable indent */
   return (c === 0x30/* 0 */) ? '\x00' :
         (c === 0x61/* a */) ? '\x07' :
         (c === 0x62/* b */) ? '\x08' :
         (c === 0x74/* t */) ? '\x09' :
         (c === 0x09/* Tab */) ? '\x09' :
         (c === 0x6E/* n */) ? '\x0A' :
         (c === 0x76/* v */) ? '\x0B' :
         (c === 0x66/* f */) ? '\x0C' :
         (c === 0x72/* r */) ? '\x0D' :
         (c === 0x65/* e */) ? '\x1B' :
         (c === 0x20/* Space */) ? ' ' :
         (c === 0x22/* " */) ? '\x22' :
         (c === 0x2F/* / */) ? '/' :
         (c === 0x5C/* \ */) ? '\x5C' :
         (c === 0x4E/* N */) ? '\x85' :
         (c === 0x5F/* _ */) ? '\xA0' :
         (c === 0x4C/* L */) ? '\u2028' :
         (c === 0x50/* P */) ? '\u2029' : '';
 }
 
 function charFromCodepoint(c) {
   if (c <= 0xFFFF) {
     return String.fromCharCode(c);
   }
   // Encode UTF-16 surrogate pair
   // https://en.wikipedia.org/wiki/UTF-16#Code_points_U.2B010000_to_U.2B10FFFF
   return String.fromCharCode(
     ((c - 0x010000) >> 10) + 0xD800,
     ((c - 0x010000) & 0x03FF) + 0xDC00
   );
 }
 
 var simpleEscapeCheck = new Array(256); // integer, for fast access
 var simpleEscapeMap = new Array(256);
 for (var i = 0; i < 256; i++) {
   simpleEscapeCheck[i] = simpleEscapeSequence(i) ? 1 : 0;
   simpleEscapeMap[i] = simpleEscapeSequence(i);
 }
 
 
 function State(input, options) {
   this.input = input;
 
   this.filename  = options['filename']  || null;
   this.schema    = options['schema']    || DEFAULT_FULL_SCHEMA;
   this.onWarning = options['onWarning'] || null;
   this.legacy    = options['legacy']    || false;
   this.json      = options['json']      || false;
   this.listener  = options['listener']  || null;
 
   this.implicitTypes = this.schema.compiledImplicit;
   this.typeMap       = this.schema.compiledTypeMap;
 
   this.length     = input.length;
   this.position   = 0;
   this.line       = 0;
   this.lineStart  = 0;
   this.lineIndent = 0;
 
   this.documents = [];
 
   /*
   this.version;
   this.checkLineBreaks;
   this.tagMap;
   this.anchorMap;
   this.tag;
   this.anchor;
   this.kind;
   this.result;*/
 
 }
 
 
 function generateError(state, message) {
   return new YAMLException(
     message,
     new Mark(state.filename, state.input, state.position, state.line, (state.position - state.lineStart)));
 }
 
 function throwError(state, message) {
   throw generateError(state, message);
 }
 
 function throwWarning(state, message) {
   if (state.onWarning) {
     state.onWarning.call(null, generateError(state, message));
   }
 }
 
 
 var directiveHandlers = {
 
   YAML: function handleYamlDirective(state, name, args) {
 
     var match, major, minor;
 
     if (state.version !== null) {
       throwError(state, 'duplication of %YAML directive');
     }
 
     if (args.length !== 1) {
       throwError(state, 'YAML directive accepts exactly one argument');
     }
 
     match = /^([0-9]+)\.([0-9]+)$/.exec(args[0]);
 
     if (match === null) {
       throwError(state, 'ill-formed argument of the YAML directive');
     }
 
     major = parseInt(match[1], 10);
     minor = parseInt(match[2], 10);
 
     if (major !== 1) {
       throwError(state, 'unacceptable YAML version of the document');
     }
 
     state.version = args[0];
     state.checkLineBreaks = (minor < 2);
 
     if (minor !== 1 && minor !== 2) {
       throwWarning(state, 'unsupported YAML version of the document');
     }
   },
 
   TAG: function handleTagDirective(state, name, args) {
 
     var handle, prefix;
 
     if (args.length !== 2) {
       throwError(state, 'TAG directive accepts exactly two arguments');
     }
 
     handle = args[0];
     prefix = args[1];
 
     if (!PATTERN_TAG_HANDLE.test(handle)) {
       throwError(state, 'ill-formed tag handle (first argument) of the TAG directive');
     }
 
     if (_hasOwnProperty.call(state.tagMap, handle)) {
       throwError(state, 'there is a previously declared suffix for "' + handle + '" tag handle');
     }
 
     if (!PATTERN_TAG_URI.test(prefix)) {
       throwError(state, 'ill-formed tag prefix (second argument) of the TAG directive');
     }
 
     state.tagMap[handle] = prefix;
   }
 };
 
 
 function captureSegment(state, start, end, checkJson) {
   var _position, _length, _character, _result;
 
   if (start < end) {
     _result = state.input.slice(start, end);
 
     if (checkJson) {
       for (_position = 0, _length = _result.length; _position < _length; _position += 1) {
         _character = _result.charCodeAt(_position);
         if (!(_character === 0x09 ||
               (0x20 <= _character && _character <= 0x10FFFF))) {
           throwError(state, 'expected valid JSON character');
         }
       }
     } else if (PATTERN_NON_PRINTABLE.test(_result)) {
       throwError(state, 'the stream contains non-printable characters');
     }
 
     state.result += _result;
   }
 }
 
 function mergeMappings(state, destination, source, overridableKeys) {
   var sourceKeys, key, index, quantity;
 
   if (!common.isObject(source)) {
     throwError(state, 'cannot merge mappings; the provided source object is unacceptable');
   }
 
   sourceKeys = Object.keys(source);
 
   for (index = 0, quantity = sourceKeys.length; index < quantity; index += 1) {
     key = sourceKeys[index];
 
     if (!_hasOwnProperty.call(destination, key)) {
       destination[key] = source[key];
       overridableKeys[key] = true;
     }
   }
 }
 
 function storeMappingPair(state, _result, overridableKeys, keyTag, keyNode, valueNode, startLine, startPos) {
   var index, quantity;
 
   // The output is a plain object here, so keys can only be strings.
   // We need to convert keyNode to a string, but doing so can hang the process
   // (deeply nested arrays that explode exponentially using aliases).
   if (Array.isArray(keyNode)) {
     keyNode = Array.prototype.slice.call(keyNode);
 
     for (index = 0, quantity = keyNode.length; index < quantity; index += 1) {
       if (Array.isArray(keyNode[index])) {
         throwError(state, 'nested arrays are not supported inside keys');
       }
 
       if (typeof keyNode === 'object' && _class(keyNode[index]) === '[object Object]') {
         keyNode[index] = '[object Object]';
       }
     }
   }
 
   // Avoid code execution in load() via toString property
   // (still use its own toString for arrays, timestamps,
   // and whatever user schema extensions happen to have @@toStringTag)
   if (typeof keyNode === 'object' && _class(keyNode) === '[object Object]') {
     keyNode = '[object Object]';
   }
 
 
   keyNode = String(keyNode);
 
   if (_result === null) {
     _result = {};
   }
 
   if (keyTag === 'tag:yaml.org,2002:merge') {
     if (Array.isArray(valueNode)) {
       for (index = 0, quantity = valueNode.length; index < quantity; index += 1) {
         mergeMappings(state, _result, valueNode[index], overridableKeys);
       }
     } else {
       mergeMappings(state, _result, valueNode, overridableKeys);
     }
   } else {
     if (!state.json &&
         !_hasOwnProperty.call(overridableKeys, keyNode) &&
         _hasOwnProperty.call(_result, keyNode)) {
       state.line = startLine || state.line;
       state.position = startPos || state.position;
       throwError(state, 'duplicated mapping key');
     }
     _result[keyNode] = valueNode;
     delete overridableKeys[keyNode];
   }
 
   return _result;
 }
 
 function readLineBreak(state) {
   var ch;
 
   ch = state.input.charCodeAt(state.position);
 
   if (ch === 0x0A/* LF */) {
     state.position++;
   } else if (ch === 0x0D/* CR */) {
     state.position++;
     if (state.input.charCodeAt(state.position) === 0x0A/* LF */) {
       state.position++;
     }
   } else {
     throwError(state, 'a line break is expected');
   }
 
   state.line += 1;
   state.lineStart = state.position;
 }
 
 function skipSeparationSpace(state, allowComments, checkIndent) {
   var lineBreaks = 0,
       ch = state.input.charCodeAt(state.position);
 
   while (ch !== 0) {
     while (is_WHITE_SPACE(ch)) {
       ch = state.input.charCodeAt(++state.position);
     }
 
     if (allowComments && ch === 0x23/* # */) {
       do {
         ch = state.input.charCodeAt(++state.position);
       } while (ch !== 0x0A/* LF */ && ch !== 0x0D/* CR */ && ch !== 0);
     }
 
     if (is_EOL(ch)) {
       readLineBreak(state);
 
       ch = state.input.charCodeAt(state.position);
       lineBreaks++;
       state.lineIndent = 0;
 
       while (ch === 0x20/* Space */) {
         state.lineIndent++;
         ch = state.input.charCodeAt(++state.position);
       }
     } else {
       break;
     }
   }
 
   if (checkIndent !== -1 && lineBreaks !== 0 && state.lineIndent < checkIndent) {
     throwWarning(state, 'deficient indentation');
   }
 
   return lineBreaks;
 }
 
 function testDocumentSeparator(state) {
   var _position = state.position,
       ch;
 
   ch = state.input.charCodeAt(_position);
 
   // Condition state.position === state.lineStart is tested
   // in parent on each call, for efficiency. No needs to test here again.
   if ((ch === 0x2D/* - */ || ch === 0x2E/* . */) &&
       ch === state.input.charCodeAt(_position + 1) &&
       ch === state.input.charCodeAt(_position + 2)) {
 
     _position += 3;
 
     ch = state.input.charCodeAt(_position);
 
     if (ch === 0 || is_WS_OR_EOL(ch)) {
       return true;
     }
   }
 
   return false;
 }
 
 function writeFoldedLines(state, count) {
   if (count === 1) {
     state.result += ' ';
   } else if (count > 1) {
     state.result += common.repeat('\n', count - 1);
   }
 }
 
 
 function readPlainScalar(state, nodeIndent, withinFlowCollection) {
   var preceding,
       following,
       captureStart,
       captureEnd,
       hasPendingContent,
       _line,
       _lineStart,
       _lineIndent,
       _kind = state.kind,
       _result = state.result,
       ch;
 
   ch = state.input.charCodeAt(state.position);
 
   if (is_WS_OR_EOL(ch)      ||
       is_FLOW_INDICATOR(ch) ||
       ch === 0x23/* # */    ||
       ch === 0x26/* & */    ||
       ch === 0x2A/* * */    ||
       ch === 0x21/* ! */    ||
       ch === 0x7C/* | */    ||
       ch === 0x3E/* > */    ||
       ch === 0x27/* ' */    ||
       ch === 0x22/* " */    ||
       ch === 0x25/* % */    ||
       ch === 0x40/* @ */    ||
       ch === 0x60/* ` */) {
     return false;
   }
 
   if (ch === 0x3F/* ? */ || ch === 0x2D/* - */) {
     following = state.input.charCodeAt(state.position + 1);
 
     if (is_WS_OR_EOL(following) ||
         withinFlowCollection && is_FLOW_INDICATOR(following)) {
       return false;
     }
   }
 
   state.kind = 'scalar';
   state.result = '';
   captureStart = captureEnd = state.position;
   hasPendingContent = false;
 
   while (ch !== 0) {
     if (ch === 0x3A/* : */) {
       following = state.input.charCodeAt(state.position + 1);
 
       if (is_WS_OR_EOL(following) ||
           withinFlowCollection && is_FLOW_INDICATOR(following)) {
         break;
       }
 
     } else if (ch === 0x23/* # */) {
       preceding = state.input.charCodeAt(state.position - 1);
 
       if (is_WS_OR_EOL(preceding)) {
         break;
       }
 
     } else if ((state.position === state.lineStart && testDocumentSeparator(state)) ||
                withinFlowCollection && is_FLOW_INDICATOR(ch)) {
       break;
 
     } else if (is_EOL(ch)) {
       _line = state.line;
       _lineStart = state.lineStart;
       _lineIndent = state.lineIndent;
       skipSeparationSpace(state, false, -1);
 
       if (state.lineIndent >= nodeIndent) {
         hasPendingContent = true;
         ch = state.input.charCodeAt(state.position);
         continue;
       } else {
         state.position = captureEnd;
         state.line = _line;
         state.lineStart = _lineStart;
         state.lineIndent = _lineIndent;
         break;
       }
     }
 
     if (hasPendingContent) {
       captureSegment(state, captureStart, captureEnd, false);
       writeFoldedLines(state, state.line - _line);
       captureStart = captureEnd = state.position;
       hasPendingContent = false;
     }
 
     if (!is_WHITE_SPACE(ch)) {
       captureEnd = state.position + 1;
     }
 
     ch = state.input.charCodeAt(++state.position);
   }
 
   captureSegment(state, captureStart, captureEnd, false);
 
   if (state.result) {
     return true;
   }
 
   state.kind = _kind;
   state.result = _result;
   return false;
 }
 
 function readSingleQuotedScalar(state, nodeIndent) {
   var ch,
       captureStart, captureEnd;
 
   ch = state.input.charCodeAt(state.position);
 
   if (ch !== 0x27/* ' */) {
     return false;
   }
 
   state.kind = 'scalar';
   state.result = '';
   state.position++;
   captureStart = captureEnd = state.position;
 
   while ((ch = state.input.charCodeAt(state.position)) !== 0) {
     if (ch === 0x27/* ' */) {
       captureSegment(state, captureStart, state.position, true);
       ch = state.input.charCodeAt(++state.position);
 
       if (ch === 0x27/* ' */) {
         captureStart = state.position;
         state.position++;
         captureEnd = state.position;
       } else {
         return true;
       }
 
     } else if (is_EOL(ch)) {
       captureSegment(state, captureStart, captureEnd, true);
       writeFoldedLines(state, skipSeparationSpace(state, false, nodeIndent));
       captureStart = captureEnd = state.position;
 
     } else if (state.position === state.lineStart && testDocumentSeparator(state)) {
       throwError(state, 'unexpected end of the document within a single quoted scalar');
 
     } else {
       state.position++;
       captureEnd = state.position;
     }
   }
 
   throwError(state, 'unexpected end of the stream within a single quoted scalar');
 }
 
 function readDoubleQuotedScalar(state, nodeIndent) {
   var captureStart,
       captureEnd,
       hexLength,
       hexResult,
       tmp,
       ch;
 
   ch = state.input.charCodeAt(state.position);
 
   if (ch !== 0x22/* " */) {
     return false;
   }
 
   state.kind = 'scalar';
   state.result = '';
   state.position++;
   captureStart = captureEnd = state.position;
 
   while ((ch = state.input.charCodeAt(state.position)) !== 0) {
     if (ch === 0x22/* " */) {
       captureSegment(state, captureStart, state.position, true);
       state.position++;
       return true;
 
     } else if (ch === 0x5C/* \ */) {
       captureSegment(state, captureStart, state.position, true);
       ch = state.input.charCodeAt(++state.position);
 
       if (is_EOL(ch)) {
         skipSeparationSpace(state, false, nodeIndent);
 
         // TODO: rework to inline fn with no type cast?
       } else if (ch < 256 && simpleEscapeCheck[ch]) {
         state.result += simpleEscapeMap[ch];
         state.position++;
 
       } else if ((tmp = escapedHexLen(ch)) > 0) {
         hexLength = tmp;
         hexResult = 0;
 
         for (; hexLength > 0; hexLength--) {
           ch = state.input.charCodeAt(++state.position);
 
           if ((tmp = fromHexCode(ch)) >= 0) {
             hexResult = (hexResult << 4) + tmp;
 
           } else {
             throwError(state, 'expected hexadecimal character');
           }
         }
 
         state.result += charFromCodepoint(hexResult);
 
         state.position++;
 
       } else {
         throwError(state, 'unknown escape sequence');
       }
 
       captureStart = captureEnd = state.position;
 
     } else if (is_EOL(ch)) {
       captureSegment(state, captureStart, captureEnd, true);
       writeFoldedLines(state, skipSeparationSpace(state, false, nodeIndent));
       captureStart = captureEnd = state.position;
 
     } else if (state.position === state.lineStart && testDocumentSeparator(state)) {
       throwError(state, 'unexpected end of the document within a double quoted scalar');
 
     } else {
       state.position++;
       captureEnd = state.position;
     }
   }
 
   throwError(state, 'unexpected end of the stream within a double quoted scalar');
 }
 
 function readFlowCollection(state, nodeIndent) {
   var readNext = true,
       _line,
       _tag     = state.tag,
       _result,
       _anchor  = state.anchor,
       following,
       terminator,
       isPair,
       isExplicitPair,
       isMapping,
       overridableKeys = {},
       keyNode,
       keyTag,
       valueNode,
       ch;
 
   ch = state.input.charCodeAt(state.position);
 
   if (ch === 0x5B/* [ */) {
     terminator = 0x5D;/* ] */
     isMapping = false;
     _result = [];
   } else if (ch === 0x7B/* { */) {
     terminator = 0x7D;/* } */
     isMapping = true;
     _result = {};
   } else {
     return false;
   }
 
   if (state.anchor !== null) {
     state.anchorMap[state.anchor] = _result;
   }
 
   ch = state.input.charCodeAt(++state.position);
 
   while (ch !== 0) {
     skipSeparationSpace(state, true, nodeIndent);
 
     ch = state.input.charCodeAt(state.position);
 
     if (ch === terminator) {
       state.position++;
       state.tag = _tag;
       state.anchor = _anchor;
       state.kind = isMapping ? 'mapping' : 'sequence';
       state.result = _result;
       return true;
     } else if (!readNext) {
       throwError(state, 'missed comma between flow collection entries');
     }
 
     keyTag = keyNode = valueNode = null;
     isPair = isExplicitPair = false;
 
     if (ch === 0x3F/* ? */) {
       following = state.input.charCodeAt(state.position + 1);
 
       if (is_WS_OR_EOL(following)) {
         isPair = isExplicitPair = true;
         state.position++;
         skipSeparationSpace(state, true, nodeIndent);
       }
     }
 
     _line = state.line;
     composeNode(state, nodeIndent, CONTEXT_FLOW_IN, false, true);
     keyTag = state.tag;
     keyNode = state.result;
     skipSeparationSpace(state, true, nodeIndent);
 
     ch = state.input.charCodeAt(state.position);
 
     if ((isExplicitPair || state.line === _line) && ch === 0x3A/* : */) {
       isPair = true;
       ch = state.input.charCodeAt(++state.position);
       skipSeparationSpace(state, true, nodeIndent);
       composeNode(state, nodeIndent, CONTEXT_FLOW_IN, false, true);
       valueNode = state.result;
     }
 
     if (isMapping) {
       storeMappingPair(state, _result, overridableKeys, keyTag, keyNode, valueNode);
     } else if (isPair) {
       _result.push(storeMappingPair(state, null, overridableKeys, keyTag, keyNode, valueNode));
     } else {
       _result.push(keyNode);
     }
 
     skipSeparationSpace(state, true, nodeIndent);
 
     ch = state.input.charCodeAt(state.position);
 
     if (ch === 0x2C/* , */) {
       readNext = true;
       ch = state.input.charCodeAt(++state.position);
     } else {
       readNext = false;
     }
   }
 
   throwError(state, 'unexpected end of the stream within a flow collection');
 }
 
 function readBlockScalar(state, nodeIndent) {
   var captureStart,
       folding,
       chomping       = CHOMPING_CLIP,
       didReadContent = false,
       detectedIndent = false,
       textIndent     = nodeIndent,
       emptyLines     = 0,
       atMoreIndented = false,
       tmp,
       ch;
 
   ch = state.input.charCodeAt(state.position);
 
   if (ch === 0x7C/* | */) {
     folding = false;
   } else if (ch === 0x3E/* > */) {
     folding = true;
   } else {
     return false;
   }
 
   state.kind = 'scalar';
   state.result = '';
 
   while (ch !== 0) {
     ch = state.input.charCodeAt(++state.position);
 
     if (ch === 0x2B/* + */ || ch === 0x2D/* - */) {
       if (CHOMPING_CLIP === chomping) {
         chomping = (ch === 0x2B/* + */) ? CHOMPING_KEEP : CHOMPING_STRIP;
       } else {
         throwError(state, 'repeat of a chomping mode identifier');
       }
 
     } else if ((tmp = fromDecimalCode(ch)) >= 0) {
       if (tmp === 0) {
         throwError(state, 'bad explicit indentation width of a block scalar; it cannot be less than one');
       } else if (!detectedIndent) {
         textIndent = nodeIndent + tmp - 1;
         detectedIndent = true;
       } else {
         throwError(state, 'repeat of an indentation width identifier');
       }
 
     } else {
       break;
     }
   }
 
   if (is_WHITE_SPACE(ch)) {
     do { ch = state.input.charCodeAt(++state.position); }
     while (is_WHITE_SPACE(ch));
 
     if (ch === 0x23/* # */) {
       do { ch = state.input.charCodeAt(++state.position); }
       while (!is_EOL(ch) && (ch !== 0));
     }
   }
 
   while (ch !== 0) {
     readLineBreak(state);
     state.lineIndent = 0;
 
     ch = state.input.charCodeAt(state.position);
 
     while ((!detectedIndent || state.lineIndent < textIndent) &&
            (ch === 0x20/* Space */)) {
       state.lineIndent++;
       ch = state.input.charCodeAt(++state.position);
     }
 
     if (!detectedIndent && state.lineIndent > textIndent) {
       textIndent = state.lineIndent;
     }
 
     if (is_EOL(ch)) {
       emptyLines++;
       continue;
     }
 
     // End of the scalar.
     if (state.lineIndent < textIndent) {
 
       // Perform the chomping.
       if (chomping === CHOMPING_KEEP) {
         state.result += common.repeat('\n', didReadContent ? 1 + emptyLines : emptyLines);
       } else if (chomping === CHOMPING_CLIP) {
         if (didReadContent) { // i.e. only if the scalar is not empty.
           state.result += '\n';
         }
       }
 
       // Break this `while` cycle and go to the funciton's epilogue.
       break;
     }
 
     // Folded style: use fancy rules to handle line breaks.
     if (folding) {
 
       // Lines starting with white space characters (more-indented lines) are not folded.
       if (is_WHITE_SPACE(ch)) {
         atMoreIndented = true;
         // except for the first content line (cf. Example 8.1)
         state.result += common.repeat('\n', didReadContent ? 1 + emptyLines : emptyLines);
 
       // End of more-indented block.
       } else if (atMoreIndented) {
         atMoreIndented = false;
         state.result += common.repeat('\n', emptyLines + 1);
 
       // Just one line break - perceive as the same line.
       } else if (emptyLines === 0) {
         if (didReadContent) { // i.e. only if we have already read some scalar content.
           state.result += ' ';
         }
 
       // Several line breaks - perceive as different lines.
       } else {
         state.result += common.repeat('\n', emptyLines);
       }
 
     // Literal style: just add exact number of line breaks between content lines.
     } else {
       // Keep all line breaks except the header line break.
       state.result += common.repeat('\n', didReadContent ? 1 + emptyLines : emptyLines);
     }
 
     didReadContent = true;
     detectedIndent = true;
     emptyLines = 0;
     captureStart = state.position;
 
     while (!is_EOL(ch) && (ch !== 0)) {
       ch = state.input.charCodeAt(++state.position);
     }
 
     captureSegment(state, captureStart, state.position, false);
   }
 
   return true;
 }
 
 function readBlockSequence(state, nodeIndent) {
   var _line,
       _tag      = state.tag,
       _anchor   = state.anchor,
       _result   = [],
       following,
       detected  = false,
       ch;
 
   if (state.anchor !== null) {
     state.anchorMap[state.anchor] = _result;
   }
 
   ch = state.input.charCodeAt(state.position);
 
   while (ch !== 0) {
 
     if (ch !== 0x2D/* - */) {
       break;
     }
 
     following = state.input.charCodeAt(state.position + 1);
 
     if (!is_WS_OR_EOL(following)) {
       break;
     }
 
     detected = true;
     state.position++;
 
     if (skipSeparationSpace(state, true, -1)) {
       if (state.lineIndent <= nodeIndent) {
         _result.push(null);
         ch = state.input.charCodeAt(state.position);
         continue;
       }
     }
 
     _line = state.line;
     composeNode(state, nodeIndent, CONTEXT_BLOCK_IN, false, true);
     _result.push(state.result);
     skipSeparationSpace(state, true, -1);
 
     ch = state.input.charCodeAt(state.position);
 
     if ((state.line === _line || state.lineIndent > nodeIndent) && (ch !== 0)) {
       throwError(state, 'bad indentation of a sequence entry');
     } else if (state.lineIndent < nodeIndent) {
       break;
     }
   }
 
   if (detected) {
     state.tag = _tag;
     state.anchor = _anchor;
     state.kind = 'sequence';
     state.result = _result;
     return true;
   }
   return false;
 }
 
 function readBlockMapping(state, nodeIndent, flowIndent) {
   var following,
       allowCompact,
       _line,
       _pos,
       _tag          = state.tag,
       _anchor       = state.anchor,
       _result       = {},
       overridableKeys = {},
       keyTag        = null,
       keyNode       = null,
       valueNode     = null,
       atExplicitKey = false,
       detected      = false,
       ch;
 
   if (state.anchor !== null) {
     state.anchorMap[state.anchor] = _result;
   }
 
   ch = state.input.charCodeAt(state.position);
 
   while (ch !== 0) {
     following = state.input.charCodeAt(state.position + 1);
     _line = state.line; // Save the current line.
     _pos = state.position;
 
     //
     // Explicit notation case. There are two separate blocks:
     // first for the key (denoted by "?") and second for the value (denoted by ":")
     //
     if ((ch === 0x3F/* ? */ || ch === 0x3A/* : */) && is_WS_OR_EOL(following)) {
 
       if (ch === 0x3F/* ? */) {
         if (atExplicitKey) {
           storeMappingPair(state, _result, overridableKeys, keyTag, keyNode, null);
           keyTag = keyNode = valueNode = null;
         }
 
         detected = true;
         atExplicitKey = true;
         allowCompact = true;
 
       } else if (atExplicitKey) {
         // i.e. 0x3A/* : */ === character after the explicit key.
         atExplicitKey = false;
         allowCompact = true;
 
       } else {
         throwError(state, 'incomplete explicit mapping pair; a key node is missed; or followed by a non-tabulated empty line');
       }
 
       state.position += 1;
       ch = following;
 
     //
     // Implicit notation case. Flow-style node as the key first, then ":", and the value.
     //
     } else if (composeNode(state, flowIndent, CONTEXT_FLOW_OUT, false, true)) {
 
       if (state.line === _line) {
         ch = state.input.charCodeAt(state.position);
 
         while (is_WHITE_SPACE(ch)) {
           ch = state.input.charCodeAt(++state.position);
         }
 
         if (ch === 0x3A/* : */) {
           ch = state.input.charCodeAt(++state.position);
 
           if (!is_WS_OR_EOL(ch)) {
             throwError(state, 'a whitespace character is expected after the key-value separator within a block mapping');
           }
 
           if (atExplicitKey) {
             storeMappingPair(state, _result, overridableKeys, keyTag, keyNode, null);
             keyTag = keyNode = valueNode = null;
           }
 
           detected = true;
           atExplicitKey = false;
           allowCompact = false;
           keyTag = state.tag;
           keyNode = state.result;
 
         } else if (detected) {
           throwError(state, 'can not read an implicit mapping pair; a colon is missed');
 
         } else {
           state.tag = _tag;
           state.anchor = _anchor;
           return true; // Keep the result of `composeNode`.
         }
 
       } else if (detected) {
         throwError(state, 'can not read a block mapping entry; a multiline key may not be an implicit key');
 
       } else {
         state.tag = _tag;
         state.anchor = _anchor;
         return true; // Keep the result of `composeNode`.
       }
 
     } else {
       break; // Reading is done. Go to the epilogue.
     }
 
     //
     // Common reading code for both explicit and implicit notations.
     //
     if (state.line === _line || state.lineIndent > nodeIndent) {
       if (composeNode(state, nodeIndent, CONTEXT_BLOCK_OUT, true, allowCompact)) {
         if (atExplicitKey) {
           keyNode = state.result;
         } else {
           valueNode = state.result;
         }
       }
 
       if (!atExplicitKey) {
         storeMappingPair(state, _result, overridableKeys, keyTag, keyNode, valueNode, _line, _pos);
         keyTag = keyNode = valueNode = null;
       }
 
       skipSeparationSpace(state, true, -1);
       ch = state.input.charCodeAt(state.position);
     }
 
     if (state.lineIndent > nodeIndent && (ch !== 0)) {
       throwError(state, 'bad indentation of a mapping entry');
     } else if (state.lineIndent < nodeIndent) {
       break;
     }
   }
 
   //
   // Epilogue.
   //
 
   // Special case: last mapping's node contains only the key in explicit notation.
   if (atExplicitKey) {
     storeMappingPair(state, _result, overridableKeys, keyTag, keyNode, null);
   }
 
   // Expose the resulting mapping.
   if (detected) {
     state.tag = _tag;
     state.anchor = _anchor;
     state.kind = 'mapping';
     state.result = _result;
   }
 
   return detected;
 }
 
 function readTagProperty(state) {
   var _position,
       isVerbatim = false,
       isNamed    = false,
       tagHandle,
       tagName,
       ch;
 
   ch = state.input.charCodeAt(state.position);
 
   if (ch !== 0x21/* ! */) return false;
 
   if (state.tag !== null) {
     throwError(state, 'duplication of a tag property');
   }
 
   ch = state.input.charCodeAt(++state.position);
 
   if (ch === 0x3C/* < */) {
     isVerbatim = true;
     ch = state.input.charCodeAt(++state.position);
 
   } else if (ch === 0x21/* ! */) {
     isNamed = true;
     tagHandle = '!!';
     ch = state.input.charCodeAt(++state.position);
 
   } else {
     tagHandle = '!';
   }
 
   _position = state.position;
 
   if (isVerbatim) {
     do { ch = state.input.charCodeAt(++state.position); }
     while (ch !== 0 && ch !== 0x3E/* > */);
 
     if (state.position < state.length) {
       tagName = state.input.slice(_position, state.position);
       ch = state.input.charCodeAt(++state.position);
     } else {
       throwError(state, 'unexpected end of the stream within a verbatim tag');
     }
   } else {
     while (ch !== 0 && !is_WS_OR_EOL(ch)) {
 
       if (ch === 0x21/* ! */) {
         if (!isNamed) {
           tagHandle = state.input.slice(_position - 1, state.position + 1);
 
           if (!PATTERN_TAG_HANDLE.test(tagHandle)) {
             throwError(state, 'named tag handle cannot contain such characters');
           }
 
           isNamed = true;
           _position = state.position + 1;
         } else {
           throwError(state, 'tag suffix cannot contain exclamation marks');
         }
       }
 
       ch = state.input.charCodeAt(++state.position);
     }
 
     tagName = state.input.slice(_position, state.position);
 
     if (PATTERN_FLOW_INDICATORS.test(tagName)) {
       throwError(state, 'tag suffix cannot contain flow indicator characters');
     }
   }
 
   if (tagName && !PATTERN_TAG_URI.test(tagName)) {
     throwError(state, 'tag name cannot contain such characters: ' + tagName);
   }
 
   if (isVerbatim) {
     state.tag = tagName;
 
   } else if (_hasOwnProperty.call(state.tagMap, tagHandle)) {
     state.tag = state.tagMap[tagHandle] + tagName;
 
   } else if (tagHandle === '!') {
     state.tag = '!' + tagName;
 
   } else if (tagHandle === '!!') {
     state.tag = 'tag:yaml.org,2002:' + tagName;
 
   } else {
     throwError(state, 'undeclared tag handle "' + tagHandle + '"');
   }
 
   return true;
 }
 
 function readAnchorProperty(state) {
   var _position,
       ch;
 
   ch = state.input.charCodeAt(state.position);
 
   if (ch !== 0x26/* & */) return false;
 
   if (state.anchor !== null) {
     throwError(state, 'duplication of an anchor property');
   }
 
   ch = state.input.charCodeAt(++state.position);
   _position = state.position;
 
   while (ch !== 0 && !is_WS_OR_EOL(ch) && !is_FLOW_INDICATOR(ch)) {
     ch = state.input.charCodeAt(++state.position);
   }
 
   if (state.position === _position) {
     throwError(state, 'name of an anchor node must contain at least one character');
   }
 
   state.anchor = state.input.slice(_position, state.position);
   return true;
 }
 
 function readAlias(state) {
   var _position, alias,
       ch;
 
   ch = state.input.charCodeAt(state.position);
 
   if (ch !== 0x2A/* * */) return false;
 
   ch = state.input.charCodeAt(++state.position);
   _position = state.position;
 
   while (ch !== 0 && !is_WS_OR_EOL(ch) && !is_FLOW_INDICATOR(ch)) {
     ch = state.input.charCodeAt(++state.position);
   }
 
   if (state.position === _position) {
     throwError(state, 'name of an alias node must contain at least one character');
   }
 
   alias = state.input.slice(_position, state.position);
 
   if (!state.anchorMap.hasOwnProperty(alias)) {
     throwError(state, 'unidentified alias "' + alias + '"');
   }
 
   state.result = state.anchorMap[alias];
   skipSeparationSpace(state, true, -1);
   return true;
 }
 
 function composeNode(state, parentIndent, nodeContext, allowToSeek, allowCompact) {
   var allowBlockStyles,
       allowBlockScalars,
       allowBlockCollections,
       indentStatus = 1, // 1: this>parent, 0: this=parent, -1: this<parent
       atNewLine  = false,
       hasContent = false,
       typeIndex,
       typeQuantity,
       type,
       flowIndent,
       blockIndent;
 
   if (state.listener !== null) {
     state.listener('open', state);
   }
 
   state.tag    = null;
   state.anchor = null;
   state.kind   = null;
   state.result = null;
 
   allowBlockStyles = allowBlockScalars = allowBlockCollections =
     CONTEXT_BLOCK_OUT === nodeContext ||
     CONTEXT_BLOCK_IN  === nodeContext;
 
   if (allowToSeek) {
     if (skipSeparationSpace(state, true, -1)) {
       atNewLine = true;
 
       if (state.lineIndent > parentIndent) {
         indentStatus = 1;
       } else if (state.lineIndent === parentIndent) {
         indentStatus = 0;
       } else if (state.lineIndent < parentIndent) {
         indentStatus = -1;
       }
     }
   }
 
   if (indentStatus === 1) {
     while (readTagProperty(state) || readAnchorProperty(state)) {
       if (skipSeparationSpace(state, true, -1)) {
         atNewLine = true;
         allowBlockCollections = allowBlockStyles;
 
         if (state.lineIndent > parentIndent) {
           indentStatus = 1;
         } else if (state.lineIndent === parentIndent) {
           indentStatus = 0;
         } else if (state.lineIndent < parentIndent) {
           indentStatus = -1;
         }
       } else {
         allowBlockCollections = false;
       }
     }
   }
 
   if (allowBlockCollections) {
     allowBlockCollections = atNewLine || allowCompact;
   }
 
   if (indentStatus === 1 || CONTEXT_BLOCK_OUT === nodeContext) {
     if (CONTEXT_FLOW_IN === nodeContext || CONTEXT_FLOW_OUT === nodeContext) {
       flowIndent = parentIndent;
     } else {
       flowIndent = parentIndent + 1;
     }
 
     blockIndent = state.position - state.lineStart;
 
     if (indentStatus === 1) {
       if (allowBlockCollections &&
           (readBlockSequence(state, blockIndent) ||
            readBlockMapping(state, blockIndent, flowIndent)) ||
           readFlowCollection(state, flowIndent)) {
         hasContent = true;
       } else {
         if ((allowBlockScalars && readBlockScalar(state, flowIndent)) ||
             readSingleQuotedScalar(state, flowIndent) ||
             readDoubleQuotedScalar(state, flowIndent)) {
           hasContent = true;
 
         } else if (readAlias(state)) {
           hasContent = true;
 
           if (state.tag !== null || state.anchor !== null) {
             throwError(state, 'alias node should not have any properties');
           }
 
         } else if (readPlainScalar(state, flowIndent, CONTEXT_FLOW_IN === nodeContext)) {
           hasContent = true;
 
           if (state.tag === null) {
             state.tag = '?';
           }
         }
 
         if (state.anchor !== null) {
           state.anchorMap[state.anchor] = state.result;
         }
       }
     } else if (indentStatus === 0) {
       // Special case: block sequences are allowed to have same indentation level as the parent.
       // http://www.yaml.org/spec/1.2/spec.html#id2799784
       hasContent = allowBlockCollections && readBlockSequence(state, blockIndent);
     }
   }
 
   if (state.tag !== null && state.tag !== '!') {
     if (state.tag === '?') {
       // Implicit resolving is not allowed for non-scalar types, and '?'
       // non-specific tag is only automatically assigned to plain scalars.
       //
       // We only need to check kind conformity in case user explicitly assigns '?'
       // tag, for example like this: "!<?> [0]"
       //
       if (state.result !== null && state.kind !== 'scalar') {
         throwError(state, 'unacceptable node kind for !<?> tag; it should be "scalar", not "' + state.kind + '"');
       }
 
       for (typeIndex = 0, typeQuantity = state.implicitTypes.length; typeIndex < typeQuantity; typeIndex += 1) {
         type = state.implicitTypes[typeIndex];
 
         if (type.resolve(state.result)) { // `state.result` updated in resolver if matched
           state.result = type.construct(state.result);
           state.tag = type.tag;
           if (state.anchor !== null) {
             state.anchorMap[state.anchor] = state.result;
           }
           break;
         }
       }
     } else if (_hasOwnProperty.call(state.typeMap[state.kind || 'fallback'], state.tag)) {
       type = state.typeMap[state.kind || 'fallback'][state.tag];
 
       if (state.result !== null && type.kind !== state.kind) {
         throwError(state, 'unacceptable node kind for !<' + state.tag + '> tag; it should be "' + type.kind + '", not "' + state.kind + '"');
       }
 
       if (!type.resolve(state.result)) { // `state.result` updated in resolver if matched
         throwError(state, 'cannot resolve a node with !<' + state.tag + '> explicit tag');
       } else {
         state.result = type.construct(state.result);
         if (state.anchor !== null) {
           state.anchorMap[state.anchor] = state.result;
         }
       }
     } else {
       throwError(state, 'unknown tag !<' + state.tag + '>');
     }
   }
 
   if (state.listener !== null) {
     state.listener('close', state);
   }
   return state.tag !== null ||  state.anchor !== null || hasContent;
 }
 
 function readDocument(state) {
   var documentStart = state.position,
       _position,
       directiveName,
       directiveArgs,
       hasDirectives = false,
       ch;
 
   state.version = null;
   state.checkLineBreaks = state.legacy;
   state.tagMap = {};
   state.anchorMap = {};
 
   while ((ch = state.input.charCodeAt(state.position)) !== 0) {
     skipSeparationSpace(state, true, -1);
 
     ch = state.input.charCodeAt(state.position);
 
     if (state.lineIndent > 0 || ch !== 0x25/* % */) {
       break;
     }
 
     hasDirectives = true;
     ch = state.input.charCodeAt(++state.position);
     _position = state.position;
 
     while (ch !== 0 && !is_WS_OR_EOL(ch)) {
       ch = state.input.charCodeAt(++state.position);
     }
 
     directiveName = state.input.slice(_position, state.position);
     directiveArgs = [];
 
     if (directiveName.length < 1) {
       throwError(state, 'directive name must not be less than one character in length');
     }
 
     while (ch !== 0) {
       while (is_WHITE_SPACE(ch)) {
         ch = state.input.charCodeAt(++state.position);
       }
 
       if (ch === 0x23/* # */) {
         do { ch = state.input.charCodeAt(++state.position); }
         while (ch !== 0 && !is_EOL(ch));
         break;
       }
 
       if (is_EOL(ch)) break;
 
       _position = state.position;
 
       while (ch !== 0 && !is_WS_OR_EOL(ch)) {
         ch = state.input.charCodeAt(++state.position);
       }
 
       directiveArgs.push(state.input.slice(_position, state.position));
     }
 
     if (ch !== 0) readLineBreak(state);
 
     if (_hasOwnProperty.call(directiveHandlers, directiveName)) {
       directiveHandlers[directiveName](state, directiveName, directiveArgs);
     } else {
       throwWarning(state, 'unknown document directive "' + directiveName + '"');
     }
   }
 
   skipSeparationSpace(state, true, -1);
 
   if (state.lineIndent === 0 &&
       state.input.charCodeAt(state.position)     === 0x2D/* - */ &&
       state.input.charCodeAt(state.position + 1) === 0x2D/* - */ &&
       state.input.charCodeAt(state.position + 2) === 0x2D/* - */) {
     state.position += 3;
     skipSeparationSpace(state, true, -1);
 
   } else if (hasDirectives) {
     throwError(state, 'directives end mark is expected');
   }
 
   composeNode(state, state.lineIndent - 1, CONTEXT_BLOCK_OUT, false, true);
   skipSeparationSpace(state, true, -1);
 
   if (state.checkLineBreaks &&
       PATTERN_NON_ASCII_LINE_BREAKS.test(state.input.slice(documentStart, state.position))) {
     throwWarning(state, 'non-ASCII line breaks are interpreted as content');
   }
 
   state.documents.push(state.result);
 
   if (state.position === state.lineStart && testDocumentSeparator(state)) {
 
     if (state.input.charCodeAt(state.position) === 0x2E/* . */) {
       state.position += 3;
       skipSeparationSpace(state, true, -1);
     }
     return;
   }
 
   if (state.position < (state.length - 1)) {
     throwError(state, 'end of the stream or a document separator is expected');
   } else {
     return;
   }
 }
 
 
 function loadDocuments(input, options) {
   input = String(input);
   options = options || {};
 
   if (input.length !== 0) {
 
     // Add tailing `\n` if not exists
     if (input.charCodeAt(input.length - 1) !== 0x0A/* LF */ &&
         input.charCodeAt(input.length - 1) !== 0x0D/* CR */) {
       input += '\n';
     }
 
     // Strip BOM
     if (input.charCodeAt(0) === 0xFEFF) {
       input = input.slice(1);
     }
   }
 
   var state = new State(input, options);
 
   var nullpos = input.indexOf('\0');
 
   if (nullpos !== -1) {
     state.position = nullpos;
     throwError(state, 'null byte is not allowed in input');
   }
 
   // Use 0 as string terminator. That significantly simplifies bounds check.
   state.input += '\0';
 
   while (state.input.charCodeAt(state.position) === 0x20/* Space */) {
     state.lineIndent += 1;
     state.position += 1;
   }
 
   while (state.position < (state.length - 1)) {
     readDocument(state);
   }
 
   return state.documents;
 }
 
 
 function loadAll(input, iterator, options) {
   if (iterator !== null && typeof iterator === 'object' && typeof options === 'undefined') {
     options = iterator;
     iterator = null;
   }
 
   var documents = loadDocuments(input, options);
 
   if (typeof iterator !== 'function') {
     return documents;
   }
 
   for (var index = 0, length = documents.length; index < length; index += 1) {
     iterator(documents[index]);
   }
 }
 
 
 function load(input, options) {
   var documents = loadDocuments(input, options);
 
   if (documents.length === 0) {
     /*eslint-disable no-undefined*/
     return undefined;
   } else if (documents.length === 1) {
     return documents[0];
   }
   throw new YAMLException('expected a single document in the stream, but found more');
 }
 
 
 function safeLoadAll(input, iterator, options) {
   if (typeof iterator === 'object' && iterator !== null && typeof options === 'undefined') {
     options = iterator;
     iterator = null;
   }
 
   return loadAll(input, iterator, common.extend({ schema: DEFAULT_SAFE_SCHEMA }, options));
 }
 
 
 function safeLoad(input, options) {
   return load(input, common.extend({ schema: DEFAULT_SAFE_SCHEMA }, options));
 }
 
 
 module.exports.loadAll     = loadAll;
 module.exports.load        = load;
 module.exports.safeLoadAll = safeLoadAll;
 module.exports.safeLoad    = safeLoad;