546 lines
20 KiB
JavaScript
546 lines
20 KiB
JavaScript
'use strict';
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const Utf8Stream = require('./utils/Utf8Stream');
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const patterns = {
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value1: /^(?:[\"\{\[\]\-\d]|true\b|false\b|null\b|\s{1,256})/,
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string: /^(?:[^\"\\]{1,256}|\\[bfnrt\"\\\/]|\\u[\da-fA-F]{4}|\")/,
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key1: /^(?:[\"\}]|\s{1,256})/,
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colon: /^(?:\:|\s{1,256})/,
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comma: /^(?:[\,\]\}]|\s{1,256})/,
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ws: /^\s{1,256}/,
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numberStart: /^\d/,
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numberDigit: /^\d{0,256}/,
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numberFraction: /^[\.eE]/,
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numberExponent: /^[eE]/,
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numberExpSign: /^[-+]/
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};
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const MAX_PATTERN_SIZE = 16;
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let noSticky = true;
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try {
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new RegExp('.', 'y');
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noSticky = false;
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} catch (e) {
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// suppress
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}
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!noSticky &&
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Object.keys(patterns).forEach(key => {
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let src = patterns[key].source.slice(1); // lop off ^
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if (src.slice(0, 3) === '(?:' && src.slice(-1) === ')') {
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src = src.slice(3, -1);
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}
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patterns[key] = new RegExp(src, 'y');
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});
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patterns.numberFracStart = patterns.numberExpStart = patterns.numberStart;
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patterns.numberFracDigit = patterns.numberExpDigit = patterns.numberDigit;
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const values = {true: true, false: false, null: null},
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expected = {object: 'objectStop', array: 'arrayStop', '': 'done'};
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// long hexadecimal codes: \uXXXX
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const fromHex = s => String.fromCharCode(parseInt(s.slice(2), 16));
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// short codes: \b \f \n \r \t \" \\ \/
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const codes = {b: '\b', f: '\f', n: '\n', r: '\r', t: '\t', '"': '"', '\\': '\\', '/': '/'};
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class Parser extends Utf8Stream {
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static make(options) {
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return new Parser(options);
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}
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constructor(options) {
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super(Object.assign({}, options, {readableObjectMode: true}));
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this._packKeys = this._packStrings = this._packNumbers = this._streamKeys = this._streamStrings = this._streamNumbers = true;
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if (options) {
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'packValues' in options && (this._packKeys = this._packStrings = this._packNumbers = options.packValues);
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'packKeys' in options && (this._packKeys = options.packKeys);
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'packStrings' in options && (this._packStrings = options.packStrings);
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'packNumbers' in options && (this._packNumbers = options.packNumbers);
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'streamValues' in options && (this._streamKeys = this._streamStrings = this._streamNumbers = options.streamValues);
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'streamKeys' in options && (this._streamKeys = options.streamKeys);
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'streamStrings' in options && (this._streamStrings = options.streamStrings);
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'streamNumbers' in options && (this._streamNumbers = options.streamNumbers);
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this._jsonStreaming = options.jsonStreaming;
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}
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!this._packKeys && (this._streamKeys = true);
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!this._packStrings && (this._streamStrings = true);
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!this._packNumbers && (this._streamNumbers = true);
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this._done = false;
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this._expect = this._jsonStreaming ? 'done' : 'value';
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this._stack = [];
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this._parent = '';
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this._open_number = false;
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this._accumulator = '';
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}
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_flush(callback) {
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this._done = true;
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super._flush(error => {
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if (error) return callback(error);
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if (this._open_number) {
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if (this._streamNumbers) {
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this.push({name: 'endNumber'});
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}
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this._open_number = false;
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if (this._packNumbers) {
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this.push({name: 'numberValue', value: this._accumulator});
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this._accumulator = '';
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}
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}
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callback(null);
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});
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}
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_processBuffer(callback) {
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let match,
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value,
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index = 0;
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main: for (;;) {
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switch (this._expect) {
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case 'value1':
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case 'value':
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patterns.value1.lastIndex = index;
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match = patterns.value1.exec(this._buffer);
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if (!match) {
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if (this._done || index + MAX_PATTERN_SIZE < this._buffer.length) {
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if (index < this._buffer.length) return callback(new Error('Parser cannot parse input: expected a value'));
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return callback(new Error('Parser has expected a value'));
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}
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break main; // wait for more input
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}
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value = match[0];
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switch (value) {
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case '"':
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this._streamStrings && this.push({name: 'startString'});
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this._expect = 'string';
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break;
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case '{':
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this.push({name: 'startObject'});
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this._stack.push(this._parent);
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this._parent = 'object';
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this._expect = 'key1';
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break;
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case '[':
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this.push({name: 'startArray'});
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this._stack.push(this._parent);
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this._parent = 'array';
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this._expect = 'value1';
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break;
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case ']':
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if (this._expect !== 'value1') return callback(new Error("Parser cannot parse input: unexpected token ']'"));
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if (this._open_number) {
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this._streamNumbers && this.push({name: 'endNumber'});
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this._open_number = false;
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if (this._packNumbers) {
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this.push({name: 'numberValue', value: this._accumulator});
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this._accumulator = '';
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}
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}
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this.push({name: 'endArray'});
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this._parent = this._stack.pop();
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this._expect = expected[this._parent];
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break;
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case '-':
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this._open_number = true;
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if (this._streamNumbers) {
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this.push({name: 'startNumber'});
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this.push({name: 'numberChunk', value: '-'});
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}
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this._packNumbers && (this._accumulator = '-');
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this._expect = 'numberStart';
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break;
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case '0':
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this._open_number = true;
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if (this._streamNumbers) {
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this.push({name: 'startNumber'});
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this.push({name: 'numberChunk', value: '0'});
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}
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this._packNumbers && (this._accumulator = '0');
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this._expect = 'numberFraction';
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break;
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case '1':
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case '2':
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case '3':
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case '4':
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case '5':
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case '6':
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case '7':
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case '8':
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case '9':
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this._open_number = true;
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if (this._streamNumbers) {
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this.push({name: 'startNumber'});
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this.push({name: 'numberChunk', value: value});
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}
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this._packNumbers && (this._accumulator = value);
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this._expect = 'numberDigit';
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break;
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case 'true':
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case 'false':
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case 'null':
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if (this._buffer.length - index === value.length && !this._done) break main; // wait for more input
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this.push({name: value + 'Value', value: values[value]});
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this._expect = expected[this._parent];
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break;
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// default: // ws
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}
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if (noSticky) {
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this._buffer = this._buffer.slice(value.length);
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} else {
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index += value.length;
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}
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break;
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case 'keyVal':
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case 'string':
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patterns.string.lastIndex = index;
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match = patterns.string.exec(this._buffer);
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if (!match) {
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if (index < this._buffer.length && (this._done || this._buffer.length - index >= 6))
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return callback(new Error('Parser cannot parse input: escaped characters'));
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if (this._done) return callback(new Error('Parser has expected a string value'));
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break main; // wait for more input
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}
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value = match[0];
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if (value === '"') {
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if (this._expect === 'keyVal') {
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this._streamKeys && this.push({name: 'endKey'});
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if (this._packKeys) {
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this.push({name: 'keyValue', value: this._accumulator});
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this._accumulator = '';
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}
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this._expect = 'colon';
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} else {
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this._streamStrings && this.push({name: 'endString'});
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if (this._packStrings) {
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this.push({name: 'stringValue', value: this._accumulator});
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this._accumulator = '';
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}
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this._expect = expected[this._parent];
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}
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} else if (value.length > 1 && value.charAt(0) === '\\') {
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const t = value.length == 2 ? codes[value.charAt(1)] : fromHex(value);
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if (this._expect === 'keyVal' ? this._streamKeys : this._streamStrings) {
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this.push({name: 'stringChunk', value: t});
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}
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if (this._expect === 'keyVal' ? this._packKeys : this._packStrings) {
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this._accumulator += t;
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}
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} else {
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if (this._expect === 'keyVal' ? this._streamKeys : this._streamStrings) {
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this.push({name: 'stringChunk', value: value});
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}
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if (this._expect === 'keyVal' ? this._packKeys : this._packStrings) {
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this._accumulator += value;
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}
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}
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if (noSticky) {
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this._buffer = this._buffer.slice(value.length);
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} else {
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index += value.length;
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}
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break;
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case 'key1':
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case 'key':
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patterns.key1.lastIndex = index;
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match = patterns.key1.exec(this._buffer);
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if (!match) {
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if (index < this._buffer.length || this._done) return callback(new Error('Parser cannot parse input: expected an object key'));
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break main; // wait for more input
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}
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value = match[0];
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if (value === '"') {
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this._streamKeys && this.push({name: 'startKey'});
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this._expect = 'keyVal';
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} else if (value === '}') {
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if (this._expect !== 'key1') return callback(new Error("Parser cannot parse input: unexpected token '}'"));
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this.push({name: 'endObject'});
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this._parent = this._stack.pop();
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this._expect = expected[this._parent];
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}
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if (noSticky) {
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this._buffer = this._buffer.slice(value.length);
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} else {
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index += value.length;
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}
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break;
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case 'colon':
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patterns.colon.lastIndex = index;
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match = patterns.colon.exec(this._buffer);
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if (!match) {
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if (index < this._buffer.length || this._done) return callback(new Error("Parser cannot parse input: expected ':'"));
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break main; // wait for more input
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}
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value = match[0];
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value === ':' && (this._expect = 'value');
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if (noSticky) {
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this._buffer = this._buffer.slice(value.length);
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} else {
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index += value.length;
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}
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break;
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case 'arrayStop':
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case 'objectStop':
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patterns.comma.lastIndex = index;
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match = patterns.comma.exec(this._buffer);
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if (!match) {
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if (index < this._buffer.length || this._done) return callback(new Error("Parser cannot parse input: expected ','"));
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break main; // wait for more input
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}
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if (this._open_number) {
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this._streamNumbers && this.push({name: 'endNumber'});
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this._open_number = false;
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if (this._packNumbers) {
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this.push({name: 'numberValue', value: this._accumulator});
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this._accumulator = '';
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}
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}
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value = match[0];
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if (value === ',') {
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this._expect = this._expect === 'arrayStop' ? 'value' : 'key';
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} else if (value === '}' || value === ']') {
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if (value === '}' ? this._expect === 'arrayStop' : this._expect !== 'arrayStop') {
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return callback(new Error("Parser cannot parse input: expected '" + (this._expect === 'arrayStop' ? ']' : '}') + "'"));
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}
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this.push({name: value === '}' ? 'endObject' : 'endArray'});
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this._parent = this._stack.pop();
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this._expect = expected[this._parent];
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}
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if (noSticky) {
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this._buffer = this._buffer.slice(value.length);
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} else {
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index += value.length;
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}
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break;
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// number chunks
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case 'numberStart': // [0-9]
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patterns.numberStart.lastIndex = index;
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match = patterns.numberStart.exec(this._buffer);
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if (!match) {
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if (index < this._buffer.length || this._done) return callback(new Error('Parser cannot parse input: expected a starting digit'));
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break main; // wait for more input
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}
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value = match[0];
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this._streamNumbers && this.push({name: 'numberChunk', value: value});
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this._packNumbers && (this._accumulator += value);
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this._expect = value === '0' ? 'numberFraction' : 'numberDigit';
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if (noSticky) {
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this._buffer = this._buffer.slice(value.length);
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} else {
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index += value.length;
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}
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break;
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case 'numberDigit': // [0-9]*
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patterns.numberDigit.lastIndex = index;
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match = patterns.numberDigit.exec(this._buffer);
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if (!match) {
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if (index < this._buffer.length || this._done) return callback(new Error('Parser cannot parse input: expected a digit'));
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break main; // wait for more input
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}
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value = match[0];
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if (value) {
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this._streamNumbers && this.push({name: 'numberChunk', value: value});
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this._packNumbers && (this._accumulator += value);
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if (noSticky) {
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this._buffer = this._buffer.slice(value.length);
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} else {
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index += value.length;
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}
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} else {
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if (index < this._buffer.length) {
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this._expect = 'numberFraction';
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break;
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}
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if (this._done) {
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this._expect = expected[this._parent];
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break;
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}
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break main; // wait for more input
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}
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break;
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case 'numberFraction': // [\.eE]?
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patterns.numberFraction.lastIndex = index;
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match = patterns.numberFraction.exec(this._buffer);
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if (!match) {
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if (index < this._buffer.length || this._done) {
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this._expect = expected[this._parent];
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break;
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}
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break main; // wait for more input
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}
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value = match[0];
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this._streamNumbers && this.push({name: 'numberChunk', value: value});
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this._packNumbers && (this._accumulator += value);
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this._expect = value === '.' ? 'numberFracStart' : 'numberExpSign';
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if (noSticky) {
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this._buffer = this._buffer.slice(value.length);
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} else {
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index += value.length;
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}
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break;
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case 'numberFracStart': // [0-9]
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patterns.numberFracStart.lastIndex = index;
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match = patterns.numberFracStart.exec(this._buffer);
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if (!match) {
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if (index < this._buffer.length || this._done) return callback(new Error('Parser cannot parse input: expected a fractional part of a number'));
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break main; // wait for more input
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}
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value = match[0];
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this._streamNumbers && this.push({name: 'numberChunk', value: value});
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this._packNumbers && (this._accumulator += value);
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this._expect = 'numberFracDigit';
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if (noSticky) {
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this._buffer = this._buffer.slice(value.length);
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} else {
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index += value.length;
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}
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break;
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case 'numberFracDigit': // [0-9]*
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patterns.numberFracDigit.lastIndex = index;
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match = patterns.numberFracDigit.exec(this._buffer);
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value = match[0];
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if (value) {
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this._streamNumbers && this.push({name: 'numberChunk', value: value});
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this._packNumbers && (this._accumulator += value);
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if (noSticky) {
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this._buffer = this._buffer.slice(value.length);
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} else {
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index += value.length;
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}
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} else {
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if (index < this._buffer.length) {
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this._expect = 'numberExponent';
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break;
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}
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if (this._done) {
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this._expect = expected[this._parent];
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break;
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}
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break main; // wait for more input
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}
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break;
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case 'numberExponent': // [eE]?
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patterns.numberExponent.lastIndex = index;
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match = patterns.numberExponent.exec(this._buffer);
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if (!match) {
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if (index < this._buffer.length) {
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this._expect = expected[this._parent];
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break;
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}
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if (this._done) {
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this._expect = 'done';
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break;
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}
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break main; // wait for more input
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}
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value = match[0];
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this._streamNumbers && this.push({name: 'numberChunk', value: value});
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this._packNumbers && (this._accumulator += value);
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this._expect = 'numberExpSign';
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if (noSticky) {
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this._buffer = this._buffer.slice(value.length);
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} else {
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index += value.length;
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}
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break;
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case 'numberExpSign': // [-+]?
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patterns.numberExpSign.lastIndex = index;
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match = patterns.numberExpSign.exec(this._buffer);
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if (!match) {
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if (index < this._buffer.length) {
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this._expect = 'numberExpStart';
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break;
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}
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if (this._done) return callback(new Error('Parser has expected an exponent value of a number'));
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break main; // wait for more input
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}
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value = match[0];
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this._streamNumbers && this.push({name: 'numberChunk', value: value});
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this._packNumbers && (this._accumulator += value);
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this._expect = 'numberExpStart';
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if (noSticky) {
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this._buffer = this._buffer.slice(value.length);
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} else {
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index += value.length;
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}
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break;
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case 'numberExpStart': // [0-9]
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patterns.numberExpStart.lastIndex = index;
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match = patterns.numberExpStart.exec(this._buffer);
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if (!match) {
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if (index < this._buffer.length || this._done) return callback(new Error('Parser cannot parse input: expected an exponent part of a number'));
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break main; // wait for more input
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}
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value = match[0];
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this._streamNumbers && this.push({name: 'numberChunk', value: value});
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this._packNumbers && (this._accumulator += value);
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this._expect = 'numberExpDigit';
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if (noSticky) {
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this._buffer = this._buffer.slice(value.length);
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} else {
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index += value.length;
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}
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break;
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case 'numberExpDigit': // [0-9]*
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patterns.numberExpDigit.lastIndex = index;
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match = patterns.numberExpDigit.exec(this._buffer);
|
|
value = match[0];
|
|
if (value) {
|
|
this._streamNumbers && this.push({name: 'numberChunk', value: value});
|
|
this._packNumbers && (this._accumulator += value);
|
|
if (noSticky) {
|
|
this._buffer = this._buffer.slice(value.length);
|
|
} else {
|
|
index += value.length;
|
|
}
|
|
} else {
|
|
if (index < this._buffer.length || this._done) {
|
|
this._expect = expected[this._parent];
|
|
break;
|
|
}
|
|
break main; // wait for more input
|
|
}
|
|
break;
|
|
case 'done':
|
|
patterns.ws.lastIndex = index;
|
|
match = patterns.ws.exec(this._buffer);
|
|
if (!match) {
|
|
if (index < this._buffer.length) {
|
|
if (this._jsonStreaming) {
|
|
this._expect = 'value';
|
|
break;
|
|
}
|
|
return callback(new Error('Parser cannot parse input: unexpected characters'));
|
|
}
|
|
break main; // wait for more input
|
|
}
|
|
value = match[0];
|
|
if (this._open_number) {
|
|
this._streamNumbers && this.push({name: 'endNumber'});
|
|
this._open_number = false;
|
|
if (this._packNumbers) {
|
|
this.push({name: 'numberValue', value: this._accumulator});
|
|
this._accumulator = '';
|
|
}
|
|
}
|
|
if (noSticky) {
|
|
this._buffer = this._buffer.slice(value.length);
|
|
} else {
|
|
index += value.length;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
!noSticky && (this._buffer = this._buffer.slice(index));
|
|
callback(null);
|
|
}
|
|
}
|
|
Parser.parser = Parser.make;
|
|
Parser.make.Constructor = Parser;
|
|
|
|
module.exports = Parser;
|