486 lines
16 KiB
JavaScript
486 lines
16 KiB
JavaScript
'use strict';
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const {Writable} = require('stream');
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const {StringDecoder} = require('string_decoder');
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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 eol = /[\u000A\u2028\u2029]|\u000D\u000A|\u000D/g;
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const expected = {object: 'objectStop', array: 'arrayStop', '': 'done'};
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class Verifier extends Writable {
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static make(options) {
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return new Verifier(options);
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}
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constructor(options) {
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super(Object.assign({}, options, {objectMode: false}));
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if (options) {
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this._jsonStreaming = options.jsonStreaming;
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}
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this._buffer = '';
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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._line = this._pos = 1;
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this._offset = 0;
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}
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_write(chunk, encoding, callback) {
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if (typeof chunk == 'string') {
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this._write = this._writeString;
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} else {
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this._stringDecoder = new StringDecoder();
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this._write = this._writeBuffer;
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}
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this._write(chunk, encoding, callback);
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}
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_writeBuffer(chunk, _, callback) {
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this._buffer += this._stringDecoder.write(chunk);
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this._processBuffer(callback);
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}
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_writeString(chunk, _, callback) {
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this._buffer += chunk.toString();
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this._processBuffer(callback);
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}
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_final(callback) {
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if (this._stringDecoder) {
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this._buffer += this._stringDecoder.end();
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}
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this._done = true;
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this._processBuffer(callback);
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}
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_makeError(msg) {
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const error = new Error('ERROR at ' + this._offset + ' (' + this._line + ', ' + this._pos + '): ' + msg);
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error.line = this._line;
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error.pos = this._pos;
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error.offset = this._offset;
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return error;
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}
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_updatePos(value) {
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let len = value.length;
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this._offset += len;
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value.replace(eol, (match, offset) => {
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len = value.length - match.length - offset;
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++this._line;
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this._pos = 1;
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return '';
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});
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this._pos += len;
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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(this._makeError('Verifier cannot parse input: expected a value'));
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return callback(this._makeError('Verifier 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._expect = 'string';
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break;
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case '{':
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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._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(this._makeError("Verifier cannot parse input: unexpected token ']'"));
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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._expect = 'numberStart';
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break;
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case '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._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._expect = expected[this._parent];
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break;
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// default: // ws
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}
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this._updatePos(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 '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(this._makeError('Verifier cannot parse input: escaped characters'));
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if (this._done) return callback(this._makeError('Verifier 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._expect = 'colon';
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} else {
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this._expect = expected[this._parent];
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}
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}
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this._updatePos(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 '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(this._makeError('Verifier 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._expect = 'keyVal';
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} else if (value === '}') {
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if (this._expect !== 'key1') return callback(this._makeError("Verifier cannot parse input: unexpected token '}'"));
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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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this._updatePos(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 '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(this._makeError("Verifier 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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this._updatePos(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(this._makeError("Verifier 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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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(this._makeError("Verifier cannot parse input: expected '" + (this._expect === 'arrayStop' ? ']' : '}') + "'"));
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}
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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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this._updatePos(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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// 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(this._makeError('Verifier 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._expect = value === '0' ? 'numberFraction' : 'numberDigit';
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this._updatePos(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 '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(this._makeError('Verifier 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._updatePos(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._expect = value === '.' ? 'numberFracStart' : 'numberExpSign';
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this._updatePos(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 '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)
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return callback(this._makeError('Verifier 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._expect = 'numberFracDigit';
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this._updatePos(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 '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._updatePos(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._expect = 'numberExpSign';
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this._updatePos(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 '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(this._makeError('Verifier 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._expect = 'numberExpStart';
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this._updatePos(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 '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)
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return callback(this._makeError('Verifier 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._expect = 'numberExpDigit';
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this._updatePos(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 'numberExpDigit': // [0-9]*
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patterns.numberExpDigit.lastIndex = index;
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match = patterns.numberExpDigit.exec(this._buffer);
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value = match[0];
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if (value) {
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this._updatePos(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 || 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 'done':
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patterns.ws.lastIndex = index;
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match = patterns.ws.exec(this._buffer);
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if (!match) {
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if (index < this._buffer.length) {
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if (this._jsonStreaming) {
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this._expect = 'value';
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break;
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}
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return callback(this._makeError('Verifier cannot parse input: unexpected characters'));
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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._updatePos(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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}
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}
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!noSticky && (this._buffer = this._buffer.slice(index));
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callback(null);
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}
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}
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Verifier.verifier = Verifier.make;
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Verifier.make.Constructor = Verifier;
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module.exports = Verifier;
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