papaparse.js

/* @license
Papa Parse
v5.5.3
https://github.com/mholt/PapaParse
License: MIT
*/

(function(root, factory)
{
	/* globals define */
	if (typeof define === 'function' && define.amd)
	{
		// AMD. Register as an anonymous module.
		define([], factory);
	}
	else if (typeof module === 'object' && typeof exports !== 'undefined')
	{
		// Node. Does not work with strict CommonJS, but
		// only CommonJS-like environments that support module.exports,
		// like Node.
		module.exports = factory();
	}
	else
	{
		// Browser globals (root is window)
		root.Papa = factory();
	}
	// in strict mode we cannot access arguments.callee, so we need a named reference to
	// stringify the factory method for the blob worker
	// eslint-disable-next-line func-name
}(this, function moduleFactory()
{
	'use strict';

	var global = (function() {
		// alternative method, similar to `Function('return this')()`
		// but without using `eval` (which is disabled when
		// using Content Security Policy).

		if (typeof self !== 'undefined') { return self; }
		if (typeof window !== 'undefined') { return window; }
		if (typeof global !== 'undefined') { return global; }

		// When running tests none of the above have been defined
		return {};
	})();


	function getWorkerBlob() {
		var URL = global.URL || global.webkitURL || null;
		var code = moduleFactory.toString();
		return Papa.BLOB_URL || (Papa.BLOB_URL = URL.createObjectURL(new Blob(["var global = (function() { if (typeof self !== 'undefined') { return self; } if (typeof window !== 'undefined') { return window; } if (typeof global !== 'undefined') { return global; } return {}; })(); global.IS_PAPA_WORKER=true; ", '(', code, ')();'], {type: 'text/javascript'})));
	}

	var IS_WORKER = !global.document && !!global.postMessage,
		IS_PAPA_WORKER = global.IS_PAPA_WORKER || false;

	var workers = {}, workerIdCounter = 0;

	var Papa = {};

	Papa.parse = CsvToJson;
	Papa.unparse = JsonToCsv;

	Papa.RECORD_SEP = String.fromCharCode(30);
	Papa.UNIT_SEP = String.fromCharCode(31);
	Papa.BYTE_ORDER_MARK = '\ufeff';
	Papa.BAD_DELIMITERS = ['\r', '\n', '"', Papa.BYTE_ORDER_MARK];
	Papa.WORKERS_SUPPORTED = !IS_WORKER && !!global.Worker;
	Papa.NODE_STREAM_INPUT = 1;

	// Configurable chunk sizes for local and remote files, respectively
	Papa.LocalChunkSize = 1024 * 1024 * 10;	// 10 MB
	Papa.RemoteChunkSize = 1024 * 1024 * 5;	// 5 MB
	Papa.DefaultDelimiter = ',';			// Used if not specified and detection fails

	// Exposed for testing and development only
	Papa.Parser = Parser;
	Papa.ParserHandle = ParserHandle;
	Papa.NetworkStreamer = NetworkStreamer;
	Papa.FileStreamer = FileStreamer;
	Papa.StringStreamer = StringStreamer;
	Papa.ReadableStreamStreamer = ReadableStreamStreamer;
	if (typeof PAPA_BROWSER_CONTEXT === 'undefined') {
		Papa.DuplexStreamStreamer = DuplexStreamStreamer;
	}

	if (global.jQuery)
	{
		var $ = global.jQuery;
		$.fn.parse = function(options)
		{
			var config = options.config || {};
			var queue = [];

			this.each(function(idx)
			{
				var supported = $(this).prop('tagName').toUpperCase() === 'INPUT'
								&& $(this).attr('type').toLowerCase() === 'file'
								&& global.FileReader;

				if (!supported || !this.files || this.files.length === 0)
					return true;	// continue to next input element

				for (var i = 0; i < this.files.length; i++)
				{
					queue.push({
						file: this.files[i],
						inputElem: this,
						instanceConfig: $.extend({}, config)
					});
				}
			});

			parseNextFile();	// begin parsing
			return this;		// maintains chainability


			function parseNextFile()
			{
				if (queue.length === 0)
				{
					if (isFunction(options.complete))
						options.complete();
					return;
				}

				var f = queue[0];

				if (isFunction(options.before))
				{
					var returned = options.before(f.file, f.inputElem);

					if (typeof returned === 'object')
					{
						if (returned.action === 'abort')
						{
							error('AbortError', f.file, f.inputElem, returned.reason);
							return;	// Aborts all queued files immediately
						}
						else if (returned.action === 'skip')
						{
							fileComplete();	// parse the next file in the queue, if any
							return;
						}
						else if (typeof returned.config === 'object')
							f.instanceConfig = $.extend(f.instanceConfig, returned.config);
					}
					else if (returned === 'skip')
					{
						fileComplete();	// parse the next file in the queue, if any
						return;
					}
				}

				// Wrap up the user's complete callback, if any, so that ours also gets executed
				var userCompleteFunc = f.instanceConfig.complete;
				f.instanceConfig.complete = function(results)
				{
					if (isFunction(userCompleteFunc))
						userCompleteFunc(results, f.file, f.inputElem);
					fileComplete();
				};

				Papa.parse(f.file, f.instanceConfig);
			}

			function error(name, file, elem, reason)
			{
				if (isFunction(options.error))
					options.error({name: name}, file, elem, reason);
			}

			function fileComplete()
			{
				queue.splice(0, 1);
				parseNextFile();
			}
		};
	}


	if (IS_PAPA_WORKER)
	{
		global.onmessage = workerThreadReceivedMessage;
	}

	// Strip character from UTF-8 BOM encoded files that cause issue parsing the file
	function stripBom(string) {
		if (string.charCodeAt(0) === 0xfeff) {
			return string.slice(1);
		}
		return string;
	}

	function CsvToJson(_input, _config)
	{
		_config = _config || {};
		var dynamicTyping = _config.dynamicTyping || false;
		if (isFunction(dynamicTyping)) {
			_config.dynamicTypingFunction = dynamicTyping;
			// Will be filled on first row call
			dynamicTyping = {};
		}
		_config.dynamicTyping = dynamicTyping;

		_config.transform = isFunction(_config.transform) ? _config.transform : false;

		if (_config.worker && Papa.WORKERS_SUPPORTED)
		{
			var w = newWorker();

			w.userStep = _config.step;
			w.userChunk = _config.chunk;
			w.userComplete = _config.complete;
			w.userError = _config.error;

			_config.step = isFunction(_config.step);
			_config.chunk = isFunction(_config.chunk);
			_config.complete = isFunction(_config.complete);
			_config.error = isFunction(_config.error);
			delete _config.worker;	// prevent infinite loop

			w.postMessage({
				input: _input,
				config: _config,
				workerId: w.id
			});

			return;
		}

		var streamer = null;
		if (_input === Papa.NODE_STREAM_INPUT && typeof PAPA_BROWSER_CONTEXT === 'undefined')
		{
			// create a node Duplex stream for use
			// with .pipe
			streamer = new DuplexStreamStreamer(_config);
			return streamer.getStream();
		}
		else if (typeof _input === 'string')
		{
			_input = stripBom(_input);
			if (_config.download)
				streamer = new NetworkStreamer(_config);
			else
				streamer = new StringStreamer(_config);
		}
		else if (_input.readable === true && isFunction(_input.read) && isFunction(_input.on))
		{
			streamer = new ReadableStreamStreamer(_config);
		}
		else if ((global.File && _input instanceof File) || _input instanceof Object)	// ...Safari. (see issue #106)
			streamer = new FileStreamer(_config);

		return streamer.stream(_input);
	}






	function JsonToCsv(_input, _config)
	{
		// Default configuration

		/** whether to surround every datum with quotes */
		var _quotes = false;

		/** whether to write headers */
		var _writeHeader = true;

		/** delimiting character(s) */
		var _delimiter = ',';

		/** newline character(s) */
		var _newline = '\r\n';

		/** quote character */
		var _quoteChar = '"';

		/** escaped quote character, either "" or <config.escapeChar>" */
		var _escapedQuote = _quoteChar + _quoteChar;

		/** whether to skip empty lines */
		var _skipEmptyLines = false;

		/** the columns (keys) we expect when we unparse objects */
		var _columns = null;

		/** whether to prevent outputting cells that can be parsed as formulae by spreadsheet software (Excel and LibreOffice) */
		var _escapeFormulae = false;

		unpackConfig();

		var quoteCharRegex = new RegExp(escapeRegExp(_quoteChar), 'g');

		if (typeof _input === 'string')
			_input = JSON.parse(_input);

		if (Array.isArray(_input))
		{
			if (!_input.length || Array.isArray(_input[0]))
				return serialize(null, _input, _skipEmptyLines);
			else if (typeof _input[0] === 'object')
				return serialize(_columns || Object.keys(_input[0]), _input, _skipEmptyLines);
		}
		else if (typeof _input === 'object')
		{
			if (typeof _input.data === 'string')
				_input.data = JSON.parse(_input.data);

			if (Array.isArray(_input.data))
			{
				if (!_input.fields)
					_input.fields = _input.meta && _input.meta.fields || _columns;

				if (!_input.fields)
					_input.fields =  Array.isArray(_input.data[0])
						? _input.fields
						: typeof _input.data[0] === 'object'
							? Object.keys(_input.data[0])
							: [];

				if (!(Array.isArray(_input.data[0])) && typeof _input.data[0] !== 'object')
					_input.data = [_input.data];	// handles input like [1,2,3] or ['asdf']
			}

			return serialize(_input.fields || [], _input.data || [], _skipEmptyLines);
		}

		// Default (any valid paths should return before this)
		throw new Error('Unable to serialize unrecognized input');


		function unpackConfig()
		{
			if (typeof _config !== 'object')
				return;

			if (typeof _config.delimiter === 'string'
                && !Papa.BAD_DELIMITERS.filter(function(value) { return _config.delimiter.indexOf(value) !== -1; }).length)
			{
				_delimiter = _config.delimiter;
			}

			if (typeof _config.quotes === 'boolean'
				|| typeof _config.quotes === 'function'
				|| Array.isArray(_config.quotes))
				_quotes = _config.quotes;

			if (typeof _config.skipEmptyLines === 'boolean'
				|| typeof _config.skipEmptyLines === 'string')
				_skipEmptyLines = _config.skipEmptyLines;

			if (typeof _config.newline === 'string')
				_newline = _config.newline;

			if (typeof _config.quoteChar === 'string')
				_quoteChar = _config.quoteChar;

			if (typeof _config.header === 'boolean')
				_writeHeader = _config.header;

			if (Array.isArray(_config.columns)) {

				if (_config.columns.length === 0) throw new Error('Option columns is empty');

				_columns = _config.columns;
			}

			if (_config.escapeChar !== undefined) {
				_escapedQuote = _config.escapeChar + _quoteChar;
			}

			if (_config.escapeFormulae instanceof RegExp) {
				_escapeFormulae = _config.escapeFormulae;
			} else if (typeof _config.escapeFormulae === 'boolean' && _config.escapeFormulae) {
				_escapeFormulae =  /^[=+\-@\t\r].*$/;
			}
		}

		/** The double for loop that iterates the data and writes out a CSV string including header row */
		function serialize(fields, data, skipEmptyLines)
		{
			var csv = '';

			if (typeof fields === 'string')
				fields = JSON.parse(fields);
			if (typeof data === 'string')
				data = JSON.parse(data);

			var hasHeader = Array.isArray(fields) && fields.length > 0;
			var dataKeyedByField = !(Array.isArray(data[0]));

			// If there a header row, write it first
			if (hasHeader && _writeHeader)
			{
				for (var i = 0; i < fields.length; i++)
				{
					if (i > 0)
						csv += _delimiter;
					csv += safe(fields[i], i);
				}
				if (data.length > 0)
					csv += _newline;
			}

			// Then write out the data
			for (var row = 0; row < data.length; row++)
			{
				var maxCol = hasHeader ? fields.length : data[row].length;

				var emptyLine = false;
				var nullLine = hasHeader ? Object.keys(data[row]).length === 0 : data[row].length === 0;
				if (skipEmptyLines && !hasHeader)
				{
					emptyLine = skipEmptyLines === 'greedy' ? data[row].join('').trim() === '' : data[row].length === 1 && data[row][0].length === 0;
				}
				if (skipEmptyLines === 'greedy' && hasHeader) {
					var line = [];
					for (var c = 0; c < maxCol; c++) {
						var cx = dataKeyedByField ? fields[c] : c;
						line.push(data[row][cx]);
					}
					emptyLine = line.join('').trim() === '';
				}
				if (!emptyLine)
				{
					for (var col = 0; col < maxCol; col++)
					{
						if (col > 0 && !nullLine)
							csv += _delimiter;
						var colIdx = hasHeader && dataKeyedByField ? fields[col] : col;
						csv += safe(data[row][colIdx], col);
					}
					if (row < data.length - 1 && (!skipEmptyLines || (maxCol > 0 && !nullLine)))
					{
						csv += _newline;
					}
				}
			}
			return csv;
		}

		/** Encloses a value around quotes if needed (makes a value safe for CSV insertion) */
		function safe(str, col)
		{
			if (typeof str === 'undefined' || str === null)
				return '';

			if (str.constructor === Date)
				return JSON.stringify(str).slice(1, 25);

			var needsQuotes = false;

			if (_escapeFormulae && typeof str === "string" && _escapeFormulae.test(str)) {
				str = "'" + str;
				needsQuotes = true;
			}

			var escapedQuoteStr = str.toString().replace(quoteCharRegex, _escapedQuote);

			needsQuotes = needsQuotes
							|| _quotes === true
							|| (typeof _quotes === 'function' && _quotes(str, col))
							|| (Array.isArray(_quotes) && _quotes[col])
							|| hasAny(escapedQuoteStr, Papa.BAD_DELIMITERS)
							|| escapedQuoteStr.indexOf(_delimiter) > -1
							|| escapedQuoteStr.charAt(0) === ' '
							|| escapedQuoteStr.charAt(escapedQuoteStr.length - 1) === ' ';

			return needsQuotes ? _quoteChar + escapedQuoteStr + _quoteChar : escapedQuoteStr;
		}

		function hasAny(str, substrings)
		{
			for (var i = 0; i < substrings.length; i++)
				if (str.indexOf(substrings[i]) > -1)
					return true;
			return false;
		}
	}


	/** ChunkStreamer is the base prototype for various streamer implementations. */
	function ChunkStreamer(config)
	{
		this._handle = null;
		this._finished = false;
		this._completed = false;
		this._halted = false;
		this._input = null;
		this._baseIndex = 0;
		this._partialLine = '';
		this._rowCount = 0;
		this._start = 0;
		this._nextChunk = null;
		this.isFirstChunk = true;
		this._completeResults = {
			data: [],
			errors: [],
			meta: {}
		};
		replaceConfig.call(this, config);

		this.parseChunk = function(chunk, isFakeChunk)
		{
			// First chunk pre-processing
			const skipFirstNLines = parseInt(this._config.skipFirstNLines) || 0;
			if (this.isFirstChunk && skipFirstNLines > 0) {
				let _newline = this._config.newline;
				if (!_newline) {
					const quoteChar = this._config.quoteChar || '"';
					_newline = this._handle.guessLineEndings(chunk, quoteChar);
				}
				const splitChunk = chunk.split(_newline);
				chunk = [...splitChunk.slice(skipFirstNLines)].join(_newline);
			}
			if (this.isFirstChunk && isFunction(this._config.beforeFirstChunk))
			{
				var modifiedChunk = this._config.beforeFirstChunk(chunk);
				if (modifiedChunk !== undefined)
					chunk = modifiedChunk;
			}
			this.isFirstChunk = false;
			this._halted = false;

			// Rejoin the line we likely just split in two by chunking the file
			var aggregate = this._partialLine + chunk;
			this._partialLine = '';
			var results = this._handle.parse(aggregate, this._baseIndex, !this._finished);

			if (this._handle.paused() || this._handle.aborted()) {
				this._halted = true;
				return;
			}

			var lastIndex = results.meta.cursor;

			if (!this._finished)
			{
				this._partialLine = aggregate.substring(lastIndex - this._baseIndex);
				this._baseIndex = lastIndex;
			}

			if (results && results.data)
				this._rowCount += results.data.length;

			var finishedIncludingPreview = this._finished || (this._config.preview && this._rowCount >= this._config.preview);

			if (IS_PAPA_WORKER)
			{
				global.postMessage({
					results: results,
					workerId: Papa.WORKER_ID,
					finished: finishedIncludingPreview
				});
			}
			else if (isFunction(this._config.chunk) && !isFakeChunk)
			{
				this._config.chunk(results, this._handle);
				if (this._handle.paused() || this._handle.aborted()) {
					this._halted = true;
					return;
				}
				results = undefined;
				this._completeResults = undefined;
			}

			if (!this._config.step && !this._config.chunk) {
				this._completeResults.data = this._completeResults.data.concat(results.data);
				this._completeResults.errors = this._completeResults.errors.concat(results.errors);
				this._completeResults.meta = results.meta;
			}

			if (!this._completed && finishedIncludingPreview && isFunction(this._config.complete) && (!results || !results.meta.aborted)) {
				this._config.complete(this._completeResults, this._input);
				this._completed = true;
			}

			if (!finishedIncludingPreview && (!results || !results.meta.paused))
				this._nextChunk();

			return results;
		};

		this._sendError = function(error)
		{
			if (isFunction(this._config.error))
				this._config.error(error);
			else if (IS_PAPA_WORKER && this._config.error)
			{
				global.postMessage({
					workerId: Papa.WORKER_ID,
					error: error,
					finished: false
				});
			}
		};

		function replaceConfig(config)
		{
			// Deep-copy the config so we can edit it
			var configCopy = copy(config);
			configCopy.chunkSize = parseInt(configCopy.chunkSize);	// parseInt VERY important so we don't concatenate strings!
			if (!config.step && !config.chunk)
				configCopy.chunkSize = null;  // disable Range header if not streaming; bad values break IIS - see issue #196
			this._handle = new ParserHandle(configCopy);
			this._handle.streamer = this;
			this._config = configCopy;	// persist the copy to the caller
		}
	}


	function NetworkStreamer(config)
	{
		config = config || {};
		if (!config.chunkSize)
			config.chunkSize = Papa.RemoteChunkSize;
		ChunkStreamer.call(this, config);

		var xhr;

		if (IS_WORKER)
		{
			this._nextChunk = function()
			{
				this._readChunk();
				this._chunkLoaded();
			};
		}
		else
		{
			this._nextChunk = function()
			{
				this._readChunk();
			};
		}

		this.stream = function(url)
		{
			this._input = url;
			this._nextChunk();	// Starts streaming
		};

		this._readChunk = function()
		{
			if (this._finished)
			{
				this._chunkLoaded();
				return;
			}

			xhr = new XMLHttpRequest();

			if (this._config.withCredentials)
			{
				xhr.withCredentials = this._config.withCredentials;
			}

			if (!IS_WORKER)
			{
				xhr.onload = bindFunction(this._chunkLoaded, this);
				xhr.onerror = bindFunction(this._chunkError, this);
			}

			xhr.open(this._config.downloadRequestBody ? 'POST' : 'GET', this._input, !IS_WORKER);
			// Headers can only be set when once the request state is OPENED
			if (this._config.downloadRequestHeaders)
			{
				var headers = this._config.downloadRequestHeaders;

				for (var headerName in headers)
				{
					xhr.setRequestHeader(headerName, headers[headerName]);
				}
			}

			if (this._config.chunkSize)
			{
				var end = this._start + this._config.chunkSize - 1;	// minus one because byte range is inclusive
				xhr.setRequestHeader('Range', 'bytes=' + this._start + '-' + end);
			}

			try {
				xhr.send(this._config.downloadRequestBody);
			}
			catch (err) {
				this._chunkError(err.message);
			}

			if (IS_WORKER && xhr.status === 0)
				this._chunkError();
		};

		this._chunkLoaded = function()
		{
			if (xhr.readyState !== 4)
				return;

			if (xhr.status < 200 || xhr.status >= 400)
			{
				this._chunkError();
				return;
			}

			// Use chunckSize as it may be a diference on reponse lentgh due to characters with more than 1 byte
			this._start += this._config.chunkSize ? this._config.chunkSize : xhr.responseText.length;
			this._finished = !this._config.chunkSize || this._start >= getFileSize(xhr);
			this.parseChunk(xhr.responseText);
		};

		this._chunkError = function(errorMessage)
		{
			var errorText = xhr.statusText || errorMessage;
			this._sendError(new Error(errorText));
		};

		function getFileSize(xhr)
		{
			var contentRange = xhr.getResponseHeader('Content-Range');
			if (contentRange === null) { // no content range, then finish!
				return -1;
			}
			return parseInt(contentRange.substring(contentRange.lastIndexOf('/') + 1));
		}
	}
	NetworkStreamer.prototype = Object.create(ChunkStreamer.prototype);
	NetworkStreamer.prototype.constructor = NetworkStreamer;


	function FileStreamer(config)
	{
		config = config || {};
		if (!config.chunkSize)
			config.chunkSize = Papa.LocalChunkSize;
		ChunkStreamer.call(this, config);

		var reader, slice;

		// FileReader is better than FileReaderSync (even in worker) - see http://stackoverflow.com/q/24708649/1048862
		// But Firefox is a pill, too - see issue #76: https://github.com/mholt/PapaParse/issues/76
		var usingAsyncReader = typeof FileReader !== 'undefined';	// Safari doesn't consider it a function - see issue #105

		this.stream = function(file)
		{
			this._input = file;
			slice = file.slice || file.webkitSlice || file.mozSlice;

			if (usingAsyncReader)
			{
				reader = new FileReader();		// Preferred method of reading files, even in workers
				reader.onload = bindFunction(this._chunkLoaded, this);
				reader.onerror = bindFunction(this._chunkError, this);
			}
			else
				reader = new FileReaderSync();	// Hack for running in a web worker in Firefox

			this._nextChunk();	// Starts streaming
		};

		this._nextChunk = function()
		{
			if (!this._finished && (!this._config.preview || this._rowCount < this._config.preview))
				this._readChunk();
		};

		this._readChunk = function()
		{
			var input = this._input;
			if (this._config.chunkSize)
			{
				var end = Math.min(this._start + this._config.chunkSize, this._input.size);
				input = slice.call(input, this._start, end);
			}
			var txt = reader.readAsText(input, this._config.encoding);
			if (!usingAsyncReader)
				this._chunkLoaded({ target: { result: txt } });	// mimic the async signature
		};

		this._chunkLoaded = function(event)
		{
			// Very important to increment start each time before handling results
			this._start += this._config.chunkSize;
			this._finished = !this._config.chunkSize || this._start >= this._input.size;
			this.parseChunk(event.target.result);
		};

		this._chunkError = function()
		{
			this._sendError(reader.error);
		};

	}
	FileStreamer.prototype = Object.create(ChunkStreamer.prototype);
	FileStreamer.prototype.constructor = FileStreamer;


	function StringStreamer(config)
	{
		config = config || {};
		ChunkStreamer.call(this, config);

		var remaining;
		this.stream = function(s)
		{
			remaining = s;
			return this._nextChunk();
		};
		this._nextChunk = function()
		{
			if (this._finished) return;
			var size = this._config.chunkSize;
			var chunk;
			if(size) {
				chunk = remaining.substring(0, size);
				remaining = remaining.substring(size);
			} else {
				chunk = remaining;
				remaining = '';
			}
			this._finished = !remaining;
			return this.parseChunk(chunk);
		};
	}
	StringStreamer.prototype = Object.create(StringStreamer.prototype);
	StringStreamer.prototype.constructor = StringStreamer;


	function ReadableStreamStreamer(config)
	{
		config = config || {};

		ChunkStreamer.call(this, config);

		var queue = [];
		var parseOnData = true;
		var streamHasEnded = false;

		this.pause = function()
		{
			ChunkStreamer.prototype.pause.apply(this, arguments);
			this._input.pause();
		};

		this.resume = function()
		{
			ChunkStreamer.prototype.resume.apply(this, arguments);
			this._input.resume();
		};

		this.stream = function(stream)
		{
			this._input = stream;

			this._input.on('data', this._streamData);
			this._input.on('end', this._streamEnd);
			this._input.on('error', this._streamError);
		};

		this._checkIsFinished = function()
		{
			if (streamHasEnded && queue.length === 1) {
				this._finished = true;
			}
		};

		this._nextChunk = function()
		{
			this._checkIsFinished();
			if (queue.length)
			{
				this.parseChunk(queue.shift());
			}
			else
			{
				parseOnData = true;
			}
		};

		this._streamData = bindFunction(function(chunk)
		{
			try
			{
				queue.push(typeof chunk === 'string' ? chunk : chunk.toString(this._config.encoding));

				if (parseOnData)
				{
					parseOnData = false;
					this._checkIsFinished();
					this.parseChunk(queue.shift());
				}
			}
			catch (error)
			{
				this._streamError(error);
			}
		}, this);

		this._streamError = bindFunction(function(error)
		{
			this._streamCleanUp();
			this._sendError(error);
		}, this);

		this._streamEnd = bindFunction(function()
		{
			this._streamCleanUp();
			streamHasEnded = true;
			this._streamData('');
		}, this);

		this._streamCleanUp = bindFunction(function()
		{
			this._input.removeListener('data', this._streamData);
			this._input.removeListener('end', this._streamEnd);
			this._input.removeListener('error', this._streamError);
		}, this);
	}
	ReadableStreamStreamer.prototype = Object.create(ChunkStreamer.prototype);
	ReadableStreamStreamer.prototype.constructor = ReadableStreamStreamer;


	function DuplexStreamStreamer(_config) {
		var Duplex = require('stream').Duplex;
		var config = copy(_config);
		var parseOnWrite = true;
		var writeStreamHasFinished = false;
		var parseCallbackQueue = [];
		var stream = null;

		this._onCsvData = function(results)
		{
			var data = results.data;
			if (!stream.push(data) && !this._handle.paused()) {
				// the writeable consumer buffer has filled up
				// so we need to pause until more items
				// can be processed
				this._handle.pause();
			}
		};

		this._onCsvComplete = function()
		{
			// node will finish the read stream when
			// null is pushed
			stream.push(null);
		};

		config.step = bindFunction(this._onCsvData, this);
		config.complete = bindFunction(this._onCsvComplete, this);
		ChunkStreamer.call(this, config);

		this._nextChunk = function()
		{
			if (writeStreamHasFinished && parseCallbackQueue.length === 1) {
				this._finished = true;
			}
			if (parseCallbackQueue.length) {
				parseCallbackQueue.shift()();
			} else {
				parseOnWrite = true;
			}
		};

		this._addToParseQueue = function(chunk, callback)
		{
			// add to queue so that we can indicate
			// completion via callback
			// node will automatically pause the incoming stream
			// when too many items have been added without their
			// callback being invoked
			parseCallbackQueue.push(bindFunction(function() {
				this.parseChunk(typeof chunk === 'string' ? chunk : chunk.toString(config.encoding));
				if (isFunction(callback)) {
					return callback();
				}
			}, this));
			if (parseOnWrite) {
				parseOnWrite = false;
				this._nextChunk();
			}
		};

		this._onRead = function()
		{
			if (this._handle.paused()) {
				// the writeable consumer can handle more data
				// so resume the chunk parsing
				this._handle.resume();
			}
		};

		this._onWrite = function(chunk, encoding, callback)
		{
			this._addToParseQueue(chunk, callback);
		};

		this._onWriteComplete = function()
		{
			writeStreamHasFinished = true;
			// have to write empty string
			// so parser knows its done
			this._addToParseQueue('');
		};

		this.getStream = function()
		{
			return stream;
		};
		stream = new Duplex({
			readableObjectMode: true,
			decodeStrings: false,
			read: bindFunction(this._onRead, this),
			write: bindFunction(this._onWrite, this)
		});
		stream.once('finish', bindFunction(this._onWriteComplete, this));
	}
	if (typeof PAPA_BROWSER_CONTEXT === 'undefined') {
		DuplexStreamStreamer.prototype = Object.create(ChunkStreamer.prototype);
		DuplexStreamStreamer.prototype.constructor = DuplexStreamStreamer;
	}


	// Use one ParserHandle per entire CSV file or string
	function ParserHandle(_config)
	{
		// One goal is to minimize the use of regular expressions...
		var MAX_FLOAT = Math.pow(2, 53);
		var MIN_FLOAT = -MAX_FLOAT;
		var FLOAT = /^\s*-?(\d+\.?|\.\d+|\d+\.\d+)([eE][-+]?\d+)?\s*$/;
		var ISO_DATE = /^((\d{4}-[01]\d-[0-3]\dT[0-2]\d:[0-5]\d:[0-5]\d\.\d+([+-][0-2]\d:[0-5]\d|Z))|(\d{4}-[01]\d-[0-3]\dT[0-2]\d:[0-5]\d:[0-5]\d([+-][0-2]\d:[0-5]\d|Z))|(\d{4}-[01]\d-[0-3]\dT[0-2]\d:[0-5]\d([+-][0-2]\d:[0-5]\d|Z)))$/;
		var self = this;
		var _stepCounter = 0;	// Number of times step was called (number of rows parsed)
		var _rowCounter = 0;	// Number of rows that have been parsed so far
		var _input;				// The input being parsed
		var _parser;			// The core parser being used
		var _paused = false;	// Whether we are paused or not
		var _aborted = false;	// Whether the parser has aborted or not
		var _delimiterError;	// Temporary state between delimiter detection and processing results
		var _fields = [];		// Fields are from the header row of the input, if there is one
		var _results = {		// The last results returned from the parser
			data: [],
			errors: [],
			meta: {}
		};

		if (isFunction(_config.step))
		{
			var userStep = _config.step;
			_config.step = function(results)
			{
				_results = results;

				if (needsHeaderRow())
					processResults();
				else	// only call user's step function after header row
				{
					processResults();

					// It's possbile that this line was empty and there's no row here after all
					if (_results.data.length === 0)
						return;

					_stepCounter += results.data.length;
					if (_config.preview && _stepCounter > _config.preview)
						_parser.abort();
					else {
						_results.data = _results.data[0];
						userStep(_results, self);
					}
				}
			};
		}

		/**
		 * Parses input. Most users won't need, and shouldn't mess with, the baseIndex
		 * and ignoreLastRow parameters. They are used by streamers (wrapper functions)
		 * when an input comes in multiple chunks, like from a file.
		 */
		this.parse = function(input, baseIndex, ignoreLastRow)
		{
			var quoteChar = _config.quoteChar || '"';
			if (!_config.newline)
				_config.newline = this.guessLineEndings(input, quoteChar);

			_delimiterError = false;
			if (!_config.delimiter)
			{
				var delimGuess = guessDelimiter(input, _config.newline, _config.skipEmptyLines, _config.comments, _config.delimitersToGuess);
				if (delimGuess.successful)
					_config.delimiter = delimGuess.bestDelimiter;
				else
				{
					_delimiterError = true;	// add error after parsing (otherwise it would be overwritten)
					_config.delimiter = Papa.DefaultDelimiter;
				}
				_results.meta.delimiter = _config.delimiter;
			}
			else if(isFunction(_config.delimiter))
			{
				_config.delimiter = _config.delimiter(input);
				_results.meta.delimiter = _config.delimiter;
			}

			var parserConfig = copy(_config);
			if (_config.preview && _config.header)
				parserConfig.preview++;	// to compensate for header row

			_input = input;
			_parser = new Parser(parserConfig);
			_results = _parser.parse(_input, baseIndex, ignoreLastRow);
			processResults();
			return _paused ? { meta: { paused: true } } : (_results || { meta: { paused: false } });
		};

		this.paused = function()
		{
			return _paused;
		};

		this.pause = function()
		{
			_paused = true;
			_parser.abort();

			// If it is streaming via "chunking", the reader will start appending correctly already so no need to substring,
			// otherwise we can get duplicate content within a row
			_input = isFunction(_config.chunk) ? "" : _input.substring(_parser.getCharIndex());
		};

		this.resume = function()
		{
			if(self.streamer._halted) {
				_paused = false;
				self.streamer.parseChunk(_input, true);
			} else {
				// Bugfix: #636 In case the processing hasn't halted yet
				// wait for it to halt in order to resume
				setTimeout(self.resume, 3);
			}
		};

		this.aborted = function()
		{
			return _aborted;
		};

		this.abort = function()
		{
			_aborted = true;
			_parser.abort();
			_results.meta.aborted = true;
			if (isFunction(_config.complete))
				_config.complete(_results);
			_input = '';
		};

		this.guessLineEndings = function(input, quoteChar)
		{
			input = input.substring(0, 1024 * 1024);	// max length 1 MB
			// Replace all the text inside quotes
			var re = new RegExp(escapeRegExp(quoteChar) + '([^]*?)' + escapeRegExp(quoteChar), 'gm');
			input = input.replace(re, '');

			var r = input.split('\r');

			var n = input.split('\n');

			var nAppearsFirst = (n.length > 1 && n[0].length < r[0].length);

			if (r.length === 1 || nAppearsFirst)
				return '\n';

			var numWithN = 0;
			for (var i = 0; i < r.length; i++)
			{
				if (r[i][0] === '\n')
					numWithN++;
			}

			return numWithN >= r.length / 2 ? '\r\n' : '\r';
		};

		function testEmptyLine(s) {
			return _config.skipEmptyLines === 'greedy' ? s.join('').trim() === '' : s.length === 1 && s[0].length === 0;
		}

		function testFloat(s) {
			if (FLOAT.test(s)) {
				var floatValue = parseFloat(s);
				if (floatValue > MIN_FLOAT && floatValue < MAX_FLOAT) {
					return true;
				}
			}
			return false;
		}

		function processResults()
		{
			if (_results && _delimiterError)
			{
				addError('Delimiter', 'UndetectableDelimiter', 'Unable to auto-detect delimiting character; defaulted to \'' + Papa.DefaultDelimiter + '\'');
				_delimiterError = false;
			}

			if (_config.skipEmptyLines)
			{
				_results.data = _results.data.filter(function(d) {
					return !testEmptyLine(d);
				});
			}

			if (needsHeaderRow())
				fillHeaderFields();

			return applyHeaderAndDynamicTypingAndTransformation();
		}

		function needsHeaderRow()
		{
			return _config.header && _fields.length === 0;
		}

		function fillHeaderFields()
		{
			if (!_results)
				return;

			function addHeader(header, i)
			{
				header = stripBom(header);
				if (isFunction(_config.transformHeader))
					header = _config.transformHeader(header, i);

				_fields.push(header);
			}

			if (Array.isArray(_results.data[0]))
			{
				for (var i = 0; needsHeaderRow() && i < _results.data.length; i++)
					_results.data[i].forEach(addHeader);

				_results.data.splice(0, 1);
			}
			// if _results.data[0] is not an array, we are in a step where _results.data is the row.
			else
				_results.data.forEach(addHeader);
		}

		function shouldApplyDynamicTyping(field) {
			// Cache function values to avoid calling it for each row
			if (_config.dynamicTypingFunction && _config.dynamicTyping[field] === undefined) {
				_config.dynamicTyping[field] = _config.dynamicTypingFunction(field);
			}
			return (_config.dynamicTyping[field] || _config.dynamicTyping) === true;
		}

		function parseDynamic(field, value)
		{
			if (shouldApplyDynamicTyping(field))
			{
				if (value === 'true' || value === 'TRUE')
					return true;
				else if (value === 'false' || value === 'FALSE')
					return false;
				else if (testFloat(value))
					return parseFloat(value);
				else if (ISO_DATE.test(value))
					return new Date(value);
				else
					return (value === '' ? null : value);
			}
			return value;
		}

		function applyHeaderAndDynamicTypingAndTransformation()
		{
			if (!_results || (!_config.header && !_config.dynamicTyping && !_config.transform))
				return _results;

			function processRow(rowSource, i)
			{
				var row = _config.header ? {} : [];

				var j;
				for (j = 0; j < rowSource.length; j++)
				{
					var field = j;
					var value = rowSource[j];

					if (_config.header)
						field = j >= _fields.length ? '__parsed_extra' : _fields[j];

					if (_config.transform)
						value = _config.transform(value,field);

					value = parseDynamic(field, value);

					if (field === '__parsed_extra')
					{
						row[field] = row[field] || [];
						row[field].push(value);
					}
					else
						row[field] = value;
				}


				if (_config.header)
				{
					if (j > _fields.length)
						addError('FieldMismatch', 'TooManyFields', 'Too many fields: expected ' + _fields.length + ' fields but parsed ' + j, _rowCounter + i);
					else if (j < _fields.length)
						addError('FieldMismatch', 'TooFewFields', 'Too few fields: expected ' + _fields.length + ' fields but parsed ' + j, _rowCounter + i);
				}

				return row;
			}

			var incrementBy = 1;
			if (!_results.data.length || Array.isArray(_results.data[0]))
			{
				_results.data = _results.data.map(processRow);
				incrementBy = _results.data.length;
			}
			else
				_results.data = processRow(_results.data, 0);


			if (_config.header && _results.meta)
				_results.meta.fields = _fields;

			_rowCounter += incrementBy;
			return _results;
		}

		function guessDelimiter(input, newline, skipEmptyLines, comments, delimitersToGuess) {
			var bestDelim, bestDelta, fieldCountPrevRow, maxFieldCount;

			delimitersToGuess = delimitersToGuess || [',', '\t', '|', ';', Papa.RECORD_SEP, Papa.UNIT_SEP];

			for (var i = 0; i < delimitersToGuess.length; i++) {
				var delim = delimitersToGuess[i];
				var delta = 0, avgFieldCount = 0, emptyLinesCount = 0;
				fieldCountPrevRow = undefined;

				var preview = new Parser({
					comments: comments,
					delimiter: delim,
					newline: newline,
					preview: 10
				}).parse(input);

				for (var j = 0; j < preview.data.length; j++) {
					if (skipEmptyLines && testEmptyLine(preview.data[j])) {
						emptyLinesCount++;
						continue;
					}
					var fieldCount = preview.data[j].length;
					avgFieldCount += fieldCount;

					if (typeof fieldCountPrevRow === 'undefined') {
						fieldCountPrevRow = fieldCount;
						continue;
					}
					else if (fieldCount > 0) {
						delta += Math.abs(fieldCount - fieldCountPrevRow);
						fieldCountPrevRow = fieldCount;
					}
				}

				if (preview.data.length > 0)
					avgFieldCount /= (preview.data.length - emptyLinesCount);

				if ((typeof bestDelta === 'undefined' || delta <= bestDelta)
					&& (typeof maxFieldCount === 'undefined' || avgFieldCount > maxFieldCount) && avgFieldCount > 1.99) {
					bestDelta = delta;
					bestDelim = delim;
					maxFieldCount = avgFieldCount;
				}
			}

			_config.delimiter = bestDelim;

			return {
				successful: !!bestDelim,
				bestDelimiter: bestDelim
			};
		}

		function addError(type, code, msg, row)
		{
			var error = {
				type: type,
				code: code,
				message: msg
			};
			if(row !== undefined) {
				error.row = row;
			}
			_results.errors.push(error);
		}
	}

	/** https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions */
	function escapeRegExp(string)
	{
		return string.replace(/[.*+?^${}()|[\]\\]/g, '\\$&'); // $& means the whole matched string
	}

	/** The core parser implements speedy and correct CSV parsing */
	function Parser(config)
	{
		// Unpack the config object
		config = config || {};
		var delim = config.delimiter;
		var newline = config.newline;
		var comments = config.comments;
		var step = config.step;
		var preview = config.preview;
		var fastMode = config.fastMode;
		var quoteChar;
		var renamedHeaders = null;
		var headerParsed = false;

		if (config.quoteChar === undefined || config.quoteChar === null) {
			quoteChar = '"';
		} else {
			quoteChar = config.quoteChar;
		}
		var escapeChar = quoteChar;
		if (config.escapeChar !== undefined) {
			escapeChar = config.escapeChar;
		}

		// Delimiter must be valid
		if (typeof delim !== 'string'
			|| Papa.BAD_DELIMITERS.indexOf(delim) > -1)
			delim = ',';

		// Comment character must be valid
		if (comments === delim)
			throw new Error('Comment character same as delimiter');
		else if (comments === true)
			comments = '#';
		else if (typeof comments !== 'string'
			|| Papa.BAD_DELIMITERS.indexOf(comments) > -1)
			comments = false;

		// Newline must be valid: \r, \n, or \r\n
		if (newline !== '\n' && newline !== '\r' && newline !== '\r\n')
			newline = '\n';

		// We're gonna need these at the Parser scope
		var cursor = 0;
		var aborted = false;

		this.parse = function(input, baseIndex, ignoreLastRow)
		{
			// For some reason, in Chrome, this speeds things up (!?)
			if (typeof input !== 'string')
				throw new Error('Input must be a string');

			// We don't need to compute some of these every time parse() is called,
			// but having them in a more local scope seems to perform better
			var inputLen = input.length,
				delimLen = delim.length,
				newlineLen = newline.length,
				commentsLen = comments.length;
			var stepIsFunction = isFunction(step);

			// Establish starting state
			cursor = 0;
			var data = [], errors = [], row = [], lastCursor = 0;

			if (!input)
				return returnable();

			if (fastMode || (fastMode !== false && input.indexOf(quoteChar) === -1))
			{
				var rows = input.split(newline);
				for (var i = 0; i < rows.length; i++)
				{
					row = rows[i];
					cursor += row.length;

					if (i !== rows.length - 1)
						cursor += newline.length;
					else if (ignoreLastRow)
						return returnable();
					if (comments && row.substring(0, commentsLen) === comments)
						continue;
					if (stepIsFunction)
					{
						data = [];
						pushRow(row.split(delim));
						doStep();
						if (aborted)
							return returnable();
					}
					else
						pushRow(row.split(delim));
					if (preview && i >= preview)
					{
						data = data.slice(0, preview);
						return returnable(true);
					}
				}
				return returnable();
			}

			var nextDelim = input.indexOf(delim, cursor);
			var nextNewline = input.indexOf(newline, cursor);
			var quoteCharRegex = new RegExp(escapeRegExp(escapeChar) + escapeRegExp(quoteChar), 'g');
			var quoteSearch = input.indexOf(quoteChar, cursor);

			// Parser loop
			for (;;)
			{
				// Field has opening quote
				if (input[cursor] === quoteChar)
				{
					// Start our search for the closing quote where the cursor is
					quoteSearch = cursor;

					// Skip the opening quote
					cursor++;

					for (;;)
					{
						// Find closing quote
						quoteSearch = input.indexOf(quoteChar, quoteSearch + 1);

						//No other quotes are found - no other delimiters
						if (quoteSearch === -1)
						{
							if (!ignoreLastRow) {
								// No closing quote... what a pity
								errors.push({
									type: 'Quotes',
									code: 'MissingQuotes',
									message: 'Quoted field unterminated',
									row: data.length,	// row has yet to be inserted
									index: cursor
								});
							}
							return finish();
						}

						// Closing quote at EOF
						if (quoteSearch === inputLen - 1)
						{
							var value = input.substring(cursor, quoteSearch).replace(quoteCharRegex, quoteChar);
							return finish(value);
						}

						// If this quote is escaped, it's part of the data; skip it
						// If the quote character is the escape character, then check if the next character is the escape character
						if (quoteChar === escapeChar &&  input[quoteSearch + 1] === escapeChar)
						{
							quoteSearch++;
							continue;
						}

						// If the quote character is not the escape character, then check if the previous character was the escape character
						if (quoteChar !== escapeChar && quoteSearch !== 0 && input[quoteSearch - 1] === escapeChar)
						{
							continue;
						}

						if(nextDelim !== -1 && nextDelim < (quoteSearch + 1)) {
							nextDelim = input.indexOf(delim, (quoteSearch + 1));
						}
						if(nextNewline !== -1 && nextNewline < (quoteSearch + 1)) {
							nextNewline = input.indexOf(newline, (quoteSearch + 1));
						}
						// Check up to nextDelim or nextNewline, whichever is closest
						var checkUpTo = nextNewline === -1 ? nextDelim : Math.min(nextDelim, nextNewline);
						var spacesBetweenQuoteAndDelimiter = extraSpaces(checkUpTo);

						// Closing quote followed by delimiter or 'unnecessary spaces + delimiter'
						if (input.substr(quoteSearch + 1 + spacesBetweenQuoteAndDelimiter, delimLen) === delim)
						{
							row.push(input.substring(cursor, quoteSearch).replace(quoteCharRegex, quoteChar));
							cursor = quoteSearch + 1 + spacesBetweenQuoteAndDelimiter + delimLen;

							// If char after following delimiter is not quoteChar, we find next quote char position
							if (input[quoteSearch + 1 + spacesBetweenQuoteAndDelimiter + delimLen] !== quoteChar)
							{
								quoteSearch = input.indexOf(quoteChar, cursor);
							}
							nextDelim = input.indexOf(delim, cursor);
							nextNewline = input.indexOf(newline, cursor);
							break;
						}

						var spacesBetweenQuoteAndNewLine = extraSpaces(nextNewline);

						// Closing quote followed by newline or 'unnecessary spaces + newLine'
						if (input.substring(quoteSearch + 1 + spacesBetweenQuoteAndNewLine, quoteSearch + 1 + spacesBetweenQuoteAndNewLine + newlineLen) === newline)
						{
							row.push(input.substring(cursor, quoteSearch).replace(quoteCharRegex, quoteChar));
							saveRow(quoteSearch + 1 + spacesBetweenQuoteAndNewLine + newlineLen);
							nextDelim = input.indexOf(delim, cursor);	// because we may have skipped the nextDelim in the quoted field
							quoteSearch = input.indexOf(quoteChar, cursor);	// we search for first quote in next line

							if (stepIsFunction)
							{
								doStep();
								if (aborted)
									return returnable();
							}

							if (preview && data.length >= preview)
								return returnable(true);

							break;
						}


						// Checks for valid closing quotes are complete (escaped quotes or quote followed by EOF/delimiter/newline) -- assume these quotes are part of an invalid text string
						errors.push({
							type: 'Quotes',
							code: 'InvalidQuotes',
							message: 'Trailing quote on quoted field is malformed',
							row: data.length,	// row has yet to be inserted
							index: cursor
						});

						quoteSearch++;
						continue;

					}

					continue;
				}

				// Comment found at start of new line
				if (comments && row.length === 0 && input.substring(cursor, cursor + commentsLen) === comments)
				{
					if (nextNewline === -1)	// Comment ends at EOF
						return returnable();
					cursor = nextNewline + newlineLen;
					nextNewline = input.indexOf(newline, cursor);
					nextDelim = input.indexOf(delim, cursor);
					continue;
				}

				// Next delimiter comes before next newline, so we've reached end of field
				if (nextDelim !== -1 && (nextDelim < nextNewline || nextNewline === -1))
				{
					row.push(input.substring(cursor, nextDelim));
					cursor = nextDelim + delimLen;
					// we look for next delimiter char
					nextDelim = input.indexOf(delim, cursor);
					continue;
				}

				// End of row
				if (nextNewline !== -1)
				{
					row.push(input.substring(cursor, nextNewline));
					saveRow(nextNewline + newlineLen);

					if (stepIsFunction)
					{
						doStep();
						if (aborted)
							return returnable();
					}

					if (preview && data.length >= preview)
						return returnable(true);

					continue;
				}

				break;
			}

			return finish();


			function pushRow(row)
			{
				data.push(row);
				lastCursor = cursor;
			}

			/**
             * checks if there are extra spaces after closing quote and given index without any text
             * if Yes, returns the number of spaces
             */
			function extraSpaces(index) {
				var spaceLength = 0;
				if (index !== -1) {
					var textBetweenClosingQuoteAndIndex = input.substring(quoteSearch + 1, index);
					if (textBetweenClosingQuoteAndIndex && textBetweenClosingQuoteAndIndex.trim() === '') {
						spaceLength = textBetweenClosingQuoteAndIndex.length;
					}
				}
				return spaceLength;
			}

			/**
			 * Appends the remaining input from cursor to the end into
			 * row, saves the row, calls step, and returns the results.
			 */
			function finish(value)
			{
				if (ignoreLastRow)
					return returnable();
				if (typeof value === 'undefined')
					value = input.substring(cursor);
				row.push(value);
				cursor = inputLen;	// important in case parsing is paused
				pushRow(row);
				if (stepIsFunction)
					doStep();
				return returnable();
			}

			/**
			 * Appends the current row to the results. It sets the cursor
			 * to newCursor and finds the nextNewline. The caller should
			 * take care to execute user's step function and check for
			 * preview and end parsing if necessary.
			 */
			function saveRow(newCursor)
			{
				cursor = newCursor;
				pushRow(row);
				row = [];
				nextNewline = input.indexOf(newline, cursor);
			}

			/** Returns an object with the results, errors, and meta. */
			function returnable(stopped)
			{
				if (config.header && !baseIndex && data.length && !headerParsed)
				{
					const result = data[0];
					const headerCount = Object.create(null); // To track the count of each base header
					const usedHeaders = new Set(result); // To track used headers and avoid duplicates
					let duplicateHeaders = false;

					for (let i = 0; i < result.length; i++) {
						let header = stripBom(result[i]);
						if (isFunction(config.transformHeader))
							header = config.transformHeader(header, i);

						if (!headerCount[header]) {
							headerCount[header] = 1;
							result[i] = header;
						} else {
							let newHeader;
							let suffixCount = headerCount[header];

							// Find a unique new header
							do {
								newHeader = `${header}_${suffixCount}`;
								suffixCount++;
							} while (usedHeaders.has(newHeader));

							usedHeaders.add(newHeader); // Mark this new Header as used
							result[i] = newHeader;
							headerCount[header]++;
							duplicateHeaders = true;
							if (renamedHeaders === null) {
								renamedHeaders = {};
							}
							renamedHeaders[newHeader] = header;
						}

						usedHeaders.add(header); // Ensure the original header is marked as used
					}
					if (duplicateHeaders) {
						console.warn('Duplicate headers found and renamed.');
					}
					headerParsed = true;
				}
				return {
					data: data,
					errors: errors,
					meta: {
						delimiter: delim,
						linebreak: newline,
						aborted: aborted,
						truncated: !!stopped,
						cursor: lastCursor + (baseIndex || 0),
						renamedHeaders: renamedHeaders
					}
				};
			}

			/** Executes the user's step function and resets data & errors. */
			function doStep()
			{
				step(returnable());
				data = [];
				errors = [];
			}
		};

		/** Sets the abort flag */
		this.abort = function()
		{
			aborted = true;
		};

		/** Gets the cursor position */
		this.getCharIndex = function()
		{
			return cursor;
		};
	}


	function newWorker()
	{
		if (!Papa.WORKERS_SUPPORTED)
			return false;

		var workerUrl = getWorkerBlob();
		var w = new global.Worker(workerUrl);
		w.onmessage = mainThreadReceivedMessage;
		w.id = workerIdCounter++;
		workers[w.id] = w;
		return w;
	}

	/** Callback when main thread receives a message */
	function mainThreadReceivedMessage(e)
	{
		var msg = e.data;
		var worker = workers[msg.workerId];
		var aborted = false;

		if (msg.error)
			worker.userError(msg.error, msg.file);
		else if (msg.results && msg.results.data)
		{
			var abort = function() {
				aborted = true;
				completeWorker(msg.workerId, { data: [], errors: [], meta: { aborted: true } });
			};

			var handle = {
				abort: abort,
				pause: notImplemented,
				resume: notImplemented
			};

			if (isFunction(worker.userStep))
			{
				for (var i = 0; i < msg.results.data.length; i++)
				{
					worker.userStep({
						data: msg.results.data[i],
						errors: msg.results.errors,
						meta: msg.results.meta
					}, handle);
					if (aborted)
						break;
				}
				delete msg.results;	// free memory ASAP
			}
			else if (isFunction(worker.userChunk))
			{
				worker.userChunk(msg.results, handle, msg.file);
				delete msg.results;
			}
		}

		if (msg.finished && !aborted)
			completeWorker(msg.workerId, msg.results);
	}

	function completeWorker(workerId, results) {
		var worker = workers[workerId];
		if (isFunction(worker.userComplete))
			worker.userComplete(results);
		worker.terminate();
		delete workers[workerId];
	}

	function notImplemented() {
		throw new Error('Not implemented.');
	}

	/** Callback when worker thread receives a message */
	function workerThreadReceivedMessage(e)
	{
		var msg = e.data;

		if (typeof Papa.WORKER_ID === 'undefined' && msg)
			Papa.WORKER_ID = msg.workerId;

		if (typeof msg.input === 'string')
		{
			global.postMessage({
				workerId: Papa.WORKER_ID,
				results: Papa.parse(msg.input, msg.config),
				finished: true
			});
		}
		else if ((global.File && msg.input instanceof File) || msg.input instanceof Object)	// thank you, Safari (see issue #106)
		{
			var results = Papa.parse(msg.input, msg.config);
			if (results)
				global.postMessage({
					workerId: Papa.WORKER_ID,
					results: results,
					finished: true
				});
		}
	}

	/** Makes a deep copy of an array or object (mostly) */
	function copy(obj)
	{
		if (typeof obj !== 'object' || obj === null)
			return obj;
		var cpy = Array.isArray(obj) ? [] : {};
		for (var key in obj)
			cpy[key] = copy(obj[key]);
		return cpy;
	}

	function bindFunction(f, self)
	{
		return function() { f.apply(self, arguments); };
	}
	function isFunction(func)
	{
		return typeof func === 'function';
	}

	return Papa;
}));