csv.js

// A Parslet parser for parsing CSV files
// 
// ported from http://hackage.haskell.org/packages/archive/csv/0.1.1/doc/html/Text-CSV.html
define(['./parslet'], function (parslet) {
	'use strict';

	var Parser = parslet.Parser;
	function join(arr) { return arr.join(''); }

	// csv :: Parser CSV
	// csv = do x <- record `sepEndBy` many1 (oneOf "\n\r")
	//          eof
	//          return x
	var csv = Parser.lazy(function () {
		return record.separatedBy(/[\n\r]+/)
			.followedBy(/[\n\r]*/)
			.followedBy(Parser.EOF);
	});

	// record :: Parser Record
	// record = (quotedField <|> field) `sepBy` char ','
	var record = Parser.lazy(function () {
		return quotedField.or(field).separatedBy(',');
	});

	// field :: Parser Field
	// field = many (noneOf ",\n\r\"")
	var field = Parser.noneOf(',\n\r"').zeroOrMore().map(join);

	// quotedField :: Parser Field
	// quotedField = between (char '"') (char '"') $
	//               many (noneOf "\"" <|> try (string "\"\"" >> return '"'))
	var quotedField = Parser.noneOf('"').or(Parser.Exactly('""').returns('"'))
				.zeroOrMore()
				.between('"', '"')
				.map(join);

	return { 
		csv: csv,

		parseCSV: function (source) {
			var result = csv.parse(source);
			if (!result.success) { 
				throw new Error('csv.parseCSV: Invalid CSV input');
			} else {
				return result.value.value;
			}
		},

		parseCSVFromFile: function (filename, encoding, cb) {
			require('fs').readFile(filename, encoding, function (err, data) {
				if (err) { 
					cb(err);
				} else {
					var result = csv.parse(data);
					if (!result.success) {
						cb('csv.parseCSVFromFile(filename, encoding, cb): Invalid CSV file "' + filename + '"'); 
					} else { 
						cb(null, result.value.value);
					}
				}
			});
		}
	};
});