A Scala Parboiled2 Grammar for CSV

CSVParboiledParser.scala

/*
 * Copyright (C) 2014 Juergen Pfundt
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import org.parboiled2._

import scala.util.{Failure, Success}
 
trait CSVParboiledParser extends Parser {	 
	/* start of csv parser */
	def csvfile = rule{ (hdr ~ zeroOrMore(row)) ~> makeListOfList ~ zeroOrMore(optional("\r") ~ "\n") ~ EOI}
	def hdr = rule{ row }
	def row = rule{ oneOrMore(field).separatedBy(",") ~> makeList ~ optional("\r") ~ "\n" }
	def field = rule{ string | text | MATCH ~> makeEmpty }
	def text = rule{ capture(oneOrMore(noneOf(",\"\n\r"))) ~> makeText }
	def string = rule{ WS ~ "\"" ~ capture(zeroOrMore("\"\"" | noneOf("\""))) ~> makeString ~ "\"" ~ WS }
  
    	val whitespace = CharPredicate(" \t")
	def WS = rule{ zeroOrMore(whitespace) }

	/* type conversion */
	def makeList = (r: Seq[String]) => r.toList:List[String]
	def makeListOfList = (h: List[String], r: Seq[List[String]]) => h::(r.toList:List[List[String]])
	
	/* parser action */
	def makeText: (String) => String
	def makeString: (String) => String
	def makeEmpty: () => String
}

trait CSVParserAction {
	// remove leading and trailing blanks
	def makeText = (text: String) => text.trim
	// replace sequence of two double quotes by a single double quote
	def makeString = (string: String) => string.replaceAll("\"\"", "\"")
	// modify result of EMPTY token if required
	def makeEmpty = () => ""
}
 
trait CSVParserIETFAction extends CSVParserAction {
	// no trimming of WhiteSpace
	override def makeText = (text: String) => text
}

class CSVParboiledParserCLI(val input: ParserInput) extends CSVParboiledParser with CSVParserIETFAction {
	csvfile.run() match {
		case Success(result) => println(result)
		case Failure(e: ParseError) => println("Expression is not valid: " + formatError(e))
		case Failure(e) => println("Unexpected error during parsing run: " + e)
	}   
}

object CSVParserCLI  {
	def main(args: Array[String]) {
		lazy val inputfile : ParserInput = io.Source.fromFile(args(0)).mkString
		new CSVParboiledParserCLI(inputfile)
	}
}