Mimicking grep command in Scala

	package implicits
	import java.io.File
	import scala.io.Source
	object RichFileDemo {
	class RichFile(file: String) {
	def matchLines(source: Source, pattern: String): Iterator[(String, Int)] = {
	source.getLines.zipWithIndex.filter(l => pattern.r.findFirstIn(l._1) != None)
	}
	def grep(pattern: String): Unit = {
	val source = Source.fromFile(file)
	matchLines(source,pattern).foreach(x => println("line " + x._2 + ": " + x._1))
	source.close
	}
	}
	def main(args: Array[String]): Unit = {
	val file = new RichFile("c:/scalademo/news.txt")
	file.grep("com")
	}
	}
	//news.txt
	/**
	Working together with leaders of the Play Framework, Akka, and Scala open source communities,
	Typesafe seeks to give developers the modern tools they need to build the next generation of
	software applications for the era of multicore hardware and cloud computing workloads.
	**/
	//output program
	/**
	line 0: Working together with leaders of the Play Framework, Akka, and Scala open source communities,
	line 2: software applications for the era of multicore hardware and cloud computing workloads.
	**/

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