Scala try and catch Error -

so here code:

def loadoperation(filename:string): csvlist = {   try{    val pattern = """^(.+);(\d{5});(4|2|31);(0|1);(.+);(\d+|\d+,\d+)$""".r    source.fromfile(filename).getlines().foldleft(list[csventry]())((csvlist, currentline) =>      currentline match {       case pattern(organisation,yearandquartal,medkf,trueorfalse,name,money) => new csventry(organisation,yearandquartal.toint,medkf.toint,trueorfalse.toint,name,money) :: csvlist       case default => csvlist       })   } catch {     case one: java.io.filenotfoundexception => println("this file not found!")   }} 

the problem code doesnt work, shows following error:

type mismatch found: unit required csvlist expands list[csventry]?

how can solve problem?

the problem catch clause:

println("this file not found!") 

has type unit, not csvlist. should add additional line returns empty list, such as

catch {     case one: java.io.filenotfoundexception => println("this file not found!") }  nil