gistfile1.scala

import java.io.File
 
/** A wrapper around file, allowing iteration either on direct children 
     or on directory tree */
class RichFile(file: File) {
 
  def children = new Iterable[File] {
    def elements = 
      if (file.isDirectory) file.listFiles.elements else Iterator.empty;
  }
 
  def andTree : Iterable[File] = (
    Seq.single(file) 
    ++ children.flatMap(child => new RichFile(child).andTree))
}
 
/** implicitely enrich java.io.File with methods of RichFile */
object RichFile {
  implicit def toRichFile(file: File) = new RichFile(file)
}

import RichFile.toRichFile
// ============= //


import java.util.zip.CRC32
import java.io.FileInputStream
def crc32(file: File): Long = {
  val fs = new FileInputStream(file)
  var ch = fs.read
  var crc = new CRC32();
  while (ch != -1) {
    crc.update(ch)
    ch = fs.read
  }
  crc.getValue
}

if (args.length < 2) {
  println("supply 2 params")
  exit
}
val first = args(0)
val second = args(1)
println("comparing " + first + " with " + second)

def genList(f: File) = 
  (f.andTree filter (x => !x.isDirectory) map {
    (x:File) => (x, crc32(x))
  })//.toList()//.sortBy(_._2) //((a, b) => a._2 < b._2)

val fst = genList(new File(first)).toList
val snd = genList(new File(second))

println(fst)