Scala example source code file (ParallelSeqCheck.scala)

This example Scala source code file (ParallelSeqCheck.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

colltype, colltype, comparing, gen, gen, int, int, nil, paralleliterablecheck, parallelseqcheck, parseq, seq, seq, traversable

The Scala ParallelSeqCheck.scala source code

package scala.collection.parallel



import org.scalacheck._
import org.scalacheck.Gen
import org.scalacheck.Gen._
import org.scalacheck.Prop._
import org.scalacheck.Properties

import scala.collection._
import scala.collection.parallel._





abstract class ParallelSeqCheck[T](collName: String) extends ParallelIterableCheck[T](collName) with SeqOperators[T] {
  
  type CollType <: collection.parallel.ParSeq[T]
  

  def ofSize(vals: Seq[Gen[T]], sz: Int): Seq[T]
  def fromSeq(s: Seq[T]): CollType
  
  override def instances(vals: Seq[Gen[T]]): Gen[Seq[T]] = oneOf(
    sized(
      sz =>
      ofSize(vals, sz)
    ),
    for (sz <- choose(1000, 2000)) yield ofSize(vals, sz)
  )

  
  def fromTraversable(t: Traversable[T]) = fromSeq(traversable2Seq(t))
  def traversable2Seq(t: Traversable[T]): Seq[T] = {
    if (t.isInstanceOf[Iterable[_]]) t.asInstanceOf[Iterable[T]].iterator.toList else t.toList
  }
  
  override def collectionPairs: Gen[(Seq[T], CollType)] = for (inst <- instances(values)) yield (inst, fromSeq(inst))
  
  override def collectionPairsWithLengths: Gen[(Seq[T], CollType, Int)] =
    for (inst <- instances(values); s <- choose(0, inst.size)) yield (inst, fromSeq(inst), s);
  
  def collectionPairsWithModifiedWithLengths: Gen[(Seq[T], CollType, ParSeq[T], Int)] =
    for (inst <- instances(values); s <- choose(0, inst.size);
    updateStart <- choose(0, inst.size); howMany <- choose(0, inst.size)) yield {
      val parcoll = fromSeq(inst)
      val parcollmodif = fromSeq(modifySlightly(inst, updateStart, howMany))
      (inst, parcoll, parcollmodif, s)
    }
  
  def collectionPairsWithModified: Gen[(Seq[T], CollType, ParSeq[T])] =
    for (inst <- instances(values); updateStart <- choose(0, inst.size); howMany <- choose(0, inst.size)) yield {
      val parcoll = fromSeq(inst)
      val parcollmodif = fromSeq(modifySlightly(inst, updateStart, howMany))
      (inst, parcoll, parcollmodif)
    }
  
  def collectionPairsWithSliced: Gen[(Seq[T], CollType, ParSeq[T])] =
    for (inst <- instances(values); sliceStart <- choose(0, inst.size); howMany <- choose(0, inst.size)) yield {
      val parcoll = fromSeq(inst)
      val parcollsliced = fromSeq(inst.slice(sliceStart, sliceStart + howMany))
      (inst, parcoll, parcollsliced)
    }
  
  def collectionTripletsWith2Indices: Gen[(Seq[T], CollType, Seq[T], Int, Int)] =
    for (inst <- instances(values); f <- choose(0, inst.size); s <- choose(0, inst.size - f);
      third <- instances(values); sliceStart <- choose(0, inst.size); howMany <- choose(0, inst.size)) yield {
      (inst, fromSeq(inst), inst.slice(sliceStart, sliceStart + howMany), f, s)
    }
  
  private def modifySlightly(coll: Seq[T], updateStart: Int, howMany: Int) = {
    coll.patch(updateStart, coll, howMany)
  }
  
  property("segmentLengths must be equal") = forAll(collectionPairsWithLengths) { case (s, coll, len) =>
    (for ((pred, ind) <- segmentLengthPredicates.zipWithIndex) yield {
      val slen = s.segmentLength(pred, if (len < 0) 0 else len)
      val clen = coll.segmentLength(pred, len)
      if (slen != clen) {
        println("from: " + s)
        println("and: " + coll)
        println(slen)
        println(clen)
      }
      ("operator " + ind) |: slen == clen
    }).reduceLeft(_ && _)
  }
  
  property("prefixLengths must be equal") = forAll(collectionPairs) { case (s, coll) =>
    (for ((pred, ind) <- segmentLengthPredicates.zipWithIndex) yield {
      ("operator " + ind) |: s.prefixLength(pred) == coll.prefixLength(pred)
    }).reduceLeft(_ && _)
  }
  
  property("indexWheres must be equal") = forAll(collectionPairsWithLengths) { case (s, coll, len) =>
    (for ((pred, ind) <- indexWherePredicates.zipWithIndex) yield {
      val sind = s.indexWhere(pred, len)
      val cind = coll.indexWhere(pred, len)
      if (sind != cind) {
        println("from: " + s)
        println("and: " + coll)
        println("at: " + len)
        println(sind)
        println(cind)
      }
      ("operator " + ind) |: sind == cind
    }).reduceLeft(_ && _)
  }
  
  property("lastIndexWheres must be equal") = forAll(collectionPairsWithLengths) { case (s, coll, len) =>
    (for ((pred, ind) <- lastIndexWherePredicates.zipWithIndex) yield {
      val end = if (len >= s.size) s.size - 1 else len
      val sind = s.lastIndexWhere(pred, end)
      val cind = coll.lastIndexWhere(pred, end)
      ("operator " + ind) |: sind == cind
    }).reduceLeft(_ && _)
  }
  
  property("reverses must be equal") = forAll(collectionPairs) { case (s, coll) =>
    (s.length == 0 && s.getClass == classOf[collection.immutable.Range]) ||
    {
      val sr = s.reverse
      val cr = coll.reverse
      if (sr != cr) {
        println("from: " + s)
        println("and: " + coll)
        println(sr)
        println(cr)
      }
      sr == cr
    }
  }
  
  property("reverseMaps must be equal") = forAll(collectionPairs) { case (s, coll) =>
    (for ((f, ind) <- reverseMapFunctions.zipWithIndex) yield {
      ("operator " + ind) |: s.reverseMap(f) == coll.reverseMap(f)
    }).reduceLeft(_ && _)
  }
  
  property("sameElements must be equal") = forAll(collectionPairsWithModifiedWithLengths) {
  case (s, coll, collmodif, len) =>
    val pos = if (len < 0) 0 else len
    val scm = s.sameElements(collmodif)
    val ccm = coll.sameElements(collmodif)
    if (scm != ccm) {
      println("Comparing: " + s)
      println("and: " + coll)
      println("with: " + collmodif)
      println(scm)
      println(ccm)
    }
    ("Nil" |: s.sameElements(Nil) == coll.sameElements(Nil)) &&
    ("toList" |: s.sameElements(s.toList) == coll.sameElements(coll.toList)) &&
    ("identity" |: s.sameElements(s.map(e => e)) == coll.sameElements(coll.map(e => e))) &&
    ("vice-versa" |: s.sameElements(coll) == coll.sameElements(s)) &&
    ("equal" |: s.sameElements(coll)) &&
    ("modified" |: scm == ccm) &&
    (for ((it, ind) <- sameElementsSeqs.zipWithIndex) yield {
      val sres = s.sameElements(it)
      val pres = coll.sameElements(it)
      if (sres != pres) {
        println("Comparing: " + s)
        println("and: " + coll)
        println("with: " + it)
        println(sres)
        println(pres)
      }
      ("collection " + ind) |: sres == pres
    }).reduceLeft(_ && _)
  }
  
  property("startsWiths must be equal") = forAll(collectionPairsWithModifiedWithLengths) {
  case (s, coll, collmodif, len) =>
    val pos = if (len < 0) 0 else len
    ("start with self" |: s.startsWith(s) == coll.startsWith(coll)) &&
    ("tails correspond" |: (s.length == 0 || s.startsWith(s.tail, 1) == coll.startsWith(coll.tail, 1))) &&
    ("with each other" |: coll.startsWith(s)) &&
    ("modified" |: s.startsWith(collmodif) == coll.startsWith(collmodif)) &&
    ("modified2" |: s.startsWith(collmodif, pos) == coll.startsWith(collmodif, pos)) &&
    (for (sq <- startEndSeqs) yield {
      val ss = s.startsWith(sq, pos)
      val cs = coll.startsWith(fromSeq(sq), pos)
      if (ss != cs) {
        println("from: " + s)
        println("and: " + coll)
        println("test seq: " + sq)
        println("from pos: " + pos)
        println(ss)
        println(cs)
        println(coll.iterator.psplit(pos, coll.length - pos)(1).toList)
      }
      ("seq " + sq) |: ss == cs
    }).reduceLeft(_ && _)
  }
  
  property("endsWiths must be equal") = forAll(collectionPairsWithModified) {
  case (s, coll, collmodif) =>
    ("ends with self" |: s.endsWith(s) == coll.endsWith(s)) &&
    ("ends with tail" |: (s.length == 0 || s.endsWith(s.tail) == coll.endsWith(coll.tail))) &&
    ("with each other" |: coll.endsWith(s)) &&
    ("modified" |: s.startsWith(collmodif) == coll.endsWith(collmodif)) &&
    (for (sq <- startEndSeqs) yield {
      val sew = s.endsWith(sq)
      val cew = coll.endsWith(fromSeq(sq))
      if (sew != cew) {
        println("from: " + s)
        println("and: " + coll)
        println(sew)
        println(cew)
      }
      ("seq " + sq) |: sew == cew
    }).reduceLeft(_ && _)
  }
  
  property("unions must be equal") = forAll(collectionPairsWithModified) { case (s, coll, collmodif) =>
    ("modified" |: s.union(collmodif.seq) == coll.union(collmodif)) &&
    ("empty" |: s.union(Nil) == coll.union(fromSeq(Nil)))
  }
  
  // This is failing with my views patch: array index out of bounds in the array iterator.
  // Couldn't see why this and only this was impacted, could use a second pair of eyes.
  // 
  // This was failing because some corner cases weren't added to the patch method in ParSeqLike.
  // Curiously, this wasn't detected before.
  // 
  if (!isCheckingViews) property("patches must be equal") = forAll(collectionTripletsWith2Indices) {
    case (s, coll, pat, from, repl) =>
    ("with seq" |: s.patch(from, pat, repl) == coll.patch(from, pat, repl)) &&
    ("with par" |: s.patch(from, pat, repl) == coll.patch(from, fromSeq(pat), repl)) &&
    ("with empty" |: s.patch(from, Nil, repl) == coll.patch(from, fromSeq(Nil), repl)) &&
    ("with one" |: (s.length == 0 || s.patch(from, List(s(0)), 1) == coll.patch(from, fromSeq(List(coll(0))), 1)))
  }
  
  if (!isCheckingViews) property("updates must be equal") = forAll(collectionPairsWithLengths) { case (s, coll, len) =>
    val pos = if (len >= s.length) s.length - 1 else len
    if (s.length > 0) {
      val supd = s.updated(pos, s(0))
      val cupd = coll.updated(pos, coll(0))
      if (supd != cupd) {
        println("from: " + s)
        println("and: " + coll)
        println(supd)
        println(cupd)
      }
      "from first" |: (supd == cupd)
    } else "trivially" |: true
  }
  
  property("prepends must be equal") = forAll(collectionPairs) { case (s, coll) =>
    s.length == 0 || s(0) +: s == coll(0) +: coll
  }
  
  property("appends must be equal") = forAll(collectionPairs) { case (s, coll) =>
    s.length == 0 || s :+ s(0) == coll :+ coll(0)
  }
  
  property("padTos must be equal") = forAll(collectionPairsWithLengths) { case (s, coll, len) =>
    val someValue = sampleValue
    val sdoub = s.padTo(len * 2, someValue)
    val cdoub = coll.padTo(len * 2, someValue)
    if (sdoub != cdoub) {
      println("from: " + s)
      println("and: " + coll)
      println(sdoub)
      println(cdoub)
    }
    ("smaller" |: s.padTo(len / 2, someValue) == coll.padTo(len / 2, someValue)) &&
    ("bigger" |: sdoub == cdoub)
  }
  
  property("corresponds must be equal") = forAll(collectionPairsWithModified) { case (s, coll, modified) =>
    val modifcut = modified.toSeq.slice(0, modified.length)
    ("self" |: s.corresponds(s)(_ == _) == coll.corresponds(coll)(_ == _)) &&
    ("modified" |: s.corresponds(modified.seq)(_ == _) == coll.corresponds(modified)(_ == _)) &&
    ("modified2" |: s.corresponds(modifcut)(_ == _) == coll.corresponds(modifcut)(_ == _))
  }
  
}