[ADAM-461] Fix ReferenceRegion and ReferencePosition impl

This commit mainly does 3 things:

1. Fixes impl of `ReferenceRegion.width`.

2. Removes `Option`s from `ReferencePosition`.

3. Corrected impl of liftOver.  However, it now has different semantics: in all cases, the list of regions must be provided in genome order.

4. Simplifies structure of case classes.

Fixes #461.

adam-core/src/main/scala/org/bdgenomics/adam/models/ReferencePosition.scala

@@ -27,15 +27,15 @@ object ReferencePositionWithOrientation {
 
   def apply(record: AlignmentRecord): Option[ReferencePositionWithOrientation] = {
     if (record.getReadMapped) {
-      Some(new ReferencePositionWithOrientation(ReferencePosition(record), record.getReadNegativeStrand))
+      Some(new ReferencePositionWithOrientation(ReferencePosition(record).get, record.getReadNegativeStrand))
     } else {
       None
     }
   }
 
   def fivePrime(record: AlignmentRecord): Option[ReferencePositionWithOrientation] = {
     if (record.getReadMapped) {
-      Some(new ReferencePositionWithOrientation(ReferencePosition.fivePrime(record), record.getReadNegativeStrand))
+      Some(new ReferencePositionWithOrientation(ReferencePosition.fivePrime(record).get, record.getReadNegativeStrand))
     } else {
       None
     }
@@ -57,7 +57,7 @@ object ReferencePositionWithOrientation {
    */
   def liftOverToReference(idx: Long,
                           mapping: Seq[ReferenceRegionWithOrientation]): ReferencePositionWithOrientation = {
-    val negativeStrand = mapping.headOption.fold(false)(_.negativeStrand)
+    val negativeStrand = mapping.head.negativeStrand
 
     @tailrec def liftOverHelper(regions: Iterator[ReferenceRegionWithOrientation],
                                 idx: Long): ReferencePositionWithOrientation = {
@@ -81,7 +81,7 @@ object ReferencePositionWithOrientation {
           }
 
           // return
-          ReferencePositionWithOrientation(Some(ReferencePosition(chr, pos)),
+          ReferencePositionWithOrientation(ReferencePosition(chr, pos),
             negativeStrand)
         } else {
           // recurse
@@ -91,11 +91,15 @@ object ReferencePositionWithOrientation {
     }
 
     // call out to helper
-    liftOverHelper(mapping.toIterator, idx)
+    if (negativeStrand) {
+      liftOverHelper(mapping.reverseIterator, idx)
+    } else {
+      liftOverHelper(mapping.toIterator, idx)
+    }
   }
 }
 
-case class ReferencePositionWithOrientation(refPos: Option[ReferencePosition],
+case class ReferencePositionWithOrientation(refPos: ReferencePosition,
                                             negativeStrand: Boolean)
     extends Ordered[ReferencePositionWithOrientation] {
 
@@ -113,8 +117,7 @@ case class ReferencePositionWithOrientation(refPos: Option[ReferencePosition],
    * is out of the range of the mappings given.
    */
   def liftOverFromReference(mapping: Seq[ReferenceRegionWithOrientation]): Long = {
-    assert(refPos.isDefined, "Cannot lift an undefined position.")
-    val pos = refPos.get.pos
+    val pos = refPos.pos
 
     @tailrec def liftOverHelper(regions: Iterator[ReferenceRegionWithOrientation],
                                 idx: Long = 0L): Long = {
@@ -148,16 +151,7 @@ case class ReferencePositionWithOrientation(refPos: Option[ReferencePosition],
   }
 
   override def compare(that: ReferencePositionWithOrientation): Int = {
-    if (refPos.isEmpty && that.refPos.isEmpty) {
-      return 0
-    }
-    if (refPos.isEmpty) {
-      return -1
-    }
-    if (that.refPos.isEmpty) {
-      return 1
-    }
-    val posCompare = refPos.get.compare(that.refPos.get)
+    val posCompare = refPos.compare(that.refPos)
     if (posCompare != 0) {
       posCompare
     } else {
@@ -282,25 +276,13 @@ class ReferencePositionWithOrientationSerializer extends Serializer[ReferencePos
 
   def write(kryo: Kryo, output: Output, obj: ReferencePositionWithOrientation) = {
     output.writeBoolean(obj.negativeStrand)
-    obj.refPos match {
-      case None =>
-        output.writeBoolean(false)
-      case Some(refPos) =>
-        output.writeBoolean(true)
-        referencePositionSerializer.write(kryo, output, refPos)
-    }
+    referencePositionSerializer.write(kryo, output, obj.refPos)
   }
 
   def read(kryo: Kryo, input: Input, klazz: Class[ReferencePositionWithOrientation]): ReferencePositionWithOrientation = {
     val negativeStrand = input.readBoolean()
-    val hasPos = input.readBoolean()
-    hasPos match {
-      case false =>
-        new ReferencePositionWithOrientation(None, negativeStrand)
-      case true =>
-        val referencePosition = referencePositionSerializer.read(kryo, input, classOf[ReferencePosition])
-        new ReferencePositionWithOrientation(Some(referencePosition), negativeStrand)
-    }
+    val referencePosition = referencePositionSerializer.read(kryo, input, classOf[ReferencePosition])
+    new ReferencePositionWithOrientation(referencePosition, negativeStrand)
   }
 }
 

adam-core/src/main/scala/org/bdgenomics/adam/models/ReferenceRegion.scala

@@ -26,83 +26,63 @@ import scala.math.{ max, min }
 object ReferenceRegionWithOrientation {
 
   /**
-   * Builds an oriented reference region from a given reference region
-   * and an orientation parameter.
+   * Builds an oriented reference region from the individual parameters
    *
-   * @param region Unstranded reference region.
-   * @param negativeStrand True if this region should be placed on the negative
-   * strand, else it will be on the positive strand.
-   * @return Returns an oriented reference region.
+   * @param referenceName The name of the sequence (chromosome) in the reference genome
+   * @param start The 0-based residue-coordinate for the start of the region
+   * @param end The 0-based residue-coordinate for the first residue <i>after</i> the start
+   *            which is <i>not</i> in the region -- i.e. [start, end) define a 0-based
+   *            half-open interval.
+   * @param negativeStrand Boolean flag as to whether the region is on the forward or
+   *                       reverse strand of the reference region.
    */
-  def apply(region: ReferenceRegion,
+  def apply(referenceName: String,
+            start: Long,
+            end: Long,
             negativeStrand: Boolean): ReferenceRegionWithOrientation = {
-    ReferenceRegionWithOrientation(region.referenceName,
-      region.start,
-      region.end,
-      negativeStrand)
+    ReferenceRegionWithOrientation(ReferenceRegion(referenceName, start, end), negativeStrand)
   }
 }
 
 /**
  * Represents a contiguous region of the reference genome with strand information.
  *
- * @param referenceName The name of the sequence (chromosome) in the reference genome
- * @param start The 0-based residue-coordinate for the start of the region
- * @param end The 0-based residue-coordinate for the first residue <i>after</i> the start
- *            which is <i>not</i> in the region -- i.e. [start, end) define a 0-based
- *            half-open interval.
+ * @param region The genomic locus as a ReferenceRegion
  * @param negativeStrand Boolean flag as to whether the region is on the forward or
  *                       reverse strand of the reference region.
  */
-case class ReferenceRegionWithOrientation(referenceName: String,
-                                          start: Long,
-                                          end: Long,
+case class ReferenceRegionWithOrientation(region: ReferenceRegion,
                                           negativeStrand: Boolean) extends Ordered[ReferenceRegionWithOrientation] {
-
-  assert(end >= 0)
-  assert(start >= 0)
-
-  def width: Long = end - start - 1 // need minus 1 for open end
+  def width: Long = region.width
 
   def contains(other: ReferencePositionWithOrientation): Boolean = {
-    other.refPos.fold(false)(rp => referenceName == rp.referenceName &&
-      negativeStrand == other.negativeStrand &&
-      start <= rp.pos && end > rp.pos)
+    negativeStrand == other.negativeStrand && region.contains(other.refPos)
   }
 
   def contains(other: ReferenceRegionWithOrientation): Boolean = {
-    referenceName == other.referenceName && negativeStrand == other.negativeStrand &&
-      start <= other.start && end >= other.end
+    region.contains(other.region) && negativeStrand == other.negativeStrand
   }
 
   def overlaps(other: ReferenceRegionWithOrientation): Boolean = {
-    referenceName == other.referenceName && negativeStrand == other.negativeStrand &&
-      ((start >= other.start && start <= other.end) || (end >= other.start && end <= other.end))
+    region.overlaps(other.region) && negativeStrand == other.negativeStrand
   }
 
-  def compare(that: ReferenceRegionWithOrientation): Int =
-    if (referenceName != that.referenceName) {
-      referenceName.compareTo(that.referenceName)
-    } else if (negativeStrand != that.negativeStrand) {
-      negativeStrand.compareTo(that.negativeStrand)
+  def compare(that: ReferenceRegionWithOrientation): Int = {
+    val regionCompare = region.compare(that.region)
+    if (regionCompare != 0) {
+      regionCompare
     } else {
-      if (negativeStrand) {
-        // invert comparison if on negative strand
-        if (start != that.start)
-          -start.compareTo(that.start)
-        else
-          -end.compareTo(that.end)
-      } else {
-        if (start != that.start)
-          start.compareTo(that.start)
-        else
-          end.compareTo(that.end)
-      }
+      negativeStrand.compare(that.negativeStrand)
     }
-
-  def toReferenceRegion: ReferenceRegion = {
-    ReferenceRegion(referenceName, start, end)
   }
+
+  def toReferenceRegion: ReferenceRegion = region
+
+  def referenceName: String = region.referenceName
+
+  def start: Long = region.start
+
+  def end: Long = region.end
 }
 
 object ReferenceRegion {
@@ -167,9 +147,9 @@ object ReferenceRegion {
 case class ReferenceRegion(referenceName: String, start: Long, end: Long) extends Ordered[ReferenceRegion] with Interval {
 
   assert(start >= 0)
-  assert(end >= start)
+  assert(end > start)
 
-  def width: Long = end - start - 1
+  def width: Long = end - start
 
   /**
    * Merges two reference regions that are contiguous.

adam-core/src/test/scala/org/bdgenomics/adam/models/IndelTableSuite.scala

@@ -30,7 +30,7 @@ class IndelTableSuite extends SparkFunSuite {
   }
 
   test("check for indels in a contig that doesn't exist") {
-    assert(indelTable.getIndelsInRegion(ReferenceRegion("0", 0L, 0L)).length === 0)
+    assert(indelTable.getIndelsInRegion(ReferenceRegion("0", 0L, 1L)).length === 0)
   }
 
   test("check for indels in a region without known indels") {

adam-core/src/test/scala/org/bdgenomics/adam/models/ReferencePositionSuite.scala

@@ -145,50 +145,43 @@ class ReferencePositionSuite extends FunSuite {
   }
 
   test("liftOverToReference works with a multi-block alignment on the forward strand") {
-    val exons = Seq(ReferenceRegionWithOrientation("1", 100, 201, negativeStrand = false),
-      ReferenceRegionWithOrientation("1", 300, 401, negativeStrand = false),
-      ReferenceRegionWithOrientation("1", 500, 601, negativeStrand = false))
+    val exons = Seq(ReferenceRegionWithOrientation("1", 100, 200, negativeStrand = false),
+      ReferenceRegionWithOrientation("1", 300, 400, negativeStrand = false),
+      ReferenceRegionWithOrientation("1", 500, 600, negativeStrand = false))
 
     val p0 = ReferencePositionWithOrientation.liftOverToReference(0, exons)
-    assert(p0.refPos.isDefined)
-    assert(p0.refPos.get.referenceName === "1")
-    assert(p0.refPos.get.pos === 100)
+    assert(p0.refPos.referenceName === "1")
+    assert(p0.refPos.pos === 100)
 
     val p1 = ReferencePositionWithOrientation.liftOverToReference(50, exons)
-    assert(p1.refPos.isDefined)
-    assert(p1.refPos.get.referenceName === "1")
-    assert(p1.refPos.get.pos === 150)
+    assert(p1.refPos.referenceName === "1")
+    assert(p1.refPos.pos === 150)
 
     val p2 = ReferencePositionWithOrientation.liftOverToReference(150, exons)
-    assert(p2.refPos.isDefined)
-    assert(p2.refPos.get.referenceName === "1")
-    assert(p2.refPos.get.pos === 350)
+    assert(p2.refPos.referenceName === "1")
+    assert(p2.refPos.pos === 350)
 
     val p3 = ReferencePositionWithOrientation.liftOverToReference(250, exons)
-    assert(p3.refPos.isDefined)
-    assert(p3.refPos.get.referenceName === "1")
-    assert(p3.refPos.get.pos === 550)
+    assert(p3.refPos.referenceName === "1")
+    assert(p3.refPos.pos === 550)
   }
 
   test("liftOverToReference works with a multi-block alignment on the reverse strand") {
-    val exons = Seq(ReferenceRegionWithOrientation("1", 500, 601, negativeStrand = true),
-      ReferenceRegionWithOrientation("1", 300, 401, negativeStrand = true),
-      ReferenceRegionWithOrientation("1", 100, 201, negativeStrand = true))
+    val exons = Seq(ReferenceRegionWithOrientation("1", 100, 200, negativeStrand = true),
+      ReferenceRegionWithOrientation("1", 300, 400, negativeStrand = true),
+      ReferenceRegionWithOrientation("1", 500, 600, negativeStrand = true))
 
     val p1 = ReferencePositionWithOrientation.liftOverToReference(50, exons)
-    assert(p1.refPos.isDefined)
-    assert(p1.refPos.get.referenceName === "1")
-    assert(p1.refPos.get.pos === 550)
+    assert(p1.refPos.referenceName === "1")
+    assert(p1.refPos.pos === 549)
 
     val p2 = ReferencePositionWithOrientation.liftOverToReference(150, exons)
-    assert(p2.refPos.isDefined)
-    assert(p2.refPos.get.referenceName === "1")
-    assert(p2.refPos.get.pos === 350)
+    assert(p2.refPos.referenceName === "1")
+    assert(p2.refPos.pos === 349)
 
     val p3 = ReferencePositionWithOrientation.liftOverToReference(250, exons)
-    assert(p3.refPos.isDefined)
-    assert(p3.refPos.get.referenceName === "1")
-    assert(p3.refPos.get.pos === 150)
+    assert(p3.refPos.referenceName === "1")
+    assert(p3.refPos.pos === 149)
   }
 
   test("lift over between two transcripts on the forward strand") {
@@ -200,9 +193,8 @@ class ReferencePositionSuite extends FunSuite {
     // check forward strand
     val pos = ReferencePositionWithOrientation.liftOverToReference(60, t1)
 
-    assert(pos.refPos.isDefined)
-    assert(pos.refPos.get.referenceName === "chr0")
-    assert(pos.refPos.get.pos === 60L)
+    assert(pos.refPos.referenceName === "chr0")
+    assert(pos.refPos.pos === 60L)
     assert(!pos.negativeStrand)
 
     val idx = pos.liftOverFromReference(t2)
@@ -217,16 +209,15 @@ class ReferencePositionSuite extends FunSuite {
       ReferenceRegionWithOrientation("chr0", 50L, 101L, negativeStrand = true))
 
     // check reverse strand
-    val idx = ReferencePositionWithOrientation(Some(ReferencePosition("chr0", 190L)), negativeStrand = true)
+    val idx = ReferencePositionWithOrientation(ReferencePosition("chr0", 190L), negativeStrand = true)
       .liftOverFromReference(t2)
 
     assert(idx === 11L)
 
     val pos = ReferencePositionWithOrientation.liftOverToReference(idx, t1)
 
-    assert(pos.refPos.isDefined)
-    assert(pos.refPos.get.referenceName === "chr0")
-    assert(pos.refPos.get.pos === 189L)
+    assert(pos.refPos.referenceName === "chr0")
+    assert(pos.refPos.pos === 189L)
     assert(pos.negativeStrand)
   }
 }