improve integration of DenseVector into collection framework:

* factor out similarities between *Wrapped and *Ops to *Like
* remove custom builder (use array buffer instead sonce DenseVectors are backed by arrays)
* refactor CanBuildFroms
* make LowPriority implicits to a trait

6 files changed, 53 insertions, 38 deletions

diff --git a/src/main/scala/scalam/LowPriorityImplicits.scala b/src/main/scala/scalam/LowPriorityImplicits.scala
index ca0f378..4eec21a 100644
--- a/src/main/scala/scalam/LowPriorityImplicits.scala
+++ b/src/main/scala/scalam/LowPriorityImplicits.scala
@@ -3,7 +3,7 @@ package scalam
 import breeze.linalg.DenseVector
 import scalam.collection._
 
-object LowPriorityImplicits {
+trait LowPriorityImplicits {
   
   implicit def wrapDenseVector[A: ClassManifest](v: DenseVector[A]) = new WrappedDenseVector(v)
   implicit def unwrapDenseVector[A: ClassManifest](w: WrappedDenseVector[A]) = w.self
diff --git a/src/main/scala/scalam/collection/DenseVectorBuilder.scala b/src/main/scala/scalam/collection/DenseVectorBuilder.scala
deleted file mode 100644
index 84501bd..0000000
--- a/src/main/scala/scalam/collection/DenseVectorBuilder.scala
+++ /dev/null
@@ -1,16 +0,0 @@
-package scalam.collection
-
-import scala.collection.mutable.Builder
-import scala.collection.mutable.ArrayBuffer
-import breeze.linalg.DenseVector
-
-class DenseVectorBuilder[Elem: ClassManifest] extends Builder[Elem, DenseVector[Elem]] {
-  private val buffer = new ArrayBuffer[Elem]
-  
-  override def +=(elem: Elem) = {buffer += elem; this}
-  override def clear() = buffer.clear
-  override def result() = {
-   val a = buffer.mapResult(_.toArray).result
-   DenseVector(a)
-  }
-} 
\ No newline at end of file
diff --git a/src/main/scala/scalam/collection/DenseVectorLike.scala b/src/main/scala/scalam/collection/DenseVectorLike.scala
new file mode 100644
index 0000000..e34f05c
--- /dev/null
+++ b/src/main/scala/scalam/collection/DenseVectorLike.scala
@@ -0,0 +1,12 @@
+package scalam.collection
+
+import scala.collection.mutable.IndexedSeqLike
+import breeze.linalg.DenseVector
+
+trait DenseVectorLike[Elem, Repr] extends IndexedSeqLike[Elem, Repr]{
+  def self: DenseVector[Elem]
+  
+  override def apply(index: Int): Elem = self.apply(index)
+  override def update(index: Int, value: Elem): Unit = self.update(index, value)
+  override def length: Int = self.length
+}
\ No newline at end of file
diff --git a/src/main/scala/scalam/collection/DenseVectorOps.scala b/src/main/scala/scalam/collection/DenseVectorOps.scala
index b7b6446..7f8e9f9 100644
--- a/src/main/scala/scalam/collection/DenseVectorOps.scala
+++ b/src/main/scala/scalam/collection/DenseVectorOps.scala
@@ -1,16 +1,32 @@
 package scalam.collection
 
-import scala.collection.mutable.IndexedSeqOptimized
 import breeze.linalg.DenseVector
+import scala.collection.mutable.ArrayBuffer
+import scala.collection.generic.CanBuildFrom
+import scala.collection.mutable.Builder
 
 /* TODO find solution to remove class manifest */
-class DenseVectorOps[Elem: ClassManifest](self: DenseVector[Elem]) extends IndexedSeqOptimized/*Like*/[Elem, DenseVector[Elem]] {
-  override def newBuilder = new DenseVectorBuilder[Elem]
+class DenseVectorOps[Elem: ClassManifest](override val repr: DenseVector[Elem]) extends DenseVectorLike[Elem, DenseVector[Elem]] {
+  val self = repr
+  def newBuilder = DenseVectorOps.newBuilder[Elem]
   
-  override def apply(index: Int) = self.apply(index)
-  override def update(index: Int, value: Elem) = self.update(index, value)
-  override def length = self.length
-  
-  override def seq = this
+  override protected[this] def thisCollection = new WrappedDenseVector(self)
+  override protected[this] def toCollection(repr: DenseVector[Elem]): WrappedDenseVector[Elem] = new WrappedDenseVector(repr)
+  override def seq = thisCollection
 }
 
+object DenseVectorOps {
+  def newBuilder[Elem: ClassManifest] = new ArrayBuffer[Elem]  mapResult (x => new DenseVector(x.toArray))
+  
+  implicit def canBuildFrom[T: ClassManifest] = new CanBuildFrom[DenseVector[_], T, DenseVector[T]] {
+    def apply(from: DenseVector[_]): Builder[T, DenseVector[T]] = newBuilder[T]
+    def apply: Builder[T, DenseVector[T]] = newBuilder[T]
+  }
+  /*
+   implicit def denseVectorBuildFrom[A: ClassManifest]: CanBuildFrom[DenseVector[_], A, DenseVector[A]] =
+    new CanBuildFrom[DenseVector[_], A, DenseVector[A]] {
+      def apply(from: DenseVector[_]): Builder[A, DenseVector[A]] = apply()
+      def apply(): Builder[A, DenseVector[A]] = collection.DenseVectorOps.newBuilder[A]
+    }
+    */
+}
diff --git a/src/main/scala/scalam/collection/WrappedDenseVector.scala b/src/main/scala/scalam/collection/WrappedDenseVector.scala
index 43638c6..36926d9 100644
--- a/src/main/scala/scalam/collection/WrappedDenseVector.scala
+++ b/src/main/scala/scalam/collection/WrappedDenseVector.scala
@@ -1,25 +1,20 @@
 package scalam.collection
 
-import scala.collection.mutable.IndexedSeqOptimized
+import scala.collection.mutable.IndexedSeq
 import breeze.linalg.DenseVector
 import scala.collection.mutable.Builder
 import scala.collection.generic.CanBuildFrom
-import scala.collection.generic.SeqFactory
-import scala.collection.generic.GenericCompanion
-import scala.collection.mutable.IndexedSeqLike
+import scala.collection.mutable.ArrayBuffer
 
-class WrappedDenseVector[Elem: ClassManifest](val self: DenseVector[Elem]) extends IndexedSeq[Elem] with IndexedSeqLike[Elem, WrappedDenseVector[Elem]] {
-  override def update(index: Int, value: Elem) = self.update(index, value)
-  override def apply(index: Int) = self.apply(index)
-  override def length = self.length
-  override protected[this] def newBuilder: Builder[Elem, WrappedDenseVector[Elem]] = (new DenseVectorBuilder[Elem]) mapResult (new WrappedDenseVector(_))
+class WrappedDenseVector[Elem: ClassManifest](val self: DenseVector[Elem]) extends IndexedSeq[Elem] with DenseVectorLike[Elem, WrappedDenseVector[Elem]] {
+  override protected[this] def newBuilder: Builder[Elem, WrappedDenseVector[Elem]] = WrappedDenseVector.newBuilder[Elem]
 }
 
 object WrappedDenseVector {
-  def newBuilder[Elem: ClassManifest] = (new DenseVectorBuilder[Elem]) mapResult (new WrappedDenseVector(_))
+  def newBuilder[Elem: ClassManifest] = (new ArrayBuffer[Elem]) mapResult (x => new WrappedDenseVector(DenseVector(x.toArray)))
 
   implicit def canBuildFrom[T: ClassManifest] = new CanBuildFrom[WrappedDenseVector[_], T, WrappedDenseVector[T]] {
-    def apply(from: WrappedDenseVector[_]): Builder[T, WrappedDenseVector[T]] = newBuilder
-    def apply: Builder[T, WrappedDenseVector[T]] = newBuilder
+    def apply(from: WrappedDenseVector[_]): Builder[T, WrappedDenseVector[T]] = newBuilder[T]
+    def apply: Builder[T, WrappedDenseVector[T]] = newBuilder[T]
   }
 }
\ No newline at end of file
diff --git a/src/main/scala/scalam/package.scala b/src/main/scala/scalam/package.scala
index 76957fe..da0888c 100644
--- a/src/main/scala/scalam/package.scala
+++ b/src/main/scala/scalam/package.scala
@@ -1,8 +1,16 @@
 import breeze.linalg.DenseVector
 import scalam.collection._
+import scala.collection.generic.CanBuildFrom
+import scala.collection.mutable.Builder
 
-package object scalam extends LowPriorityImplicits{
+package object scalam extends LowPriorityImplicits {
   
   implicit def denseVector2Ops[A: ClassManifest](v: DenseVector[A]) = new DenseVectorOps(v)
 
+  implicit def denseVectorBuildFrom[A: ClassManifest]: CanBuildFrom[DenseVector[_], A, DenseVector[A]] =
+    new CanBuildFrom[DenseVector[_], A, DenseVector[A]] {
+      def apply(from: DenseVector[_]): Builder[A, DenseVector[A]] = apply()
+      def apply(): Builder[A, DenseVector[A]] = collection.DenseVectorOps.newBuilder[A]
+    }
+  
 }
\ No newline at end of file