From 280192f2c5e92f9f8fb3238f1b4bfdf2566e6fdf Mon Sep 17 00:00:00 2001
From: Martin Odersky <odersky@gmail.com>
Date: Wed, 15 Feb 2012 15:33:09 +0100
Subject: New scheme for "Rows" of value classes.

---
 src/library/scala/Boxed.scala                      | 18 ++++++++
 .../scala/collection/generic/RowFactory.scala      | 49 ++++++++++++++++++++++
 2 files changed, 67 insertions(+)
 create mode 100644 src/library/scala/Boxed.scala
 create mode 100644 src/library/scala/collection/generic/RowFactory.scala

(limited to 'src')

diff --git a/src/library/scala/Boxed.scala b/src/library/scala/Boxed.scala
new file mode 100644
index 0000000000..6055b3f436
--- /dev/null
+++ b/src/library/scala/Boxed.scala
@@ -0,0 +1,18 @@
+/*                     __                                               *\
+**     ________ ___   / /  ___     Scala API                            **
+**    / __/ __// _ | / /  / _ |    (c) 2002-2011, LAMP/EPFL             **
+**  __\ \/ /__/ __ |/ /__/ __ |    http://www.scala-lang.org/           **
+** /____/\___/_/ |_/____/_/ | |                                         **
+**                          |/                                          **
+\*                                                                      */
+
+package scala
+
+/** A trait that can be implemented by user-defined value classes
+ */
+trait Boxed[Unboxed] extends Any {
+
+  /** The underlying value wrapped by the value class */
+  def unbox: Unboxed
+}
+ 
diff --git a/src/library/scala/collection/generic/RowFactory.scala b/src/library/scala/collection/generic/RowFactory.scala
new file mode 100644
index 0000000000..c1559c9397
--- /dev/null
+++ b/src/library/scala/collection/generic/RowFactory.scala
@@ -0,0 +1,49 @@
+package scala.collection
+package generic
+
+import mutable.{Builder, ArrayBuffer}
+import scala.specialized
+
+/** A factory class for rows -- flat arrays of value classes that use the unboxed representation
+ *  of the element type.
+ *  
+ */
+abstract class RowFactory[@specialized Unboxed: ClassManifest, Boxed <: scala.Boxed[Unboxed]] extends (Unboxed => Boxed) { box =>
+  
+  /** Convert to boxed representation
+   */
+  def apply(x: Unboxed): Boxed
+
+  class Row(elems: Array[Unboxed]) extends mutable.IndexedSeq[Boxed] with mutable.IndexedSeqLike[Boxed, Row] {
+
+    override protected[this] def newBuilder: Builder[Boxed, Row] = Row.newBuilder
+    
+    def apply(idx: Int): Boxed = box(elems(idx))
+    
+    def update(idx: Int, elem: Boxed): Unit = elems(idx) = elem.unbox
+    
+    def length = elems.length
+    
+    override def foreach[U](f: Boxed => U): Unit = elems foreach (elem => f(box(elem)))
+
+  }
+
+  object Row {
+    def fromSeq(elems: Seq[Boxed]): Row = {
+      val xs: Array[Unboxed] = new Array[Unboxed](elems.length)
+      var i = 0
+      for (elem <- elems) { xs(i) = elem.unbox; i += 1 }
+      new Row(xs)
+    }
+      
+    def apply(elems: Boxed*) = fromSeq(elems)
+    
+    def newBuilder: Builder[Boxed, Row] = new ArrayBuffer mapResult fromSeq
+    
+    implicit def canBuildFrom: CanBuildFrom[Row, Boxed, Row] = 
+      new CanBuildFrom[Row, Boxed, Row] {
+        def apply(): Builder[Boxed, Row] = newBuilder
+        def apply(from: Row): Builder[Boxed, Row] = newBuilder
+      }
+  }
+}
-- 
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