SI-6908 Makes FlatHashTable as well as derived classes support null values

This change adds a null sentinel object which is used to indicate that a null
value has been inserted in FlatHashTable. It also makes a strong distinction
between logical elements of the Set vs entries in the hash table. Changes
are made to mutable.HashSet and ParHashSet accordingly.

2 files changed, 74 insertions, 0 deletions

diff --git a/test/files/run/hashset.check b/test/files/run/hashset.check
new file mode 100644
index 0000000000..9542a1ff48
--- /dev/null
+++ b/test/files/run/hashset.check
@@ -0,0 +1,26 @@
+*** HashSet primitives
+0 true,1 true,10 true,11 true,12 true,13 true,14 true,15 true,16 true,17 true,18 true,19 true,2 true,3 true,4 true,5 true,6 true,7 true,8 true,9 true
+20 false,21 false,22 false,23 false,24 false,25 false,26 false,27 false,28 false,29 false,30 false,31 false,32 false,33 false,34 false,35 false,36 false,37 false,38 false,39 false
+0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19
+
+*** HashSet Strings with null
+null true
+0 true,1 true,10 true,11 true,12 true,13 true,14 true,15 true,16 true,17 true,18 true,19 true,2 true,3 true,4 true,5 true,6 true,7 true,8 true,9 true
+20 false,21 false,22 false,23 false,24 false,25 false,26 false,27 false,28 false,29 false,30 false,31 false,32 false,33 false,34 false,35 false,36 false,37 false,38 false,39 false
+0,1,10,11,12,13,14,15,16,17,18,19,2,3,4,5,6,7,8,9,null
+null false
+0 false,1 true,10 true,11 true,12 true,13 true,14 true,15 true,16 true,17 true,18 true,19 true,2 true,3 true,4 true,5 true,6 true,7 true,8 true,9 true
+
+*** ParHashSet primitives
+0 true,1 true,10 true,11 true,12 true,13 true,14 true,15 true,16 true,17 true,18 true,19 true,2 true,3 true,4 true,5 true,6 true,7 true,8 true,9 true
+20 false,21 false,22 false,23 false,24 false,25 false,26 false,27 false,28 false,29 false,30 false,31 false,32 false,33 false,34 false,35 false,36 false,37 false,38 false,39 false
+0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19
+
+*** ParHashSet Strings with null
+null true
+0 true,1 true,10 true,11 true,12 true,13 true,14 true,15 true,16 true,17 true,18 true,19 true,2 true,3 true,4 true,5 true,6 true,7 true,8 true,9 true
+20 false,21 false,22 false,23 false,24 false,25 false,26 false,27 false,28 false,29 false,30 false,31 false,32 false,33 false,34 false,35 false,36 false,37 false,38 false,39 false
+0,1,10,11,12,13,14,15,16,17,18,19,2,3,4,5,6,7,8,9,null
+null false
+0 false,1 true,10 true,11 true,12 true,13 true,14 true,15 true,16 true,17 true,18 true,19 true,2 true,3 true,4 true,5 true,6 true,7 true,8 true,9 true
+
diff --git a/test/files/run/hashset.scala b/test/files/run/hashset.scala
new file mode 100644
index 0000000000..299dce3aec
--- /dev/null
+++ b/test/files/run/hashset.scala
@@ -0,0 +1,48 @@
+import scala.collection.generic.{Growable, Shrinkable}
+import scala.collection.GenSet
+import scala.collection.mutable.FlatHashTable
+import scala.collection.mutable.HashSet
+import scala.collection.parallel.mutable.ParHashSet
+
+object Test extends App {
+  test(new Creator{
+    def create[A] = new HashSet[A]
+    def hashSetType = "HashSet"
+  })
+
+  test(new Creator{
+    def create[A] = new ParHashSet[A]
+    def hashSetType = "ParHashSet"
+  })
+
+
+  def test(creator : Creator) {
+    println("*** " + creator.hashSetType + " primitives")
+    val h1 = creator.create[Int]
+    for (i <- 0 until 20) h1 += i
+    println((for (i <- 0 until 20) yield i + " " + (h1 contains i)).toList.sorted mkString(","))
+    println((for (i <- 20 until 40) yield i + " " + (h1 contains i)).toList.sorted mkString(","))
+    println(h1.toList.sorted mkString ",")
+    println
+
+    println("*** " + creator.hashSetType + " Strings with null")
+    val h2 = creator.create[String]
+    h2 += null
+    for (i <- 0 until 20) h2 +=  "" + i
+    println("null " + (h2 contains null))
+    println((for (i <- 0 until 20) yield i + " " + (h2 contains ("" + i))).toList.sorted mkString(","))
+    println((for (i <- 20 until 40) yield i + " " + (h2 contains ("" + i))).toList.sorted mkString(","))
+    println((h2.toList map {x => "" + x}).sorted mkString ",")
+
+    h2 -= null
+    h2 -= "" + 0
+    println("null " + (h2 contains null))
+    println((for (i <- 0 until 20) yield i + " " + (h2 contains ("" + i))).toList.sorted mkString(","))
+    println
+  }
+ 
+   trait Creator {
+     def create[A] : GenSet[A] with Cloneable with FlatHashTable[A] with Growable[A] with Shrinkable[A] 
+     def hashSetType : String
+  }
+}
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