From 326fa9ac4bb96a042733ad5c96ffee163895df5d Mon Sep 17 00:00:00 2001 From: Rex Kerr Date: Thu, 13 Feb 2014 15:40:18 -0800 Subject: SI-8264 scala.collection.immutable.HashSet#- returns broken Set Was an error in HashSet's handling of removal of an element when a HashTrieSet should turn into a HashSet1. Also slightly modified HashMap's filter0 to more closely match HashSet (by adding the same comment). --- src/library/scala/collection/immutable/HashMap.scala | 2 ++ src/library/scala/collection/immutable/HashSet.scala | 11 +++++------ 2 files changed, 7 insertions(+), 6 deletions(-) (limited to 'src/library') diff --git a/src/library/scala/collection/immutable/HashMap.scala b/src/library/scala/collection/immutable/HashMap.scala index 8a24f721d7..3b3e65ea61 100644 --- a/src/library/scala/collection/immutable/HashMap.scala +++ b/src/library/scala/collection/immutable/HashMap.scala @@ -350,6 +350,8 @@ object HashMap extends ImmutableMapFactory[HashMap] with BitOperations.Int { Array.copy(elems, 0, elemsNew, 0, offset) Array.copy(elems, offset + 1, elemsNew, offset, elems.length - offset - 1) val sizeNew = size - sub.size + // if we have only one child, which is not a HashTrieSet but a self-contained set like + // HashSet1 or HashSetCollision1, return the child instead if (elemsNew.length == 1 && !elemsNew(0).isInstanceOf[HashTrieMap[_,_]]) elemsNew(0) else diff --git a/src/library/scala/collection/immutable/HashSet.scala b/src/library/scala/collection/immutable/HashSet.scala index 67e9d18da7..726937efd9 100644 --- a/src/library/scala/collection/immutable/HashSet.scala +++ b/src/library/scala/collection/immutable/HashSet.scala @@ -431,15 +431,12 @@ object HashSet extends ImmutableSetFactory[HashSet] { case 0 => // the empty set null - case size if size == ks.size => - // We do this check first since even if the result is of size 1 since - // it is preferable to return the existing set for better structural sharing - // we can not rely on ks.- returning the same instance if we subtract an element that is not in it - // so we need to do the size check - this case 1 => // create a new HashSet1 with the hash we already know new HashSet1(ks1.head, hash) + case size if size == ks.size => + // Should only have HSC1 if size > 1 + this case _ => // create a new HashSetCollison with the hash we already know and the new keys new HashSetCollision1(hash, ks1) @@ -861,6 +858,8 @@ object HashSet extends ImmutableSetFactory[HashSet] { new HashTrieSet(bitmapNew, elemsNew, sizeNew) } else null + } else if(elems.length == 1 && !subNew.isInstanceOf[HashTrieSet[_]]) { + subNew } else { val elemsNew = new Array[HashSet[A]](elems.length) Array.copy(elems, 0, elemsNew, 0, elems.length) -- cgit v1.2.3