[CALCITE-460] Add ImmutableBitSet and replace uses of BitSet

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.0.0-incubating
• Assignee: Julian Hyde
• Reporter: Julian Hyde
• Created: 10/Nov/14 17:50
• Updated: 08/Feb/15 08:56
• Resolved: 14/Nov/14 22:01

Description

Calcite makes heavy use of bit sets. java.util.BitSet has a convenient API but (a) is mutable, (b) uses quite a lot of memory, (c) is not iterable.

Propose to implement ImmutableBitSet, which addresses those deficiencies.