JDK-4938537 : (coll) Extension of Collection Framework
  • Type: Enhancement
  • Status: Closed
  • Resolution: Cannot Reproduce
  • Component: core-libs
  • Sub-Component: java.util:collections
  • Priority: P4
  • Affected Version: 1.4.2
  • OS: windows_xp
  • CPU: x86
  • Submit Date: 2003-10-16
  • Updated Date: 2012-10-08
  • Resolved Date: 2011-04-05
Description
Name: rmT116609			Date: 10/15/2003


A DESCRIPTION OF THE REQUEST :
The package adds to the Collection Framework several classes for representing
multisets (bags) or "sets of sets" backed by a hash table. Also, there is now
a class for representing "mathematical sets" implementing the usual
mathematical functions in a non-destructive fashion (as you would expect a
"function" to behave).

The new methods offer a much improved runtime performance due to the use
of effective hash code routines.

The design and implementation of the new classes and methods is very
consistent with the existing CFW structures.

JUSTIFICATION :
Most importantly, the Collection Framework was lacking efficient classes
for handling multisets, "sets of sets" and handling normal sets in a
way that would be suitable for mathematical applications.
Furthermore, the existing hash code methods for sets or collections were not
as efficient as they could be. Simply summing up the hash codes of the set
elements could lead to suboptimal runtime behavior. The new classes and
methods offer significantly increased performance resulting from the use
of more effective hash code routines.
A consistent extension of the CFW that implements the improvements mentioned
above can be found at
http://www.informatik.uni-stuttgart.de/ifi/is/Personen/lippold/MathCollection/
(Incident Review ID: 215942) 
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Comments
EVALUATION Offered samples at "http://www.informatik.uni-stuttgart.de/ifi/is/Personen/lippold/MathCollection/" are no longer available.
2011-04-05