[GROOVY-1986] Optimizing DefaultGroovyMethods.intersect()

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.1-beta-3
• Component/s: groovy-jdk
• Flags: Patch
• Assignee: Jochen Theodorou
• Reporter: Ken Bloom
• Created: 16/Jul/07 10:56
• Updated: 05/Apr/15 14:44
• Resolved: 17/Sep/07 14:42

Description

The current version of DefaultGroovyMethods.intersect can be improved for better performance, by using a HashSet instead of a TreeSet, and by swapping the two collections if necessary, so as to iterate across the smaller one. Rather than being O(n log m) with n possibly much larger than m, performance increases to O where n is the smaller of the two Collections.

I've attached a patch.