[GROOVY-5283] Add a collate method to List

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.8.5
• Fix Version/s: 1.8.6, 2.0-beta-3
• Assignee: Guillaume Sauthier
• Reporter: Tim Yates
• Created: 06/Feb/12 09:29
• Updated: 12/Feb/12 04:03
• Resolved: 06/Feb/12 15:14

Description

I have often found a need for collating or partitioning a List into a List of sub-lists of a given size.

This question has been asked on StackOverflow a couple of times as well

ie:

[1,2,3,4,5].collate( 3 ) == [ [ 1, 2, 3 ], [ 4, 5 ] ]

This could be chained to generate a multi-dimensional list of lists, ie:

(1..9).collate( 3 ).collate( 2 ) == [ [ [1,2,3], [4,5,6] ],
                                      [ [7,8,9]          ] ]