require 'enumerator' module ActiveSupport #:nodoc: module CoreExtensions #:nodoc: module Array #:nodoc: module Grouping # Iterates over the array in groups of size +number+, padding any remaining # slots with +fill_with+ unless it is +false+. # # %w(1 2 3 4 5 6 7).in_groups_of(3) {|g| p g} # ["1", "2", "3"] # ["4", "5", "6"] # ["7", nil, nil] # # %w(1 2 3).in_groups_of(2, ' ') {|g| p g} # ["1", "2"] # ["3", " "] # # %w(1 2 3).in_groups_of(2, false) {|g| p g} # ["1", "2"] # ["3"] def in_groups_of(number, fill_with = nil, &block) if fill_with == false collection = self else # size % number gives how many extra we have; # subtracting from number gives how many to add; # modulo number ensures we don't add group of just fill. padding = (number - size % number) % number collection = dup.concat([fill_with] * padding) end if block_given? collection.each_slice(number, &block) else returning [] do |groups| collection.each_slice(number) { |group| groups << group } end end end # Divides the array into one or more subarrays based on a delimiting +value+ # or the result of an optional block. # # [1, 2, 3, 4, 5].split(3) # => [[1, 2], [4, 5]] # (1..10).to_a.split { |i| i % 3 == 0 } # => [[1, 2], [4, 5], [7, 8], [10]] def split(value = nil, &block) block ||= Proc.new { |e| e == value } inject([[]]) do |results, element| if block.call(element) results << [] else results.last << element end results end end end end end end