class Array

Public Instance Methods

in_groups(number, fill_with = nil) { |g| ... } click to toggle source

Splits or iterates over the array in number of groups, padding any remaining slots with fill_with unless it is false.

%w(1 2 3 4 5 6 7 8 9 10).in_groups(3) {|group| p group}
["1", "2", "3", "4"]
["5", "6", "7", nil]
["8", "9", "10", nil]

%w(1 2 3 4 5 6 7 8 9 10).in_groups(3, '&nbsp;') {|group| p group}
["1", "2", "3", "4"]
["5", "6", "7", "&nbsp;"]
["8", "9", "10", "&nbsp;"]

%w(1 2 3 4 5 6 7).in_groups(3, false) {|group| p group}
["1", "2", "3"]
["4", "5"]
["6", "7"]

# File lib/compressor.rb, line 109
def in_groups(number, fill_with = nil)
  # size / number gives minor group size;
  # size % number gives how many objects need extra accommodation;
  # each group hold either division or division + 1 items.
  division = size.div number
  modulo = size % number

  # create a new array avoiding dup
  groups = []
  start = 0

  number.times do |index|
    length = division + (modulo > 0 && modulo > index ? 1 : 0)
    groups << last_group = slice(start, length)
    last_group << fill_with if fill_with != false &&
      modulo > 0 && length == division
    start += length
  end

  if block_given?
    groups.each { |g| yield(g) }
  else
    groups
  end
end