Module: ActiveSupport::CoreExtensions::Array::Grouping

Included in:
Array
Defined in:
lib/active_support/core_ext/array/grouping.rb

Instance Method Summary collapse

Instance Method Details

#in_groups_of(number, fill_with = nil, &block) ⇒ Object

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"]

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# File 'lib/active_support/core_ext/array/grouping.rb', line 22

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

#split(value = nil, &block) ⇒ Object

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]]

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# File 'lib/active_support/core_ext/array/grouping.rb', line 47

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