Module: Enumerable

Defined in:
lib/nanoc3/extra/core_ext/enumerable.rb

Instance Method Summary collapse

Instance Method Details

#group_by {|obj| ... } ⇒ Hash

Returns a hash, which keys are evaluated result from the block, and values are arrays of elements in enum corresponding to the key. This method is provided for backward compatibility with Ruby 1.8.6 and lower, since #group_by is only available in 1.8.7 and higher.

Examples:

Grouping integers by rest by division through 3


(1..6).group_by { |i| i % 3 }
# => { 0 => [3, 6], 1 => [1, 4], 2 => [2, 5] }

Yield Parameters:

  • obj (Object) —

    The object to classify

Returns:



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# File 'lib/nanoc3/extra/core_ext/enumerable.rb', line 20

def group_by
  groups = {}
  each do |item|
    key = yield(item)

    groups[key] ||= []
    groups[key] << item
  end
  groups
end