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unless Array.method_defined? :repeated_combination
require 'backports/tools/arguments'
require 'backports/1.8.7/array/index'
class Array
# Note: Combinations are not yielded in the same order as MRI.
# This is not a bug; the spec states that the order is implementation dependent
def repeated_combination(num)
return to_enum(:repeated_combination, num) unless block_given?
num = Backports.coerce_to_int(num)
if num <= 0
yield [] if num == 0
else
copy = dup
indices = Array.new(num, 0)
indices[-1] = size
while dec = indices.index{|x| x != 0}
indices.fill indices[dec]-1, 0, dec + 1
yield copy.values_at(*indices)
end
end
self
end
end
end
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