This is a Ruby tree! It shows every object from the Ruby Programming Language in a tree format.
# Array.repeated_combination (from ruby core) --- array.repeated_combination(n) {|combination| ... } -> self array.repeated_combination(n) -> new_enumerator --- Calls the block with each repeated combination of length `n` of the elements of `self`; each combination is an Array; returns `self`. The order of the combinations is indeterminate. When a block and a positive Integer argument `n` are given, calls the block with each `n`-tuple repeated combination of the elements of `self`. The number of combinations is `(n+1)(n+2)/2`. `n` = 1: a = [0, 1, 2] a.repeated_combination(1) {|combination| p combination } Output: [0] [1] [2] `n` = 2: a.repeated_combination(2) {|combination| p combination } Output: [0, 0] [0, 1] [0, 2] [1, 1] [1, 2] [2, 2] If `n` is zero, calls the block once with an empty Array. If `n` is negative, does not call the block: a.repeated_combination(-1) {|combination| fail 'Cannot happen' } Returns a new Enumerator if no block given: a = [0, 1, 2] a.repeated_combination(2) # => #<Enumerator: [0, 1, 2]:combination(2)> Using Enumerators, it's convenient to show the combinations and counts for some values of `n`: e = a.repeated_combination(0) e.size # => 1 e.to_a # => [[]] e = a.repeated_combination(1) e.size # => 3 e.to_a # => [[0], [1], [2]] e = a.repeated_combination(2) e.size # => 6 e.to_a # => [[0, 0], [0, 1], [0, 2], [1, 1], [1, 2], [2, 2]]
This is MURDOC! A Ruby documentation browser inspired by Smalltalk-80. It allows you to learn about Ruby by browsing through its class hierarchies, and see any of its methods.