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37 lines
585 B
Ruby
37 lines
585 B
Ruby
# frozen_string_literal: true
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module Gem
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class List
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include Enumerable
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attr_accessor :value, :tail
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def initialize(value = nil, tail = nil)
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@value = value
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@tail = tail
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end
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def each
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n = self
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while n
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yield n.value
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n = n.tail
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end
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end
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def to_a
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super.reverse
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end
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def prepend(value)
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List.new value, self
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end
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def pretty_print(q) # :nodoc:
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q.pp to_a
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end
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def self.prepend(list, value)
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return List.new(value) unless list
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List.new value, list
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end
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end
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end
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