# Copyright (c) 2007-2015, Evan Phoenix and contributors
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#
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# modification, are permitted provided that the following conditions are met:
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# * Redistributions of source code must retain the above copyright notice, this
#   list of conditions and the following disclaimer.
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#   may be used to endorse or promote products derived from this software
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module Comparable
  def ==(other)
    return true if equal?(other)

    return false if Thread.detect_recursion(self, other) do
      begin
        unless comp = (self <=> other)
          return false
        end

        return Comparable.compare_int(comp) == 0
      rescue StandardError
        return false
      end
    end
  end

  def >(other)
    unless comp = (self <=> other)
      raise ArgumentError, "comparison of #{self.class} with #{other.class}"
    end

    Comparable.compare_int(comp) > 0
  end

  def >=(other)
    unless comp = (self <=> other)
      raise ArgumentError, "comparison of #{self.class} with #{other.class}"
    end

    Comparable.compare_int(comp) >= 0
  end

  def <(other)
    unless comp = (self <=> other)
      raise ArgumentError, "comparison of #{self.class} with #{other.class}"
    end

    Comparable.compare_int(comp) < 0
  end

  def <=(other)
    unless comp = (self <=> other)
      raise ArgumentError, "comparison of #{self.class} with #{other.class}"
    end

    Comparable.compare_int(comp) <= 0
  end

  def between?(min, max)
    # This could be more elegant, but we need to use <= and => on self to match
    # MRI.
    return false if self < min
    return false if self > max
    return true
  end

  # A version of MRI's rb_cmpint (sort of)
  def self.compare_int(int)
    return int if int.kind_of? Fixnum

    return 1  if int > 0
    return -1 if int < 0
    return 0
  end
end

