range.rb

##
# Range
#
# ISO 15.2.14
class Range
  ##
  # Range is enumerable
  #
  # ISO 15.2.14.3
  include Enumerable

  ##
  # Calls the given block for each element of +self+
  # and pass the respective element.
  #
  # ISO 15.2.14.4.4
  def each(&block)
    return to_enum :each unless block

    val = self.begin
    last = self.end

    if val.kind_of?(Integer) && last.nil?
      i = val
      while true
        block.call(i)
        i += 1
      end
      return self
    end

    if val.kind_of?(String) && last.nil?
      if val.respond_to? :__upto_endless
        return val.__upto_endless(&block)
      else
        str_each = true
      end
    end

    if val.kind_of?(Integer) && last.kind_of?(Integer) # integers are special
      lim = last
      lim += 1 unless exclude_end?
      i = val
      while i < lim
        block.call(i)
        i += 1
      end
      return self
    end

    if val.kind_of?(String) && last.kind_of?(String) # strings are special
      if val.respond_to? :upto
        return val.upto(last, exclude_end?, &block)
      else
        str_each = true
      end
    end

    raise TypeError, "can't iterate" unless val.respond_to? :succ

    return self if (val <=> last) > 0

    while (val <=> last) < 0
      block.call(val)
      val = val.succ
      if str_each
        break if val.size > last.size
      end
    end

    block.call(val) if !exclude_end? && (val <=> last) == 0
    self
  end

  # redefine #hash 15.3.1.3.15
  def hash
    h = first.hash ^ last.hash
    h += 1 if self.exclude_end?
    h
  end

  ##
  # call-seq:
  #    rng.to_a                   -> array
  #    rng.entries                -> array
  #
  # Returns an array containing the items in the range.
  #
  #   (1..7).to_a  #=> [1, 2, 3, 4, 5, 6, 7]
  #   (1..).to_a   #=> RangeError: cannot convert endless range to an array
  def to_a
    a = __num_to_a
    return a if a
    super
  end
  alias entries to_a
end