class Range

Public Instance Methods

bsearch() { |cur = call| ... } click to toggle source
# File lib/backports/2.0.0/range/bsearch.rb, line 5
def bsearch
  return to_enum(:bsearch) unless block_given?
  from = self.begin
  to   = self.end
  unless from.is_a?(Numeric) && to.is_a?(Numeric)
    raise TypeError, "can't do binary search for #{from.class}"
  end

  midpoint = nil
  if from.is_a?(Integer) && to.is_a?(Integer)
    convert = Proc.new{ midpoint }
  else
    from = Backports.float_to_integer(from.to_f)
    to   = Backports.float_to_integer(to.to_f)
    convert = Proc.new{ Backport.integer_to_float(midpoint) }
  end
  to -= 1 if exclude_end?
  satisfied = nil
  while from <= to do
    midpoint = (from + to).div(2)
    result = yield(cur = convert.call)
    case result
    when Numeric
      return cur if result == 0
      result = result < 0
    when true
      satisfied = cur
    when nil, false
      # nothing to do
    else
      raise TypeError, "wrong argument type #{result.class} (must be numeric, true, false or nil)"
    end

    if result
      to = midpoint - 1
    else
      from = midpoint + 1
    end
  end
  satisfied
end
size() click to toggle source
# File lib/backports/2.0.0/range/size.rb, line 3
def size
  return nil unless self.begin.is_a?(Numeric) && self.end.is_a?(Numeric)
  size = self.end - self.begin
  return 0 if size <= 0
  return size if size == Float::INFINITY
  if exclude_end?
    size.ceil
  else
    size.floor + 1
  end
end