module Overpunch

# File lib/overpunch.rb, line 22
def self.format(number, width: nil)
  overpunch_set = if number < 0
    NEG_OVERPUNCH_SET
  else
    POS_OVERPUNCH_SET
  end
  abs_number = number.abs
  formatted = abs_number.to_s[0..-2] + overpunch_set[abs_number % 10]
  padding = [ (width || 0) - formatted.size, 0 ].max
  ("0" * padding) + formatted
end

# File lib/overpunch.rb, line 9
def self.parse(string)
  unless matches = string.match(OVERPUNCH_PATTERN)
    raise ArgumentError, "Invalid overpunch string: \"#{string}\""
  end

  sign, overpunch_set = if matches[3]
    [  1, POS_OVERPUNCH_SET ]
  else
    [ -1, NEG_OVERPUNCH_SET ]
  end
  sign * matches[1].tr(overpunch_set, '0-9').to_i
end