Script to reformat ascii tabs to a given maximum width

tab-format.rb

#!/usr/bin/env ruby
#
# Usage: tab-format <max-width> <input-file>
#    eg. tab-format 120 tango.txt > out.txt
#
#   Reformats ascii tabs to different widths. Will complain if tab contains any
#   other text. So <file> will look like (obviously with numbers in):
#
#     E |---------- ...
#     B |---------- ...
#     G |---------- ...
#     D |---------- ...
#     A |---------- ...
#     E |---------- ...
#
#     |------------ ...
#     |------------ ...
#     |------------ ...
#     |------------ ...
#     |------------ ...
#     |------------ ...
#
#   And output will be in the same format but with the correct line widths.
#

class Bar
  attr_reader :strings

  def initialize(strings)
    @strings = strings
  end

  def size
    @strings.first.size + 1
  end

  def <<(other)
    0.upto(5) {|i| @strings[i] += '|' + other.strings[i] }
    self
  end

  def to_s
    @strings.map {|i| i + "|" }.join("\n")
  end
end

class Score
  def initialize(width, bars)
    @width = width
    @bars = bars
  end

  def build
    final = []
    temp = @bars[0]
    @bars[1..-1].each do |bar|
      if temp.size + bar.size > @width
        final << temp
        temp = bar
      else
        temp << bar
      end
    end
    final << temp
  end

  def to_s
    build.map(&:to_s).join("\n\n")
  end
end

width = ARGV[0].to_i
text  = File.read(ARGV[1])

lines = text.split /\n\s*\n/
bars = lines.map {|line| line.split("\n").map {|i| i.split("|") }.transpose }.
  flatten(1).map {|i| Bar.new(i) }

score = Score.new(width, bars)
puts score.to_s