cabbage_cc.rb

#!/usr/bin/env ruby

require 'prawn'

class CabbageCheatSheet

  EMACS_KEY_REGEX       = /\".+\"|\[.+\]/
  EMACS_FUNCTION_REGEX  = /'(.+)$/
  EMACS_KEYSTROKE_REGEX = /cabbage-global-set-key/

  def initialize
    @pdf = Prawn::Document.new(:margin => 5)
  end

  def build!
    @pdf.font("Courier", :size => 18)
    @pdf.text 'Cabbage'

    @pdf.table(table_header + keystrokes,
                        :width => @pdf.bounds.width,
                        :row_colors => ["FFFFFF", "EEEEEE"],
                        :cell_style => {
                          :size => 7,
                          :font => "Courier",
                          :padding => [0, 0, 5, 5],
                          :borders => []
               }) do
      row(0).font_style = :bold
    end
  end

  def save_as(filename)
    build!
    @pdf.render_file filename
  end

  def table_header
    [['function name', 'keystroke'] * 2]
  end
  private :table_header

  def keystrokes
    make_two_strokes_per_row(parse_keystrokes)
  end
  private :keystrokes

  def make_two_strokes_per_row(keystrokes)
    rows = []

    (keystrokes.size / 2).times do |count|
      rows << keystrokes.shift(2).flatten
    end

    rows
  end
  private :make_two_strokes_per_row

  def parse_keystrokes
    file_with_keys = File.expand_path('../../bundles/ergonomic/bundle.el', __FILE__)

    keystrokes = []

    File.open(file_with_keys, 'r').each_line do |line|
      if keystroke?(line)
        key      = extract_keystroke(line)
        function = extract_function_name(line)

        keystrokes << [function, key]
      end
    end

    keystrokes
  end
  private :parse_keystrokes

  def keystroke?(line)
    line =~ EMACS_KEYSTROKE_REGEX
  end
  private :keystroke?

  def extract_keystroke(line)
    line[EMACS_KEY_REGEX].gsub(/[\[\]]/, '').gsub(/"+/, '')
  end
  private :extract_keystroke

  def extract_function_name(line)
    line[EMACS_FUNCTION_REGEX, 1].gsub(/\)+/, '')
  end
  private :extract_function_name

end

cheat_sheet = CabbageCheatSheet.new
cheat_sheet.save_as("cheat-sheet.pdf")