dugga2 Cheat Sheet by Dockson

require './rdparse'

MONTHS = {'januari' => 1, 'februari' => 2, 'mars' => 3, 'april' => 4,
  'maj' => 5, 'juni' => 6, 'juli' => 7, 'augusti' => 8, 'september' => 9,
  'oktober' => 10, 'november' => 11, 'december' => 12} 

class Calendar
        
  def initialize
    @calendarParser = Parser.new("calendar parser") do
      @c = Time.now
      logger.level = Logger::WARN

      token(/'.*?'/) { |m| m[1..-2] }   # quoted strings
      token(/\s+/)                      # whitespaces (ignored) 
      token(/\d+/) { |m| m.to_i }       # integers
      token(/\w+/) { |m| m }            # alphanumerical strings
      token(/./) { |m| m }              # other characters, individually
      
      start :expr do 
        match(:date) { [] }
        match(:meeting)
      end
      
      rule :date do
        match('-', Integer, String, Integer, '-') do |_, d, m, y, _|
          @c = Time.local(y, MONTHS[m.downcase], d)
        end
      end

      rule :meeting do
        match(:time, '-', :time, String) do | start, _, stop, text |
          [text, start, stop]
        end
      end

      rule :time do 
        match(Integer, '.', Integer) do |h, _, m| 
          Time.local(@c.year, @c.month, @c.day, h, m)
        end
      end

    end
  end
  
  def read_meetings(filename)
    result = []
    content = IO.readlines(filename)
    content.each do |line|
      line.strip!
      if line.length > 0 then
        r = @calendarParser.parse(line)
        if r != [] then
          result << r
        end
      end
    end
    result
  end
end

class TripleStore

  def initialize
    @db = {}
  end
  
  def TripleStore.load(filename)
    r = new
    r.instance_eval(File.read(filename))
    r
  end
  
  def method_missing(property,arg1,arg2)
    table = @db[property.to_s]
    if table then
      table << [arg1,arg2]
    else
      @db[property.to_s] = [[arg1,arg2]]
    end
  end

  def find(property,arg1,arg2)
    table = @db[property]
    result = []
    table.each do |pair|
      if arg1 != '' and arg2 != '' then
        result << pair if (pair[0]==arg1) and (pair[1]==arg2)
      elsif arg1 != '*' then
        result << pair if pair[0]==arg1
      elsif arg2 != '*' then
        result << pair if pair[1]==arg2
      end
    end
    result
  end
end

require "./constraint_networks"

class Squarer
  include PrettyPrint

  attr_accessor :a, :sq_a
  attr_reader :logger

  def initialize(a,sq_a)
    @logger=Logger.new(STDOUT)
    @a,@sq_a=[a,sq_a]
    [a,sq_a].each {|x| x.add_constraint(self)}
  end
  
  def to_s
    "#{a}^2 == #{sq_a}"
  end
  
  def new_value(connector)
    if a==connector and a.has_value? and (not sq_a.has_value?) then
      logger.debug("#{self} : #{sq_a} updated")
      sq_a.assign(a.value*a.value,self)
    elsif sq_a==connector and sq_a.has_value? and (not a.has_value?) then
      logger.debug("#{self} : #{a} updated")
      a.assign(Math::sqrt(sq_a.value),self)
    end
    self
  end
  
  # A connector lost its value, so propagate this information to all
  # others
  def lost_value(connector)
    ([a,sq_a]-[connector]).each { |connector| connector.forget_value(self) }
  end
  
end

def circle_area_network

  radius=Connector.new('radius')
  radius_sq=Connector.new('radius_sq')
  area=Connector.new('area')
  pi=ConstantConnector.new('pi',Math::PI)

  Squarer.new(radius,radius_sq)
  Multiplier.new(pi,radius_sq,area)

  [radius,area]
end

$radius,$area=circle_area_network

def circle_area(radius)
  $radius.forget_value "user" if $radius.has_value?
  $radius.user_assign radius
  $area.value
end