Please Forward: Ruby Quiz Submission

ruby-talk
1

From: Pusztai Tibor <kondi@inf.elte.hu>
Date: October 15, 2007 4:09:41 PM CDT
To: submission@rubyquiz.com
Cc: gbence@cs.bme.hu
Subject: Please Forward: Ruby Quiz Submission

Hello,

Please forward my solution to the Ruby Talk mailing list!

Thanks,
Tibor
# This solution is my homework for a ruby lesson
# Pusztai Tibor (PUTNAAI.ELTE)

MAX_REPEAT = 3
DOT_MATCH = /[a-zA-Z\d\.,;\^\- ]/

class Concatenate < Array

  def multiIndex indexes
    n = -1
    indexes.map { |index|
      at(n += 1).at(index)
    }
  end

  def cartesian
    indexes = Array.new length, 0
    out = Select.new
    while true
      out << multiIndex(indexes).join
      n = length - 1
      while (indexes[n] += 1) >= at(n).length
        indexes[n] = 0
        if (n -= 1) < 0
          return out
        end
      end
    end
  end
  
  def unfold
    if length == 0
      return Select.new(1, "")
    end
    map! { |item|
      if item.is_a? String
        Select.new 1, item
      else
        item.unfold
      end
    }
    cartesian
  end

  def simplify
    genSimplify self
    self
  end

end

class Select < Array

  def to_a
    map { |item| item }
  end
  
  def unfold
    out = Select.new
    each { |item|
      if item.is_a? String
        out << item
      else
        out.concat item.unfold
      end
    }
    out
  end

  def simplify
    genSimplify self
    self
  end

end

def genSimplify x
  if x.is_a? String
    x
  elsif x.length == 1
    genSimplify x[0]
  else
    x.map! { |y|
      genSimplify y
    }
  end
end

def toTree source
  stack = Concatenate.new
  dotMatch = nil
  source.scan(/(\.)|\[(.*?[^\\])\]|\{([\d,]+)\}|([\(\)\|\?\+\*])|((\\.|[^\.\(\)\|\[\]\?\+\*\{\}])+)/) {
      >dot, charClass, nTimes, control, s|
    if dot
      charClass = DOT_MATCH.inspect[2..-3]
    end
    if s
      stack << s.gsub(/\\(.)/, "\\1")
    elsif charClass
      charClass.gsub!(/(^|[^\\])\\d/, "\\10-9")
      charClass.gsub!(/\\([^-])/, "\\1")
      charClass.gsub!(/([^\\])-(.)/) {
        ($1..$2).to_a.join
      }
      charClass.gsub!(/\\-/, "-")
      select = Select.new
      if charClass[0..0] == '^'
        if !dotMatch
          dotMatch = DOT_MATCH.generate.join
        end
        charClass = dotMatch.delete charClass[1..-1].gsub(/[\^\-]/, "\\\\\\0")
      end
      charClass.scan(/./m) { |ch|
        select << ch
      }
      stack << select
    elsif control
      case control
        when "("
          stack << :select_open
        when "|"
          stack << :select_pipe
        when ")"
          select = Select.new
          conc = Concatenate.new
          while (elem = stack.pop) != :select_open
            if (elem == :select_pipe)
              select.unshift conc
              conc = Concatenate.new
            else
              conc.unshift elem
            end
          end
          select.unshift conc
          stack << select
        when "?"
          nTimes = "0,1"
        when "*"
          nTimes = "0," + MAX_REPEAT.to_s
        when "+"
          nTimes = "1," + MAX_REPEAT.to_s
      end
    end
    if nTimes
      if nTimes.include? ','
        from, to = nTimes.split(',').map { |x| x.to_i }
        if !to
          to = MAX_REPEAT
        end
      else
        from = to = nTimes.to_i
      end
      last = stack.pop
      if last.is_a? String
        stack << last.chop
        last = last[-1..-1]
      end
      stack << Select.new(
        (from..to).map { |n|
          Concatenate.new n, last
        }
      )
    end
  }
  stack
end

class Regexp

  def generate
    toTree("("+self.inspect[1..-2]+")").simplify.unfold.to_a.uniq
  end

end

···

Begin forwarded message: