class Regexp::Expression::Conditional::Expression

def <<(exp)
  @expressions.last << exp
end

def branch(exp = nil)
  raise TooManyBranches.new if @branches.length == 2
  sequence = Branch.new(level, set_level, conditional_level + 1)
  @expressions << sequence
  @branches << @expressions.last
end

def branches
  @branches
end

def condition(exp = nil)
  return @condition unless exp
  @condition = exp
  @expressions << exp
end

def initialize(token)
  super(token)
  @condition = nil
  @branches  = []
end

def quantify(token, text, min = nil, max = nil, mode = :greedy)
  branches.last.last.quantify(token, text, min, max, mode)
end

def to_s
  s = @text.dup
  s << @condition.text
  s << branches.map{|e| e.to_s}.join('|')
  s << ')'
end