class Opal::Nodes::RegexpNode

def extract_flags_and_value
  *values, flags_sexp = *children
  self.flags = flags_sexp.children.map(&:to_s)
  self.value = if values.empty?
                 # empty regexp, we can process it inline
                 s(:str, '')
               elsif single_line?(values)
                 # simple plain regexp, we can put it inline
                 values[0]
               else
                 s(:dstr, *values)
               end
  # trimming when //x provided
  # required by parser gem, but JS doesn't support 'x' flag
  if flags.include?('x')
    parts = value.children.map do |part|
      if part.is_a?(::Opal::AST::Node) && part.type == :str
        trimmed_value = part.children[0].gsub(/\A\s*\#.*/, '').gsub(/\s/, '')
        s(:str, trimmed_value)
      else
        part
      end
    end
    self.value = value.updated(nil, parts)
    flags.delete('x')
  end
  if value.type == :str
    # Replacing \A -> ^, \z -> $, required for the parser gem
    self.value = s(:str, value.children[0].gsub('\A', '^').gsub('\z', '$'))
  end
end