class ActionDispatch::Routing::RouteSet

def build_path(path, requirements, separators, anchor)
  strexp = Journey::Router::Strexp.new(
      path,
      requirements,
      SEPARATORS,
      anchor)
  pattern = Journey::Path::Pattern.new(strexp)
  builder = Journey::GTG::Builder.new pattern.spec
  # Get all the symbol nodes followed by literals that are not the
  # dummy node.
  symbols = pattern.spec.grep(Journey::Nodes::Symbol).find_all { |n|
    builder.followpos(n).first.literal?
  }
  # Get all the symbol nodes preceded by literals.
  symbols.concat pattern.spec.find_all(&:literal?).map { |n|
    builder.followpos(n).first
  }.find_all(&:symbol?)
  symbols.each { |x|
    x.regexp = /(?:#{Regexp.union(x.regexp, '-')})+/
  }
  pattern
end