module Regexp::Lexer

def self.merge_literal(current)

get normalized (as in the case of posix/bre) and end up becoming literals.
called by scan to merge two consecutive literals. this happens when tokens 
def self.merge_literal(current)
  last = @tokens.pop
  Regexp::Token.new(
    :literal,
    :literal,
    last.text + current.text,
    last.ts,
    current.te,
    @nesting,
    @set_nesting,
    @conditional_nesting
  )
end