class Regexp::Scanner

def emit_literal

using the total start (ts) and end (te) offsets of the run.
Emits the literal run collected by calls to the append_literal method, 
def emit_literal
  ts, te = literal.first[1], literal.last[2]
  text = literal.map {|t| t[0]}.join
  text.force_encoding('utf-8') if text.respond_to?(:force_encoding)
  self.literal = nil
  emit(:literal, :literal, text, ts, te)
end