def _compile_firstset(info, fs):
 reverse = bool((info.flags & REVERSE))
 fs = _check_firstset(info, reverse, fs)
 if (not fs):
  return []
 return fs.compile(reverse)

def _compile_firstset ( info , fs ) : reverse = bool ( ( info . flags & REVERSE ) ) fs = _check_firstset ( info , reverse , fs ) if ( not fs ) : return [ ] return fs . compile ( reverse )
compiles the firstset for the pattern .