'Iterate over the source code tokens.'

def source_token_lines(self):

    if os.path.exists(self.filename):
        with open_source_file(self.filename) as f:
            for line in f:
                (yield [('txt', line.rstrip('\n'))])
    else:
        for line in self._iter_source_tokens():
            (yield [('txt', line)])
