Method setpos

Tools/cases_generator/plexer.py:21–24

(self, pos: int)

        return self.pos >= len(self.tokens)

    def setpos(self, pos: int) -> None:
        # Reset position
        assert 0 <= pos <= len(self.tokens), (pos, len(self.tokens))
        self.pos = pos

    def backup(self) -> None:
        # Back up position by 1