ParserATNFactory.java 文件源码

/** From an empty alternative build {@code o-e->o}. */

    @Override
    public Handle epsilon(GrammarAST node) {
        ATNState left = newState(node);
        ATNState right = newState(node);
        epsilon(left, right);
        node.atnState = left;
        return new Handle(left, right);
    }