AntlrCharStream.java 文件源码

@Override
public int LA(int i) {
    if (i == 0) {
        // undefined behavior, precondition is violated
        return 0;
    }

    if (i < 0) {
        throw new UnsupportedOperationException("Not implemented yet");
    }

    int symbol = 0;

    for (int j = 0; j < i && symbol != IntStream.EOF; j++) {
        symbol = read();
    }

    backup(i);
    return symbol;
}