CaseInsensitiveInputStream.java 文件源码

@Override
public int LA(int i) {
    if (i == 0) {
        return 0; // undefined
    }
    if (i < 0) {
        i++; // e.g., translate LA(-1) to use offset i=0; then data[p+0-1]
        if ((p + i - 1) < 0) {
            return IntStream.EOF; // invalid; no char before first char
        }
    }

    if ((p + i - 1) >= n) {
        return IntStream.EOF;
    }

    return lookaheadData[p + i - 1];
}