DiagnosticErrorListener.java 文件源码

/**
 * Computes the set of conflicting or ambiguous alternatives from a
 * configuration set, if that information was not already provided by the
 * parser.
 *
 * @param reportedAlts The set of conflicting or ambiguous alternatives, as
 * reported by the parser.
 * @param configs The conflicting or ambiguous configuration set.
 * @return Returns {@code reportedAlts} if it is not {@code null}, otherwise
 * returns the set of alternatives represented in {@code configs}.
 */
@NotNull
protected BitSet getConflictingAlts(@Nullable BitSet reportedAlts, @NotNull ATNConfigSet configs) {
    if (reportedAlts != null) {
        return reportedAlts;
    }

    BitSet result = new BitSet();
    for (ATNConfig config : configs) {
        result.set(config.alt);
    }

    return result;
}