ParseTrees.java 文件源码

@CheckForNull
public static <ContextClass> ContextClass findAncestor(@NonNull ParseTree tree, @NonNull Class<ContextClass> nodeType) {
    for (ParseTree current = tree; current != null; current = current.getParent()) {
        if (!(current instanceof RuleNode)) {
            continue;
        }

        RuleNode ruleNode = (RuleNode)current;
        RuleContext ruleContext = ruleNode.getRuleContext();
        if (nodeType.isInstance(ruleContext)) {
            return nodeType.cast(ruleContext);
        }
    }

    return null;
}