ParseTrees.java 文件源码

public static Token getStartSymbol(ParseTree context) {
    TerminalNode node = getStartNode(context);
    if (node != null) {
        return node.getSymbol();
    }

    if (!(context instanceof RuleNode)) {
        return null;
    }

    RuleContext ruleContext = ((RuleNode)context).getRuleContext();
    if (ruleContext instanceof ParserRuleContext) {
        return ((ParserRuleContext)ruleContext).getStart();
    }

    return null;
}