CypherCstToAstVisitor.java 文件源码

@Override
public CypherAstBase visitExpression4(CypherParser.Expression4Context ctx) {
    int neg = 0;
    for (ParseTree child : ctx.children) {
        if (child instanceof TerminalNode && child.getText().equals("-")) {
            neg++;
        }
    }
    CypherAstBase expr = visitExpression3(ctx.expression3());
    if (neg % 2 == 1) {
        return new CypherNegateExpression(expr);
    } else {
        return expr;
    }
}