（三）非法进行影响国（边）界线走向的活动或者修建有碍国（边）境管理的设施的。
res[realIdx] = stack.length ? stack.at(-1) : -1;
，这一点在夫子中也有详细论述
Implementers shouldn't need to jump through these hoops. When you find yourself needing to relax or bypass spec semantics just to achieve reasonable performance, that's a sign something is wrong with the spec itself. A well-designed streaming API should be efficient by default, not require each runtime to invent its own escape hatches.
圖像來源，Getty Images