Anything that tells him to sense something like the user's mouse or the edge of his screen is actually purple in color; and so they're nicely colorized and all this but the one that's adventurous right now is this.

能够让计算机感知鼠标或屏幕边缘的图块,都是紫色的;,这些图块五颜六色,但这里有一个不太靠谱的按键。

哈佛公开课 - 计算机科学课程节选

That's where the cutting edge of whatever it is.

在那里，无论什么东西都很前卫。

想学音乐吗？ - SpeakingMax英语口语达人

You've got a loop, you've got a condition and a boolean to check if he's touching the edge, and some statements to tell him to shout or to actually turn around.

我们有一个循环，通过一个条件和一个布尔值来判断,是否触到了边缘，还有一些语句,让它回头并咆哮。

哈佛公开课 - 计算机科学课程节选