n.考虑未来(预先作准备
Positive lookahead and lookbehind do not backtrack. 积极的预测先行和追溯不回溯。
This “lookahead” into cool/hot spot movement is supplied to you each turn. 这些对于冷/热场的的移动信息在每次移动之前会提供给你。
Provides information about regular expression lookahead and lookbehind behavior. 提供关于正则表达式预测先行和追溯行为的信息。
Assertions do not change: lookahead looks to the right; lookbehind looks to the left. 断言不改变:预测先行向右搜索;回顾后发向左搜索。
Our eyes are placed in front because it's more important to lookahead than to look back. 我们的眼睛长在前面是因为向前看比向后看更重要.
