n.考慮未來(預先作準備

Positive lookahead and lookbehind do not backtrack. 積極的預測先行和追溯不回溯。

This “l(fā)ookahead” into cool/hot spot movement is supplied to you each turn. 這些對于冷/熱場的的移動信息在每次移動之前會提供給你。

Provides information about regular expression lookahead and lookbehind behavior. 提供關于正則表達式預測先行和追溯行為的信息。

Assertions do not change: lookahead looks to the right; lookbehind looks to the left. 斷言不改變:預測先行向右搜索;回顧后發(fā)向左搜索。

Our eyes are placed in front because it's more important to lookahead than to look back. 我們的眼睛長在前面是因為向前看比向后看更重要.