lookahead

基本解释

Positive lookahead and lookbehind do not backtrack.
積極的預測先行和追溯不廻溯。
The biggest limitation is that yacc is limited to one token of lookahead.
最大的侷限在於,yacc被限定爲一個預讀標記。
This “lookahead” into cool/hot spot movement is supplied to you each turn.
這些對於冷/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.
提供關於正則表達式預測先行和追溯行爲的信息。
Assertions do not change: lookahead looks to the right; lookbehind looks to the left.
斷言不改變:預測先行曏右搜索;廻顧後發曏左搜索。