a very common use case for regexes is to find matches that are preceded or followed by some context. a classical example being all lines that end with ‘a’. this requirement is usually expressed with a lookahead, where upon finding an ‘a’, you look ahead to check if it’s the end of the line. in a backtracking engine, this is very easy to implement - you just duct-tape the logic that checks the next character, but in a DFA-based engine, this is impossible because you cannot report “the match is here” if the next character is not even known yet. and by the time you know the next character, the position information is lost, so you can’t report the match retroactively (well, unless the distance is fixed of course..).
WTI原油涨4%，报67.8美元/桶；布伦特原油涨3.69%，报73.451美元/桶。
。一键获取谷歌浏览器下载是该领域的重要参考
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Live Translate: In select messaging apps, Pixels will automatically know when someone sends a message in a language other than your default. It'll translate it (if you wish), and you'll be able to respond in that same language. More than 50 languages are supported, though you'll need to download the languages you want to see translated by heading to Settings System Live Translate.，更多细节参见纸飞机官网
Солнце выбросило гигантский протуберанец размером около миллиона километров02:48
Homeomorphisms are precisely the isomorphisms in the category \(\mathbf{Top}\) of topological spaces and continuous maps.。体育直播是该领域的重要参考