[請益] 有 Compiler 達人嗎? Orz

看板Programming作者itchy (Lucky we love you.)時間17年前 (2008/06/27 19:20)推噓0(0推 0噓 5→)

留言5則, 2人參與討論串1/3 (看更多)

這個問題我一直想不透. 痛苦極了啊~~ Orz (抓頭) 問題如下: Assume G is an LR(0) grammar. Let F --> ε be a production that is not currently in G. Assume F is a nonterminal that is already in G. Let G* be the new grammar obtained from G by inserting the new production F --> ε. Describe the possible impacts (in the areas of conflicts, expressive power and parsing complexities) of adding this new production. ========= 痛苦分隔線 =============== 我怎麼想都覺得不會有影響啊 (哭) 舉例來說, 若原本的 grammar: E' --> E E --> E + T T --> T * F F --> (E) | id 加了 ε的 grammar: (舉例來說) E' --> E E --> E + T | ε T --> T * F F --> (E) | id 則最後的 LR(0) sets 也不會變啊. 有誰知道到底有什麼影響嗎? Orz 頭髮都快抓光了 (繼續抓頭.. Q_Q) 大感謝 Orz -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 218.160.33.61

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MOONRAKER

06/27 20:14, , 1^F

06/27 20:14, 1^F

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MOONRAKER

06/27 20:15, , 2^F

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MOONRAKER

06/27 20:15, , 3^F

06/27 20:15, 3^F