Hi, Thanks.
Can you attach the performance comparison? Best, ----------------------------------- Xiangdong Huang School of Software, Tsinghua University 黄向东 清华大学 软件学院 康愈圆 <ky...@mails.tsinghua.edu.cn> 于2019年9月1日周日 下午9:03写道： > Hi, > > PR#336 is related to issue IOTDB-190. > > ANTLR v4 has some advanteges over ANTLR v3: > > 1. ANTLRv4 uses visitor and listener mechanism，which allows the grammer > definition independent from programming language (e.g. Java). > So it is much easier to maintain. > > 2. In Antlr v3, developers explicitly defines the structure of the tree to > build using operator '->'. However, Antlr v4 hides the tree structure > from developers, which simplifies grammer definition and increases the > code readability. > > 3. ANTLR v3’s LL(* ) parsing strategy is weaker than v4’s ALL(* ), so v3 > sometimes relied on backtracking to properly parse input phrases. > > 4. ANTLR v3 cannot handle left-recursive rules, while ANTLR v4 can now > handle direct left recursion. Therefore, ANTLR v4 can handle more > grammer rules. > > 5. ANTLR v4 works faster than ANTLR v3. > > Now, I'm working on this issue. > > --------------------------------------------- > Yuyuan KANG > School of Software, Tsinghua University > > 康愈圆 > 清华大学 软件学院 > > 在2019-09-01 23:58:55,Christofer Dutz<christofer.d...@c-ware.de>写道： > > Hi all, > > > > let me give some points I know from the past: > > - With Anlr4 grammars you seem to be able to express more rules > > - Antlr4 parsers appear to be a lot faster than Anltr3 parsers > > - Antlr4 grammars are easier to read (at least this is my impression) > > - Implementing Parsers/Compilers with an Antlr4 grammar is a lot easier > as there is no longer a mixture of Antlr3 and Java code (the grammar > contains absolutely no code and all is implemented by overriding "enterXYZ" > and "exitXYZ" methods). > > > > So I was happy when reading that you're switching to antlr4. > > > > Chrus > > > > > > Am 01.09.19, 17:38 schrieb "Xiangdong Huang" <saint...@gmail.com>: > > > > Hi, > > > > Let's discuss about PR#336.. > > > > 1. Which issue the PR is for. > > > > 2. As you (@Ring-K) upgrade the parser from antlr 3 to antlr 4, what > > benefit can we get? > > > > Best, > > ----------------------------------- > > Xiangdong Huang > > School of Software, Tsinghua University > > > > 黄向东 > > 清华大学 软件学院 > > > > > >
