You are viewing a plain text version of this content. The canonical link for it is here.
Posted to notifications@accumulo.apache.org by "keith-turner (via GitHub)" <gi...@apache.org> on 2023/09/09 02:34:03 UTC
[GitHub] [accumulo-access] keith-turner opened a new pull request, #5: removes left recursion from specification
keith-turner opened a new pull request, #5:
URL: https://github.com/apache/accumulo-access/pull/5
(no comment)
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: notifications-unsubscribe@accumulo.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [accumulo-access] keith-turner commented on pull request #5: removes left recursion from specification
Posted by "keith-turner (via GitHub)" <gi...@apache.org>.
keith-turner commented on PR #5:
URL: https://github.com/apache/accumulo-access/pull/5#issuecomment-1712596297
I tried literally converting the new spec in this PR to code in this [branch][1] creating [Parser.java][2] and [ParserTest.java][3] and it worked out really nicely, Passes all the test we have for parsing expressions. We could use this as a concrete example for writing a parser and also use the concepts in it as a basis for cleaning up the current java code to make it align more closely to the spec.
[1]: https://github.com/keith-turner/accumulo-access/tree/new-parser
[2]: https://github.com/keith-turner/accumulo-access/blob/new-parser/src/main/java/org/apache/accumulo/access/Parser.java
[3]: https://github.com/keith-turner/accumulo-access/blob/new-parser/src/test/java/org/apache/accumulo/access/ParserTest.java
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: notifications-unsubscribe@accumulo.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [accumulo-access] keith-turner commented on pull request #5: removes left recursion from specification
Posted by "keith-turner (via GitHub)" <gi...@apache.org>.
keith-turner commented on PR #5:
URL: https://github.com/apache/accumulo-access/pull/5#issuecomment-1712578638
> Are these changes based on the the ANTLR4 grammar in https://github.com/apache/accumulo-access/pull/4/files#diff-f1fd96e8a466678a24201ba1c54b96d5a1d0024e3f734d3eebac3aaae7ddfcf3? Just wondering if I need to make changes in that based on these changes.
Not quite, that still has left recusion with rules `expression : expression AND_OPERATOR expression`. This PR is an attempt to remove all left recursion while still parsing the exact same language. So I think it would still reject something like `A|B&C`. I think that ANTLR grammar would accept `A|B&C`. I am curious if this set of rules w/o left recursion could almost directly be adapted to ANTLR.
W/o left recursion each rule has a character or set of characters that starts the rule and makes choosing the next rule unnambiguous based on the next character/token seen. I think with this simplified grammar a parser could be written with a tokenizer and a function for each rule, but not sure. Thinking this set of rules more easily converts directly to code for parsing because the lack of ambiguity about which rule to follow next makes it easy to code. So maybe this version of the grammar is easy to code directly or use with something like ANTLR or Javacc.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: notifications-unsubscribe@accumulo.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [accumulo-access] dlmarion merged pull request #5: removes left recursion from specification
Posted by "dlmarion (via GitHub)" <gi...@apache.org>.
dlmarion merged PR #5:
URL: https://github.com/apache/accumulo-access/pull/5
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: notifications-unsubscribe@accumulo.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [accumulo-access] dlmarion commented on pull request #5: removes left recursion from specification
Posted by "dlmarion (via GitHub)" <gi...@apache.org>.
dlmarion commented on PR #5:
URL: https://github.com/apache/accumulo-access/pull/5#issuecomment-1712501300
Are these changes based on the the ANTLR4 grammar in https://github.com/apache/accumulo-access/pull/4/files#diff-f1fd96e8a466678a24201ba1c54b96d5a1d0024e3f734d3eebac3aaae7ddfcf3? Just wondering if I need to make changes in that based on these changes.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: notifications-unsubscribe@accumulo.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [accumulo-access] keith-turner commented on pull request #5: removes left recursion from specification
Posted by "keith-turner (via GitHub)" <gi...@apache.org>.
keith-turner commented on PR #5:
URL: https://github.com/apache/accumulo-access/pull/5#issuecomment-1712603696
After comparing the code to the spec I realized I could simplify the spec and did that in 373c192
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: notifications-unsubscribe@accumulo.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org