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neogeny
TatSu
Python2018–2026
neogeny / TatSu

TatSu

竜 TatSu generates Python parsers from grammars in a variation of EBNF

4Distinct people
4Mentions
0Explicit recommenders
452GitHub stars
REPOSITORY AT A GLANCE

What to know before exploring

What it is

竜 TatSu generates Python parsers from grammars in a variation of EBNF

GitHub

Where it is used

No documented product use has been verified yet.

What people are saying

No recommendation phrase was found in the indexed comments.

No classified warning is attached to this page. Read the discussions before treating silence as approval.

Also in these discussions

No other repository is repeatedly linked in the same discussions.

This week on Hacker News

Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 5:04:57 PM UTC.

No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.

Mentions over time

HN mentions by year4 dated mentions

Observed mentions: 2018-02-16 15:12:56 UTC to 2026-10-06 06:08:06 UTC.

0122018-01-01 00:00:00 UTC to 2019-01-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments20182019-01-01 00:00:00 UTC to 2020-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2020-01-01 00:00:00 UTC to 2021-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2021-01-01 00:00:00 UTC to 2022-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2022-01-01 00:00:00 UTC to 2023-01-01 00:00:00 UTC (exclusive): 2 mentions; 1 submissions, 1 comments20222023-01-01 00:00:00 UTC to 2024-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2024-01-01 00:00:00 UTC to 2025-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2025-01-01 00:00:00 UTC to 2026-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2026-01-01 00:00:00 UTC to 2027-01-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments. Incomplete calendar period.2026*

* An incomplete calendar period is marked with an outlined bar. Its count is not directly comparable with a full period.

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges
UTC ranges include their start and exclude their end. Select a period to filter the source evidence.
PeriodStart (UTC)End (exclusive, UTC)MentionsSubmissionsComments
20182018-01-01 00:00:00 UTC2019-01-01 00:00:00 UTC101
20192019-01-01 00:00:00 UTC2020-01-01 00:00:00 UTC000
20202020-01-01 00:00:00 UTC2021-01-01 00:00:00 UTC000
20212021-01-01 00:00:00 UTC2022-01-01 00:00:00 UTC000
20222022-01-01 00:00:00 UTC2023-01-01 00:00:00 UTC211
20232023-01-01 00:00:00 UTC2024-01-01 00:00:00 UTC000
20242024-01-01 00:00:00 UTC2025-01-01 00:00:00 UTC000
20252025-01-01 00:00:00 UTC2026-01-01 00:00:00 UTC000
2026 (partial)2026-01-01 00:00:00 UTC2027-01-01 00:00:00 UTC101

What Hacker News says

4 sources
I believe lark [1] is the common Python solution. Personally, I like tatsu [2], which generates a parser in Python (and there appear to be projects doing the same for other languages from the same grammar, check the README). Another choice, though not necessarily taking in an EBNF, could be Racket [3]. [1]: https://lark-parser.readthedocs.io/ [2]: https://github.com/neogeny/TatSu [3]: https://docs.racket-lang.org/guide/hash-languages.html
In Plain text is still one of the best technologies we have
Yep. "Something equivalent" is pretty easy. To be able to regenerate the original input (spacing and other foibles) is a bit harder but also possible. Commercial vendors developed tools that can do this in the 00's to support UML and UML-like tooling. Related to this is getting sensible output structures. For instance, many parsing libraries based on parsing combinators output a "lispy" combination of lists/dicts/scalars which is dependent on the details of the grammar, for ex. https://github.com/neogeny/tatsu it is particularly obnoxious when operator precedence is implemented by creating extra nodes in the parse tree, and even more obnoxious when you have to copy those already over-complicated structures in your grammar to deal with complex context. Even in 2018 people are still using some compiler compilers that use a "callback he
Read the rest
ll" interface that dates back to yacc. That might have been OK in 1978, but it is one of the many unergonomic things that put compiler compilers out of reach for many application programmers.
In Just what does “code as data” mean anyway? (2014)

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