Where do I get grammars :P

[ShalokShalom]

Hi there 👍🏻

I look for a FSharp ANTLR implementation. Your project seems to be promising, considering that it outouts ANTLR, and I also read that you have an OCaml backend.

I probably miss something, because I know about a treesitter and an ANTLR grammar repository. And there seems to be no such thing for LBNF, BNF, ABNF or EBNF.

I understand that you only parse from LBNF, but J haven't found a grammar collection of existing languages at all.

Do you know, where I can get a F# xBNF grammar, or alternatively one from OCaml?

Thanks a lot ☀️

[andreasabel]

Do you know, where I can get a F# xBNF grammar, or alternatively one from OCaml?

Sorry, I don't know anything off the top of my head, but I leave this issue open for a while so folks can chime in. If you find something, please let us know.

[ShalokShalom]

Well, I found a couple, and all of them were about a different implementation. How compatible is BNFC with BNF, EBNF and others? How much is the labeling required?

That list is huge and out of date since 2015: https://slebok.github.io/zoo/index.html And here is a list from EBNF files, that got translated from treesitter. https://github.com/mingodad/plgh

[andreasabel]

In labelled BNF (BNFC), each rule needs a distinct label. It does not cover all of EBNF, which also has * for lists etc. (and ? and +).

[ShalokShalom]

Aha. So I wont be able to convert EBNF files properly. But partly? Your website doesnt make this clear. Lots of BNF files are out there, and you dont seem to know about a lot of grammars for LBNF.

Does it seem to make sense, that full compatibility could raise the usefulness of this tool since we could produce a lot of grammars?

In terms of backends and overall maintenance seems this project to be one of the leading figures. 😄

[andreasabel]

BNFC's concept is to be a common front-end to YACC-like parser generators in different languages. So we are just serving the common feature set.

• E.g. for Haskell, we use the happy parser generator which does not have lists built-in but you have to code them yourself as in https://haskell-happy.readthedocs.io/en/latest/using.html#parsing-sequences.
• For the C-family (C, C++) we use bison which also only supports BNF and not EBNF: https://www.gnu.org/software/bison/manual/html_node/Rules-Syntax.html

There are feature requests, though, that ask for an extension of the LBNF formalism, e.g. for ?:

• https://github.com/BNFC/bnfc/issues/65

[ShalokShalom]

Ok? I didnt know you are supporting Yacc either?

I am looking for a Yacc translator.

Can you help me to translate the FSharp grammar?

https://github.com/dotnet/fsharp/blob/main/src/Compiler/pars.fsy https://github.com/dotnet/fsharp/blob/main/src/Compiler/pppars.fsy

[andreasabel]

Can you help me to translate the FSharp grammar?

FSharp uses layout, so this does not fit into pure BNF or LBNF: https://fsharpforfunandprofit.com/posts/fsharp-syntax/