grammars-v4 VS ANTLR

Perhaps the one from ANTLR's collection [0] is a good start (there are also others ANTLR VB6 grammars documented elsewhere). It does require knowing ANTLR, but that should be less effort for someone already familiar with language implementation, particularly, the visitor pattern (my favorite reference [1]).

[0] https://github.com/antlr/grammars-v4/tree/master/vb6

[1] https://craftinginterpreters.com/representing-code.html

Where is the SQLite test suite, please? I'd be very interested.

There are already SQL grammars, check https://github.com/antlr/grammars-v4 specifically in here I think https://github.com/antlr/grammars-v4/tree/master/sql I contributed to one of them, and I wrote my own for some personal work. Be warned, it's very involved, very complex and MSSQL is rather ill-defined.

Names bracket identifiers) in SQL are bloody awful. Sometimes square brackets are even compulsory, and why you can usually replace [...] with the SQL standard "..." , not always! Trust me, it gets worse.

I don't find antlr grammars to be brittle, and while they can lose in performance (by how much I don't know, perhaps quite considerably) they are very easy to maintain and I am very fortunate to have antlr to work with.

This grammar "library" was cited as an example of what the format could look like:.

https://github.com/antlr/grammars-v4

There is everything from assembly and C++ to glsl and scripting languages, arithmetic, games, and other weird formats.

> Which brings me to the other approach: steering the LLM's output __as it is generating tokens__

A relevant PR:

https://github.com/ggerganov/llama.cpp/pull/1773

The plan is to support arbitrary grammar files to constrain tokens as they are generated, like the ones here:

https://github.com/antlr/grammars-v4

Have a look at jooq - I know this has been used to rewrite SQL from one dialect to another, so it MUST be capable of collating code activity metrics. Look here. Otherwise, you might want to look into writing your own parser. ANTLR has a T-SQL dialect parser script here.

Find a Perl grammar file for ANTLR, like https://github.com/antlr/grammars-v4/tree/master/perl Save the grammar file as Perl.g4 in your project. Now, you can create the Kotlin program: import org.antlr.v4.runtime.* import org.antlr.v4.runtime.tree.ParseTree import java.io.File

Antlr is another option. You could generate a parser using the JSON antlr grammar.

antlr https://github.com/antlr/antlr4

Download the ANTLR jar from https://www.antlr.org/download/antlr-4.9.2-complete.jar Add the ANTLR jar to your project's classpath. Install the ANTLR Kotlin target by following the instructions at https://github.com/antlr/antlr4/blob/master/doc/targets/Kotlin.md Next, you'll need a Perl grammar file for ANTLR:

Write a context-free grammar for it, commonly written in Backus Naur Form, and use that to write a parser. There are tools named "parser generators" like antlr4 that can automatically convert a BNF grammar into a parser.

Tutorial on using it in Java: https://www.baeldung.com/java-antlr Github project itself with docs and examples: https://github.com/antlr/antlr4

Depending on how complex your expressions are, you might consider using something like antlr and writing your own parser for it. Setting up something to handle math and string operations wouldn’t be very hard and then you can control the syntax however you like. You can use a visitor and visit each node in the syntax tree and return the result of each sub-expression.

> ...than it would be to learn the exact syntax and quirks and possibly bugs of someone else's implementation...

Yup. Also, having deep knowledge of the language is required.

SQLite's grammar is neat. Creating a compatible parser would make a fun project. Here's a pretty good example: https://github.com/bkiers/sqlite-parser (Actual ANTLR 4 grammar: https://github.com/bkiers/sqlite-parser/blob/master/src/main... )

Postgres, which tries to be compliant with the latest standards, however...

SQL-2016 is a beast. Not to mention all the dialects.

I'm updating my personal (soon to be FOSS) grammar from ANTLR 3 LL(k) to ANTLR 4 ALL().

I've long had a working knowledge of SQL-92, with some SQL-1999 (eg common table expressions).

But the new structures and extensions are a bit overwhelming.

Fortunately, ANTLR project has ~dozen FOSS grammars to learn from. https://github.com/antlr/grammars-v4/tree/master/sql

They mostly mechanically translate BNFs to LL(k) with some ALL(). Meaning few take advantage of left-recursion. https://github.com/antlr/antlr4/blob/master/doc/left-recursi...

Honestly, I struggled to understand these grammars. Plus, not being conversant with the SQL-2016 was a huge impediment. Just finding a succinct corbis of test cases was a huge hurdle for me.

Fortunately, the H2 Database project is a great resource. https://github.com/h2database/h2database/tree/master/h2/src/...

Now for the exciting conclusion...

My ANTLR grammar which passes all of H2's tests looks nothing like any of the official or product specific BNFs.

Further, I found discrepancy between the product specific BNFs and their implementations.

So a lot of trial & error is required for a "real world" parser. Which would explain why the professional SQL parsing tools charge money.

I still think creating a parser for SQLite is a great project.

can be used to parse

I already posted here about a project, but I could also use help on Mantle. It's a new command framework powered by ANTLR, if that's something you're interested in.

ive been tryng to work with antlr4 and go but it seems that i cant import the runtime, it says that the antlr runtime isnt in the gopath but ive already done go get github.com/antlr/antlr4/runtime/antlr4 and i dont know what to do now, im on windows if anyone knows what to do it would be very helpful. thanks already