refactor!: prqlc-parser major reorg changes, remove prqlc-ast

[m-span]

From #4603 , we have the following new terminology:

stage	sub-stage	AST
parse	lexer	string -> LR — Lexer Representation
parse	parser	tokens -> PR — Parser Representation
semantic	ast_expand	PR -> PL — Pipelined Language
semantic	resolver	PL
semantic	flatten	PL
semantic	lowering	PL -> RQ — Resolved Query
sql	preprocess	RQ
sql	srq-compiler	RQ -> PQ — Partitioned Query
sql	postprocess	PQ
sql	sql-compiler	PQ -> sqlparser::ast
sql	codegen	sqlparser::ast -> string

Goals:

• Move all files from prqlc-ast to prqlc-parser. prqlc-ast is to be deprecated
• Within parser stage, rename objects, modules and methods to meet new spec. Organize lexer and parser stage into separate modules.

[m-span]

still a wip, need to make sure all references are updated correctly, but feel free to take a look and comment at how prqlc-parser is now organized

[max-sixty]

Looking great at first glance!

(Unfortunately it looks like it may not be based off the latest main and so have some conflicts; worth pulling the latest main... really hope that's not a painful merge. To the extent it's caused by #4522, there are instructions there for how to reproduce that; so running the same commands on this branch should produce a very similar, easily-mergable result)

[max-sixty]

Super minor but possibly standards are for pr to be lowercase; no view from me beyond following the rust naming standards

[m-span]

There's more work to be done, but this is a good first step. We might need to talk about how we want to be re-exporting our imports.
These changes are absolutely Major version number update-API-breaking changes, since we are re-naming our objects.

[m-span]

I tried to do the least amount of changes that accomplishes the goal, but its still a lot. Requesting many eyes on this. Also, some test are suddenly failing - trying to figure it out, but if anyone has any solutions, feel free to suggest or push.

[max-sixty]

I tried to do the least amount of changes that accomplishes the goal, but its still a lot. Requesting many eyes on this. Also, some test are suddenly failing - trying to figure it out, but if anyone has any solutions, feel free to suggest or push.

Yes perfect. I have a few small things to merge, and possibly a fairly big thing in #4639, so great if we can do these in smallish PRs with smaller conflicts.

A couple test failures indeed look surprising. Sometimes I realize I'm importing the wrong Expr etc; so I guess that's possible here?!

(a couple are easy clippy ones, will probably auto-fix with clippy --fix)

[m-span]

there seems to be issues with the ast_code_matches.rs tests. What is the purpose of these tests? They don't seem to tolerate refactors well...

[max-sixty]

there seems to be issues with the ast_code_matches.rs tests. What is the purpose of these tests? They don't seem to tolerate refactors well...

Funny you asked, I actually just pushed a change removing them. (They existed as a compromise to having multiple copies of similar AST structs around...)

[max-sixty]

Same here — IIUC it would be strictly better to have only one of these — no strong view on which

[max-sixty]

I'm sure we'll find some more refinements but looking really good for the moment — will hit the big button.

I made some small-ish refinements, feel free to object to anything if I went against your intention...

[max-sixty]

(could definitely do with a changelog entry, doesn't need to be part of this PR tho)

[m-span]

Looking good from this side. Cleanups were great. Just a small shame I coudln't get the refactor on prqlc_parser::parse_source() working that I had to undo it via this commit.
It did some nice things like hide stuff that didn't need to be exposed

[m-span]

(could definitely do with a changelog entry, doesn't need to be part of this PR tho)

I'll add it.
Also, this is a breaking api change...should we increment the working version number to a major increment?

[max-sixty]

Also, this is a breaking api change...should we increment the working version number to a major increment?

Let's add ! in the PR description and then we'll do it at release time

(your approach is reasonable but it may not generalize well to multiple breaking changes in a release without another mechanism...)

[max-sixty]

Thank you @m-span !