rakudo VS ts-sql

Fix IO::Path::parent #4795: merged 2022-02-19 Add more IO::Path::parent tests #801: merged 2022-02-19 Change parent to always just remove the last element #4800: merged 2022-02-26 Change .parent behavior to "stupid" resolving #802: merged 2022-02-26

This then became the Formatter class. And since this was a completely new feature, it only became available for use by opting into the 6.e.PREVIEW language version. And then it went largely unnoticed and uncared for the next 1.5 year. As clearly the time wasn't right for it yet.

The intended audience are those people willing to be early adopters of these exciting new features in the Raku Programming Language. The examples in this blog post will work in the next release of the Rakudo compiler (probably 2023.06), but are now already available in the bleeding edge version.

If you really want to look at this, you can find the code in src/Perl6/Grammar.nqp, src/Perl6/Actions.nqp and src/Perl6/World.nqp.

If you find this very interesting, you probably want to read the RakuAST README. And the actual source code of the RakuAST classes can be found in the same directory. And if you're really feeling adventurous and you have the Rakudo repository checked out, you can have a look at the generated NQP code in gen/moar/ast.nqp.

Yes, it would. But until there was RakuAST, that was virtually impossible to do because there was no proper API for building ASTs. Nor was there an interface to execute those ASTs. And now that there is RakuAST, it is actually possible to do this. And there is actually already an implementation of that idea in the new Formatter class. Although this is definitely not intended as an entry point into grokking RakuAST.

I have opened one. https://github.com/rakudo/rakudo/issues/5205.

Will Coleda has made a Pull Request

There's an issue pertaining to this. This is something I'd like to resolve, but I'm unsure on how to better debug this to see if it really is the deserialization of a setting file triggering it. JDK 11 should at least be capable of building Rakudo, but being an experimental backend people don't always align with MoarVM immediately, I can't make any guarantees about tests. You may be disappointed in its performance at the moment.

(NB. While the PL is just a toy (and just a tiny bit of the toy too), the tech is actually industrial strength, used to power the production Raku compiler, which is written in Raku using its grammar construct. Starting easy doesn't mean you can't go far. Quite the opposite in fact -- you can go as far as you want.)

There is an implementation of SQL that operates on a table shaped type, entirely at type level. For your amusement: https://github.com/codemix/ts-sql

There are a bunch of more practical takes that codegen types from your database and generate types for your queries, eg: https://github.com/adelsz/pgtyped

To me the second approach seems much more pragmatic because you don’t need to run a SQL parser in a fairly potato interpreter on every build

> If I would level criticisms at dialyzer it would be its sometimes difficult to read warnings, it’s speed (despite being multithreaded) and the race conditions in the VS Code plugin (which is looking for extra maintainers – if I had time I would help).

One of the advantages of TypeScript is that VSCode is written in TypeScript, and both VSCode and TypeScript are developed by the same company, so there's a really nice synergy there. I imagine Kotlin users feel the same way using Jetbrains products, and Swift users feel the same way about XCode.

Dialyzer looks interesting, but I can't imagine giving up on the expressiveness of TypeScript. Some of the things you can do with generics, mapped types, intersection types, template literal types, conditional types, and utility types are almost mind boggling. It's difficult to reap all of the benefits of static analysis without some of these advanced type operators. The type manipulation section of the TS manual is really underrated.

Someone for example wrote an SQL parser in TypeScript that requires no runtime code [1]. It can infer the types of an SQL query's result based on an SQL string without any runtime code execution. There was a similar project where someone built a JSON parser entirely using the type system [2]. There's also an ongoing discussion on Github about the the fact that TypeScript's type system appears to be a Turing-complete language with some other cool examples [3]. My point is that the type system is incredibly expressive. You rarely run into an idiom that can't be typed effectively.

[1] https://github.com/codemix/ts-sql

[2] https://twitter.com/buildsghost/status/1301976526603206657

[3] https://github.com/microsoft/TypeScript/issues/14833

If anyone saw this meme and thought, "damn parsing a type from a SQL query, that looks useful" (as I did), the source appears to be from here.

I mean, why stop there? https://github.com/codemix/ts-sql

Which allows for things like this type that implements a simplified SQL query parser checked against a provided 'database' object:

https://github.com/codemix/ts-sql

This project was my go-to "nifty but pointless" example for TS string literal types before this article :)

author of ts-sql[0] here, this looks great (and a way more practical approach!)

[0] https://github.com/codemix/ts-sql