proposal-slice-notation VS ts-sql

> Switch statements

JS has had switch statements for a long time. Do you mean switch "expressions" that can be used inline? It's not pretty but JS has long supported that too using either eval() "hacks" or IIFEs: https://stackoverflow.com/questions/32451049/is-eval-the-onl...

Do you mean pattern matching? There are two Stage 1 TC39 proposals with different approaches to it:

More hands-on/direct: https://github.com/tc39/proposal-pattern-matching

More indirect: https://github.com/tc39/proposal-do-expressions

> list comprehensions

There are several libraries with strong Iterator support today that while not syntactically gorgeous do great jobs at allowing you to write simple list operations. Off the top of my head are IxJS and iter-tools, but also classic mainstays like up to date versions of lodash and Ramda.

There's a Stage 2 proposal to bring more of them into "the standard library": https://github.com/tc39/proposal-iterator-helpers

There's also a Stage 2 proposal for an operator to make the syntax generally nicer no matter the library: https://github.com/tc39/proposal-pipeline-operator

> array slicing

Array.prototype.slice() was added back in ES2015: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

Array.prototype.at() was "just added" in ES2022 for unary "slice" (ability to use negative indexes): https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

If you prefer syntax to function calls, there's a Stage 1 proposal still live for that: https://github.com/tc39/proposal-slice-notation

> better equality operators

That ship has probably sailed. Most projects at this point just have linter rules to standardize everything to the more reliable "triple equals" (===, and !==).

There are proposals for more structural equality functions in the standard library, though, for instance: https://github.com/tc39/proposal-array-equality

Both are stage 1 proposals that I hope get in there some day.

https://github.com/tc39/proposal-slice-notation

https://github.com/tc39/proposal-pattern-matching

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