proposal-explicit-resource-managemen VS pidove

In addition to this, is the new (stage 3 even!)explicit resource management proposal[0], supported by TypeScript version >= 5.2[1]

Though I agree that async context is better fit for this generally, the RMP should be good for telemetry around objects that have defined lifetime semantics, which is a step in the right direction you can use today

[0]: https://github.com/tc39/proposal-explicit-resource-managemen...

[1]: https://www.totaltypescript.com/typescript-5-2-new-keyword-u...

There's a conversation I had with Ron Buckton, the proposal champion, mainly on this specific issue. [1]

Short answer: Yes, Disposable can leak if you forget "using" it. And it will leak if the Disposable is not guarded by advanced GC mechanisms like the FinalizationRegistry.

Unlike C# where it's relatively easier to utilize its GC to dispose undisposed resources [2], properly utilizing FinalizationRegistry to do the same thing in JavaScript is not that simple. In response to our conversation, Ron is proposing adding the use of FinalizationRegistry as a best practice note [3], but only for native handles. It's mainly meant for JS engine developers.

Most JS developers wrapping anything inside a Disposable would not go through the complexity of integrating with FinalizationRegistry, thus cannot gain the same level of memory-safety, and will leak if not "using" it.

IMO this design will cause a lot of problems, misuses and abuses. But making JS to look more like C# is on Microsoft's agenda so they are probably not going to change anything.

[1]: https://github.com/tc39/proposal-explicit-resource-managemen...

I'm not _entirely_ sure which RAII you mean, but if you mean something like C#'s `using` or Java's `try-with-resources` or Python's `with`, then https://github.com/tc39/proposal-explicit-resource-managemen... and https://github.com/tc39/proposal-async-explicit-resource-man... are in stage 3 (of 4 stages) in ECMAScript's language proposal lifecycle and will be coming to a JS engine near you behind a flag soon-ish.

I'd prefer something with a more sound type system, and something that makes cleaning up resources easier and more ergonomic.

This might help with cleanup: https://github.com/tc39/proposal-explicit-resource-managemen...

But I'm not sure anything will help with the type system. For example, this drives me absolutely insane: https://www.typescriptlang.org/play#code/MYewdgziA2CmB00QHMA...

There's a proposal for syntax to help with this in JS, incidentally: https://github.com/tc39/proposal-explicit-resource-managemen...

There is no reason why you could not, in principle, have Rust-style compile-time borrow checking in a managed language.

As an extreme example (that I have occasionally thought about doing though probably won't), you could fork TypeScript and add ownership and lifetime and inherited-mutability annotations to it, and have the compiler enforce single-ownership and shared-xor-mutable except in code that has specifically opted out of this. As with existing features of TypeScript's type system, this wouldn't affect the emitted code at all—heap allocations would still be freed nondeterministically by the tracing GC at runtime, not necessarily at the particular point in the program where they stop being used—but you'd get the maintainability benefits of not allowing unrestricted aliasing.

(Since you wouldn't have destructors, you might need to use linear instead of affine types, to ensure that programmers can't forget to call a resource object's cleanup method when they're done with it. Alternatively, you could require https://github.com/tc39/proposal-explicit-resource-managemen... to be used, once that gets added to JavaScript.)

Of course, if you design a runtime specifically to be targeted by such a language, more becomes possible. See https://without.boats/blog/revisiting-a-smaller-rust/ for one sketch of what this might look like.

Things like https://github.com/tc39/proposal-explicit-resource-managemen.... Essentially better language level support for objects which represent some IO resource that should be reliably closed when a user is done with it. Something like the `defer` statement in Go is really missing from JS.

Streams is too complex for what it does and it doesn’t even parallelize well. Here is something that does roughly the same thing but I think is way better

See https://github.com/paulhoule/pidove

https://central.sonatype.com/artifact/com.ontology2/pidove

(1) It's a bit of a bad smell (which he points out) that records aren't being used much at all in the Java stdlib, I wrote something that built out stubs for the 17 and 18 stdlibs and that stood out like a sore thumb. I do like using records though.

(2) I've looked at other ways to extend the collections API and related things, see

https://github.com/paulhoule/pidove

and I think the sequenced collections could have been done better.

(3) Virtual Threads are kinda cool but overrated. Real Threads in Java are already one of the wonders of the web and perform really well for most applications. The cases where Virtual Threads are really a win will be unusual but probably important for somebody. It's a good thing it sticks to the threads API as well as it did because I know in the next five years I'm going to find some case where somebody used Virtual Threads because they thought it was cool and I'll have to switch to Real Threads but won't have a hard time doing so.

I think that guy just made up a generator class for fun. It’s not too different from the integrator except it doesn’t have a hasNext() method so it either returns results forever or it has to return a sentinel value like null or return an exception to end iteration.

Somebody could make the case that returning a sentinel value or an exception is a better API since there is no risk somebody else is going to call the next() method after you call hasNext() and next(). Writing a generator that wraps a generator is a little simpler than writing an interest or that wraps an iteration because you don’t have to write a hasNext() function, which can occasionally be awkward.

That generator library has a few functions, like map that work on generators, unfortunately the Java stdlib doesn’t come with anything like that. (There is the streams API but it is over-complicated.)

I’ll point out this library I wrote

https://github.com/paulhoule/pidove

which does a lot of what the Steams library does but it works on iterators without creating streams. If you like those generator examples you might like pidove.

As for Python it is kinda accidental that generators would up related to coroutines, that is, generators were an easy way to implement coroutines, later async/await and stuff like that got added.

I find this alien to my point of view. On the other hand, my side projects aren't driven by FOMO but are more like the "special interests" of autistic people.

Most of the time I have three side projects going on, maybe two of which are really getting the attention they deserve and one that is languishing. (See my profile to see about my current three.) Occasionally I get inspired to spend 1-4 weekends on some sudden inspiration, of which

https://github.com/paulhoule/pidove

came to completion but

https://github.com/paulhoule/ferocity

probably won't. The project I'm working the hardest on now is something that I was baffled that it didn't exist 18 years ago but felt compelled to do something out because of the Twitterinsanity last December and it turned out the technological conditions right now make it the perfect time to work on.

When I saw sequenced collections earlier I didn’t like the design but I completely approve of the latest revision. One nice thing about the process they use to develop Java is that they really do work and rework new features to make them great.

I just wish that instead of Streams they’d made something more like

https://github.com/paulhoule/pidove

... or you can just use a sane FP library like

https://github.com/paulhoule/pidove

Some people don't like the Lispy signatures so I did start coding up a version with with a fluent interface but didn't quite finish.

Inner classes are pretty useful.

This library contains a huge number of Iterables, each of which has at least one Iterator implementation.

https://github.com/paulhoule/pidove

It is convenient to let the Iterator be immutable and the Iterator be an inner class that gets its configuration information out of the Iterable.

(That said, if people really thought seriously about Iterator being a Supplier people might think more rationally about error handling. Also in a slightly parallel universe the Iterator would only have one method since remove() hardly ever gets used and having both hasNext() and next() methods is asking for bugs.)

If you were programming in Python or many other languages you could download documentation locally.

In both Python and Java doing a mini-project I frequently challenge myself to only use the standard library. It's good for practicing HackerRank-rank style programming (the fun of single-file Java)

When I am waiting for builds I sometimes hack on this

https://github.com/paulhoule/pidove

because I don't really like the Streams API and want to perfect my mastery of generics and internal DSLs.

Now that I think of it, standard-library only for node seems like a good challenge for me because I code a lot of front-end Javascript but just barely know the node API.