4 ms·

There is pretty strong precedent for this design over in .NET land - if it was awful or notably inferior to `defer` I'm sure the Chrome engineering team would h

There is pretty strong precedent for this design over in .NET land - if it was awful or notably inferior to `defer` I'm sure the Chrome engineering team would have taken notice.

creata 1y ago
C# has the advantage of being a typed language, which allows compilers and IDEs to warn in the circumstances I mentioned. JavaScript isn't a typed language, which limits the potential for such warnings. Anyway, I didn't say it was "inferior to defer", I said that it seemed more error-prone than RAII in languages like Rust and C++. Edit: Sorry if I'm horribly wrong (I don't use C#) but the relevant code analysis rules look like CA2000 and CA2213.
- masklinn 1y ago
  > Anyway, I didn't say it was "inferior to defer", I said that it seemed more error-prone than RAII in languages like Rust and C++. It is, but RAII really isn't an option if you have an advanced GC, as it is lifetime-based and requires deterministic destruction of individual objects, and much of the performance of an advanced GC comes from not doing that. Most GC'd language have some sort of finalizers (so does javascript: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/FinalizationRegistry https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...) but those are unreliable and often have subtle footguns when used for cleanup.
- legulere 1y ago
  It’s still difficult to get right in cases where you hold a disposable as a member. Its not obvious if disposables passed in also get disposed and what’s right depends on the situation (think a string based TextWriter getting passed in a byte-based Stream) and you will need to handle double disposes. Further C# has destructors that get used as a last resort effort on native resources like file descriptors.
  - creata 1y ago
    > Further C# has destructors that get used as a last resort effort on native resources like file descriptors. True, I was going to mention that, but I saw that JS also has "finalization registries", which seem to provide finalizer support in JS, so I figured it wasn't a fundamental difference.
- electroly 1y ago
  As a practical matter it's easy to forget in C# and it's up to you to remember. Those two analyzers are disabled by default and prone to both false positives and false negatives. They hardcoded the known behavior of a bunch of .NET classes to get it to be usable at all.
deleted 1y ago
[deleted]

There is pretty strong precedent for this design over in .NET land - if it was awful or notably inferior to `defer` I'm sure the Chrome engineering team would have taken notice.

creata 1y ago

C# has the advantage of being a typed language, which allows compilers and IDEs to warn in the circumstances I mentioned. JavaScript isn't a typed language, which limits the potential for such warnings. Anyway, I didn't say it was "inferior to defer", I said that it seemed more error-prone than RAII in languages like Rust and C++. Edit: Sorry if I'm horribly wrong (I don't use C#) but the relevant code analysis rules look like CA2000 and CA2213.

masklinn 1y ago
> Anyway, I didn't say it was "inferior to defer", I said that it seemed more error-prone than RAII in languages like Rust and C++. It is, but RAII really isn't an option if you have an advanced GC, as it is lifetime-based and requires deterministic destruction of individual objects, and much of the performance of an advanced GC comes from not doing that. Most GC'd language have some sort of finalizers (so does javascript: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/FinalizationRegistry https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...) but those are unreliable and often have subtle footguns when used for cleanup.
legulere 1y ago
It’s still difficult to get right in cases where you hold a disposable as a member. Its not obvious if disposables passed in also get disposed and what’s right depends on the situation (think a string based TextWriter getting passed in a byte-based Stream) and you will need to handle double disposes. Further C# has destructors that get used as a last resort effort on native resources like file descriptors.
- creata 1y ago
  > Further C# has destructors that get used as a last resort effort on native resources like file descriptors. True, I was going to mention that, but I saw that JS also has "finalization registries", which seem to provide finalizer support in JS, so I figured it wasn't a fundamental difference.
electroly 1y ago
As a practical matter it's easy to forget in C# and it's up to you to remember. Those two analyzers are disabled by default and prone to both false positives and false negatives. They hardcoded the known behavior of a bunch of .NET classes to get it to be usable at all.

deleted 1y ago

[deleted]