I Want Off Mr. Golang's Wild Ride

Post by Fellshard » Fri, Feb 28, 2020, 9:29 PM UTC

klodolph wrote: post #251

Fellshard wrote: post #202

Earlier quoted context omitted.

Isn't the point of OsString that it's essentially a faux-union type that is intended to be immediately converted to some concrete representation which /is/ richly manipulable?

The problem is that this is not good enough. It’s not uncommon to need to do a small amount of manipulation of OsString and there is no good way to do it. In C++, it’s fairly easy. In Rust, it’s a damn nightmare. In theory, in Rust, since OsString is basically Vec on the inside (like String), you could implement e.g. Path::has_extension in the same way as str::ends_with. However, anyone who has gone in and tried to i…

Post by _bxg1 » Fri, Feb 28, 2020, 9:30 PM UTC

zug_zug wrote: post #281

_bxg1 wrote: post #83

I think the mistake may be assuming that Go is meant to be a general-purpose language. From what I can tell, it's purpose-built to be a "web services" language, and its design-decisions center around that. What does that mean? - It's expected to be run on Linux servers (not Windows) and developer workstations (probably not Windows). - It needs to be fast but not blisteringly fast. Micro-performance concerns like the…

Except docker is written in go. Guess they never got the memo to not use go for non-webservices...

Post by [deleted] » Fri, Feb 28, 2020, 9:34 PM UTC

klodolph wrote: post #251

Fellshard wrote: post #202

Earlier quoted context omitted.

Isn't the point of OsString that it's essentially a faux-union type that is intended to be immediately converted to some concrete representation which /is/ richly manipulable?

The problem is that this is not good enough. It’s not uncommon to need to do a small amount of manipulation of OsString and there is no good way to do it. In C++, it’s fairly easy. In Rust, it’s a damn nightmare. In theory, in Rust, since OsString is basically Vec on the inside (like String), you could implement e.g. Path::has_extension in the same way as str::ends_with. However, anyone who has gone in and tried to i…

Post by steveklabnik » Fri, Feb 28, 2020, 9:36 PM UTC

samatman wrote: post #308

steveklabnik wrote: post #126

Earlier quoted context omitted.

C++ has been adding things like optional types; std::optional was released in C++17, there's talk of maybe pattern matching coming soon...

Java has Optional as well, but as you well know, you can't just bolt ADTs onto the side of a language and wash your hands of it. The whole system has to be designed around it to get the benefit of it. Java programmers will be checking for null until the last line of Java is written.

Post by dilap » Fri, Feb 28, 2020, 9:42 PM UTC

joshuamorton wrote: post #295

dilap wrote: post #291

Earlier quoted context omitted.

No, the name is definitely mutable. Consider: x = 1 capture = lambda: x x = 'foo' print capture() If python were just shadowing, this would print 1. But it prints foo.

That's an issue of scoping, not capturing. The x in the lambda isn't scoped to the lambda, it's scoped to the surrounding environment. So the x closes not over the lambda but the outer scope. So it's as expected given shadowing. Edit: Since I'm getting throttled: No, I'm saying that scoping rules are different in python and rust. In Rust (and cpp) there's the concept of scopes/closures as a first class feature. This…

  fn main() {
   let x = 1;
   let capture = || x;
   let x = 2;
   println!("{}", capture());
   println!("{}", x)
  }

  fn main() {
   let mut x = 1;
   let ptr = &x as *const i32;
   let capture = || unsafe{ *ptr };
   x = 2;
   println!("{}", capture());
   println!("{}", x);
  }