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Kiel

•Created by Olipro on 11/14/2024 in #help

IDisposable ownership semantics

to answer your question bluntly, no C# does not have first class support for...whatever it is you're trying to express. We have try/finally, try/catch, and the various forms of using. But it seems like you're pretty much asking for a way to create an object, do work with it, and return it, and dispose it ONLY if an exception is thrown. If you're re-using this logic lots, you could probably use the above suggestion as a wrapper, but otherwise yeah the way you're doing it is probably about as clean as it's gonna get without re-throwing

28 replies

•Created by Olipro on 11/14/2024 in #help

IDisposable ownership semantics

what exactly are you trying to accomplish here then, if not what I'm suggesting?

28 replies

•Created by Olipro on 11/14/2024 in #help

IDisposable ownership semantics

your original example was a little weird re-assigning result to a new variable so it threw me off

28 replies

•Created by Olipro on 11/14/2024 in #help

IDisposable ownership semantics

otherwise, return it

28 replies

•Created by Olipro on 11/14/2024 in #help

IDisposable ownership semantics

if I'm reading your messages right you want result disposed ONLY if an exception is thrown

28 replies

•Created by Olipro on 11/14/2024 in #help

IDisposable ownership semantics

but keep in mind this approach would swallow exceptions, you should still probably log or whatever your system does to handle them

28 replies

•Created by Olipro on 11/14/2024 in #help

IDisposable ownership semantics

var result = new SomeDisposable();

try
{
    var ret = result.PossiblyThrows();
    return ret;
}
catch
{
    result.Dispose();
    return // whatever you want
}

var result = new SomeDisposable();

try
{
    var ret = result.PossiblyThrows();
    return ret;
}
catch
{
    result.Dispose();
    return // whatever you want
}

Is this closer to what you're looking for? You could use try/catch instead of try/finally

28 replies

•Created by Olipro on 11/14/2024 in #help

IDisposable ownership semantics

So you only want result disposed if an exception is thrown?

28 replies

•Created by Olipro on 11/14/2024 in #help

IDisposable ownership semantics

if you prefer nesting and/or your true method is larger than this, you can also use a using expression instead:

using (var result = new SomeDisposable())
{
    var ret = result.PossiblyThrows();
    return ret;
}

using (var result = new SomeDisposable())
{
    var ret = result.PossiblyThrows();
    return ret;
}

28 replies

•Created by Olipro on 11/14/2024 in #help

IDisposable ownership semantics

If you are using only try { } finally { }, perhaps consider using a, well...using statement or expression?

public SomeDisposable GetDisposable()
{
    using var result = new SomeDisposable();
    var ret = result.PossiblyThrows();
    return ret;
}

public SomeDisposable GetDisposable()
{
    using var result = new SomeDisposable();
    var ret = result.PossiblyThrows();
    return ret;
}

I'm not sure what the point of setting result to null is in your original code, but what I just posted above is syntactically equivalent to

public SomeDisposable GetDisposable()
{
  var result = new SomeDisposable();
  try
  {
      var ret = result.PossiblyThrows();
      return ret;
  }
  finally
  {
      result.Dispose();
  }
}

public SomeDisposable GetDisposable()
{
  var result = new SomeDisposable();
  try
  {
      var ret = result.PossiblyThrows();
      return ret;
  }
  finally
  {
      result.Dispose();
  }
}

28 replies

•Created by Daiko Games on 9/30/2024 in #help

How to convert a whole json file to C# classes with Newtonsoft.Json?

Personally in the past I used https://quicktype.io/ to make a quick and dirty concept and then I'd refine it from there to my liking

43 replies

•Created by SpookyToad on 9/30/2024 in #help

✅ Is it possible to clean up all this in a vs release folder?

It looks like you're using Humanizer, it might help to install Humanizer.Core if you JUST want english-language features - it won't produce just an exe file like above mentioned but it will at least keep all those extra folders from being generated

7 replies

•Created by Merineth 🇸🇪 on 9/28/2024 in #help

✅ Exception handling

keep in mind that in a catch block, thrown exceptions are not caught - you would need ANOTHER try { } catch { } block inside it lol

31 replies

•Created by Merineth 🇸🇪 on 9/28/2024 in #help

✅ Exception handling

There's nothing stopping you from throwing your own exception in a catch block, but generally you should have a good reason for doing so. A proper real-world usecase could be if you have your own generic ErrorException type which wraps other exceptions so you can display more detailed information than a plain old DivideByZeroException can

31 replies

•Created by Merineth 🇸🇪 on 9/28/2024 in #help

✅ Exception handling

(even just new Exception(...) too)

31 replies

•Created by Merineth 🇸🇪 on 9/28/2024 in #help

✅ Exception handling

You can make your own exception class, or you can throw any of the base exceptions

31 replies

•Created by Merineth 🇸🇪 on 9/28/2024 in #help

✅ Exception handling

Correct, you can throw an exception at any time if you so choose

31 replies

•Created by Merineth 🇸🇪 on 9/28/2024 in #help

✅ Exception handling

Ignoring the fact I'm using int.Parse instead of int.TryParse, here's an example of handling multiple exceptions in different ways

31 replies

•Created by Merineth 🇸🇪 on 9/28/2024 in #help

✅ Exception handling

try
{
    var input = Console.ReadLine();
    var number = int.Parse(input);
    var division = 5 / number;
}
catch (NullReferenceException)
{
    // input was null!
}
catch (FormatException)
{
    // number failed to parse (int.Parse failed)
}
catch (DivideByZeroException)
{
    // input was 0
}

try
{
    var input = Console.ReadLine();
    var number = int.Parse(input);
    var division = 5 / number;
}
catch (NullReferenceException)
{
    // input was null!
}
catch (FormatException)
{
    // number failed to parse (int.Parse failed)
}
catch (DivideByZeroException)
{
    // input was 0
}

31 replies

•Created by Merineth 🇸🇪 on 9/28/2024 in #help

✅ Exception handling

You can name the variable whatever you like, most people I see name it ex or just e, or if you don't need to use the variable, you can omit it entirely like I do below

31 replies