4 ms·

It might fail, but usually doesn't. In C#, to handle an e.g. file open failure, you can just write try { using var file = File.OpenWrite("test.txt"

It might fail, but usually doesn't. In C#, to handle an e.g. file open failure, you can just write try { using var file = File.OpenWrite("test.txt"); file.Write("Hello, World!"u8); } catch (IOException e) { Console.WriteLine(e.Message); } The exception handler is an enclosing scope for both file open and dispose (flush and close) operations. You can also hoist file variable to an outer scope to, for example, decide what to do if dispose throws for some reason. In practical terms, this is as much of an edge case as it gets, but can be expressed in a fairly straightforward way.

lostmsu 2y ago
I don't think this does the right thing. You are catching exception if Close fails and nothing else. The problem thought is what to do when after file is opened something fails first, and then Close also fails.
- neonsunset 2y ago
  I'm catching any exception that occurs within the scope of try block. This includes an exception when trying to open or write to the file. If I fail to write to a file, it will try to dispose the stream, which flushes it and closes the file handle. If disposing the file handle itself fails, which should never happen, the exception will occur in the finally block, which this exception handler catches too. If you need to disambiguate and handle each case differently, which is rarely needed, you can order try-catch-finally blocks differently with explicit dispose and different nesting. This, again, is not a practical scenario and most user code will just `using file = File.OpenWrite` it and let the exception bubble up.
  - lostmsu 2y ago
    Yes, and this ignoring of the original exception is the core of the problem discussed. If you are willing to lose supposedly written data, your approach is golden.
    - neonsunset 2y ago
      As said in the previous comment, you can place a variable in an outside scope and assign to it from within an try-catch block to handle an open file stream in a particular way upon failure. You can simply write more code to disambiguate and specifically handle errors from separate parts of the execution flow. In any case closing a file handle should never fail, but if it does - there are tools to deal with this.
      - lostmsu 2y ago
        Well the point it: the problem is not as simple in C# as your initial snippet suggests.
    - kaba0 2y ago
      With exceptions you don’t silently ignore error and go on as if nothing happened. Just simply not explicitly handling every single possible error is the correct choice in many scenarios - in which case it bubbles up to a general error handler, e.g. telling the user that something bad happened here and here.

lostmsu 2y ago

I don't think this does the right thing. You are catching exception if Close fails and nothing else. The problem thought is what to do when after file is opened something fails first, and then Close also fails.

neonsunset 2y ago
I'm catching any exception that occurs within the scope of try block. This includes an exception when trying to open or write to the file. If I fail to write to a file, it will try to dispose the stream, which flushes it and closes the file handle. If disposing the file handle itself fails, which should never happen, the exception will occur in the finally block, which this exception handler catches too. If you need to disambiguate and handle each case differently, which is rarely needed, you can order try-catch-finally blocks differently with explicit dispose and different nesting. This, again, is not a practical scenario and most user code will just `using file = File.OpenWrite` it and let the exception bubble up.
- lostmsu 2y ago
  Yes, and this ignoring of the original exception is the core of the problem discussed. If you are willing to lose supposedly written data, your approach is golden.
  - neonsunset 2y ago
    As said in the previous comment, you can place a variable in an outside scope and assign to it from within an try-catch block to handle an open file stream in a particular way upon failure. You can simply write more code to disambiguate and specifically handle errors from separate parts of the execution flow. In any case closing a file handle should never fail, but if it does - there are tools to deal with this.
    - lostmsu 2y ago
      Well the point it: the problem is not as simple in C# as your initial snippet suggests.
  - kaba0 2y ago
    With exceptions you don’t silently ignore error and go on as if nothing happened. Just simply not explicitly handling every single possible error is the correct choice in many scenarios - in which case it bubbles up to a general error handler, e.g. telling the user that something bad happened here and here.