On 11/16/21 12:30 AM, bauss wrote:
> On Monday, 15 November 2021 at 22:44:35 UTC, Ali Çehreli wrote:
>> On 11/15/21 2:28 PM, pascal111 wrote:
>> > I want to know where the list of exceptions names that
>> "throw" statement
>> > uses.
>>
>> Such a list is not very useful. Normally all we need is Exception and
>> occasionally one or two other specific types.
>>
>
> It's actually very useful when you want to throw exceptions yourself,

That's very different from how I use exceptions perhaps because mine have been command line tools. I would love to learn more about how others use exceptions.

The existing exception type that I reuse is Exception :), which I throw indirectly by enforce:

  enforce(isOk, format!"There is a problem with %s"(x));

I even convert a ConvException that I catch to Exception with the same method just to give a little bit of more

  catch (ConvException ex) {
    enforce(false,
      format!"Failed to parse '%s' as blah: %s"(y, ex.msg));
  }

That shows how lazy I am. :)

> because instead of writing your own custom exception then you could use
> an existing implementation.

Unless there are standardized exceptions, that feels weird to me because such reused exceptions may have constructor parameters which may not make sense where I throw that exception.

Luckily, there is basicExceptionCtors, which trivializes implementing exception types anyway. For example, I copied the following from /usr/include/dmd/phobos/std/conv.d:

class ConvException : Exception
{
    import std.exception : basicExceptionCtors;
    ///
    mixin basicExceptionCtors;
}

Further, it doesn't feel right to throw e.g. std.conv.ConvException from my foo.bar module. The cases where another module's exception fitting my use closely feels so rare that I wouldn't even think about reaching for an existing exception of another module or a library.

I don't know... That's my comfortable and lazy use of exceptions. :)

Ali