Idiomatic way to express errors without resorting to exceptions

[Simen Kjærås]

On Saturday, 7 March 2020 at 15:44:38 UTC, Arine wrote:
> The case when there isn't a value should be handled explicitly, 
> not implicitly. Propogating a None value
> isn't useful

Except when it is useful, and shouldn't be handled explicitly. I 
have code in D, C and C++ that looks like this:

     ReturnValue result = someInitialValue;
     auto foo = getFoo();
     if (!foo) return result;
     auto bar = foo.fun();
     if (!bar) return result;
     return bar.gun();

In C#, this would be:

     return getFoo()?.fun().gun() ?? someInitialValue;

And with implicit handling in Optional!T, it looks like this:

     return getFoo().oc.fun().gun().or(someInitialValue);

Clearly the latter two are more readable, and I'm not gonna care 
that it's a little slower in the 99% of cases where speed is not 
important.

--
   Simen