Which D features to emphasize for academic review article

[Walter Bright]

On 8/11/2012 7:30 AM, Jakob Ovrum wrote:
> On Saturday, 11 August 2012 at 09:40:39 UTC, Walter Bright wrote:
>> Of course it is doing what the language requires, but it is an incorrect
>> diagnostic because a dead assignment is required.
>>
>> And being a dead assignment, it can lead to errors when the code is later
>> modified, as I explained. I also dislike on aesthetic grounds meaningless code
>> being required.
>
> It is not meaningless, it's declarative. The same resulting code as now would be
> generated, but it's easier for the maintainer to understand what's being meant.

No, it is not easier to understand, because there's no way to determine if the 
intent is to:

1. initialize to a valid value -or-
2. initialize to get the compiler to stop complaining


> I do, however, believe that D programmers are perfectly capable of doing the
> right thing if informed.

Of course they are capable of it. But experience shows they simply don't.


> Consider `pure` member functions - turns out most of them are actually pure
> because the implicit `this` parameter is allowed to be mutated and it's rare for
> a member function to mutate global state, yet we all strive to correctly
> decorate our methods `pure` when applicable.

A better design would be to have pure be the default and impure would require 
annotation. The same for const/immutable. Unfortunately, it's too late for that 
now. My fault.


> Java exception specifications have widespread implications for the entire
> codebase, while the difference between '0' and 'float.nan' is constant and
> entirely a local improvement.

I believe there's a lot more potential for success when you have a design where 
the easiest way is the correct way, and you've got to make some effort to do it 
wrong. Much of my attitude on that goes back to my experience at Boeing on 
designing things (yes, my boring Boeing anecdotes again), and Boeing's long 
experience with pilots and mechanics and what they actually do vs what they're 
trained to do. (And not only are these people professionals, not fools, but 
their lives depend on doing it right.)

Over and over and over again, the easy way had better be the correct way. I 
could bore you even more with the aviation horror stories I heard that justified 
that attitude.