A Philosophy of Software Design

[Walter Bright]

On 5/23/2026 11:18 PM, Richard (Rikki) Andrew Cattermole wrote:
> In this particular case, the ideas presented in those books haven't evolved 
> since then.

See the book I suggested, "A Philosophy of Software Design", which shows an 
evolved understanding.


> TLDR: exceptions and replacement characters are both nominal approaches in 
> Unicode handling.

I cannot say I automatically accept programming advice from the Unicode people. 
After all, they invented normalized code points, an astonishingly bad idea. I've 
never encountered anyone able to defend it beyond 2 rounds.


>> The first problem is you cannot use any string code in Phobos without 
>> supporting exceptions and memory allocations. The second problem is throwing 
>> an exception is the wrong solution.
> 
> It is not necessarily the wrong decision, which is why its so predominant.

It was the wrong decision. Even Andrei came around on this, to his great credit.


> We have had trouble with it sure, and we would like to change it. But the 
> problem domain does suggest it /can/ be the right choice. Even if I personally 
> wouldn't do it with exceptions. There are some very nice boundaries in the 
> algorithms and plenty of opportunities for specialization of functions including 
> of decoding for specific error handling requirements.

I'm not convinced. I've never found any utility in generating exceptions on 
Unicode decoding.


> If that exception is escaping the editor component rendering and causing the 
> program to crash, that is a MAJOR BUG. Exceptions are supposed to be caught and 
> handled much more locally in components like this, if there is potential for 
> them to be thrown. Under no circumstances should that exception impact the user 
> beyond a error alert. You should try Intellij out some time, sadly the D plugin 
> still produces exceptions but yet its still quite functional. When applications 
> are written properly, they handle exceptions gracefully and don't just fail at 
> the first bad input.

Yes, you can write Exception handling correctly and it will behave as required. 
But that's not the point. The point is it is an over-complication and exposes 
dirty laundry when trying to encapsulate the functionality of a module.


> I considered it, but the $70 price tag ended that thought process beyond adding 
> to a wish list lol.

$9.99 for the Kindle version. $22.95 for paperback.