[Info-vax] BASIC (and Horizon)

[Arne Vajhøj]

On 2/1/2024 10:38 PM, Dave Froble wrote:
> On 2/1/2024 9:49 PM, Arne Vajhøj wrote:
>> It gets even more clear in the nested case.
>>
>>     do {
>>         allocate(o1);
>>         ...
>>         if(...) break;
>>         ...
>>         flag = FALSE;
>>         do {
>>             allocate(o2)
>>             ...
>>             if(...) {
>>                 flag = TRUE;
>>                 break;
>>             }
>>             ...
>>         }
>>         deallocate(o2)
>>         if(flag) break;
>>         ...
>>     } while(false);
>>     deallocate(o1);
>>
>> vs:
>>
>>     allocate(o1);
>>     ...
>>     if(...) goto cleanup_1;
>>     ...
>>     allocate(o2);
>>     ...
>>     if(...) goto cleanup_1_and_2;
>>     ...
>> cleanup_1_and_2:
>>     deallocate(o2);
>> cleanup_1:
>>     deallocate(o1);
>>
>> The nested do while loop is a big mess. The goto solution
>> is still simple.
> 
> Well, I'd use:
> 
> Select <something>
>      Case = "1"
>          Some code
>      Case = "2"
>          Some other code
> End Select

That code does something completely different.

> But even that can be abused.
> 
> Got a friend that got carried away with Select and indenting.
> 
> When the Select statements got nested a dozen times, and indents became 
> 8-10 tabs, and the code for each CASE was several pages long ...
> 
> If the damn code was going to be so massive and complex, he should have 
> just branched/performed/whatever to a separate place to do all that work.

To quote from Linux kernel coding style doc:

<quote>
Now, some people will claim that having 8-character indentations makes 
the code move too far to the right, and makes it hard to read on a 
80-character terminal screen. The answer to that is that if you need 
more than 3 levels of indentation, you’re screwed anyway, and should fix 
your program.

In short, 8-char indents make things easier to read, and have the added 
benefit of warning you when you’re nesting your functions too deep. Heed 
that warning.
</quote>

Arne