Re: More on RPG style

[Joe Pluta <joepluta@xxxxxxxxxxxxxxxxx>]

Scott Klement wrote:
> This, to me, is getting convoluted. The negatives in the "not notvalid" 
> make things complex... but that's still a relatively simple example. 
> Even so, it's nicer to have something like this:
>
> chain ItemNo ItemMaster;
> if not %found;
>    Valid = *on;
> endif;
>
> . . . 100 lines of code . . .
>
> if Valid;
>    // use item
> endif;
>
> The more positives in your logic, the easier it is to understand.  There 
> are certainly cases where negative logic is easy and not a problem.. 
> but it should be tempered with judgement.  If it looks too complex, the 
> logic should be cleaned up a bit.
>   

Yet, you still got it wrong.  Because clearly the item is valid if it is 
found in the ItemMaster.  Not that your basic premise is bad; it's just 
that there really is no magic bullet.  You need to code what makes sense 
to you, and then secondarily you need to consider the person who will 
maintain the code after you.  I have my own coding technique that 
probably most people wouldn't want to use, but it hugely simplifies my 
programming and makes error checking routines for complex screens one 
half to one third the size they would normally be by removing 
superfluous if/endif blocks.  When someone first maintains one of my 
programs, I sometimes have to explain it.  But once they understand, 
they're quite comfortable.

Tradeoff?  A few minutes of spin-up to save hundreds of lines of code.  
And the possible downside that everyone who understands the technique 
all go down in the same plane crash and someone else has to wade through it.

Joe