Re: [Jsynthlib-devel] Okay... so why can't I edit a patch with this?

[Joe E. <jo...@em...>]

Bill Zwicky wrote:

> I got a better idea:  Since we're using an object-oriented language, 
> why not use objects?
>
> synthdrivers.Generic.Checksum
> synthdrivers.Boss.DRChecksum
> synthdrivers.Casio.CZ1000.Driver implements Checksum
>
> This way if a new checksum is developed, noone needs to go edit the 
> existing code base, nor twiddle the double-indirection constants, nor 
> edit documentation in multiple places (source, Wiki).

Well.... a few reasons why that could be bad are:

1 - There's probably a lot of redundancy/commonality in checksum 
algorithms, and that redundancy doesn't follow any lines of inheirtance 
of the classes. In other words, it would probably be pretty rare that a 
synthdriver would get the apropriate checksum method from its superclass 
(if at all). Without benefitting from inheritance, each synthdriver 
still has to define their checksum method, which means that you'd get a 
lot of stuff like this:
    public Checksum generateChecksum(Patch p) {
         return synthdrivers.Casio.CZ1000.Driver.generateChecksum(p);
    }

2 - Not only is the above code unsightly, it also causes synthdrivers to 
stick their fingers into other synthdrivers' business. This is bad for 
two reasons. First, (and this might just be personal preference) I've 
found that it's poor design to have low-level parts of the software try 
to have any sort of awareness of other parts. A synthdriver should have 
absolutely no clue (and, ideally, no way of finding out) if it's the 
only driver loaded, or one of 100. Usually, this ideal is merely good 
for helping to promote good OO design, which isn't a life-or-death 
situation. However, the *second* reason makes it a little more crucial. 
The second reason is that I'm still holding out hopes that, someday, JSL 
will allow the user to dynamically browse/retrieve/update their drivers 
over the net. If this ever becomes reality, then we can't be certain 
*which* synthdrivers are currently installed on the user's machine and 
which aren't. Unless we want to come up with some kooky requirement 
system (ie, "Korg ER-1" requries "CasioCZ1000"), then this could be a 
deal-killer for any future net-based driver download system.

3 - This solution would make it harder on the XML driver. I'd personally 
like to see
     <Checksum type="YAMAHA_PRE_1996" />
instead of
     <Checksum class="synthdrivers.Yamaha.EX5.BankDriver" />

- Joe