[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: The Prob class
From: |
Joe Neeman |
Subject: |
Re: The Prob class |
Date: |
Fri, 21 Aug 2009 13:47:17 -0700 |
On Thu, 2009-08-20 at 23:38 +0100, Trevor Daniels wrote:
> I'm trying to complete the 'prob' entry in the Technical glossary.
> From a position of ignorance I've come up with this:
>
> "PRoperty OBjects, or @strong{probs} for short, are instances of
> the @code{Prob} class, a simple base class for objects which have
> mutable and immutable property alists. The @code{Music} class
> derives from @code{Prob}. Instances of the @code{Prob} class are
> also created to hold the formatted content of system grobs and
> titling blocks during page layout."
>
> Is this correct, accurate, complete?
>
> As an aside, why does the Grob class not derive from Prob?
Properties of Grobs have extra functionality: you can set any grob
property to be a callback function, in which case the callback will be
evaluated transparently the first time you try to read that property.
Probs don't support that (I'm not sure why not).
Also, I think there are issues with doing inheritance properly on types
that are exposed to scheme. There were some discussions in that
direction regarding Pitch and Pitchclass.
Joe