Cachable deductible structures

[Benjamin Fallenstein <b.fallenstein@xxxxxx>]

Hi Tuomas--

do you think it makes sense to implement objects which are deducted from
the structure (e.g., nile paragraph ftexts or ZOb) as observers (ZZObs)
and have them refresh themselves when the structure changes? Then we
could cache them -- much more of a memory save than having style objects
for ftext parts, I should think.

For ZOb stuff, that should be quite straightforward -- we'd just need to
change the parser. OTOH, we need to write a caching system that knows
when to dispose of these things -- not that easy. And ZOb stuff really
aren't a bottleneck -- nile paragraphs would be better, I'd think.
However, there implementation is probably not as easy...

-b.