[Fenfire-dev] Please read & comment on the functional PEG I posted

[Tuomas Lukka]

I've just tested some changes and realized that to make FenPDF work
fluidly in some situations we need either 
1) a HUGE kludge
2) the functional API I posted

So could people (especially Benja) read that PEG and say whether
there's anything there that should be done differently.

The situation:

Start from the main node, move to the "Hypertext Conferences" node
and then move immediately to "HT03" node.

It'll take forever for the red squares to be made into actualy transclusions,
because it's also making those that were visible in the previous frame.

I tried to alleviate this by making a version of PriorityQueue that uses
last-in-first-out semantics when the values are equal, but that doesn't
work right for the pipeline here, since there's another cache (that's also
needed) further down the pipeline. It made things worse, as the latest 
ones to be requested were ones in some buoy of the "Hypertext Conferences" 
canvas.

To resolve, we need to either kludge the caches or the functional API.
There are some other solutions but they involve expending more memory 
which is also not nice (i.e. making DispatchingNodeView return the Function,
so that its choice can be cached and the choices have their caches separately).

        Tuomas