[Chart] data-accessor, lens, and Chart

[Ben Gamari]

Tim Docker <tim at dockerz.net> writes:

> (Looks like the github migration may be paying off already)
>
> I've had the same feelings about data-accessor, but have not yet used 
> lens. So I'm broadly in favour of this idea, but I'd like a little time 
> to get comfortable with lens, or at least the elements of it used by 
> your code .
>
Sorry I let this drop for so long. Has your opinion on this solidified
in the past few months?

I'll admit at this rate I'm a bit concerned that this set willjust
bitrot into oblivion unless some sort of timeline for reevaluation is
kept. This is especially true given the GSoC project; it's likely not
too late to rebase the abstract-drawing branch without too much pain.

> It would be good to hear the opinions of other chart users.
>
It seems those that responded last time were generally supportive with
one neutral.

Cheers,

- Ben