Generator for array_like

[jonwarneke]

To allow for much larger data sets, it would be nice if the array_like argument could accept a generator. This would require the "data structure" for the plot to be a "histogram" (a collection of bins, and for each bin a count/frequency) and probably an additional parameter indicating the sample size (which indicates the bin resolution).

[dfm]

It would be a pretty non-trivial refactor of the code to support something like this and I feel like this might lead to a deeper discussion of how matplotlib itself interacts with data. I'd certainly consider a specific proposal if it was presented but I'm unlikely to work on it myself!