Support nonstandard representations?

[krlmlr]

• POSIXlt (list of 11, each element has length n)
• intervals (n x 2 matrix)
• S4 classes
• ...

[edzer]

• list-column with geometries, as in sf and in PostGIS tables

[hadley]

I think part of vctrs will be defining a "standard" representation to support. I suspect objects that "lie" about their length (like POSIXlt) will not qualify.

I think we'll need a base class (like "vctr"), and contract about how vctr methods handle attributes, and lists of generics that you need to provide methods for giving desired behaviours.

[hadley]

Now implemented :)