how to determine if a character vector is a valid numeric or integer vector

Question

I am trying to turn a nested list structure into a dataframe. The list looks similar to the following (it is serialized data from parsed JSON read in using the httr package)

Answer 1

I don't see any advantage of plyr::ldply over regular base R methods:

 do.call(rbind, lapply(myList, data.frame) )
#-------------

        w x.y x.z
object1 1 0.1 cat
object2 2 0.2 dog

The trouble was arising because of a misguided attempt to "flatten" the data without consideration for it's intrinsic structure.